Chika Obele1, Christopher Sibley2, Jatin Matta1, Roderic I. Pettigrew1, Ahmed M. Gharib1
1Integrative Cardiovascular Imaging Section, The National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States; 2Radiology and Imaging Sciences Department, National Institutes of Health.
We demonstrate the feasibility of obtaining free-breathing cine images utilizing a single respiratory navigator gating technique. This method was made possible by utilizing the high signal-to-noise ratio (SNR) available at 3T to apply parallel imaging methods allowing the acquisition of up to 30 cardiac phases within clinically acceptable imaging time. Compared to traditional breath-holding techniques this methods showed no statistical difference in qualitative and quantitative imaging parameters, thereby, could be used as an alternative for children and patients who are unable to hold their breath.
Ning Hua1, Zhongjing Chen1, Sherman Bigornia1, Alkystis Phinikaridou1, Ye Qiao1, Caroline Apovian1, Hernan Jara1, Frederick Ruberg1, James Hamilton1
1Boston University, Boston, MA, United States
We imaged 40 metabolic syndrome (MetS) subjects as well as 17 healthy controls using MRI to determine if left ventricular (LV) function would be better correlated with LV fat instead of total pericardial fat. We found that in MetS subjects, stroke volume, cardiac output(CO), wall mass, end-diastolic volume and early filling (E) rate were inversely related to LV fat but not RV fat. The total pericardial fat was only correlated with CO and E-rate. This study suggests that LV pericardial fat rather than total pericardial fat might better correlate to LV function, the mechanism of which remains to be defined.
Joseph Yitan Cheng1, Juan M. Santos1,2, John M. Pauly1
1Electrical Engineering, Stanford University, Stanford, CA, United States; 2HeartVista, Inc., Los Altos, CA, United States
The lack of proper visual guidance greatly impairs and lengthens cardiac procedures, such as atrial fibrillation therapy. In this work, we present a practical approach for fast data acquisition and 3D visualization. Acquisition is achieved with a fast multi-slice spiral sequence, and the visualization is achieved with a simple tissue segmentation and surface rendering. With the introduced depth perception, we provide real-time visual feedback for better control in interventional cardiac treatment.
15:30 3555. Assessment of Cardiac Remodelling After Myocardial Infarction in Diabetic Mice Using Self-Gated MRI - not available
Kristine Skårdal1, Natale Rolim1, Ole Christian Eidheim2, Marius Widerøe1, Ulrik Wisløff1, Pål Erik Goa3, Marte Thuen1
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway; 3Department of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway
Type II diabetic patients suffer from higher susceptibility to develop post myocardial infarction (MI) heart failure. By adapting a self-gated FLASH to a murine model of the diabetic heart, we obtained multiple slices of the left ventricle and assessed changes in cardiac physiology post MI. Diabetic MI mice displayed decreased cardiac contractility and increased end-systolic volume, while non-diabetic MI mice presented increased end-diastolic volume with preserved ejection fraction. These data suggest that imaging of murine hearts is achievable using a self-gated FLASH, and the results are accurate enough to detect differences in functional analysis between genotypes and interventions.
Melanie S. Kotys1, Xiaopeng Zhou2, Scott D. Flamm2, Randy M. Setser2
1MR Clinical Science, Philips Healthcare, Cleveland, OH, United States; 2Imaging Institute, Cleveland Clinic, Cleveland, OH, United States
Myocardial tags applied in radial orientation using selective saturation bands may have distinct advantages over SPAMM methods for routine clinical examinations. We compared radial tagged images with 4-16 tag lines and grid tagged images in five volunteers. Analysis revealed that radial tags persisted longer than grid tags and had a comparable first acquired cardiac phase. There was no significant difference in end systolic strain or rotation and 12 radial tag lines had the least variation in both measures. Application of radial tags appears to be as efficient as SPAMM tagging with the potential for clinical analysis of circumferential myocardial function.
Marzena Wylezinska1, Jordi L. Tremoleda1, Jelena Anastasovska2, Willy Gsell1, Jimmy Bell2
1Biological Imaging Centre, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College, London, United Kingdom; 2Metabolic Imaging Group, MRC Clinical Sciences Centre, Imperial College, London, United Kingdom
The aim was to investigate the effect of high fat diet on myocardial triglyceride and function in preclinical model. Male C57/Bl6 mice were maintained on a high (21%) fat (HF n=6) or a normal (3%) fat diet (C, n=5). Using MRI left ventricular ejection fraction (LVEF) was measured, while localized 1H MRS was used to estimate lipids content in the interventricular septum in animals. Lipid content was significantly increased in HF group, while trend was observed in LVEF decrease in HF group. These preliminary results suggest that high fat diet may have implications on myocardial lipid content and cardiac function.
Katrien Vandoorne1, Inbal E. Biton2, Alon Harmelin2, Michal Neeman1
1Biological Regulation, Weizmann Institute, Rehovot, Israel; 2Veterinary Resources, Weizmann Institute, Rehovot, Israel
The PKB/Akt family of intracellular protein kinases regulates cellular growth, proliferation, survival and metabolism. It is known that Akt1/PKBalpha controls heart size and function. Baseline left ventricular structure and function of Akt1/PKBalpha; null, heterozygote and wild type mice, were assessed using retrospectively reconstructed FLASH cine scans with the aid of navigator scans. Here, we showed in vivo, that LV mass and cardiac output are reduced in knockout animals. This reduction is consistent with the reduced body weight. Surprisingly, cardiac hypertrophy observed here by MRI of heterozygote mice, and noted also previously by ultrasound, was resolved in the full Akt1 knockout.
June Cheng-Baron1, Kelvin Chow1, Ben T. Esch2, Jessica M. Scott2, Mark J. Haykowsky2, John V. Tyberg3, Richard B. Thompson1
1Biomedical Engineering, University of Alberta, Edmonton, AB, Canada; 2Physical Therapy, University of Alberta, Edmonton, AB, Canada; 3Cardiac Sciences, University of Calgary, Calgary, AB, Canada
Left ventricular (LV) volume estimated using ventricular dimensions or surface markers have shown increasing volume during isovolumic relaxation, despite closed mitral and aortic valves. The goal of this study is to explain and interpret this volume increase in the context of ventricular relaxation. We measure a 4.6 mL mean increase in LV volume, which is correlated with changes in principle myocardial strains and compensated for by the descent of the mitral leaflets towards the apex. The motion of the leaflets and conformational changes in the LV during isovolumic relaxation likely reflect LV pressure decline and the development of ventricular suction.
Gert Jan Mauritz1, J. Tim Marcus1, Jochem Bosboom1, Anton Vonk Noordegraaf1
1VU University Medical Center, Amsterdam, Netherlands
The aim of this study is to assess whether the Left-Right (L-R) mechanical synchrony in Chronic Thrombo-Embolic Pulmonary Hypertension recovers after pulmonary endarterectomy. Nine patients were included, and underwent MRI myocardial tagging at baseline before, and 1 year after endarterectomy. The L-R delay in peak myocardial circumferential shortening decreased from 95 ± 61 ms at baseline, to 2 ± 47 ms after endarterectomy (p < 0.05). Cardiac output increased from 3.7 ± 0.9 lit/min, to 4.8 ± 0.6 lit/min (p<0.01). The L-R resynchronization and functional RV recovery are in line with reverse RV remodeling after endarterectomy.
Marion de Roquefeuil1,2, Anne Menini1,2, Jean-Marie Escanyé3, Pierre-Yves Marie3, Jacques Felblinger1,2
1U947, INSERM, Vandoeuvre-lès-Nancy, France, France; 2IADI, Nancy-Université, Nancy, France, France; 3Department of Nuclear Medicine, CHU, Nancy, France
Heart Rate (HR) variation is around 30 % during healthy subject breath-holds necessary for cardiac MR acquisition. As MR system is synchronized with R peaks, image contrast depends on HR evolution. Especially, cardiac T2 mapping used in heart transplantations and pathologies follow up is biased by HR variation. We propose a method to compensate this systematic error and to improve diagnostic quality: a RR-adjusted corrective factor applied on SE signal in k-space.
14:30 3562. Cardiac Torsion and Strain in Fatigued Primary Biliary Cirrhosis Patients Investigated by 3T Cardiac Tagging Show Evidence of Accelerated Ageing Processes - not available
Kieren Grant Hollingsworth1, David Emerys Jones2, Roy Taylor1, Guy A. MacGowan3, Julia Lindsay Newton4, Andrew Mark Blamire1
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 3Cardiology, Freeman Hospital, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 4Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom
Primary biliary cirrhosis (PBC) is an autoimmune liver disease affecting females from middle age. After our previous observation that PBC patients have impaired cardiac energetics compared to matched controls while preserving normal cardiac morphology, the same cohort was studied with cardiac tagging at 3T to assess cardiac torsion and strain. Those PBC patients with severe fatigue were found to have significant increases in myocardial peak torsion and reduction in peak strain which have previously been seen to be typical of healthy ageing. This suggests that cardiac changes in fatigued PBC patients may reflect an accelerated ageing process.
Hasan Alsaid1, Weike Bao1, Mary V. Rambo1, Gregory A. Logan1, David J. Figueroa1, Stephen C. Lenhard1, Charles J. Kotzer1, Mark E. Burgert1, Beat M. Jucker1
1GlaxoSmithKline, 709 Swedeland Rd, King of Prussia, PA, 19406, United States
In this study, MRI was used for the first time to non-invasively and serially assess cardiac dysfunction and lung congestion in a chronic heart failure model, myocardial infarction (MI), in mice. Cardiac and lung MRI were performed at baseline then every three days up to 13 days post-MI. MRI results revealed that MI induced significant pulmonary congestion/edema as detected by increased MRI signal intensity and was associated with increased lung volume and decreased cardiac function. Additionally, significant correlations were observed between lung signal intensity, lung volume, ejection fraction, left ventricular mass and lung wet weight/body weight ratio.
Xiao Chen1, Xiaodong Zhong, 1,2, Frederick H. Epstein3
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2MR R&D Collaboration, Siemens Healthcare, Atlanta, GA, United States; 3Radiology, University of Virginia, Charlottesville, VA, United States
The purpose of the present study was to develop a cine DENSE pulse sequence for quantitative imaging of longitudinal motion, where two adjacent short-axis slices are encoded for through-plane (longitudinal) displacement and are simultaneously acquired. Displacement trajectories measured from the two slices are used to calculate longitudinal strain. By acquiring both slices within a single breathhold, a fixed and consistent distance between the slices is maintained, which enables the accurate calculation of longitudinal strain from the measured longitudinal displacement fields. The sequence and theory were evaluated and demonstrated in normal volunteers.
Fabian Hezel1, Tobias Frauenrath1, Wolfgang Renz2, Jeanette Schulz-Menger1,3, Thoralf Niendorf1,3
1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2Siemens Healthcare, Erlangen, Germany; 3Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany
This study is designed to demonstrate the promise of susceptibility weighted 2D CINE FLASH and T2* Mapping of the heart at 7T.
14:30 3566. Longitudinal Functional and Structural Characterization of Inducible Heart Specific SOD2 Knock-Out Mice by Cardiac MRI - not available
Thomas Kaulisch1, Heiko G. Niessen1, David Kind1, Michael Neumaier1, Julia Tillmanns1, Lothar Kussmaul2, Simon Melov3, Detlef Stiller1
1In-Vivo Imaging Unit, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Dept. of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 3Buck Institute for Age Research, Novato, CA, United States
Oxidative stress induced by reactive oxygen species (ROS) plays an important role in heart diseases. Because fatty acid oxidation is carried out in the mitochondria, their dysfunction will have a severe impact on cardiac function. Because ROS are usually reduced by SOD2, a new mouse model (Fsod2H) with inducible knock-down of SOD2 gene was generated. In-vivo imaging was performed from week 32 to 57 of animal age. A significant reduction of heart contractibility and an increase in heart volume were measured for tgSOD2 mice. Overall, MRI allows for longitudinal quantitative assessment of functional and structural changes in the mouse heart.
15:00 3567. Quantitative Assessment of Left Ventricular Function Using Cardiac Phase-Contrast and Cine Magnetic Resonance Imaging Comparison with Pressure-Volume Loops Analysis: In Vivo Validation on a Swine Model
Hung-Yu Lin1, Fei Wang2, Waiel Almoustadi3, Bo Xiang2, Trevor Lee3, Rakesh Arora3, Scott B. King2, Boguslaw Tomanek2, Darren Freed3, Ganghong Tian2
1Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Manitoba, Canada; 2Institute for Biodiagnostics, National Research Coincil of Canada; 3Saint Boniface General Hospital, Winnipeg, Manitoba, Canada
Noninvasive PC-MRI and cine MRI have been recognized as a valuable and accurate technique to evaluate hemodynamics and heart function. Previous clinical studies suggest that evaluation of the passive relaxation properties serves as a useful indicator of quantitative contractility and function without the influence of relative ventricular load. To our knowledge, the correlation of LV function obtained from noninvasive PC-MRI, cine MRI and invasive P-V loops relation has not been investigated and reported. The aim of the present study was to determine the validity of PC-MRI, cine MRI in the assessment of LV function comparing with dynamic P-V loops analysis.
HuaLei Zhang1, Hui Qiao1, Nataliya Petrenko2, Vickas Patel2, Bin Huang3, Kenneth Boheler4, Victor Ferrari2, Rong Zhou1
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Dept of Medicine(cardiovascular), University of Pennsylvania; 3Department of Radiology, University of Pennsylvania, PA; 4National Institute of Aging, NIH
Highly enriched embryonic stem cell derived cardiomyocytes (ESC-CMs) were obtained in large numbers for in vivo study that examined the potential of these cells in the treatment of myocardial infarction. Our data suggest that ESC-CM mediated a teratoma free myocardial repair with significant recovery of regional and global contractile function over the period of 2 months.
Ahmed Amr Harouni1, Tamer A. Basha1, Monda L. Shehata2, Nael Fakhry Osman1,2
1Electrical and computer Engineering, Johns Hopkins University, Baltimore, MD, United States; 2Department of Radiology, Johns Hopkins University, Baltimore, MD, United States
Many techniques have been proposed for real-time interactive cardiac MR imaging. However, most of these techniques are limited to only the anatomical information. In this work, we propose to use fast strain-Encoded functional imaging technique to acquire real-time images then use a fully automated segmentation algorithm to provide online anatomical and functional information of regional myocardial regions. This can be useful in real-time monitoring of cardiac strain changes during either stress test, valsalva exercise or interventional operations.
Xiao Chen1, Alistair Young2, Frederick H. Epstein, 1,3
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Anatomy with Radiology, University of Auckland, Auckland, New Zealand; 3Radiology, University of Virginia, Charlottesville, VA, United States
The purpose of the present study was to develop a cine DENSE sequence with dual displacement encoding, where two distinct stimulated echoes with different displacement-encoding frequencies are simultaneously stored along the longitudinal axis, and where either can be recalled at any particular time to to better accommodate a temporal sequence of images with different amounts of displacement and deformation at different times. The sequence was implemented on a 1.5T scanner and was evaluated and demonstrated by using a deformable phantom and by imaging the hearts of normal volunteers.
Daniel James Stuckey1, Hikaru Ishii2, Aldo R. Boccaccini2, Carolyn A. Carr1, Judith A. Roether2, Qi Zhi Chen2, Hedeer Jawad2, Damian J. Tyler1, Nadire N. Ali2, Kieran Clarke1, Sian E. Harding2
1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxon, United Kingdom; 2National Heart and Lung Institute, Imperial College, London, United Kingdom
MRI was used to test three different scaffold materials designed for myocardial tissue engineering. Scaffold location, degradation and effect on cardiac function were measured in vivo at 1 and 6 weeks after grafting of scaffold onto infarcted rat hearts. The rigid TiO2-PED scaffold induced microvascular occlusion and necrosis adjacent to the scaffold, resulting in reduced cardiac function by six weeks. The PGS scaffold was not detrimental to function, but MRI showed that the material degraded between 1 and 6 weeks in vivo. This study demonstrates the feasibility and importance of using MRI to optimise myocardial tissue engineering strategies.
Abbas Nasiraei Moghaddam1, J. Paul Finn1
1Radiology, UCLA, Los Angeles, CA, United States
The angular information of the left ventricle, including the twist, shear and circumferential strain, are of fundamental importance to quantify the regional or global myocardial function . Radial tagging facilitates the measurement of this information . In particular when the density of radial taglines are sufficiently high, it was theoretically shown that the circumferential strain can be measured directly from the K-Space data . In this study we present the application of the circumferential encoding method on the actual cardiac MR images which are tightly tagged in the radial direction using our newly developed sequence. We also show the transmural differences in rotational motion of the left ventricle using these images.
Behzad Sharif1, John Andrew Derbyshire2, Yoram Bresler1
1Electrical and Computer Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 2Translational Medicine Branch, NHLBI, National Institutes of Health, Bethesda, MD, United States
Patient-Adaptive Reconstruction and Acquisition Dynamic Imaging with Sensitivity Encoding (PARADISE), is a highly accelerated non-gated dynamic imaging scheme that enables artifact-free imaging while providing performance guarantees on achievable SNR and spatio-temporal resolution. In addition to parallel imaging, the method gains acceleration from a sparse physiologically-driven spectral support model (in x-y-f space); hence it is doubly accelerated and adaptive. In this work, we present a modification of the PARADISE method that enables high spatio-temporal fidelity nongated 2D cine imaging with short scan times (3 seconds per slice). The method uses prospective adjustments to the x-y-f-space support to accommodate short scan times.
Gert Jan Mauritz1, J. Tim Marcus1, Nico Westerhof1, Pieter E. Postmus1, Anton Vonk Noordegraaf1
1VU University Medical Center, Amsterdam, Netherlands
In PAH a prolonged time interval between pulmonary valve closure and tricuspid valve opening is observed. This period is assumed to measure a prolonged right ventricular (RV) relaxation, and to reflect diastolic dysfunction. In this study it was shown that this period is the consequence of a prolonged contraction of the RV free wall which continues after pulmonary valve closure causing a post-systolic contraction. In contrast the RV isovolumic relaxation period is not increased. Therefore, in clinical practice the isovolumic period between pulmonary valve closure and tricuspid valve opening is not a real measure of diastolic dysfunction in PAH patients.
Yong Chen1,2, Julian E. Stelzer3, Xin Yu1,2
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; 3Department of Physiology and Biophysics, Case Western Reserve University
In the present study, we evaluated the impact of shift in myosin heavy chain (MHC) isoforms on in vivo ventricular function in thyroid-deficient rats. Our results show that increased expression of β-MHC not only reduced the magnitude of peak systolic strain and torsion, but also altered the timing when the myocardium reached peak systole, leading to deteriorated cardiac function in hypothyroid rat hearts.
Iris Rüssel1, Wessel Brouwer1, Tjeerd Germans1, Paul Knaapen1, J Tim Marcus1, Jolanda van der Velden1, Marco Götte1, Albert van Rossum1
1VU University Medical Center, Amsterdam, Netherlands
Hypertrophic cardiomyopathy (HCM) is caused by mutations in mainly sarcomeric genes. Increased left ventricular (LV) torsion has been observed in patients with manifest hypertrophy, but abnormalities in myocardial contractility might already be present in HCM mutation carriers with normal wall thickness. Therefore, LV torsion and endocardial circumferential strain were studied in HCM mutation carriers using MRI tagging. Increased LV torsion and torsion to endocardial circumferential strain-ratio were found in carriers with respect to controls. The observed difference might be due to HCM-related endocardial myocardial dysfunction.
Sung-Min Gho1, Narae Choi1, Dong-Hyun Kim1,2
1Electrical and Electronic Engineering, Yonsei University, Shinchon-Dong, Seoul, Korea, Republic of; 2Radiology, Yonsei University, Shinchon-Dong, Seoul, Korea, Republic of
RF tagging in cardiac imaging can be used to analyze the heart wall motion. There is always a push towards higher spatial and/or temporal resolution to enable more accurate quantification. This work is on combining line tagged cardiac imaging with the compressed sensing (CS) algorithm and exploiting the distinct k-space feature of tagged images.
Samuel Ting1, Paaladinesh Thavendiranathan1, Helene Houle2, Gianni Pedrizzetti3, Subha V. Raman1, Mani Vannan1, Orlando Simonetti1
1The Ohio State University, Columbus, OH, United States; 2Siemens Medical Solutions, Mountain View, CA, United States; 3University of Trieste, Trieste, Italy
Characterization of vortex formation and flow within the heart may be used as tool for diagnosing and understanding pathophysiological conditions of the heart. We present preliminary results demonstrating that phase contrast magnetic resonance imaging may be used to quantitatively evaluate and characterize formation of vortices within blood flow in the left ventricle of the heart.
Reena Anand1, Sohae Chung1, Sharath Bhagavatula, Leon Axel1
1Radiology, NYU Langone Medical Center, New York, NY, United States
In conventional cine MRI, it is observed that the atrioventricular (AV) plane of the heart descends towards the apex during systole and moves back towards the atrium during the diastole. The displacement of the AV plane through the cardiac cycle is an expression of the systolic and diastolic performance of the heart, so that it can be used to detect early diastolic dysfunction. In this study, we have investigated the potential of MRI measurement of left AV plane displacement as a means to assess diastolic dysfunction.
Anja Lutz1, Axel Bornstedt1, Robert Manzke2, Gerd Ulrich Nienhaus3, Volker Rasche1
1University Hospital of Ulm, Ulm, BW, Germany; 2Philips Research Europe, Hamburg; 3Institute of Technology, University of Karlsruhe, Germany
Cardiac motion assessment can be performed by tagged imaging combined with HARP analysis and with tissue phase mapping (TPM). The tagging approach enables fast assessment of the in-plane motion component, where TPM can be applied for full assessment of the motion vector in 3D but requires at least fourfold measurement time. In this contribution tagging is combined with TPM for 3D + time motion assessment. There is no information loss of the through plane motion, when tag lines are applied. The combination can be used to reduce imaging time for motion encoding in 3D.
Eric L. Foster1, Mihaela Jekic1,2, Jacob A. Bender1,2, John W. Arnold3, Subha V. Raman1,4, Orlando P. Simonetti1,5
1Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States; 2Biomedical Engineering, The Ohio State University; 3Agricultural Technical Institute, The Ohio State University; 4Internal Medicine, The Ohio State University; 5Internal Medicine and Radiology, The Ohio State University
Treadmill exercise testing in conjunction with MRI may offer improved diagnosis of heart disease compared to current modalities; however, traditional treadmills can not operate safely within the MR environment. An MR compatible treadmill was developed using hydraulic drive and elevation systems and fiber-optic data transmission, allowing the treadmill to be positioned immediately adjacent to the MR examination table. The treadmill successfully passed MR safety and compatibility tests. Six healthy volunteers were exercised to peak cardiovascular stress and transferred to the MR table. Real time cine imaging was completed within 38±6.4 s, meeting the AHA guideline of imaging within 60 s.
Ziheng Zhang1, Donald P. Dione1, Peter B. Brown1, Erik M. Shapiro1, Chengqing Wu2, Robert Todd Constable1, Albert J. Sinusas1, Smita Sampath1
1Yale University School of Medicine, New Haven, CT, United States; 2Yale University School of Public Health, New Haven, CT, United States
A novel MR imaging technique, spatial modulation of magnetization with polarity alternated velocity encoding (SPAMM-PAVE), is presented to investigate the left ventricular early diastolic strain-velocity relationships. This technique provides simultaneous measurements of 1-D myocardial displacement and chamber blood velocity with a high temporal resolution of 14 ms, sensitive to early diastolic events undetectable by current state-of-the-art methods. The reliability of the measurement is demonstrated by an intra-subject study of a normal volunteer. The interplay of regional volumetric changes in the left ventricle in response to filling patterns is investigated through comparing the regional strain and blood inflow velocity curves in 8 normal volunteer studies.
Matthias Alexander Dieringer1,2, Wolfgang Renz, 1,3, Tomasz Lindel, 1,4, Frank Seifert, 1,4, Tobias Frauenrath1, Helmar Waiczies, 1,4, Florian von Knobelsdorff-Brenkhoff5, Davide Santoro1, Werner Hoffmann4, Bernd Ittermann, 1,4, Jeanette Schulz-Menger2,5, Thoralf Niendorf1,2
1Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany; 2Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany; 5CMR-Unit Charité Campus Buch, Berlin, Germany
Practical impediments of ultra high field cardiovascular MR (CVMR) can be catalogued in exacerbated magnetic field and radio frequency (RF) inhomogeneities, susceptibility and off-resonance effects, conductive and dielectric effects in tissue, and RF power deposition constraints, which all bear the potential to spoil the benefit of CVMR at 7T. Therefore, a four element cardiac transceive surface coil array was developed. Cardiac imaging provided clinically acceptable signal homogeneity with an excellent blood myocardium contrast. Subtle anatomic structures, such as pericardium, mitral and tricuspid valves and their apparatus, papillary muscles, and trabecles were accurately delineated.
Daniela Foell1, Bernd Jung2, Elfriede Schilli3, Felix Staehle2, Christoph Bode3, Michael Markl2
1Cardiology , University Hospital , Freiburg, Germany; 2Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany; 3Cardiology, University Hospital, Freiburg, Germany
MR tissue phase mapping (TPM) was employed to study the relationships of age, heart rate, left ventricular (LV) ejection fraction (EF), and LV-mass with myocardial dyssynchrony among 95 subjects with normal and pathological cardiac function. Compared to age-matched controls significantly (p<0.01) enhanced myocardial dyssynchrony was found in patients with hypertensive heart disease (n=18) and dilated cardiomyopathy (n=12) with most prominent changes if left bundle branch block was present (n=7). Multiple regressions revealed significant relationships of dyssynchrony with LV-EF, LV-mass, and age. As sensitive markers for LV dysfunction, both radial systolic and long-axis diastolic dyssynchrony were superior to systolic long-axis dyssynchrony.
Karen G. Ordovas1, Marcus Carlsson2, Elyse Foster3, Alison Meadows4, Alastair Martin4, Michael Hope4, Loi Do4, Charles Higgins4, Maythem Saeed4
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States; 2Clinical Physiology, Lund University, Lund, Sweden; 3Cariology, UCSF, San Francisco, CA, United States; 4Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States
Anthony N. Price1, Shiang Y. Lim2, Johannes Riegler1, Derek M. Yellon2, Derek J. Hausenloy2, Mark F. Lythgoe1
1Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, London, United Kingdom; 2The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, United Kingdom
Coronary heart disease (CHD) remains one of the leading causes of morbidity and mortality worldwide. A principal symptom of CHD is myocardial infarction (MI), which leads to a complex process of ventricular remodelling and ultimately heart failure. Novel treatment strategies which are capable of limiting myocardial infarct size, preventing LV remodelling and preserving cardiac function are needed to improve clinical outcomes. The inhibition of mitochondrial cyclophilin-D (CypD), has been reported to reduce infarct size in pre-clinical studies. Here we present the first MRI assessment of cardiac function and infarct size in CypD-/- mice at 48 hours following myocardial infarction.
15:30 3587. Healthy Ageing in Females Is Associated with Altered Cardiac Energetics Related to Both Systolic and Diastolic Function: A Comparison of MRS, Cardiac Tagging and Cine Imaging - not available
Kieren Grant Hollingsworth1, David Emerys Jones2, Julia Lindsay Newton3, Bernard D. Keavney4, Guy A. MacGowan5, Andrew Mark Blamire1
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 3Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 4Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 5Cardiology, Freeman Hospital, Newcastle upon Tyne, Tyne and Wear, United Kingdom
It is unclear whether there are relationships between cardiac energetics and age-related decline of systolic and diastolic function. 25 healthy females with no previous history of cardiac disease were recruited, covering the age range 18-65. Phosphorus spectroscopy, cine imaging and cardiac tagging were carried out. PCr/ATP ratio was found to decline significantly with age, most strongly in the over 60 group. E/A ratio, peak circumferential strain and torsion recoil rates declined with age, with the first two significantly associated with the PCr/ATP ratio. This suggests that both systolic and diastolic function are associated with energetic changes in ageing.
Sean Charles Forbes1, Sean Germain2, Nathan Bryant3, Glenn A. Walter3
1Department of Physical Therapy, University of Florida, Gainesville, FL, United States; 2Department of Pediatrics, University of Florida, United States; 3Department of Physiology and Functional Genomics, University of Florida, United States
Limb Girdle muscular dystrophy Type 2C is characterized by a deficiency in γ-sarcoglycan, a protein associated with the dystrophin-glycoprotein complex on the cell membrane. In this study, the effects of a lack of γ-sarcoglycan (Sgsg-/-) and dystrophin (mdx) on cardiac function and myocardium T2 in old mice were examined. The findings indicate that Sgsg-/- and mdx have a reduced left ventricular ejection fraction compared to age-matched controls, with no differences in Sgsg-/- and mdx. Also, a shorter T2 was observed in the myocardium of Sgsg-/- compared to controls, suggesting an increased prevalence of fibrosis in Sgsg-/-.
Alan Groves1, Gaia Chiesa2, Giuliana Durighel2, Stephen Goldring2, Julie Fitzpatrick2, Sergio Uribe3, Reza Razavi4, Jo Hajnal2, A David Edwards2
1Institute of Clinical Sciences, Imperial College , London, United Kingdom; 2Institute of Clinical Sciences, Imperial College, London, United Kingdom; 3Division of Imaging Sciences, King's College , London, United Kingdom; 4Division of Imaging Sciences, King's College, London, United Kingdom
The ability to reliably monitor and support the circulation in preterm and term newborns may have a key role in optimising outcome in this population. Cardiac magnetic resonance (CMR) imaging has the potential to significantly advance understanding of cardiac function in sick preterm and term infants. In this work we describe optimisation of cine and phase contrast CMR imaging in newborn infants; assess repeatability of CMR methods and compare this to existing echocardiographic methods; and describe preliminary normative values for cardiac output and systemic flow volume in stable preterm and term infants.
Elsayed H. Ibrahim1, Wolfgang Rehwald2, Sven Zuehlsdorff2, Richard D. White1
1University of Florida, College of Medicine, Jacksonville, FL, United States; 2Siemens AG Healthcare Sector, Cardiovscular MR R&D, Chicago, IL, United States
Strain encoding (SENC) is a newly-developed MRI technique for measuring myocardial strain in the through-plane direction. It requires simple post-processing and gives resolution on the pixel level. With conventional SENC sequence, two separate scans are required to obtain the strain images. Such approach increases scan time and could result in image misregistration in post-processing. Non-Cartesian k-space trajectories are becoming more popular because they allow for large undersampling with acceptable image quality. In this work, SENC was combined with radial k-space acquisition using interleaved SENC tunings and radial undersampling. Scan time was reduced to one breath-hold with comparable image quality.
Tobias Wech1, Marcel Gutberlet1, Daniel Stäb1, Dietbert Hahn1, Herbert Köstler1
1Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany
To achieve a sufficient temporal and spatial resolution in functional cardiac MRI, real time acquisition has to be accelerated by a factor of 8 – 10 compared to Fourier MRI. In this work, a combination of compressed sensing and parallel imaging has been implemented, tested in a simulation using undersampled data of a segmented cine acquisition and finally applied to in-vivo data sampled in real time. The reconstructions for the real time acquisition and for the simulated data result in high resolution images with an excellent SNR and do not show any visible artefacts.
Scott David Swanson1, Gisela C. Mueller1, David Raffel1, Dorthea Happ1, Claire S. Duvernoy2,3, Rodica Pop-Busui4
1Department of Radiology, University of Michigan, Ann Arbor, MI, United States; 2Cardiology Section, VA Ann Arbor Health Care System, United States; 3Department of Internal Medicine, University of Michigan; 4Department of Internal Medicine; Division of Metabolism, Endocrinology and Diabetes, , University of Michigan
We compare left ventricular torsion as measured by cardiac MR tagging with sympathetic denervation as measure by PET and find that increased torsion is correlated with denervation.
Lei Zhang1, Huiying Zhang1, Gregory M. Lanza1, Samuel A. Wickline1, Junjie Chen1
1Washington University School of Medicine, St. Louis, MO, United States
Cardiac function in pre and post-natal stages are different because of reduced workload of right ventricle relative to left ventricle after birth. We hypothesize that myocardial fiber structure in fetal hearts differs from that of adult hearts as a response to the change of cardiac function. Diffusion tensor MRI was used to quantitatively evaluate myofiber structure in mid-gestation, pre-born and adult pig hearts. Helix angle and transverse angle in septum and LV/RV fusion sites were compared between the three groups. Our results showed that contributions of RV myofibers to septum was higher in fetal pig hearts than adult pig hearts. The current observations were in agree with change of cardiac function and reflect the plasticity of myocardial fiber development in response to programmed differential contractile functions before and after birth.
Daniel Stäb1, Tobias Wech1, Christian Ritter1, Dietbert Hahn1, Herbert Köstler1
1Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany
A combination of CAIPIRINHA simultaneous multi-slice imaging with Compressed Sensing is presented. A technique is generated, effectively accelerating the imaging procedure in slice and phase encoding direction. Several slices are excited simultaneously and shifted with respect to each other in the FOV using RF phase cycles, while k-space is undersampled randomly in incoherent fashion. In the reconstruction process, Compressed Sensing is used to eliminate incoherent artifacts, while a parallel imaging reconstruction separates the simultaneously excited slices. The method shows potential for high quality multi-slice imaging with high acceleration factor.
Andreas Sigfridsson1,2, Henrik Haraldsson1,2, Tino Ebbers1,2, Hans Knutsson, 23, Hajime Sakuma4
1Clinical Physiology, Linköping University, Linköping, Sweden; 2CMIV, Linköping University, Linköping, Sweden; 3Biomedical Engineering, Linköping University, Linköping, Sweden; 4Radiology, Mie University, Tsu, Mie, Japan
The in-vivo SNR for DENSE MRI was evaluated for 32 channel cardiac coils compared to standard 5 and 6 channel coils at 1.5 and 3T. On average, the 32 channel coils provided 50% higher SNR. The SNR improvement was more pronounced at 3T than at 1.5T, and closest to the chest wall. The higher SNR provides the opportunity for DENSE imaging in a longer portion of the cardiac cycle.
Joseph J. Suttie1, Lance DelaBarre2, Greg J. Metzger2, Pierre Francois van de Moortele2, Carl J. Snyder2, Peter Weale3, Stefan Neubauer1, Matthew D. Robson1, J Thomas Vaughan2
1Department of Cardiovascular Medicine, University of Oxford, Oxford Centre for Clinical Magnetic Resonance Research, Headington, Oxfordshire, United Kingdom; 2University of Minnesota, Radiology Center for Magnetic Resonance Research, Minneapolis, MN, United States; 3Cardiovascular MR Research and Development, Siemens Healthcare, Chicago, IL, United States
Clinical cardiac imaging at 7 T is attractive for spectroscopy, coronary and perfusion imaging. It offers improved signal and contrast to noise, provided technical challenges of ECG and artifacts can be overcome. This study compares SSFP and FLASH imaging at different field strengths: 1.5, 3 and 7 Tesla.
Daniel Alejandro Auger1, Xiaodong Zhong2, Ernesta Meintjes1, Fred Epstein3, Bruce Spottiswoode1,4
1MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa; 2MR R&D Collaborations, Siemens Medical Solutions, Atlanta, GA, United States; 33Departments of Radiology and Biomedical Engineering, University of Virginia, , Charlottesville VA, United States; 4Radiology, University of Stellenbosch, Cape Town, South Africa.
Displacement encoding with stimulated echoes (DENSE) is a quantitative MRI technique used for measuring myocardial displacement and strain at a high spatial resolution. Studies quantifying the motion of the right ventricle (RV) have been limited by the RV’s thin wall, asymmetric geometry and complex motion. A free-breathing navigator gated spiral 3D cine DENSE sequence has recently been developed, thus providing a well suited tool for capturing the complex behavior of the RV. This study involves analyzing the RV’s 3D motion and strain at a previously unattainable spatial resolution. The results are consistent with previous studies using myocardial tagging.
Patricia Dreessen de Gervai1, Victor Yang, Uta Sboto-Frankenstein, Valery Kupriyanov, Lawrence Ryner
1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada
Diffusion Tensor Magnetic Resonance Imaging (DTI) was used to assess myocardial architecture in healthy and in injured excised pig hearts in which cryo-ablation was used to produce targeted infarctions. Using the lesion and penumbral region as seed points, fibers were not detectable in the infarct region, FA was reduced and ADC values increased compared to healthy excised hearts. The penumbral region contained traceable fibers although FA and ADC values were affected. This work suggests that the changes in fiber architecture, FA and ADC involve not only the infarct area but also the adjacent tissue.
Noel C. Codella1, Pascal Spincemaille2, Jing Liu2, Martin Prince2, Yi Wang2
1Physiology, Cornell Weill Medical College, New York, NY, United States; 2Radiology, Cornell Weill Medical College
In this study, a 3D free-breathing self-calibrated radial GRAPPA cine-SSFP pulse sequence was developed to overcome the limitations of 2D breath-hold imaging. Radial k-space sampling was employed to provide z-profile self-navigator to monitor respiratory motion, and to allow for GRAPPA self-calibration.
Yong Chen1,2, Jia Zhong1,2, Xin Yu1,2
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States
In the current study, we developed a multi-phase DENSE imaging method for quantification of 3D myocardial motion in mice. Only five acquisitions were required to quantify both in-plane and longitudinal displacements on one slice. The results showed strong agreement with 2D DENSE methods.
Pierre-André Vuissoz1,2, Freddy Odille3, Brice Fernandez, 1,4, Maelene Lohezic, 1,4, Adnane Benhadid1,2, Damien Mandry2,5, Jacques Felblinger1,6
1Imagerie Adaptative Diagnostique et Interventionnelle, Nancy-Université, Nancy, France; 2U947, INSERM, Nancy, France; 3Centre for Medical Image Computing, University College London, London, United Kingdom; 4Global Applied Science Lab., GE healthcare, Nancy, France; 5Departments of Radiology, University Hospital Nancy, Nancy, France; 6CIC801, INSERM, Nancy, France
Clinical assessment of MRI data (e.g. myocardium function) is usually performed with breath-hold acquisitions. However, cardiac functional parameters are affected by breath-hold. The generalized reconstruction technique GRICS allows free-breathing acquisition protocols, and corrects for motion artifacts by inherently establishing a motion model. Here we show how this model can be used to decouple cardiac and respiratory motion, based on the available ECG and respiratory sensors. In 5 healthy volunteers, we analyzed the respective cardiac and respiratory contribution, in terms of motion vectors, in various regions of interest from the heart, enabling new insights in thoracic motion analysis.
Li Feng1, Ricardo Otazo2, Monvadi B. Srichai2,3, Ruth P. Lim2, Ding Xia2, Daniel K. Sodickson2, Daniel Kim2
1Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States; 2Radiology, New York University School of Medicine, New York, NY, United States; 3Medicine, New York University School of Medicine, New York, NY, United States
Real-time cine MRI is a necessary cardiac MRI pulse sequence for patients with reduced breath-hold capacity and/or arrhythmia. Currently, dynamic parallel imaging methods, such as TSENSE and TGRAPPA, can be used to achieve an acceleration rate (R) of 2-3, which typically yields relatively low spatial and temporal resolution. We propose to use a joint acceleration technique that combines compressed sensing (CS) and parallel imaging (PI) to exploit joint sparsity for randomly undersampled multicoil data. This study describes highly-accelerated (R>4) real-time cine MRI using the joint CS-PI technology and shows encouraging results using this technology.
Anne Brants1, Maarten Versluis1, Albert de Roos1, Jos Westenberg1, Andrew Webb1
1Radiology, Leiden University Medical Center, Leiden, Netherlands
Recent advances in coil technology have enabled cardiac imaging to be performed at 7T, with high spatial resolution cine-imaging showing particular promise. However, there has been no quantitative assessment of clinically-relevant derived measures of cardiac mass, volume or function. In this current study, ten healthy volunteers underwent cardiac scans at both 1.5T, the gold standard for such measures, and 7T. Values of end-systolic and end-diastolic volumes, ejection fraction, stroke volume an left ventricular end diastolic mass showed no statistical difference between 1.5 and 7T, providing strong validation for the continuing development of high-field cardiac imaging.
Ting Song1,2, Alexander I. Bustamante3, Jeffrey A. Stainsby4, Maureen N. Hood2,5, Vincent B. Ho2,5
1GE Healthcare Applied Science Laboratory, Bethesda, MD, United States; 2Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; 3Cardiology, National Navy Medical Center, Bethesda, MD, United States; 4GE Healthcare Applied Science Laboratory, Toronto, ON, Canada; 5Radiology, National Navy Medical Center, Bethesda, MD, United States
This paper presents Centerline Trajectory Mapping (CTM) method as a quantitative tool for characterization of focal and global wall motion abnormalities using long axis views of the left ventricle. Evaluation of CTM with myocardial delayed enhancement imaging and echocardiography with great consistency in wall motion abnormality detection. The proposed method does not add any extra scans to existing clinical cardiac MR routine and can be utilized in retrospective studies.
Chun Xu1, Kevin Koomalsingh1, Gamaliel Isaac2, Joseph H. Gorman2, Robert C. Gorman2, Lawrence Dougherty2, James Pilla2
1University of Pennsylvania , Philadelphia, PA, United States; 2University of Pennsylvania, Philadelphia, PA, United States
Accurate assessment of regional and global left ventricular (LV) functions is critical for ischemic heart disease. The orientation and the magnitude of the myocardial principal strains have been shown to be sensitive to ischemic development. This study presents a method to fully characterize the alterations in the magnitude and orientations of principal strains in a pig left ventricle. The computaed decreases in principal strains due to introduced infarct are confirmed by implanted markers and perfusion image, indicating impaired transmural thickening and circumferential shortening. Characterization of the remote, border zone and infarct 3D strain is paramount in understanding infarct expansion and in the development of therapies to mitigate remodeling.
Hendrikus Joseph Alphons Crooijmans1, Philippe C. Cattin2, Oliver M. Weber1,3, Klaus Scheffler1
1Division of Radiological Physics, Department of Medical Radiology, University of Basel Hospital, Basel, Switzerland; 2Medical Image Analysis Center (MIAC), University of Basel, Basel, Switzerland; 3Siemens Healthcare, Zürich, Switzerland
The interest point detector and region descriptor SURF finds features in every image/phase of a series of CINE-bSSFP images. By the help of user input, the best feature is selected in a Matlab program and corresponding features are automatically detected. If no feature is found within preset limits, it is created by linear interpolation. User indicated points of interest are described as a function of the position and diameter of the feature (all in the first image/phase), and can therefore be repositioned based on the corresponding features in the succeeding images/phases. This method provides reliable fast online valve position detection.
Tobias Frauenrath1, Meike Becker2,3, Fabian Hezel1, Gabriele A. Krombach2, Ute Kremer2, Jeanette Schulz-Menger1,3, Thoralf Niendorf1,3
1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, 13125 Berlin, Germany; 2Department of Radiology, University Hospital, RWTH, 52074 Aachen, Germany; 3Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, 13125 Berlin, Germany
As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to distortions and mistriggering increases and with it the motivation for a cardiac triggering alternative. Hence, this study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects at 1.5T and 3.0T.
13:30 3608. Improved Myocardial Mechanics as Assessed by MRI Generated Pressure-Volume Loops Following AAV6-Mediated βARKct Gene Delivery.
James J. Pilla1, Jabaris D. Swain, Michael G. Katz, Anthony Fargnoli, Marina Sumaroka, Catherine Tomasulo, Mihail Petrov, Rose Nolen-Walston, JanLee Jensen, Hansell Stedman, Walter J. Koch2, Joseph Rabinowitz2, Charles R. Bridges
1University of Pennsylvania, Philadelphia, PA, United States; 2Thomas Jefferson University
Genetic modulation of ventricular function and remodeling may offer a novel therapeutic strategy for patients with acute ischemic left ventricular (LV) dysfunction. We hypothesize that âARKct gene therapy will amplify the cardiac response to a beta-adrenergic agonist resulting in improved function and efficiency as measured by MRI. MRI generated PV loops demonstrated that âARKct expression improves global LV systolic performance and efficiency relative to controls. These results in a normal ovine subject, using a novel, cardiac-specific gene delivery platform (MCARDTM) are predictive of long term efficacy in a clinically relevant large animal HF model.
Yeon Hyeon Choe1, Eun Young Kim2
1Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 2Radiology, Samsung Medical Center, Seoul, Korea, Republic of
Diastolic function parameters (mitral inflow velocities, deceleration time, E/A ratio) using phase contrast MRI showed good correlation with that of echocardiography in patients with hypertrophic cardiomyopathy. Analysis of pulmonary vein flow velocity was feasible on MRI and give additional information on diastolic function analysis.
Amir H. Davarpanah1, Aya Kino1, Kirsi Taimen1, Philip Hodnet1, Cormac Farrelly1, Jeremy Collins1, Sanjiv Shah2, Karin Dill1, Richard Burt3, James Carr1
1Department of Radiology, Cardiovascular Imaging, Northwestern University, chicago, IL, United States; 2Department of Cardiology, Northwestern University, chicago, IL, United States; 3Department of Immunotherapy, Northwestern University, chicago, IL, United States
Using time to peak systole (TPS) from volumetric assessment of right ventricle, may have an important role in detecting both the presence and severity of pulmonary hypertension (PH); It may apply to patients with systemic sclerosis overall, in whom early detection of PH is of significant clinical importance.
Christakis Constantinides1, Richard Mean1, Laurence W. Hedlund2
1Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus; 2Radiology, Duke University Medical Center, Durham, NC, United States
While cardiac mechanical functional studies initially focused on large mammals and the human, the mouse emerged as the preferred animal species for research in recent years. Albeit evidence supports that bioenergetically and hemodynamically the mouse scales linearly with larger mammals and humans, important physiological questions still remain for the appropriateness of this model for extrapolation of conclusions to man. Since the complete characterization of the mouse and human genomes in 2002 and 2003 respectively, there has been a plethora of transgenic mouse studies targeting the cardiovascular system. Equally important were non-invasive imaging studies of such animals for phenotypic and genotypic screening, often conducted under inhalational anesthesia. Anesthetics, however, are known to cause severe cardio-depression with adverse physiological effects on hormonal release, centrally to the heart and peripherally to the vasculature, at the cellular level, affecting calcium entry through L-type Ca2+ channels, the calcium binding sensitivity of the contractile proteins to calcium, and on conduction and excitability. The objective of this study was to determine the isoflurane dose in normal mice for optimal physiological status (respiration, cardiac function, and metabolism) for a period of 1-2 hours post-induction, facilitating migration of such work to the non-invasive imaging platform of MRI, with tremendous potential for future basic science towards the phenotypic screening of transgenic mice and translational research.
13:30 3612. The Patho-Physiological Sensitivity of Cardiac MR Elastography: Preliminary Results. - not available
Thomas Elgeti1, Mark Beling2, Dieter Klatt1, Sebastian Papazoglou1, Sebastian Hirsch1, Kerstin Riek1, Bernd Hamm1, Jürgen Braun3, Ingolf Sack1
1Institut für Radiologie, Charité Universitätsmedizin , Berlin, Germany; 2Klinik und Poliklinik für Kardiologie, Charité Universitätsmedizin , Berlin, Germany; 3Institut für Medizinische Informatik und Biometrie, Charité Universitätsmedizin , Berlin, Germany
MR Elastography (MRE) is capable to directly measure tissue stiffness. This is particularly interesting for cardiac applications, since the cardiac shear modulus changes over the cardiac cycle. It is known, that increasing myocardial stiffness yields decrease of wave amplitudes in MRE. Therefore, left ventricular shear wave amplitudes were measured in 11 healthy volunteers and 11 patients with relaxation abnormalities. It is observed, that shear wave amplitudes are significantly lower in the left ventricle of patients. This result indicates the sensitivity of amplitude-based cardiac MRE to identify increased myocardial stiffness.
June Cheng-Baron1, Jessica M. Scott2, Ben T. Esch2, Mark J. Haykowsky2, John V. Tyberg3, Richard B. Thompson1
1Biomedical Engineering, University of Alberta, Edmonton, AB, Canada; 2Physical Therapy, University of Alberta, Edmonton, AB, Canada; 3Cardiac Sciences, University of Calgary, Calgary, AB, Canada
It has been shown that blood velocity waveforms measured at the conventional mitral leaflet tips location do not match mitral flow waveforms. In this study we quantify the relationship between velocity profiles at several points along the inflow path and volumetric flow, illustrating the dependence of commonly derived diastolic parameters (E/A ratio, deceleration time) on the measurement approach. Velocity profiles and derived parameters vary significantly over small (1 cm) intervals and are distinct from flow profiles. Velocity-time curves above the conventional leaflet tip location (in the atrium) are less susceptible to measurement error and are most similar to flow curves.
Moriel H. Vandsburger1, Brent A. French1, Xiaodong Zhong1,2, Christopher M. Kramer1, Frederick H. Epstein1
1University of Virginia, Charlottesville, VA, United States; 2MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States
Dynamic manganese-enhanced MRI and cine DENSE MRI can be used to probe calcium flux and contractile function in vivo in the mouse heart. Using these methods, we sought to elucidate the role of endothelial nitric oxide synthase (eNOS) in modulating calcium flux and contractile function. Counter to the prevailing opinion, which suggests that eNOS inhibits basal calcium flux, we found that eNOS does not play a role in modulating either calcium flux or contractile function at baseline, during β-adrenergic stimulation, or during muscarinic inhibition of β-adrenergic stimulation.
Brice Fernandez1,2, Julien Oster2,3, Maelene Lohezic1,2, Damien Mandry2,4, Olivier Pietquin, 2,5, Pierre-André Vuissoz2,3, Jacques Felblinger2,3
1Global Applied Science Lab., GE Healthcare, Nancy, France; 2IADI lab., Nancy-Université, Nancy, France; 3U947, INSERM, Nancy, France; 4Departement of Radiology, CHU Nancy, Nancy, France; 5IMS Research Group, Supelec, Metz, France
Conventional Double Inversion Recovery Fast Spin Echo (DIR-FSE) sequence provides detailed anatomical information in cardiac MRI. However, the preparation time required to cancel blood signal is too long to acquire DIR-FSE during the end-systolic rest. To overcome this constraint, two methods are described. The first one relies on the assumption that the RR intervals are constant whereas the second method is based on an adaptive RR interval prediction algorithm. These approaches were evaluated on 14 healthy volunteers; results demonstrated the robustness of the adaptive method with a better delineation of the right ventricle wall than with the conventional DIR-FSE.
Sotirios A. Tsaftaris1,2, Xiangzhi Zhou2, Debiao Li2,3, Rohan Dharmakumar2
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States; 3Biomedical Engineering, Northwestern University, Evanston, IL, United States
Blood-oxygen-level dependent (BOLD) MRI may be used for detecting myocardial oxygenation changes secondary to coronary artery stenosis (CAS). Under pharmacological stress, areas of the myocardium supplied by a stenotic coronary artery appear hypointense relative to healthy regions in BOLD images. The purpose of this work is to present a fundamentally new approach for visualizing and quantifying regional myocardial BOLD signal changes. This approach, tested in canines, relies on the statistical identification of myocardial pixels affected by CAS, correlates strongly with true flow measurements, and most importantly, leads to a significant increase in sensitivity to microvascular flow changes compared to previous approaches.
Aleksandra Radjenovic1, John D. Biglands1, Abdulghani Larghat1, John P. Ridgway1, Michael Jerosch-Herold2, John P. Greenwood1, Sven Plein1
1School of Medicine, University of Leeds, Leeds, England, United Kingdom; 2Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
Dynamic contrast-enhanced MRI was performed in 17 volunteers to simultaneously assess systolic and diastolic myocardial blood flow (MBF). At rest transmural MBF estimates were similar in systole and diastole (1.6 ± 0.42 vs 1.7 ± 0.49 ml/g/min, p>0.05). During adenosine-induced hyperaemia, MBF was significantly lower in systole than diastole (4.3 ± 0.93 vs 5.7 ± 1.7 ml/g/min, p < 0.0001). Subendocardial MBF was higher than subepicaridal MBF, apart from systole at stress where this relation was reversed. In conclusion, estimates of hyperaemic MBF differ significantly between systole and diastole, following the expected physiological pattern of preferential diastolic filling.
Bram F. Coolen1, Rik PM Moonen1, Leonie EM Paulis1, Tessa Geelen1, Larry de Graaf1, Klaas Nicolay1, Gustav J. Strijkers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
A method that allows myocardial first-pass perfusion measurements in mice is presented. Using a combination of segmented saturation-prepared FISP acquisition and GRAPPA parallel imaging allows a temporal resolution of one image every three heart beats with an acquisition time of less than 16 ms. First-pass perfusion images showed the influx of contrast agent into the myocardium with sufficient temporal resolution to derive semi-quantitative perfusion values. These were found significantly lower in a mouse with myocardial infarction compared to healthy control mice.
Elodie Breton1, Daniel Kim1, Sohae Chung1, Leon Axel1
1Research Radiology - Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, United States
Quantitative analysis of first-pass contrast-enhanced cardiac perfusion MRI requires the signal-time curve be converted to Gd-DTPA concentration-time curve. A theory-based single-point T1 measurement method has been proposed and validated in phantoms at 1.5T. In this study at 3T, the sensitivity to B1 variations and blood inflow of the single-point T1 mapping method was first evaluated depending on its linear or centric k-space trajectory. Then, the centric k-space trajectory T1 mapping pulse sequence was validated in vivo against a multi-point saturation recovery T1 measurement method in the left ventricular myocardium and cavity.
Michael Salerno1, Christopher M. Kramer2, Christopher Sica3, Craig H. Meyer4
1Department of Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States; 2Department of Radiology, University of Virginia, Charlottesville, VA; 3Biomedical Engineering, Hershey Medical Center, Hershey, PA; 4Biomedical Engineering, University of Virginia, Charlottesville, VA
Optimized Spiral Pulse Sequences may have advantages for clinical myocardial perfusion imaging. The goal of this project was to evaluate how variations in the readout duration per interleaf, number of spiral interleaves, and spatial resolution affect the image quality and artifacts for first-pass myocardial perfusion imaging using spiral trajectories in human subjects.
14:00 3621. A Fully Quantitative Pixel Based Approach for Measuring Myocardial Blood Flow in First-Pass Contrast-Enhanced Perfusion MRI: Microspheres Validation in Dogs and Feasibility Study in Humans
Li-Yueh Hsu1, Daniel W. Groves1, Anthony H. Aletras1, Peter Kellman1, Andrew E. Arai1
1National Institutes of Health, Bethesda, MD, United States
We developed a fully quantitative method to estimate myocardial blood flow (MBF) in first-pass contrast-enhanced perfusion MR images at the pixel level. The results were validated in an animal model and show that the MR perfusion estimates correlated with microspheres over a wide range of absolute MBF. To test feasibility in humans, the method was also applied to clinical perfusion MR images to estimate pixel-wise MBF at rest and during stress.
Daniel James Stuckey1, Carolyn A. Carr1, Stephanie Meader1, Damian J. Tyler1, Kieran Clarke1
1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxon, United Kingdom
We developed a first-pass cardiac perfusion imaging method which identified regions of perfusion deficit in the infarcted rat heart. Seven days after infarction, cine-MRI was combined with first-pass imaging, which acquired one image per heartbeat during Gd-DTPA bolus. Perfusion deficit at 7 days was larger in rats that went on to develop greater cardiac impairment by 42 days, and provided a more accuracy early indicator of the extent of myocardial infarction than ejection fraction. First-pass MRI will be useful for evaluation of rodent models of human disease and experimental therapies, including cytokine and stem-cell mediated angiogenesis in the infarcted heart.
Heng Ma1, Lan Ge2, Dong Xu1, Qing Tang1, Han Li1, Yu Zhang1, Jiabin Liu1, Qi Yang1, Jing An3, Lixin Jin4, Renate Jerecic4, Xiangying Du1, Kuncheng Li1, Debiao Li2
1Xuanwu Hospital, Capital Medical University, Beijing, China; 2Radiology, Northwestern University, Chicago, IL, United States; 3Siemens Mindit Magnetic Resonance Ltd, Shenzhen, China; 4Siemens Ltd, Healthcare Sector, China
SW-CG-HYPR is a promising method to improve the myocardial perfusion MR imaging with reduced acquisition window, increased spatial coverage, improved spatial resolution and SNR. In this work, 10 patients with suspected CAD were scanned at 3.0T with SW-CG-HYPR. Our initial results show that myocardial perfusion MRI at 3.0T with SW-CG-HYPR is feasible in a clinical population, and has high image quality and diagnostic accuracy in patients with suspected CAD.
Michael Salerno1, Christopher M. Kramer2, Craig H. Meyer3
1Department of Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States; 2Department of Radiology, University of Virginia, Charlottesville, VA; 3Biomedical Engineering, University of Virginia, Charlottesville, VA
Variable density (VD) spiral trajectories are an efficient method for data acquisition and may be advantageous for first pass myocardial perfusion imaging. By only partially correcting the variable density, k-space is weighted by a smooth function which reduces Gibbs Ringing. This strategy is employed to further reduce dark-rim artifacts for spiral myocardial perfusion imaging.
Wen Li1,2, Wei Li1,2, Chris Flask2,3, Mark Griswold2,3, Xin Yu1,2
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; 3Department of Radiology, Case Western Reserve University, Cleveland, OH, United States
A modified ECG-triggered saturation recovery Look-Locker (MSRLL) method was developed for quantification of arterial input function via rapid T1 mapping in dynamic contrast enhanced MRI (DCE-MRI) studies. High temporal resolution (< 2 min) was achieved by acquiring only the low spatial frequency lines. High spatial frequency lines acquired before contrast were used to generate composite images with higher spatial resolution. Validation was performed by comparing T1 values measured with SRLL and MSRLL method in both phantom and in vivo mouse heart. The in vivo application of MSRLL in DCE-MRI studies was demonstrated in mouse heart. These results suggest that MSRLL may provide a robust method for rapid T1 mapping of blood and myocardium in cardiac DCE-MRI studies.
Li Zhao1, Michael Salerno2, Christopher M. Kramer, 23, Craig H. Meyer1,3
1Biomedical Enginnering, University of Virginia, Charlottesville, VA, United States; 2Medicine, University of Virginia, Charlottesville, VA, United States; 3Radiology, University of Virginia, Charlottesville, VA, United States
The Dark Rim artifacts in adenosine stress perfusion imaging are not completely understood, with Gibb’s ringing and cardiac motion thought to be contributing factors. In this work we provide strong support to the idea that dark rim artifacts come from motion by experimental data, and it also shows that these artifacts are more significant in some portions of the cardiac cycle than in others. Moreover, a 1D motion model is developed and used to predict how dark rim artifacts vary over the cardiac cycle.
Michaela Schmidt1, Giso von der Recke2, Peter Speier3, Saurabh Shah4, Carmel Hayes3, David Hardung2, Heyder Omran5, Edgar Mueller6
1MR Application Development, Healthcare Sector, Siemens AG , Erlangen, Germany; 2St.-Marien-Hospital , Bonn, Germany; 3MR Application Development, Healthcare Sector, Siemens AG, Erlangen, Germany; 4MR R&D, Healthcare Sector, Siemens AG, Chicago, IL, United States; 5St.-Marien-Hospital, Bonn, Germany; 6MR Application Development, Healthcare Sector, Siemens AG, erlangen, Germany
In this study we evaluated a prototype designed for simplicity and speed in CMR examinations. Sixty five patients with suspected ischemic heart disease were imaged with the prototype. The prototype offers, among others, user guidance and patient-centric parameters, simplified, marker-based localization of the heart and automatic FOV calculation. Two users were experienced in and one user was inexperienced in CMR imaging. Without reducing the accuracy and quality of the result, examination times below 25 minutes could be achieved for the experienced users, the beginner managed to successfully complete cardiac examinations with excellent image quality in around 30 minutes.
Viton Vitanis1, Robert Manka, 1,2, Henrik Pedersen3, Peter Boesiger1, Sebastian Kozerke1
1Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland; 2German Heart Institute Berlin, Berlin, Germany; 3Functional Imaging Unit, Glostrup Hospital, Glostrup, Denmark
k-t PCA is an extension of k-t SENSE aiming at improving reconstruction of non-periodic dynamic images. It is based on a decomposition of the training and undersampled data into a temporally and a spatially invariant term using principal component analysis. In this abstract, a compartment based k-t PCA reconstruction approach is presented, which aims at improving highly undersampled, high-resolution 3D myocardial perfusion imaging by constraining the temporal content of different compartments in the image series based on the bolus arrival times and prior knowledge about the perfusion curves.
Matteo Milanesi1, Thomas K. Foo2, Luca Marinelli2, Christopher J. Hardy2, Dan W. Rettmann3, Wei Sun4, Stephen Garnier4, Ersin Bayram4, Piergiorgio Masci1, Vincenzo Positano1, Luigi Landini5, Massimo Lombardi1
1"G. Monasterio" Foundation, Pisa, Italy; 2Global Research Center, General Electric, Niskayuna, NY, United States; 3Applied Science Laboratory, GE Healthcare, Rochester, MN, United States; 4GE Healthcare, Milwaukee, WI, United States; 5Department of Information Engineering, University of Pisa, Italy
This study presents a new highly accelerated 3d saturation recovery first-pass perfusion using balanced steady state free precession (Fiesta) pulse sequence. Saturation was carried out through a 8ms adiabatic BIR4 radio frequency pulse. Acquisition was carried out at 3Tesla using a 32 channel cardiac coil, which allow 4-fold acceleration factor. Good image quality and CNR was obtained in three subjects anticipating a clinical validation of this pulse sequence
Christian Stehning1, Timothy Lockie2, Eike Nagel3, Masaki Ishida3, Sven Plein3
1Philips Research Europe, Hamburg, Germany; 2Cardiovascular Division, King's College, London, United Kingdom; 3Division of Imaging Sciences, King's College, London, United Kingdom
MR first pass perfusion imaging via the dynamic enhancement after intravenous contrast injection has become a valuable clinical tool for the assessment of myocardial perfusion. The aim of the present study was to investigate whether such a saturation effect of myocardial T1 has to be taken into account in MR-based perfusion studies involving multiple injections of Gd-DTPA.
Omar El-Sherif1,2, Robert Z. Stodilka1,2, Nathan A. Pack3,4, Edward VR Dibella3,4, James A. White5, Robert Terry Thompson1,2, Frank S. Prato1,2
1Imaging, Lawson Health Research Institute, London, Ontario, Canada; 2Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Bioengineering, University of Utah, Salt Lake City, UT, United States; 4Radiology, Utah Center for Advanced Imaging Research, Salt Lake City, UT, United States; 5Cardiology, London Health Sciences Centre, London, Ontario, Canada
We introduce a novel minimally constrained myocardial perfusion analysis technique. The technique has been implemented on dynamic contrast enhanced magnetic resonance images, obtained from 10 patients with hypertrophic cardiomyopathy. Regional myocardial perfusion estimates were directly compared to both the Fermi perfusion model and a 2 compartment perfusion model. The results indicate that there is discrepancy between Fermi and 2 compartment models during stress exams. However our technique correlates well with the Fermi model during both stress and rest exams.
Andrea Protti1, Alexander Sirker1, Xuebin Dong1, Marcelo Andia2, Ajay M. Shah1, Rene Botnar2
1Cardiovascular Division, King’s College London BHF Centre of Excellence, London, United Kingdom; 2Division of Imaging Sciences, King’s College London BHF Centre of Excellence, London, United Kingdom
In this work, we sought to investigate the merits of a very small superparamagnetic iron oxide particle (VSOP) for direct imaging of inflammation in a mouse model of MI and to quantify T2* using multi echo gradient echo images. The combined use of a very small iron-oxide particle, VSOP, and the use of short to long TE acquisition to generate T2* mapping allowed the quantitative assessment of VSOP uptake in the infarct zone.
Benjamin Waghorn1,2, Jimei Liu1, Nathan Yanasak1, Tom C.-C. Hu1,2
1Department of Radiology, Medical College of Georgia, Augusta, GA, United States; 2Nuclear and Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, Atlanta, GA, United States
Intracellular calcium (Ca2+) overloading that occurs during myocardial ischemia-reperfusion is known to exacerbate injuries. This study demonstrates the use of cardiac T1-mapping manganese-enhanced MRI for identifying and quantifying regional differences in tissue Mn2+, and therfore inferred Ca2+, handling that occur after a myocardial infarction (MI) in the murine model. Regional alterations in Mn2+ efflux were detected, suggesting changes in NCX activity and altered Mn2+ content in ischemic tissue, consistent with changes in Ca2+ handling post-MI. This technique could potentially be developed to provide and indirect in vivo assessment of Ca2+ handling alterations.
Andrea Protti1, Alexander Sirker1, Ajay M. Shah1, Rene Botnar2
1Cardiovascular Division, King’s College London BHF Centre of Excellence, London, United Kingdom; 2Division of Imaging Sciences, King’s College London BHF Centre of Excellence, London, United Kingdom
In this study we sought to investigate radial and circumferential strain in a mouse model of myocardial infarction (MI) 3 weeks post left anterior diagonal (LAD) coronary artery ligation and healthy control mice using 2D SPAMM technique. Strain was correlated with ejection fraction (EF) and left ventricular (LV) infarct size. MR tagging analysis provided important information on LV regional contraction and allowed assessment of wall motion alterations in MI mice.
Jurgen E. Schneider1, Steffen Bohl1, Erica Dall'Armellina1, Stefan K. Piechnik1, Matthew D. Robson1, Stefan Neubauer1
1Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom
T2-weighted magnetic resonance imaging (T2w-MRI) has been shown to visualize and to quantify edema in the acutely infarcted myocardium of humans and animal models. Based on relaxation time measurements, we quantitatively demonstrate that the achievable T2-contrast between normal and ischemia-reperfusion injured myocardium in mice at 9.4T is only 60% of the contrast in patients with acute myocardial infarction undergoing CMR at 3T.
Christian Kremser1, Jakob Völkl2, Bernhard Haubner2, Michael Schocke1, Bernhard Metzler2
1Dept. of Radiology, Innsbruck Medical University, Innsbruck, Tyrol, Austria; 2Dept. of Internal Medicine III (Cardiology), Innsbruck Medical University, Innsbruck, Tyrol, Austria
Delayed enhancement cardiac magnetic resonance imaging is frequently used to detect and quantify the size of myocardial infarction. In this study we demonstrate the feasibility of 3D late enhancement imaging in a mouse model on a clinical 1.5T whole body MR scanner and compare the obtained results with 2D sequences as used for clinical applications and histologic sections.
Erica Dall'Armellina1, Craig A. Lygate1, Martina McAteer1, Steffen Bohl1, Lee-Anne Stork1, Stefan Neubauer1, Robin P. Choudhury1, Jurgen E. Schneider1
1Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom
Ischemia-reperfusion (IR) injury is an important cause of tissue damage in vascular syndromes of the heart, but sensitive markers of early inflammation in reversible myocardial injury are lacking. Our study demonstrates that antibody-conjugated microparticles of iron oxide (MPIO) targeting VCAM-1 enable molecular MR imaging of endothelial activation in murine IR hearts.
William Lefrançois1, Sylvain Miraux, Guillaume Calmettes, François Vigneron2, Jean-Michel Franconi, Philippe Diolez, Eric Thiaudière
1Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS-Univ. Bordeaux 2, Bordeaux, Gironde, France, Metropolitan; 2INSERM U828, Avenue du Haut Lévêque, Bordeaux, France
This study aimed to develop a new method enabling a fast time-resolved cine 2D and cine 3D (4D) black blood imaging of mouse heart. This sequence has been applied to Manganese-Enhancement MRI (MEMRI) studies i.e. with Mn2+ infusion to improve contrast. This new method provided time- and space-resolved 3D images, respectively (200 µm) 3 and one image every 12 ms, for the first time within 30 minutes only. Lastly, associated to manganese infusion, this sequence appeared to be particularly adequate for studying cardiac pathologies such as ischemia on animal models.
Erica Dall'Armellina1, Bernd Jung2, Hannah Barnes3, Stefan Neubauer1, Michael Markl2, Jurgen E. Schneider1
1Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom; 2Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany; 3University of Oxford, Cardiovascular Medicine, Oxford, Oxon, United Kingdom
Tissue Phase Mapping (TPM) is a well-established technique to assess regional cardiac function in humans and in animal models such as mice. While TPM-studies in humans required suppression of the dominant blood signal in order to provide an accurate measurement of myocardial velocities, the murine studies were conducted without blood suppression. We show that bright-blood contrast can impact on both, absolute velocities and motion pattern, which can potentially and erroneously be identified as a local impairment of cardiac function.
Jun Lu1,2, Beau Pontre3, Stephen Pickup4, Bernard SY Choong1, Mingming Li1, Hong Xu5, Anthony RJ Phillips1, Garth JS Cooper6, Alistair A. Young7
1School of Biological Sciences, University of Auckland, Auckland, New Zealand; 2NCIECP, Auckland University of Technology, Auckland, New Zealand; 3Centre for Advance MRI, University of Auckland, Auckland, New Zealand; 4Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 5Chemistry & Chemical Engineering, Shenzhen University, Shenzhen, Guangdong, China; 6Department of Pharmacology, Oxford University, Oxford, United Kingdom; 7Department of Physiology, University of Auckland, Auckland, New Zealand
End stage diabetes is often associated with heart failure, which is the leading cause of death. We are the first to investigate the heart function in STZ-induced diabetic rats longitudinally with and without triethylenetetramine (TETA) treatment using High Field MRI. Gradient echo cine method was used to determine cardiac function. We found that the cardiac ejection fraction decreased with prolonged diabetic status and oral TETA treatment improves ejection fraction in diabetic rats. The results suggest that TETA treatment is beneficial to diabetic heart failure and warrant further clinical investigation.
Rajesh Dash1, Jaehoon Chung1, Yuka Matsuura1, Fumiaki Ikeno1, Jennifer Lyons1, Tomohiko Teramoto1, Alan C.Y. Yeung1, Michael V. McConnell1,2, Todd J. Brinton1, Phillip Harnish3, Phillip C. Yang1
1Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, CA, United States; 2Department of Electrical Engineering, Stanford University , Stanford, CA, United States; 3Eagle Vision Pharmaceutical Corporation, Exton, PA, United States
Manganese-enhanced MRI (MEMRI) detects Mn2+ uptake into viable cells, a distinct mechanism from gadolinium delayed enhancement MRI (DE-MRI). We tested whether combined DE-MRI plus MEMRI would delineate peri-infarct border zone injury in a pig ischemia-reperfusion (IR). Pigs were imaged by cardiac MRI 3 weeks post-IR. 3D DE-MRI scar volume correlated with histopathologic scar volume, but MEMRI scar volume was significantly smaller than DE-MRI scar volume. The border zones of DE-MRI scar, which were also positive by MEMRI, showed decreased SNR compared to remote zone MEMRI SNR. Combined MEMRI and DE-MRI may identify injured border zone myocardium in ischemic cardiomyopathy.
Yin Wu1,2, Ed Xuekui Wu2,3
1Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Shenzhen, Guangdong, China; 2Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong; 3Dept. of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong
Previous DTI studies on infarcted LV myocardium structure usually investigated diffusivity and diffusion anisotropy. In current study, diffusion tensor shape with a combination of linear, planar and spherical measures are examined and illustrated on a three-phase space in porcine models. Results show that the measurements of tensor shape have significant alteration in infarcted myocardium and are more sensitive to detect subtle change of diffusion properties than conventionally used parameters. Infarct location shows no apparent influence on myocardium structural degradation. This study gives insights into myocardium structural alteration and demonstrates potential application of DTI in detecting infarcted heart remodeling.
Yuesong Yang1, Kela Liu1, Dan Wang1, Mihaela Pop1, Jay Detsky1, Yingli Lu1, Alexander J. Dick1, Martin J. Yaffe1, Graham A. Wright1
1Imaging Research, Sunnybrook Health Sciences Centre, University Of Toronto, Toronto, Ontario, Canada
Triphenyltetrazolium chloride (TTC) stain is commonly used for the validation of myocardial damage in experimental cardiac MRI studies using various animal species such as mice, dogs and pigs. However, subtle myocardial damage, border zone or infarct heterogeneity associated with myocardial infarction (MI) is difficult to recognize on TTC stains. In this study, we investigated the feasibility of whole-mount heart histology that preserved the 3D morphology with a digital display at the microscopic level as a new alternative in the validation of myocardial damage in a porcine model of MI in experimental cardiac late-enhancement (LE) MRI studies.
Mihaela Pop1, Venkat Ramanan, Yuesong Yang, Nilesh Ghugre, Beiping Qiang, Elliot R. McVeigh2, Alexander J. Dick3, Graham A. Wright
1Medical Biophysics, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada; 2Biomedical Engineering, Johns Hopkins University, United States; 3Cardiology, Sunnybrook Research Institute
Accurate assessment of the scar extent and tissue remodeling during healing is very important. To better understand the scar morphology associated with chronic infarct in a porcine model, we have developed and tested (ex vivo) a 3D pulse sequence based on multi-contrast late enhancement (MCLE) and a non-contrast 3D diffusion-weighted DW sequence, and compare the results against histopathology. We have found that 3D MCLE identifies fine heterogeneity of scar, and compares well the classification of pathology to that from apparent diffusion coeficient maps using DW-MRI.
Swati Gupta1, Xiangzhi Zhou2, Xiaoming Bi3, Saurabh Shah3, Sven Zuehlsdorff3, Andrew Larson2, Debiao Li2, Rohan Dharmakumar2
1Department of Biomedical Engineeering, Northwestern University, Chicago, IL, United States; 2Department of Radiology, Northwestern University, Chicago, IL, United States; 3Siemens Medical Solutions, Chicago, IL, United States
Myocardial edema imaging with bSSFP approaches have been recently demonstrated. In this work, we investigated the utility of respiratory self-gated (RSG) 2D cine bSSFP for acquiring free-breathing myocardial edema images using a canine model subjected to ischemia-reperfusion injury. Early results show that RSG bSSFP imaging is capable of generating edema contrast similar to breath-held bSSFP imaging.
14:30 3646. Repair of Cardiac Damage Using Intrapericardial Drug Delivery by Means of MR-Trackable Alginate Beads - not available
Yamin Yang1, Marco L.H. Gruwel2, Patricia Gervai3, Jiankang Sun3, Olga Jilkina1, Eugene Gussakovsky1, Valery Kupriyanov1
1Cardiac, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada; 2MRTechnology, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada; 3MRRD, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada
Re-establishment of a vascular network is an important step in the repair of damaged myocardium. For this purpose vascular growth factors were applied at the site of injury. To prolong action of these peptides, growth factors were incorporated in alginate beads. However, visualization of the beads is not an easy task.
Maythem Saeed1, Alastair J. Martin1, Loi Do1, David Saloner1, Mark Wilson1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, Ca, United States
MR imaging was used to 1) assess the changes in LV volumes, ejection fraction, LV mass, regional wall thickness, and 3D wall strain as well as myocardial structure, edema, microvascular obstruction and intramyocardial haemorrhage in reperfused infarct in a single imaging session, to ensure image co-registration and 2) compare LV changes over 10 weeks. MR imaging provides comprehensive and serial characterization of evolved infarct. Myocardial edema, microvascular obstruction and hemorrhage are transient features of reperfusion injury. Based on the MR pulse sequences used it appears five weeks is enough time to arrest fibrosis, but not LV dilation, in reperfused infarct.
Monvadi B. Srichai1, Amelia M. Wnorowski1, Itzhak Kronzon1, Leon Axel1, Ambika Nayar1, Gila Perk1, Allison G. Hays2, Mark Fisch1, Vivian S. Lee1
1NYU School of Medicine, New York, NY, United States; 2Johns Hopkins, Baltimore, MD, United States
Echocardiography is often the sole imaging technique used for evaluation cardiac sources of embolism. However, studies have demonstrated that up to 40% of patients with ischemic strokes often have no identifiable etiology. Contrast enhanced MRI with MRA identified a cardiovascular source of embolism in an additional 20% of patient in this cohort that was undetected by echocardiography, and hence provides a valuable adjunctive diagnostic imaging method for evaluation of patients with a potential cardiovascular source of embolism, particularly in patients with a negative echocardiography study or who are unable to undergo transesophageal echocardiography.
Gerald A. Zsido II1, Julio Chirinos2, Larry Dougherty3, Kevin Koomalsingh4, James J. Pilla2,4, Walter RT Witschey1,4, Hee Kwon Song2, Joseph H. Gorman III4, Robert C. Gorman4, Ravinder Reddy1
1Radiology, University of Pennsylvania, Center for Magnetic Resonance and Optical Imaging, Philadelphia, PA, United States; 2University of Pennsylvania, Division of Cardiovascular Medicine, Philadelphia, PA, United States; 3Radiology, University of Pennsylvania, Philadelphia, PA, United States; 4Surgery, University of Pennsylvania, Philadelphia, PA, United States
A technique for rapid quantification of 1H relaxation times in the human myocardium during systole and diastole was developed. The technique makes use of a T1ρ spin locking pulse cluster, followed by a short, multiecho, radial acquisition, from which k-space-weighted image contrast reconstruction is performed. An 8-fold acceleration of data acquisition was obtained in vivo, compared to a similar set of fully sampled data. In 3 subjects, each scanned 4 times; a significant difference between left ventricular systolic and diastolic relaxation times was measured.
Thanh D. Nguyen1, Keigo Kawaji2, Pascal Spincemaille1, Beatriu Reig1, Matthew D. Cham1, Martin R. Prince1, Yi Wang1
1Radiology, Weill Cornell Medical College, New York, NY, United States; 2Biomedical Engineering, Cornell University, Ithaca, NY, United States
Black blood (BB) MRI is useful for morphologic assessment in cardiovascular diseases. While a 3D BB imaging sequence of the whole heart and chest similar to the whole-heart coronary artery imaging approach is highly desirable, commonly used BB preparation techniques rely on blood washout and do not work well in large imaging volumes. The purpose of this study is to develop a free-breathing balanced SSFP sequence for BB imaging of the whole chest using flow-independent T2prep inversion recovery preparation. This sequence was found to provide excellent blood suppression and good BB image quality within a large cardiothoracic volume.
Yuesong Yang1, Kim Connelly1, Jay Detsky1, Sumaya Al-helali1, Gideon Paul1, Rhonda Walcarius1, Graham A. Wright1, Alexander J. Dick1
1Imaging Research and Cardiology, Sunnybrook Health Sciences Centre, University Of Toronto, Toronto, Ontario, Canada
Sarcoidosis is a systemic disease with a predilection for pulmonary involvement. Although clinical cardiac involvement occurs only in 5-7% of patients with systemic sarcoidosis, the incidence of autopsy-proven disease ranges from 20% to 47%. The presence of cardiac involvement is important to recognize, as it can lead to conduction disturbance and ventricular arrhythmias. Early detection of cardiac involvement with suitable treatment plays a critical role in the prevention of sudden death in these patients. A newly developed multi-contrast late-enhancement (MCLE) MRI has shown the potential to identify subtle myocardial damages in myocardial infarction. In this study we investigated this MCLE technique in the determination of cardiac involvement in systemic sarcoidosis and compared it with conventional IR-FGRE imaging.
Yasuo Amano1, Masaki Tachi1, Yoshio Matsumura1, Yuriko Suzuki2, Shinichiro Kumita1, Yasutomo Katsumata2
1Radiology, Nippon Medical School, Tokyo, Japan; 2Philips Electronics Japan, Tokyo, Japan
This study demonstrated that phase-sensitive inversion-recovery technique was feasible for free-breathing 3D delayed-enhancement MRI at 3.0T, because it significantly improved the confidence for the presence of the hyperenhancing myocardium and the image contrast between the myocardium and blood. However, the 3D MRI without PSIR could not be omitted in some patients, because of its fewer image artifacts and no deterioration of the image quality.
Ting Song1,2, Vincent B. Ho2,3, Glenn Slavin1, Maureen N. Hood2,3, Jeffrey A. Stainsby4
1GE Healthcare Applied Science Laboratory, Bethesda, MD, United States; 2Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; 3Radiology, National Navy Medical Center, Bethesda, MD, United States; 4GE Healthcare Applied Science Laboratory, Toronto, ON, Canada
A Modified Look-Locker with saturation recovery sequence was evaluated on nine patients using different data sampling schemes. The proposed sequence enables flexibility in sampling schemes and an approach comparing a typical 16 heartbeat data acquisition with 8 samples of the signal recovery is compared to an approach that samples only 4 points during the signal recovery in 8 heartbeats. T1 values in normal myocardial tissue pre- and post-contrast, and infarcted myocardial tissue post-contrast, are measured and quantified on patients and volunteers. Accurate T1 estimates can be obtained using reduced data sampling.
Mansi Shah1, Monvadi B. Srichai2,3, Robert Donnino3, Daniel Kim2
1New York University School of Medicine, New York, NY, United States; 2Radiology, New York University School of Medicine, New York, NY, United States; 3Medicine, New York University School of Medicine, New York, NY, United States
Clinical evaluation of myocardial edema with conventional T2-weighted imaging is challenging because of non-uniform signal intensities associated with surface coil. We propose to quantitatively detect myocardial edema using a breath-hold T2 mapping pulse sequence. The accuracy of the T2 mapping pulse sequence was validated against qualitative T2-weighted imaging in seven patients with clinical evidence of heart disease. The T2 mapping pulse sequence was correlated against delayed contrast-enhanced imaging in a patient with acute myocardial infarction. Future research include comprehensive evaluation of T2 values with specific cardiac conditions and the clinical utility of T2 mapping for assessment of myocardial edema
15:00 3655. Triple Inversion Recovery Imaging of Myocardial Infarction - not available
Larry Kramer1, Catalin Loghin2, Eduardo Matta, Martin Pilat, Naveen Garg, Khader Hasan
1Diagnostic Imaging, UTHSC-Houston, Houston, TX, United States; 2Cardiology, UTHSC-Houston
Triple Inversion Recovery Imaging of the ventricular myocardium is sensitive to myocardial edema due to injury from a severe vascular event. Transmural myocardial infarcts were accurately identified relative to delayed contrast enhancement in 81% of positive cases of myocardial edema. The absence of edema in a patient with initial symptoms of chest pain and a positive electrocardiogram or coronary catheterization suggests a favorable functional outcome.
Fabian Hezel1, Gabriele Krombach2, Sebastian Kozerke3, Thoralf Niendorf1,4
1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2Department of Diagnostic Radiology, University Hospital, RWTH Aachen, Aachen, Germany; 3Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 4Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany
Myocardial T2* mapping is proven value for the assessment of myocardial iron content and tissue oxygenation. This study examines the feasibility of highly accelerated fast-spin echo based T2* mapping. Acceleration is accomplished by (i) inner volume imaging, (ii) regional saturation slab based blood suppression,(iii) partial Fourier and (iv) k-t BLAST. A four-fold acceleration is feasible without compromising image quality and the accuracy of calculated T2* values.
Sathya Vijayakumar1, Eugene G. Kholmovski1, Nassir F. Marrouche2
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, United States; 2Department of Cardiology, University of Utah, Salt Lake City, UT, United States
While imaging the left atrial wall to assess procedure outcome of RF ablation therapy in the heart, it is necessary to have optimal contrast between scar and blood and scar and normal myocardium. In this work, we present a technique to get optimal contrast between scar and both blood and myocardium using phase sensitive reconstruction and an appropriate choice of inversion time TI.
Stanislas Rapacchi1, Pierre Croisille, 1,2, Vinay Pai3, Denis Grenier1, Magalie Viallon4, Peter Kellman3, Nathan Mewton, 1,2, Han Wen3
1CREATIS, Université Lyon 1, INSA Lyon, Villeurbanne, France; 2Hopital Cardiologique et Pneumologique L. Pradel, Lyon, France, France; 3LCE/NHLBI/NIH, United States; 4Hopital Cantonal Universitaire de Genève, Switzerland
Free breathing in vivo cardiac Diffusion Weighted Imaging (DWI) is highly sensitive to physiologic motion. To cope with this issue, we designed a DWI protocol which repeats image acquisition multiple times with incremental trigger delays to cover a large time window in diastole. After registration, a localized Principal Component Analysis (PCA) is employed to reduce inter images myocardium deformation, thus improving final image quality. Then temporal Maximal Intensity Projection (tMIP) (3) is used to find the diffusion weighted intensity for each pixel. We present the benefits of our method and preliminary results in healthy and diseased volunteers.
Mohammad Imran Zia1, Nilesh R. Ghugre1, Gideon A. Paul1, Jeffrey A. Stainsby1, Venkat Ramanan1, Kim A. Connelly1, Graham A. Wright1, Alexander J. Dick1
1Sunnybrook Health Sciences Centre, Toronto, ON, Canada
Our goal was to demonstrate myocardial edema using T2 spiral and diastolic wall thickness (DWT) and myocardial hemorrhage using T2* in patients post acute myocardial infarction (AMI) at 48 hours and 3 weeks. Assessing the presence and evolution of edema and myocardial hemorrhage early post AMI demonstrates distinct patterns. If myocardial hemorrhage is present, then early scans are affected by the competing effects of T2*, counteracting an increased T2 signal. This may be important in accurately quantifying AAR and identifying those patients most likely to suffer deleterious left ventricular remodeling.
Jerry S. Cheung1,2, Wing-Yan Au3, Shau-Yin Ha4, Jens H. Jensen5, Dan Kim5, Abby Y. Ding1,2, Iris Y. Zhou1,2, Hua Guo5, Truman R. Brown6, Winnie C.W. Chu7, Darshana D. Rasalkar7, Pek-Lan Khong8, Gary M. Brittenham9, Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; 3Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; 4Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; 5Department of Radiology, New York University School of Medicine, New York, United States; 6Department of Radiology, Columbia University, New York, United States; 7Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Hong Kong SAR, China; 8Department of Diagnostic Radiology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; 9Department of Pediatrics, Columbia University, New York, United States
Accurate MRI characterization of myocardial iron is needed to improve the diagnosis and management of thalassaemia patients with transfusional iron overload. This study aimed to demonstrate that a new transverse relaxation index, the reduced R2 (RR2) that is estimated from non-monoexponential multi-echo CPMG signal decay and sensitive to ferritin iron, could detect the myocardial iron changes immediately following 1-week iron chelation suspension in thalassaemia patients at 3T.
Stefan K. Piechnik1, Erica Dall'Armellina1, Vanessa M. Ferreira1, Lowri E. Cochlin2, Jürgen E. Schneider1, Stefan Neubauer1, Matthew D. Robson1
1Cardiovascular Medicine, OCMR, Oxford University , Oxford, Oxfordshire, United Kingdom; 2Dept of Physiology, Anatomy and Genetics, Oxford University, Oxford, Oxfordshire, United Kingdom
We present preliminary results of T1- and T2-mapping at 3T in sub-acute myocardial infarction to demonstrate the ability of quantitative CMR in delineating myocardial tissue changes following an ischemic event.
Peter Kellman1, Diego Hernando2, Saurabh Shah3, Christophe Chefd'hotel4, Z-P Liang2, Andrew E. Arai1
1National Institutes of Health, Bethesda, MD, United States; 2University of Illinois, Urbana, IL, United States; 3Siemens Medical Solutions, Chicago, IL, United States; 4Siemens Corporate Research, Princeton, NJ, United States
A rapid fat/water separated imaging protocol has been developed for free-breathing cardiac applications for cases where patients have difficulty breath-holding or have significant arrhythmias. The method combines a 2 echo GRE acquisition and parallel imaging, and may be used with repeated measurements and motion corrected averaging to further improve image quality. The method has been applied to both pre-contrast and late enhancement imaging.
Raja Muthupillai1, Amol Pednekar2, Claudio Arena1, Scott D. Flamm1, Benjamin Y. Cheong1
1Diagnostic and Interventional Radiology, St. Luke's Episcopal Hospital, Houston, TX, United States; 2Philips Healthcare
We demonstrate that by using a judicious combination of reduced FOV imaging (ZOOM), Sensitivity Encoding (SENSE), and half-scan, it is feasible to obtain diagnostic quality single-shot (SSH) dual-inversion recovery prepared black blood(BB) turbo spin echo(TSE) images with minimal image blurring during normal respiration. The results of the study, performed on 8 asymptomatic subjects, show that SSH T2-TSE images acquired using ZOOM+SENSE under navigator triggering, yield images with quality that is comparable to conventional multi-shot BB-TSE images acquired over a 14-16 heart beat breathhold.
Alan Christopher O'Connor1, Mehdi Hedjazi Moghari1, Peng Hu1, Dana C. Peters1, Warren J. Manning1, Reza Nezafat1, Roger Ware Brockett2
1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2SEAS, Harvard University, Cambridge, MA, United States
Navigator correction methods were developed to increase the gating window size possible for free-breathing cardiac MRI and consequently reduce scan time. These methods typically rely on a generic scale-factor between measured diaphragm motion and heart motion. We present a novel scheme for estimating patient-, direction-, and coil-specific motion vectors directly from the scan data to correct for phase errors caused by respiratory motion of the heart.
Saskia van Elderen1, Maarten Versluis1, Jos Westenberg1, Harsh Agarwal2, Nadine Smith1, Matthias Stuber3, Albert de Roos1, Andrew Webb1
1Radiology, Leiden University Medical Center, Leiden, Netherlands; 2Johns Hopkins University; 3Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
Using a quadrature RF coil with dimensions optimized for reliable navigator gating, this study with ten volunteers shows that 7T right coronary angiograms can be acquired with improved vessel sharpness compared to those obtained at 3T using identical imaging parameters.
Bin Sun1, ZhiYong Chen2, LiXin Jin3, Qing Duan
1Radiology, FuJian Medical University Union Hospital, FuZhou, FuJian, China; 2Radiology, FuJian Medical University Union Hospital, China; 3Siemens Healthcare, MR Collaboration NE Asia, China
This article describes the influence of sublingual nitroglycerin spray on the lumen diameter, number of side branches visualized, average vessel length of 3.0-T contrast-enhanced whole-heart coronary magnetic resonance angiography. Twenty-four patients were prospectively included in this study: 12 were examined without sublingual nitroglycerin, and 12 were examined after the administration of sublingual nitroglycerin. Two blinded observers quantitatively assessed lumen diameter and length in the RCA, LAD and LCX. The number of acute marginal branches and septal branches was counted. The number of clinical side effects was evaluated. Sublingual nitroglycerin spray significantly dilates the coronary arteries and allows more side branches to be visualized at 3.0-T contrast-enhanced whole-heart CMRA without increasing resolution or increasing the number of side effects.
Saurabh Shah1, Xiaoming Bi1, Diego Hernando2, Peter Weale1, Sven Zuehlsdorff1, Sonia Nielles-Vallespin3, Peter Kellman4
1Siemens Healthcare, Chicago, IL, United States; 2University of Illinois at Urbana-Champaign, Urbana, IL, United States; 3Royal Brompton And Harefield NHS Foundation Trust, London, United Kingdom; 4National Institutes of Health / NHLBI, Bethesda, MD, United States
A 3D free-breathing navigator-gated multi-interleaved multi-echo GRE sequence is implemented with VARPRO fat-water separation and utilized in targeted acquisition of coronary arteries at 3T. This approach achieves reliable fat-suppression across field-of-view and provides clear depiction of coronaries for enhanced visualization.
Jing Yu1,2, Michael Schär, 23, Harsh Agarwal, 2,4, Matthias Stuber2,5
1Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States; 2Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 3Philips Healthcare, Cleveland, OH, United States; 4Department of Electrical and Computer Engineering, John Hopkins University, Baltimore, MD, United States; 5Department of Radiology, University Hospital Center and University of Lausanne (CHUV), Lausanne, VD, Switzerland
One of the challenges in coronary MRA is insufficient SNR. To improve the blood-pool SNR in prospective respiratory navigator gated whole-heart coronary MRA, radiofrequency excitations of the gradient echo readout train are suspended in real-time, when the respiratory position is outside the predefined gating window. Phase encoding is adapted to deposit the increased signal in central k-space and to minimize signal variation of adjacent k-space profiles. Consistent with the numerical simulation, in vivo experiments demonstrated 35% improvement in blood-pool SNR, without compromising scan time or spatial resolution. The SNR advantage affords great potential towards better depiction of the coronary arteries.
Pierre-Julien Moro1,2, Alexis Jacquier1, Frank Kober1, Jean-Louis Bonnet2, Patrick Cozzone1, Monique Bernard3
1Centre de Résonance Magnétique Biologique et Médicale, CNRS UMR 6612, Université de la Méditerranée, Faculté de Médecine, Marseille, France; 2Cardiology, CHU Timone, Marseille, France; 3Centre de Résonance Magnétique Biologique et Médicale, CNRS UMR 6612, Université de la Méditerranée , Faculté de Médecine, Marseille, France
The purpose of this study was to assess a non invasive measure of coronary endothelial function. Coronary sinus flow was measured in 14 volunteers at rest and during cold pressor test (CPT) using non breath-hold velocity encoded phase contrast cine MRI. Myocardial blood flow (MBF) significantly increased by 55 ± 38 % during CPT compared to the rest examination (p<0.0001); coronary blood flow was 0.66 ± 0.22 ml/min/g at baseline and 1.03 ± 0.41 ml/min/g after CPT. This non invasive measure may help to detect changes in endothelial function which occur early in a variety of cardiovascular diseases.
Mehdi Hedjazi Moghari1, Peng Hu1, Christian Stoeck2, Jouke Smink3, Dana C. Peters1, Beth Goddu1, Lois Goepfert1, Warren J. Manning1, Reza Nezafat1
1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2University and ETH, Biomedical Engineering, Zurich, Switzerland; 3Philips-Healthcare, Best, Netherland
The impact of correct subject-dependent slice tracking factor in whole-heart coronary imaging is studied in this paper. In preparation phase, two projection-based respiratory navigators are positioned at the diaphragm edge and center of heart to calculate the slice tracking factor. The projection-based navigator at the diaphragm with the estimated scale factor is employed for the whole-heart coronary image reconstruction. The constructed images outperform the ones acquired with the pencil beam navigator with the constant scale factor 0.6.
15:00 3671. Feasibility Study of Motion Pre-Analysis Method for Whole-Heart Magnetic Resonance Coronary Angiography (Wh Mrca) at Different Breathing Levels - not available
Shigehide Kuhara1, Tomohisa Okada2, Ayako Ninomiya1, Toshikazu Kamae2, Shotaro Kanao2, Tetsuo Sato3, Kotaro Minato3, Kaori Togashi2
1MRI Systems Division, Toshiba Medical Systems, Otawara-Shi, Tochigi, Japan; 2Department of Diagnostic Radiology, Kyoto University Hospital, Kyoto, Japan; 3Nara Institute of Science and Technology, Nara, Japan
We have developed the Motion Pre-Analysis Method to determine the appropriate RMC coefficient before WH MRCA (Whole Heart Magnetic Resonance Coronary Angiography) examinations and investigated coefficients between motions of the diaphragm and the heart at different breathing levels by using an inflatable blood pressure cuff placed under an abdominal band. The results of this study suggest that the RMC coefficient may change for each person and abdominal pressures applied. The image quality was slightly improved by using the pre-analyzed RMC coefficient. It is therefore expected that this Motion Pre-Analysis Method would improve visualization of WH MRCA examinations.
Sarah Anne Peel1, Tarique Hussain1, Gerald Greil1, Tobias Schaeffter1, René M. Botnar1
1Division of Imaging Sciences, King's College London, London, United Kingdom
In this study we sought to compare the 3D spiral coronary vessel wall imaging using the local inversion pre-pulse technique on 1.5T and 3T systems. Imaging at 1.5T resulted in consistent image quality and good blood suppression. While SNR was improved at 3T, image quality was more consistent and artifact level lower at 1.5T. Although excellent coronary vessel wall images can be acquired at 3T, improvements in shimming and f0 determination are required to improve overall robustness compared to 1.5T.
Permi Jhooti1, Jennifer Keegan2, Klaus Scheffler1, David Firmin2
1Radiological Physics, University of Basel, Basel, Switzerland; 2CMR Unit, Royal Brompton Hospital, United Kingdom
The mCLAWS technique produces whole heart images in the fastest possible time for a given respiratory pattern and gating window, as well as image datasets at end expiration and end inspiration. The end inspiratory images are generally poorer quality than the end expiratory images because the end inspiratory position is usually more variable and the end inspiratory pause shorter. We have implemented a respiratory biofeedback ‘game’ with a multi-navigator mCLAWS technique to regularise the subjects’ breathing patterns and to enable the acquisition of high quality end inspiratory and end expiratory images from a single whole heart acquisition.
14:30 3674. High Resolution 3D Spiral Coronary Vessel Wall Imaging with >99% Respiratory Efficiency Using Beat to Beat Respiratory Motion Correction: Quantitative Comparison with Navigator Gated 2D Spiral and Turbo Spin Echo Imaging
Andrew David Scott1,2, Jennifer Keegan, 1,2, David N. Firmin, 1,2
1National Heart and Lung Institute, Imperial College, London, Greater London, United Kingdom; 2Cardiovascular Magnetic Resonance Unit, The Royal Brompton Hospital, London, Greater London, United Kingdom
High resolution 3D coronary artery wall imaging potentially enables the assessment of the full 3D extent of a plaque, but is time consuming when used with navigator gating. We compare 3D spiral right coronary artery wall imaging with a highly efficient beat-to-beat respiratory-motion-correction technique using localized tracking of the fat around the artery (99.6% respiratory efficiency) with navigator gated (39% efficient) 2D spiral and 2D turbo spin echo techniques. The techniques were compared quantitatively using vessel wall thickness. The improved respiratory efficiency of the beat-to-beat respiratory-motion-correction technique facilitates high resolution 3D coronary wall imaging within a reasonable duration.
Simon Graham Duckett1, Matthew Ginks1, Benjamin R. Knowles1, Amedeo Chiribiri1, Stephen Sinclair1, Gerry Carr-White2, Aldo Rinaldi2, Rene Botnar1, Eike Nagel1, Reza Razavi1, Tobias Schaeffter1
1Kings College London, London, United Kingdom; 2Guy's and St Thomas's Hospital
As Cardiac resynchronization therapy is becoming more widely available for the treatment of patients with heart failure, there has been increased interest in imaging the coronary sinus and its tributaries. Previous studies using CMR have mainly focused on using intravascular contrast agents (CA), which give no useful information about myocardial scar, and require a separate MR-exam to assess scar and viability. Most of these studies patients with normal left ventricular function have been recruited. We present a single CMR examination imaging the coronary venous anatomy and myocardial scar in patients with HF using a high-relaxivity contrast agent.
John A. Ronald1, Yuanxin Chen2, Kem A. Rogers2, William S. Kerwin3, Brian K. Rutt1
1Radiology, Stanford University, Stanford, CA, United States; 2Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; 3Radiology, University of Washington, Seattle, WA, United States
Atherosclerotic plaques enriched in inflammatory cells and neovessels are prone to rupture, the life-threatening event underlying heart attacks and stroke. Here we performed the first successful bright-blood dynamic contrast enhanced MR imaging of rabbit atherosclerotic plaques that resemble mid-stage plaques in humans and show that the transfer constant, Ktrans, correlates well with histopathological measures of both macrophage (r=0.4438, p=0.011) and neovessel density (r=0.4186, p=0.027). This is an important extension of this technique, which through necessity has been proven useful for advanced human disease only, and holds promise for its use in assessing the effects of anti-angiogenic/anti-inflammatory therapies in earlier plaques.
Hideki Miyagi1, Hajime Sakuma1, Shingo Kato1, Kakuya Kitagawa1, Motonori Nagata1, Takase Shinichi1, Sigfridsson Andreas1, Masatoshi Miyahara2, Mashio Nakamura2, Yoshihide Mitani3, Hiroyuki Ohashi3
1Department of Radiology, Mie University Hospital, Tsu, Mie, Japan; 2Department of Cardiology, Mie University Hospital, Tsu, Mie, Japan; 3Department of Pediatrics, Mie University Hospital, Tsu, Mie, Japan
Whole heart 3D T1-weighted TSE images were acquired with 3T MR imager and 32-channel cardiac coils in 10 patients with Kawasaki disease who had coronary artery aneurysms and 5 patients with coronary artery disease (CAD). Hyperintense coronary plaque (HIP) was observed in 5 of 10 patients with Kawasaki disease and 4 of 5 CAD patients. On MDCT and IVUS, HIP corresponded to thrombus along the vessel wall or positive remodeling plaque with ultrasound attenuation. 3T T1-weighted coronary plaque MRI allows for noninvasive screening of HIP in the entire coronary artery tree with an averaged imaging time of < 10 minutes.
Stephen D. Dickson1, Esad Vucic1,2, Claudia Calcagno1, James HF Rudd1, James Lin1, Jessica Mounessa1, Michelle Roytman1, Zahi A. Fayad1,2
1Radiology, Mount Sinai School of Medicine, New York, NY, United States; 2Medicine, Mount Sinai School of Medicine, New York, NY, United States
Dynamic contrast enhanced (DCE) MRI and F18-fluorodeoxyglucose (FDG) PET/CT was performed on control and pioglitazone-treated atherosclerotic New Zealand White Rabbits at three time points over three months. After three months, treated animals showed decreased MRI contrast agent uptake in plaque as well as decreased FDG signal as compared to controls. Macrophage specific immuno-histochemistry validated anti-inflammatory observations.
Dimitris Mitsouras1,2, Praveen K. Vemula, 23, Peng Yu, 2,4, Ming Tao, 2,4, Binh T. Nguyen, 2,4, Jeffrey Karp, 23, Keith C. Ozaki, 2,4, Robert V. Mulkern, 2,5, Frank J. Rybicki1,2
1Dept of Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Harvard University, Cambridge, MA, United States; 3Dept of Medicine, Brigham and Women's Hospital, Boston, MA, United States; 4Dept of Surgery, Brigham and Women's Hospital, Boston, MA, United States; 5Dept of Radiology, Children's Hospital, Boston, MA, United States
Nearly half of 500,000 vein grafts implanted annually in the US fail. Although MR has enormous potential to assess remodeling and track disease progression, it is severely limited by excessive scan times required to resolve the graft wall (<1mm thickness). Our long-term goal is the development of an implantable MR contrast agent, immobilized on the vein graft surface ex vivo at the time of operation, used to enhance both the MR signal and tissue contrast available for subsequent imaging. We demonstrate for the first time such long-term signal enhancement using a modified Gd-DTPA complex successfully immobilized on the vein surface.
Jingsi Xie1, Zhaoyang Fan1, Debiao Li1
1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States
Develop a 3D contrast-enhanced flow-insensitive vessel wall imaging technique
14:30 3681. Quantitative Analysis of DCE-MRI to Identify and Characterize Plaque at Early Stages (AHA I-III)
Zhuoli Zhang1, Nicole Mascheri1, Jose Agraz1, Zhaoyang Fan1, Richard Tang1, Xiaoming Bi2, Peter Weale2, Debiao Li1
1Northwestern University, Chicago, IL, United States; 2Siemens Healthcare , Chicago, IL, United States
Atherosclerotic disease is thought to begin shortly after birth. Through the years, plaques grow slowly, with variable morphologic aspects and properties at different stages of development. The American Heart Association (AHA) has established criteria by which plaques are classified according to content and structure. It is important to differentiate young stable plaques with a low extracellular lipid content that are not dangerous (types I–III) from unstable more dangerous types (IV-Vc). However, the molecular mediators of atherosclerosis at type I-III are an area of great interest in basic science. Characterization of plaque using MRI at a very early stage is very important for understanding disease process, choosing appropriate prevention and treatment strategies. Dynamic contrast-enhanced MRI (DCE-MRI) may play an important role to identify and characterize plaque at type I-III.
Alkystis Phinikaridou1, Christopher Sucato1, Stephan Anderson2, James A. Hamilton1
1Physiology & Biophysics, Boston University, Boston, MA, United States; 2Radiology, Boston University, Boston, MA, United States
We used a rabbit model of controlled atherothrombosis to test whether in vivo MRI can distinguish between plaques that disrupt after pharmacological triggering (vulnerable) and those that do not (stable). We employed in vivo dynamic contrast enhanced MRI to study the contrast kinetics of gadolinium (Gd-DTPA) in a quantitative manner, which could help to understand the mechanism of gadolinium uptake and derive standardized criteria that could permit a differentiation of stable from vulnerable atherosclerotic plaques.
Niranjan Balu1, Vasily Yarnykh1, Baocheng Chu1, Jinnan Wang2, Thomas Hatsukami1, Chun Yuan1
1University of Washington, Seattle, WA, United States; 2Philips Research North America
Black-blood MRI is an established tool for carotid atherosclerotic plaque burden measurement. Accuracy of measurement can be improved by moving to isotropic imaging but can be challenging for patient compliance due to long scan times. In this work plaque assessment by an ultrafast isotropic 3D black-blood sequence (3D-MERGE) covering the entire cervical carotid arteries within 2 minutes is validated on patients with significant carotid plaque. 3D-MERGE provides good blood suppression and comparable plaque burden measurements to existing MRI protocols. Thus it provides a promising new tool for fast and accurate plaque burden assessment in patients with atherosclerotic plaque.
Tobias Breyer1,2, Oliver Kraff1,2, Stefan Maderwald1,2, Andreas Bitz1,2, Stephan Orzada1,2, Mark E. Ladd1,2, Elke R. Gizewski1,2, Harald H. Quick, 23
1Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Nordrhein-Westfalen, Germany; 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany; 3Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
Atherosclerosis is one leading cause of morbidity. In this study we implemented and adapted a plaque imaging protocol from 1.5 to 7 Tesla with use of a custom-built eight-channel transmit/receive RF array for the first time in human patients with hemodynamically relevant atherosclerosis. This approach allows for MR angiographic imaging without administration of gadolinium contrast comparable to contrast-enhanced MR angiography at lower field strengths. Plaque imaging at 7 Tesla requires different sequences compared to lower field strengths but allows a qualitatively comparable depiction of different intraplaque components, calcifications, vessel wall thickness and the luminal surface compared to lower field strenghts.
Niranjan Balu1, Jinnan Wang2, Xihai Zhao1, Thomas Hatsukami1, Chun Yuan1
1University of Washington, Seattle, WA, United States; 2Philips Research North America
Assessment of vessel wall involvement in peripheral arteries and veins can significantly improve the management of peripheral arterial disease (PAD) and deep vein thrombosis (DVT). The diffuse and bilateral disease in PAD requires bilateral large coverage. Assessment of lesion composition additionally requires multi-contrast imaging. However scan times for current black-blood MRI techniques can be prohibitively long. To address this issue we demonstrate a targeted high resolution multi-contrast imaging protocol combining bilateral isotropic large coverage 3D black-blood MRI for screening and optimized high-resolution 2D black-blood MRI. One case of DVT was identified out of six subjects scanned and characterized by multi-contrast imaging within a 30 minute scan time.
Hideki Ota1,2, Mathew J. Reeves3, David C. Zhu2, Arshad Majid4, Alonso Collar5, Nikunj Chauhan, Chun Yuan6, J.Kevin DeMarco2
1Diagnostic Radiology, Tohoku University, Sendai, Miyagi, Japan; 2Radiology, Michigan State University, East Lansing, MI, United States; 3Epidemiology, Michigan State University, East Lansing, MI, United States; 4Neurology & Ophthalmology, Michigan State University, East Lansing, MI, United States; 5Ingham Cardiothoracic & Vascular Surgeons, Lansing, MI, United States; 6Radiology, University of Washington, Seattle, WA, United States
The purpose of this study was to evaluate prevalence of complicated, high-risk carotid plaque characteristics in both men and women with a broad range of carotid artery stenosis. A total of 230 arteries (51% men) in 132 patients having 0-99% carotid stenosis were included for the analysis. After adjusting for baseline demographic characteristics as possible confounders, presence of complicated AHA VI plaque, lipid-rich/necrotic core, intraplaque hemorrhage were significantly more common in men than women. Increasing MRA stenosis was also associated with these high-risk plaque features. The present results indicate that the development of atherosclerosis appears different between men and women.
alkystis phinikaridou1, Frederick L. Ruberg, Hallock J. Kevin, Ye Qiao2, Ning Hua, Jason Viereck, James A. Hamilton
1physiology and biophysics, boston university, boston, ma, United States; 2Johns Hopkins
We used a rabbit model of controlled atherothrombosis to test whether in vivo MRI can distinguish between plaques that disrupt after pharmacological triggering (vulnerable) and those that do not (stable). In vivo MRI revealed that stable and vulnerable plaques had similar percent of stenosis, but vulnerable plaques more frequently showed: (1) positive remodeling, in which the plaque remains hidden within the vessel wall; and (2) enhanced gadolinium uptake associated with histological features of neovascularization, inflammation, and necrosis. These findings suggest that in vivo MRI may be used for localization of plaques that are prone to disruption prior to acute events.
Jingsi Xie1, Xiaoming Bi2, Zhaoyang Fan1, Himanshu Bhat1, Saurabh Shah2, Sven Zuehlsdorff2, Debiao Li1
1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Siemens Healthcare, Chicago, IL, United States
This work develops a 3D flow-insensitive technique for peripheral vessel wall imaging.
Yan Song1, Cheng Zhou, Min Chen, Nan Luo, Jiachun Liu, Lijun Wang, Yuan Fu, Xiangyang Ma2, Chun Yuan3
1Department of Radiology, Beijing Hospital, Beijing, China; 2Philips Global Clinical Research Board, Greater China Region; 3Department of radiology, University Washington, Seattle, United States
The purpose was to evaluate the efficiency of carotid plaque MRI in stent-treatment decision for patients with carotid atherosclerosis comparing with DSA. A total of 17 symptomatic and 37 asymptomatic carotid arteries were evaluated by MRI and DSA. Images were evaluated for luminal stenosis and fibrous cap (FC) rupture, and the stent treatment decision was based on these criterions. Intraplaque hemorrhage and calcification were also evaluated by MRI. The result was that MRI was superior to DSA in determining stent treatment, especially for asymptomatic patients with carotid artery narrowing of less than 70% for its ability to detect FC rupture.
Victoria Eleanor Louise Young1, Umar Sadat1, Andrew J. Patterson1, Martin J. Graves1,2, Tjun Y. Tang1, Peter J. Kirkpatrick3, Jonathan H. Gillard1
1University Department of Radiology, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; 2Department of Medical Physics, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; 3Department of Neurosurgery, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom
Multi-contrast MRI is used for detection of complex carotid plaque, however, it is time consuming. Direct thrombus imaging (DTI) has been used previously to detect intraplaque haemorrhage. The aim of this study was to assess whether DTI could be used independent of other sequences to demonstrate complex disease. 55 patients with carotid stenosis (>30%) were imaged at 1.5T using a 4 channel phased-array carotid coil. Independent observers reviewed the multi-contrast imaging and DTI separately. DTI was found to be highly sensitive/specific for detecting complex plaque. DTI can be used independent of other imaging to identify complex plaque.
Thanh D. Nguyen1, Keigo Kawaji2, Pascal Spincemaille1, Martin R. Prince1, Yi Wang1,2
1Radiology, Weill Cornell Medical College, New York, NY, United States; 2Biomedical Engineering, Cornell University, Ithaca, NY, United States
Black blood (BB) MRI can be used to characterize vessel wall and quantify atheresclerotic plaque burden in patients with peripheral vascular disease. T2prep inversion recovery (T2IR) has been shown to provide flow-insensitive BB contrast for 2D peripheral vessel wall MRI at 1.5T at the cost of reduced wall SNR The aim of this study is to achieve a considerable increase in T2IR BB imaging efficiency to obtain large field-of-view bilateral peripheral coverage with sub-millimeter isotropic resolution in reasonable scan time using SNR-efficient volumetric 3D fast spin echo acquisition at 3T. The developed sequence was capable of providing large volumetric coverage, excellent arterial and venous blood suppression and fat suppression, as well as good vessel wall visualization in healthy volunteers.
Jinnan Wang1, Marina S. Ferguson2, Niranjan Balu2, Chun Yuan2, Thomas S. Hatsukami2, Peter Boernert3
1Clinical Sites Research Program, Philips Research North America, Seattle, WA, United States; 2University of Washington; 3Philips Research Europe
Intraplaque hemorrhage (IPH) plays a critical role in the evolution of carotid atherosclerotic disease. In this study, a Slab-selective Phase-sensitive Inversion-recovery (SPI) technique, which combines both phase sensitive (PS) imaging and a specially designed IR turbo field echo (TFE) sequence, is proposed to improve the IPH contrast and blood suppression efficiency in human carotid IPH imaging. Significantly improved IPH contrast and blood suppression were found in the in vivo atherosclerotic patient scanning.
Victoria Eleanor Louise Young1, Andrew J. Patterson1, Umar Sadat1, David J. Bowden1, Martin J. Graves1,2, Andrew N. Priest1,2, Tjun Y. Tang1, Jeremy N. Skepper3, Peter J. Kirkpatrick4, Jonathan H. Gillard1
1University Department of Radiology, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; 2Department of Medical Physics, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; 3Multi-imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 4Department of Neurosurgery, Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom
Lipid-rich necrotic core (LR/NC), which is difficult to identify on MRI, has importance in predicting risk of clinical events. Previous studies using diffusion-weighted imaging (DWI) for ex-vivo imaging have demonstrated a potential role for DWI. The aim of this study was to examine if DWI can be applied in vivo to differentiate LR/NC from fibrous cap. 28 patients with confirmed carotid atheroma were imaged at 1.5T using a dedicated 4 channel phased-array carotid coil and ADC maps produced. A significant difference was found between the ADC values for LR/NC and fibrous cap. DWI may provide addition information for plaque classification.
Jianming Cai1, Qingjun Wang1, Yong Wang1, Youquan Cai1, Lin Ma1, Chun Yuan2
1Radiology, Chinese PLA General Hospital, Beijing, China; 2Radiology, University of Washington, Seattle, WA, United States
By using in vivo multi-contrast high-resolution MRI, we performed a long-term follow-up study on asymptomatic and symptomatic carotid intraplaque hemorrhage (IPH) to observe difference in signal evolution within each group and between the two groups. In the present study, each patient with eligible IPH was given a carotid MRI examination on a 3.0-T MRI scanner every 6 months during a total 3 years period. Our findings show that asymptomatic and symptomatic carotid IPH demonstrated a different MRI signal evolution. The repeated IPH may be more common in the symptomatic plaque than in the asymptomatic plaque.
Zhaoyang Fan1,2, Sven Zuehlsdorff3, Peng Lai4, YiuCho Chung3, Jose Agraz1,2, Debiao Li1,2
1Radiology, Northwestern University, Chicago, IL, United States; 2Biomedical Engineering, Northwestern University, Evanston, IL, United States; 3Cardiac MR R&D, Siemens Healthcare, Chicago, IL, United States; 4Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States
Self-gating technique has recently been used in a 3D variable-flip-angle TSE sequence to exclude data acquired during swallowing, yet two shortcomings remain. First, a single self-gating (SG) line acquired immediately before readout in each TR may not be adequate to detect motion if the readout duration is considerably long. Second, real-time update of the reference line used for the cross-correlation analysis is necessary given potentially involuntary “drift” during 3D imaging. This work demonstrated that two SG lines, acquired immediately before and after readout during each TR, in combination with real-time update of the reference line make swallowing-motion gating more robust.
Christoph Benk1, Ramona Lorenz2, JÃ¼rgen Hennig2,3, Friedhelm Beyersdorf1, Jan G. Korvink, 3,4, Michael Markl2
1Dept. of Cardiovascular Surgery, University Hospital, Freiburg, Germany; 2Dept. of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany; 3FRIAS, Freiburg Institute for Advanced Studies, Freiburg, Germany; 4Laboratory for Simulation, IMTEK - Institute of Microsystem Technology, Freiburg, Germany
The use of paracorporeal ventricular assist devices (PVAD) has become a well-established procedure for patients with cardiogenic shock or who need biventricular support. However, implantation of Ventricular assist devices (VADs) is often associated with severe complications such as thrombosis inside the VAD and subsequent embolic events. It was therefore the purpose of this study to use flow sensitive 4D MRI for a detailed analysis of local and global 3D flow dynamics in a clinical routine VAD to study the effect of different system adjustments and valve designs on flow patterns.
Federico E. Mordini1, Ioannis Koktzoglou1, Robert R. Edelman1
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States
Existing methods for intracardiac shunt evaluation have important technical limitations. We developed a time-resolved spin-labeled cineangiographic technique (SLC) to image tagged blood within the heart for visualization of intracardiac shunt. Ten subjects with known atrial septal defects (ASD) were evaluated. Tagged inflowing blood was depicted with high signal intensity (SI) while non-tagged blood was suppressed. Flow was visualized crossing the atrial septum both inplane and throughplane. In conclusion, SLC is a non-contrast, non-velocity dependent method for visualizing RF-tagged blood flowing through cardiac chambers. SLC successfully depicted intracardiac shunting in all patients. SLC has potential use in the detection and pre-procedural assessment of ASD.
Jeremy Douglas Collins1, Philip Anthony Hodnett1, Timothy Anthony Scanlon1, Amir H. Davarpanah1, Aya Kino1, Karin Dill1, Sven C. Zuehlsdorff2, James C. Carr1
1Radiology, Northwestern University, Chicago, IL, United States; 2Radiology, Siemens Healthcare, MR Research and Development, Chicago, IL, United States
Cardiac magnetic resonance is the reference standard for assessment of infiltrative heart disease and systolic function. The ability to assess diastolic dysfunction would enable comprehensive assessment of cardiac function. We evaluated 36 patients and 4 volunteers with flow quantification phase contrast imaging, comparing to Doppler echocardiography. Phase contrast imaging correctly classified all patients with grade I diastolic dysfunction. Differentiating patients with grade II dysfunction from normal diastolic function was not possible, although stratification based on E wave deceleration time was promising. A dedicated acquisition to assess the E’ lateral annulus velocity may be useful in this regard.
Daniel Giese1,2, Verena Knobloch1, Henrik Pedersen3, Tobias Schaeffter2, Sebastian Kozerke1,2
1Institute for Biomedical Engineering, Univeristy and ETH Zurich, Zurich, Switzerland; 2Division of Imaging Sciences, King's College London, London, United Kingdom; 3Functional Imaging Unit, Glostrup Hospital, Glostrup, Denmark
In this work, we present an extension of k-t PCA taking into account temporal correlations in spatial compartments. The compartment method is shown to significantly outperform conventional k-t PCA at high reduction factors. Using the approach up to 10- fold net acceleration of single-directional phase-contrast velocity mapping in the ascending and descending aorta is demonstrated with excellent agreement relative to fully sampled data even if only a single receive coil is available.
Michael Markl1, Timo Zech2, Simon Bauer1, Felix Wegent2, Aurelien F. Stalder1, Christoph Strecker2, Andreas Harloff2
1Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany; 2Neurology, University Hospital, Freiburg, Germany
The purpose of this study was to assess the physiological distribution of absolute wall shear stress and oscillatory shear index in the entire carotid bifurcation in healthy volunteers (n=64 carotid bifurcations) and to evaluate their dependence on individual bifurcation geometry. Further, the distribution of critical wall parameters was compared with findings in patients with moderate internal carotid artery (ICA) stenosis before (n=6) and after surgical recanalization (n=11). Bifurcation geometry predicted exposure to critical wall parameters and may thus be an indicator for the risk of developing flow-mediated atherosclerosis. Carotid artery stenosis and treatment altered the distribution of critical wall parameters.
Alex J. Barker1, Fuxing Zhang2, P E. Gates3, L A. Mazzaro4, A Stalder1, J Fulford3, C J. Lanning4,5, M Markl1, Robin Shandas4,5
1Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany; 2Mechanical Engineering, University of Colorado, Boulder, CO, United States; 3Peninsula Medical School, University of Exeter, United Kingdom; 4Center for Bioengineering, University of Colorado at Denver Health Sciences, CO, United States; 5Division of Cardiology, The Children's Hospital, CO, United States need to fill this out
Frank Helderman1, Gert Jan Mauritz1, J. Tim Marcus1, Kirsten Andringa1, Nico Westerhof1, Anton Vonk Noordegraaf1
1VU University Medical Center, Amsterdam, Netherlands
The objective was to assess if mean pulmonary artery pressure (mPAP) could be estimated using a standard 2D MR phase-contrast velocity quantification in the main pulmonary artery. Included were 37 Pulmonary Arterial Hypertension (PAH) patients vs 8 controls. Onset time of the retrograde flow (Retrograde Onset Time = ROT) as fraction of cardiac cycle time, and cross sectional area (CSA) of the main pulmonary artery were measured. Regression analysis revealed an association between mPAP and ROT (r=0.74; p<0.001), and between mPAP and CSA (r=0.68; p<0.001). The early retrograde flow in PAH is explained with a recirculation zone.
Zoltan Csatari1, Zoran Stankovic1, Peter Deibert2, Wulf Euringer1, Wolfgang Kreisel2, Mathias Langer1, Michael Markl1
1Department of Diagnostic Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany; 2Gastroenterology, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany
Flow-sensitive 4D-MRI allows the detailed depiction and quantification of the great hepatic vessels including the portal venous system as well as the coeliac trunc at the same time. As expected our results demonstrate differences in blood flow characteristics between the portal venous system and the arteries. In accordance with the literature lower values for velocities and higher values for areas were measured by MRI, but linear regression analysis showed an excellent agreement between MRI and the reference standard Doppler Ultrasound (r = 0,72; p < 0.001). In consideration of these results our findings underline that 4D-MRI could be an alternative, user indipendent method to Doppler US in investigating normal and pathological hemodynamics of the great hepatic vessels.
Aurelien F. Stalder1,2, Zhenyu Liu3, Ramona Lorenz2, Juergen Hennig2,4, Jan Gerrit Korvink, 4,5, Michael Markl2
1Dept. of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China; 2Dept. of Diagnostic Radiology - Medical Physics, University Hospital, Freiburg, Germany; 3Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Science, Changchun, China; 4Freiburg Institute for Advanced Studies (FRIAS), Freiburg, Germany; 5Dept. of Microsystems Engineering, University of Freiburg, Germany
Both flow-sensitive 4D MRI and computational fluid dynamics (CFD) have successfully been applied to analyze complex 3D flow. However, both modalities suffer from limitations related to measurements (MRI) or model assumptions (CFD). In this study, we compared both modalities in a model in vitro and in the complex 3D blood flow of the thoracic aorta in vivo. Although discrepancies were observed, overall coherent patterns were observed. The further potential of the method is illustrated by calculating detailed Wall Shear Stress maps using very fine boundary layer mesh. The combination of 4D flow-sensitive MRI and CFD may be used to enhance the assessment of blood flow in vivo.
Benjamin R. Landgraf1, Kevin M. Johnson2, Erik T. Bieging1, Oliver Wieben2, Christopher J. François1
1Radiology, University of Wisconsin - Madison, Madison, WI, United States; 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States
Complex blood flow patterns in the ascending aorta have been associated with the pathophysiology of various cardiovascular diseases, including ascending aortic aneurysms. Helical and vortical flow in patients with aneurysms present an increased tangential force that could lead to further aortic dilation, dissection, or rupture. Characterization and quantification of these flow patterns could help predict disease progression. This study investigates several hemodynamic parameters of the ascending aorta in 11 normal volunteers and 13 patients, including peak and mean velocities, calculation of a tangential percentage of velocity, and characterization of flow patterns.
Thomas A. Hope1, Michael D. Hope1, D Craig Miller2, Michael Markl3, John-Peder E. Kvitting2, Charles B. Higgins1, Robert J. Herfkens4
1Department of Radiology, University of California San Francisco, San Francisco, CA, United States; 2Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States; 3Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany; 4Department of Radiology, Stanford University, Stanford, CA, United States
12 patients status post valve sparing correction of ascending aortic aneurysms were imaged with 4D flow and were followed up for an average of 5 years. One patient had abnormal flow patterns in the ascending and descending aorta. Subsequently during the follow-up period, this patient developed a Stanford Type B aortic dissection. This is the first long-term follow-up study to correlate adverse outcomes to in vivo visualized abnormal flow patterns using MRI. Although this study is limited due to the small number of patients, it does suggest that abnormal flow patterns in the thoracic aorta may provide prognostic information.
Michael D. Hope1, Thomas A. Hope1, Thomas H. Urbania1, Karen G. Ordovas1, Alison K. Meadows1, Marcus T. Alley2, Charles B. Higgins1
1Radiology, UCSF, San Francisco, CA, United States; 2Stanford Radiology
4D Flow demonstrates significantly higher aortic wall shear stress in a subgroup of BAV patients with eccentric systolic flow jets. Studies have shown that only a subset of BAV patients have aortic dilation, and that those with dilation develop asymmetric aneurysms of the AsAo at the location where we have demonstrated elevated vWSS. As altered WSS can give rise to pathologic endothelial gene expression and extracellular matrix remodeling, we may have identified the mechanism that places a subgroup of BAV patients at risk for asymmetric AsAo aneurysm.
Aurelien F. Stalder1,2, Alex Frydrychowicz3, Andreas Harloff4, Qi Yang1, Jelena Bock2, Juergen Hennig2, Kuncheng Cheng Li1, Michael Markl2
1Dept. of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China; 2Dept. of Diagnostic Radiology - Medical Physics, University Hospital, Freiburg, Germany; 3Dept. of Radiology, University of Wisconsin-Madison, Freiburg, Germany; 4Dept. of Neurology, University Hospital, Freiburg, Germany
4D flow-sensitive MRI was used with 3D flow visualization techniques and a vortex core detection algorithm to detect patterns of swirling flow in the aorta, the carotid arteries as well as intracranial arteries in volunteers and patients. While aneurysms presented strong vortex cores, weaker vortex cores were identified in the healthy aortic arch and the healthy internal carotid artery. The vortex core detection provided a fast and simple way to detect locations of swirling flow within 4D flow-sensitive MRI datasets.
Jos J.M. Westenberg1, Arthur J.H.A. Scholte2, Zuzana Vaskova3, Rob J. van der Geest1, Maarten Groenink4, Gerda Labadie1, Pieter J. van den Boogaard1, Teodora R. Radonic4, Yvonne Hilhorst-Hofstee5, Lucia J.M. Kroft1, Albert de Roos1, Johan H.C. Reiber1
1Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands; 2Cardiology, Leiden University Medical Center; 3Radiology, St. Anne's University Hospital, Brno, Czech Republic; 4Cardiology, Academic Medical Center, Amsterdam, Netherlands; 5Clinical Genetics, Leiden University Medical Center
The purpose of this study is to describe age relation of aortic wall compliance, expressed in Pulse Wave Velocity, Distensibility and Stiffness Index, with Velocity-Encoded MRI in Marfan syndrome. Twenty-five patients with Marfan syndrome and twenty-five age-matched healthy volunteers are examined and measures for compliance are compared. In Marfan, the Pulse Wave Velocity is generally increased in the aortic arch, distal aorta and total aorta. Distensibility is decreased. Only the Stiffness Index is not statistically significantly different. Age-related change in compliance is best expressed in increasing Pulse Wave Velocity.
Yi Wang1, Edwin Estrada1, Jianping Zhang2
1Research and Education, St. Francis Hospital, Roslyn, NY, United States; 2Applied Mathematics and Statistics, State University of New York, Stony Brook, NY, United States
Aortic pulse wave velocity (PWV), a measurement of the flow pulse traveling along aorta as a surrogate for aortic compliance, can be assessed using a single breath-hold through-plane phase contrast imaging technique. Accurate determination of the time delay between flows in ascending and descending aorta is critical in PWV assessment. Various approaches have been studied, including measuring the intervals between flow onset points, between maximal flow points, and between parallel upslopes after least squares fittings. We compared five automated approaches for time delay detection and evaluated their effects on aortic compliance and their relationship to age in 186 normal volunteers.
Ramona Lorenz1, Christoph Benk2, Jelena Bock1, Jan Korvink3, Michael Markl1
1Dept. of Diagnostic Radiology, University Hospital, Freiburg, Germany; 2Dept. of Cardiovascular Surgery, University Hospital, Freiburg, Germany; 3Dept. of Microsystems Technology, IMTEK, Freiburg, Germany
In-vitro model systems provide a useful tool for the systematic evaluation of hemodynamic changes associated with geometric vascular modifications. However, realistic in-vivo in-flow and boundary conditions are necessary for accurate flow simulations. This paper presents a novel approach for an in-vitro model setup which includes a pulsatile pump chamber in combination with flexible and monitored pressure control using an adjustable mock loop to simulate physiological pre- and after load conditions. In contrast to measurements without pressure control an improved generation of qualitative and quantitative flow characteristics compared to in-vivo flow conditions could be achieved.
Yin Wu1,2, Ed Xuekui Wu2,3
1Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Shenzhen, Guangdong, China; 2Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong; 3Dept. of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong
Previous DTI studies on infarcted LV myocardium structure usually explored myocardial fiber orientation, diffusivity or diffusion anisotropies. In current study, superquadric glyphs were applied on infarcted porcine model. Diffusion tensor shape and laminar sheet structure were examined for the first time to describe infarcted myocardium structural alteration. Results show that significant change of diffusion tensor shape occurred in both infarct and adjacent regions. Apparent alteration of laminar sheet structure was observed in adjacent and remote regions. The current study demonstrates the ability of superquadric glyphs to detect myocardium structural degeneration and provides supplemental information for infarcted heart remodeling.
Amir H. Davarpanah1, Aya Kino1, Kirsi Taimen1, Philip Hodnet1, Jeremy Collins1, Cormac Farrelly1, Saurabh Shah2, Sven Zuehlsdorff2, James Carr1
1Department of Radiology, Cardiovascular Imaging, Northwestern University, chicago, IL, United States; 2Siemens Medical Solutions, chicago, IL, United States
The VARPRO method (multi-echo gradient echo sequence with iterative fat/water decomposition reconstruction)for fat/water separation performs better than the standard fat saturation protocol currently used at our institution. The water image from this method presents with a more uniform fat suppression.
Emilie Bollache1, Stéphanie Clément-Guinaudeau2, Ludivine Perdrix3, Magalie Ladouceur1,3, Muriel Lefort1, Alain De Cesare1, Alain Herment1, Benoît Diebold1,3, Elie Mousseaux1,2, Nadjia Kachenoura1
1INSERM U678, UPMC, Paris, France; 2Radiology department, APHP, European Hospital Georges Pompidou, Paris, France; 3Echocardiography department, APHP, European Hospital Georges Pompidou, Paris, France
Phase-contrast (PC) Magnetic Resonance (MR) is not used in clinical routine to assess diastolic function, because of the lack of automated analyses. Thus, our aim was to develop a process to automatically analyze PC data. Automated segmentation of PC images and analysis of velocity and flow rate curves to derive diastolic parameters were developed and tested on 25 controls. Segmentation was successful in all subjects. Our conventional parameters were consistent with those previously presented in literature and our new parameters highly correlated with high prognosis value parameters. Our process may provide a valuable addition to the established cardiac MR tools.
Sotirios A. Tsaftaris1,2, Xiangzhi Zhou2, Richard Tang2, Rohan Dharmakumar2
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States
It is particularly important for the evaluation of cardiac phase-resolved myocardial blood-oxygen-level-dependent (BOLD) MRI studies, to robustly and reproducibly identify end-systolic (ES) and end-diastolic (ED). Most automated methods rely on identifying the minimum and maximum of the blood pool area in the Left Ventricle chamber, but they are computationally intensive, susceptible to noise, and require prior localization and segmentation of the chamber. The purpose of this work is to develop automated methods to facilitate in the robust and reproducible evaluation of cardiac phase-resolved myocardial BOLD MRI through identification of ES and ED images.
Amol Pednekar1, Benjamin Cheong2, Raja Muthupillai2, Claudio Arena2
1Philips Healthcare, Cleveland, OH, United States; 2Diagnostic and Interventional Radiology, St. Luke's Episcopal Hospital, Houston, TX, United States
We propose an integrated real-time data acquisition and retrospective post-processing strategy to estimate parameters characterizing global function of the left ventricle. Our initial evaluation of feasibility of this approach in normal subjects shows that slice-by-slice LV volumes estimated using the real-time cine imaging approach are comparable to the LV volumes obtained using conventional, breathhold cardiac cine SSFP techniques. The combination of respiratory navigator triggering, real-time unsegmented SSFP cine imaging, and integrated retrospective automated processing may make this approach particularly useful in patients with severe arrhythmias, and/or severely compromised respiratory function.
Stefan K. Piechnik1, Vanessa M. Ferreira2, Erica Dall'Armellina2, Lowri E. Cochlin3, Stefan Neubauer2, Matthew D. Robson2
1Cardiovascular Medicine, OCMR, Oxford University , Oxford, Oxfordshire, United States; 2Cardiovascular Medicine, OCMR, Oxford University, Oxford, Oxfordshire, United States; 3Dept of Physiology, Anatomy and Genetics, Oxford University, Oxford, Oxfordshire, United States
We propose a cardiac T1-mapping method based on sequential Look-Locker measurements with conditional reconstruction of incomplete recovery periods. This new method assures that robust T1 mapping can be achieved in a 9 heartbeat breath-hold with accuracy comparable to existing methods.
Antonella Meloni1, Vincenzo Positano1, Alessia Pepe1, Pasquale Pepe1, Maria Chiara Dell'Amico1, Cristina Salvatori1, Petra Keilberg1, Gianluca Valeri2, Eliana Cracolici3, Pier Paolo Bitti4, Angelo Zuccarelli5, Maria Filomena Santarelli1, Massimo Lombardi1
1MRI Lab, “G. Monasterio Foundation” and Institute of Clinical Physiology, CNR, Pisa, Italy; 2Azienda Ospedaliero-Universitaria Ospedali Riuniti "Umberto I-Lancisi-Salesi", Ancona, Italy; 3Policlinico "Paolo Giaccone" , Palermo, Italy; 4Dipartimento dei Servizi - P. O. San Francesco, Nuoro, Italy; 5Centro trasfusionale e di microcitemia - Ospedale civile, Olbia, Italy
Multislice multiecho T2* MRI allows quantification of iron overload in the whole myocardium. A preferential pattern of iron store in anterior and inferior regions appears to be present in thalassemia major patients with severe and mild-moderate iron overload. The preserved pattern between the groups prevents attributing this datum to additive susceptibility artefacts, which are negligible in heavily iron-loaded patients. A segmental T2* CMR approach could identify early iron deposit, useful for tailoring chelation therapy and preventing myocardial dysfunction in the clinical setting.
Wei Feng1, Himanshu Gupta2, Steven Lloyd2, Louis Dell'Italia2, Thomas S. Denney Jr3
1Biomedical Engineering, MRI Institute, Detroit, MI, United States; 2Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States; 3Electrical Engineering, Auburn University, Auburn, AL, United States
This abstract presents a method for computing right-ventricular volume-versus-time curves and peak ejection and filling rates from standard cardiac cine MRI. The method uses RV contours drawn semi-automatically near end-diastole and end-systole and propagates them to the remaining time frames via a non-rigid registration technique. The propagated contours are validated by comparing them to contours manually drawn by a cardiologist with Level 3 training. In addition, peak ejection and filling rates computed from both manually-drawn and propagated contours are compared.
Bharath Ambale Venkatesh1, Steven G. Lloyd2, Mustafa I. Ahmed2, Himanshu Gupta2, Louid Dell'Italia2, Thomas S. Denney Jr. 1
1Electrical and Computer Engineering, Auburn University, Auburn, AL, United States; 2University of Alabama at Birmingham
Accurate assessment of right ventricular (RV) function is clinically important – particularly in patients with pulmonary hypertension (PHTN). Compared to the left ventricle (LV), however, analysis of RV function is relatively difficult because of relatively thin walls and lack of geometric symmetry. Also in PHTN, higher systolic blood pressure in the RV can cause excursion of the interventricular septum into the LV cavity causing it to lose its geometric symmetry. This abstract presents a method for reconstructing three-dimensional biventricular strain from tagged MRI in each imaged time frame through mid-diastole. This method is validated on normal volunteers and PHTN patients.
Ting Song1,2, Jeffrey A. Stainsby3, Maureen N. Hood2,4, Vincent B. Ho2,4
1GE Healthcare Applied Science Laboratory, Rockville, MD, United States; 2Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; 3GE Healthcare Applied Science Laboratory, Toronto, ON, Canada; 4Radiology, National Navy Medical Center, Bethesda, MD, United States
A novel long axis wall motion quantification model is proposed to provide a reliable and simple solution to cardiac function calculations. Using only routine clinical MR cine images, functional parameters can be quantified determined retrospectively.
Sotirios A. Tsaftaris1,2, Xiangzhi Zhou2, Richard Tang2, Rachel Klein2, Aggelos Katsaggelos1, Rohan Dharmakumar2
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States
It is particularly important for the evaluation of cardiac phase-resolved myocardial blood-oxygen-level-dependent (BOLD) MRI studies, to robustly and reproducibly synchronize images from rest and stress studies. The possibility of visualizing BOLD signal changes in multiple cardiac phases is expected to increase the diagnostic confidence for identifying the affected myocardial territories. The purpose of this work is to develop automated statistical methods to facilitate in the robust and reproducible evaluation of cardiac phase-resolved myocardial BOLD MRI through temporal synchronization of rest and stress images acquired at different heart rates, without resorting to LV segmentation.
Nicholas M. Dunn1, Subha Raman2, Helene Houle3, Gianni Pedrizzetti4, Mani Vannan2, Orlando Simonetti2
1The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States; 2Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH, United States; 3Siemens Medical Solutions, Mountain View, CA, United States; 4The University of Trieste, Trieste, Italy
Quantification of systolic strain and diastolic strain rate provide more sensitive indicators of myocardial dysfunction than subjective image interpretation. Vector Velocity Imaging (VVI) is a processing method developed to calculate myocardial strain and strain rate in echocardiography images. Its feasibility to calculate strain and strain rate in cine MR images was tested by analyzing short and long axis SSFP cine MR images of normal, healthy subjects and comparing the acquired values to literature values attained using other MR tissue-tagging methods. The results show that VVI may be used to calculate strain and strain rate in SSFP cine MRI.
Yonggang Lu1,2, Thanh D. Nguyen3, Noel C. F. Codella3, Dorinna D. Mendoza4, Jonathan Weinsaft4, Bruce B. Lerman5, Yi Wang3
1Wiscom Intelligent System Co.,Ltd., Nanjing, Jiangsu, China; 2Department of Radiology , Weill Medical College of Cornell University, New York, NY, United States; 3Department of Radiology, Weill Medical College of Cornell University, New York, NY, United States; 4Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York, NY, United States; 5Department of Medicine, Weill Medical College of Cornell University, New York, NY, United States
A GMM clustering method with a free-breathing 3D Navigator-Gated DE-MRI was proposed for myocardial infarction segmentation in this study. Compared to commonly used methods, the novel method has a superior performance of more accuracy and operator-independence in assessing myocardial infarction as demonstrated by preliminary experiments with in vivo human data.
Christakis Constantinides1, Nikolas Aristokleous1, Konstantinos Fokianos2, Jeff Brandenburg3, Dimitrios Perperidis1
1Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus; 2Mathematics and Statistics, University of Cyprus, Nicosia, Cyprus; 3Radiology, Duke University Medical Center, Durham, NC, United States
Quantitative characterization of ventricular function has become important for the assessment of cardiac performance in heart disease. As the manipulation of the mammalian genome becomes routine, it is now possible to generate animal models to study cardiovascular function and dysfunction. Critical to successful phenotypic screening of mouse models of the cardiovascular system using MRI are highly efficient four-dimensional (4D) acquisition protocols, and reduction of the computational image processing complexity for accurate quantification. The -goal of this study is the efficient, quantitative assessment of interstrain cardiac performance in C57BL/6J and DBA/2J mouse hearts under anesthesia, using MRI.
Vincenzo Positano1, Matteo Milanesi1, Piergiorgio Masci1, Thomas KIng Foo2, J C. Hardy2, Luca Marinelli2, Andrea Barison, 1,3, Daniele De Marchi1, Massimo Lombardi1, Luigi Landini4
1MRI Laboratory, "G- Monasterio" Foundation and Istitute of Clinical Physiology, Pisa, Italy; 2Global Research Center, General Electric, Niskayuna, NY, United States; 3Scuola Sant'Anna, Pisa, Italy; 4Department of Information Engineering, University of Pisa, Italy
Myocardial T1 mapping from Cine-IR images is feasible by warping the myocardium signal in each frame on a standardized model, evaluating the pixel-by-pixel T1 distribution on the model, and finally warping back the resulting T1 map on each frame.
Marie Xavier1, Alain Lalande1, Paul Michael Walker1, Jean-Christophe Eicher2, Jean-Eric Wolf, 1,2, François Brunotte1, Louis Legrand1
1LE2I, University of Burgundy, Dijon, France; 2Department of Cardiology, University Hospital, Dijon, France
Generally, the evaluation of myocardial motion from cine-MRI sequences requires a visual evaluation of the regional contractile function and depends on the experience of the reader. To automatically detect local myocardial wall motion abnormalities from cine-MRI sequence, an optical flow technique based on phase information was used. First, the robustness of the technique with regards to Rician noise and to brightness variations was evaluated on synthetic images. Then, in the context of cardiac cine-MRI, a segmental decomposition of the myocardium allowed us to study the mean velocity along the cardiac cycle and gave similar values to those obtained by echocardiography.
Michael Loecher1, Kevin Johnson1, Christopher Francois2, Oliver Wieben1
1Department of Medical Physics, University of Wisconsin, Madison, WI, United States; 2Department of Radiology, University of Wisconsin, Madison, WI, United States
This study aims to assess an alternative reconstruction method that utilizes the temporal information from a 4D radially encoded flow scan. The method creates and angiogram from dynamic time frames instead of a time averaged reconstruction. While the approach increases background noise, it alleviates the problem of signal drops and voids from reversing flow patterns. The utility of the algorithm was evaluated in a group of 4 volunteers and 6 patients, demonstrating improved signal consistency along the aorta.
Sotirios A. Tsaftaris1,2, Erik Offerman3, Robert R. Edelman3, Ioannis Koktzoglou3
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States; 3Radiology, NorthShore University HealthSystem, Evanston, IL, United States
Ghost magnetic resonance angiography (MRA) has been proposed as an unenhanced and ungated method for angiography. The method requires manual post-processing to identify suitable slices in a large stack from which to create an interpretable angiogram. To maximize the contrast of the final angiogram it is necessary to eliminate slices located within the body and to carefully select the slices that contain conspicuous ghost artifacts. This time-consuming process can also introduce unwanted inter- and intra- observer variability. The purpose of this work was to completely automate the reconstruction process during ungated and non-contrast-enhanced Ghost MRA using image analysis and clustering.
Andreas Deistung1, Michal Strzelecki2, Andrzej Materka2, Jürgen R. Reichenbach1
1Medical Physics Group, Department of Diagnostic and Interventional Radiology , Jena University Hospital , Jena, Germany; 2Institute of Electronics, Technical University of Lodz, Lodz, Poland
Non-invasive quantitative assessment of the cerebral vasculature is of high diagnostic and therapeutic interest. The pre-requisite for the quantitative description of blood vessels is voxel-wise classification into vessel and non-vessel structures. In this contribution, we use a hybrid level-set approach that relies on both boundary and region information to segment arterial and venous vessels from simultaneously acquired time-of-flight (ToF) and susceptibility weighted imaging (SWI) data to create a 3D representation of the arterial and venous vasculature.
Bernard Chiu1, Xihai Zhao1, Jinnan Wang2, Niranjan Balu1, Chun Yuan1, William S. Kerwin1
1Radiology, University of Washington, Seattle, WA, United States; 2Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, United States
Peripheral arterial disease (PAD) is a serious health issue in the western world. Recent advances in high-resolution MRI have allowed noninvasive and detailed assessment of PAD, including black-blood MRI visualization of the vessel wall. Because the length of a femoral artery is substantial, a long field of view is required to image the femoral artery. Manual outlining of wall boundaries along the entire length of the femoral artery is an arduous task. In this work, we proposed and demonstrated an automatic algorithm that is capable of accurately segmenting the lumen and wall boundaries along the majority of the femoral artery.
Dongxiang Xu1, Jinnan Wang2, Williams Kerwin1, Chun Yuan1
1Radiology, University of Washington, Seattle, WA, United States; 2Philips Research North America, Jinnan.Wang@philips.com, Seattle, WA, United States
Intraplaque hemorrhage (IPH) into the carotid atherosclerotic plaque has shown significant association with clinical symptoms and is believed to be a major factor causing plaque instability and progression according to previous histopathological and prospective studies. With the development of magnetic resonance imaging (MRI) in clinical diagnostics, several techniques have been developed to enable and improve the IPH evaluation. However, automated hemorrhage detection has been challenging due to either low IPH contrast or poor lumen contrast. Purpose: In this study, by incorporating the improved IPH and lumen contrasts in Slab-selection Phase-sensitive Inversion-recovery (SPI) MRI sequence, we develop a novel and robust image segmentation approach to automatically locate and delineate IPH in MR data. Quantitative IPH and lumen analysis results by this automatic segmentation technique were compared to a human reader, which demonstrated highly consistent performance.
Hui Xue1, Sven Zuehlsdorff2, Jens Guehring1
1Corporate Research, Siemens Corporation, Princeton, NJ, United States; 2CMR Research and Development, Siemens Healthcare, Chicago, IL, United States
Although the first-pass myocardial perfusion MRI has proven its effectiveness in the early diagnosis of suspected ischemic heart diseases, this technique is still not routinely used. Certain technical difficulties prevent perfusion MRI from being added into the clinical workflow. Among of them includes the B1-field inhomogeneity caused by non-uniform characteristics of the receiver coils which still lacks intensive studies, when compared to perfusion imaging sequences or motion compensation. We therefore propose algorithms to perform the surface coil inhomogeneity correction (SCC) using proton density (PD) weighted images and B-Spline Free-Form Deformation (FFD).
John David Biglands1, Abdulghani Larghat1, Sven Plein1, David L. Buckley1, Michael Jerosch-Herold2, Derek Magee3, Roger Boyle3, Aleksandra Radjenovic1
1School of Medicine, University of Leeds, Leeds, UK, United Kingdom; 2Radiology, Brigham and Womens Hospital, Boston, MA, United States; 3School of Computing, University of Leeds, Leeds, United Kingdom
Dynamic contrast enhanced magnetic resonance imaging of the myocardium using sufficiently high doses to be clinically useful generates uptake curves that require correction for signal saturation effects before they can be used for myocardial blood flow (MBF) estimation. Such corrections require knowledge of the native T1 of the blood and myocardium. This abstract shows that using an assumed blood T1 enables saturation correction of typical clinical datasets without the need for time consuming T1 measurements. MBF estimates from nine patients were consistent with literature values and were shown to be robust to variations in the assumed T1 of blood.
Taigang He1, Sanjay Prasad1, Guang-Zhong Yang1, Dudley Pennell1, David Firmin1
1Royal Brompton Hospital and Imperial College London, London, United Kingdom
Synopsis: The aim of this study was to develop a novel T2 mapping method for improved myocardial tissue characterisation. The developed T2 sequence resulted in improved resolution with shorter echo time and echo spacing. The novel technique was consequently evaluated on nine human subjects. Preliminary results demonstrated that all images acquired were of good quality. Pixel wise T2 curve is well fitted and T2 mapping in the whole myocardium appeared homogeneous. This study suggests that T2 mapping may potentially be used for assessing regional disease variations across the myocardium.
Min Sig Hwang1, Katja Odening2, Ohad Ziv2, Bum-Rak Choi2, Gideon Koren2, John R. Forder1
1McKnight Brain Institute, University of Florida, Gainesville, FL, United States; 2Cardiovascular Research Center, Rhode Island Hospital Alert Medical School of Brown University, Providence, RI, United States
In this study, we explored the potential of microscopic high angular resolution diffusion imaging (MHARDI) achieving a cellular level spatial resolution as a non-invasive tool that is sensitive to subtle changes in the heterogeneous microstructure and arrangement of the cardiac tissues. Diffusion tensor images and tensor invariants acquired with two diffusion sensitizing factors were investigated. Our results suggest that MHARDI with an optimized b-value and resolution may be a powerful tool for non-invasive monitoring of electro-mechanical property and its well-coordinated function.
YingLi Lu1, Perry Radau1, Kim A. Connelly1,2, Alexander Dick3, Graham A. Wright1
1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2Cardiology, St Michael's Hospital, Toronto, ON, Canada; 3Cardiology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
Purpose of this study is to develop a fully automatic left ventricle segmentation method from cine short-axis MR images and evaluate it on a large data set of 147 subjects grouped by pathology. Advantages of this method include that it: 1) does not require manually drawn contours; 2) provides not only endocardial and epicardial contours, but also papillary muscles and trabeculations¡¯ contours; 3) introduces a roundness measure that automatically locates the left ventricle; 4) simplifies the epicardial contour segmentation by mapping the pixels from Cartesian to approximately polar coordinates.
Xiaodong Zhong1,2, Bruce S. Spottiswoode3, Craig H. Meyer2,4, Frederick H. Epstein2,4
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa; 4Radiology, University of Virginia, Charlottesville, VA, United States
This abstract introduces novel automatic algorithms for myocardial tissue tracking and strain calculation for three-dimensional (3D) cine DENSE data. Specifically, scattered data interpolation using radial basis functions (RBF) was developed for Lagrangian tissue tracking. Also, a finite-strain based algorithm was developed to calculate the deformation gradient tensor and the Lagrangian strain tensor. The algorithms were performed on 3D cine DENSE data from five healthy volunteers to obtain 3D Lagrangian displacement and strain fields. The 3D myocardial mechanics, including normal strains, twist and torsion, were consistent with previous results from myocardial tagging in healthy volunteers.
Hans C. van Assen1, Luc M.J. Florack2, Frank F.J. Simonis1, Jos J.M. Westenberg3, Gustav J. Strijkers1, Bart M. ter Haar Romeny1
1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands; 2Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands; 3Radiology, Leiden University Medical Center, Leiden, Netherlands
This paper describes a novel image processing method for automated detection of cardiac pathology. It entails tagging analysis by means of an optical flow approach. Tag fading is overcome by exploitation of tag phase - retrieved by Gabor filtering - instead of tag brightness.
The method yields both the motion field and its first order derivative structure, necessary to calculate strain and rotation. Calculation of these derived parameters thus becomes straightforward. High-resolution in-slice cardiac strain and rotation are presented for four volunteers and a patient, and clearly show deviations for a patient with known small infarctions and wall motion abnormalities.
James W. Goldfarb1,2, Wenguo Zhao1
1Saint Francis Hospital, Roslyn, NY, United States; 2Program in Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
The purpose of this study was to investigate the temporal dynamics a two-compartment tissue-blood partition coefficient and compare it to estimates using a three-compartment model. In 25 individuals with chronic myocardial infarctions, blood Gd-concentration was modeled with a bi-exponential and myocardial tissue Gd-concentration with a three-compartment model. It was found that the measurement of the tissue-blood partition coefficient based on the ratio of T1 relaxation time differences is time dependent.. The measurement of the tissue-blood partition coefficient using a three compartment model yields similar values between infarcted and viable myocardium. T1 relaxation differences are likely due to a third trapping compartment.
Shuning Huang1, Hushan Yuan2, Howard Chen3, Guangping Dai1, Lee Josephson2, David E. Sosnovik1,3
1Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Center for Translation Nuclear and Molecular Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 3Center for Molecular Imaging Research, Massachusetts General Hospital, Charlestown, MA, United States
Delayed enhancement of gadolinium cannot discriminate acute and chronic injury since both produce similar changes in the pharmacokinetics of small gadolinium chelates, such as Gd-DTPA. Here, we demonstrated that the acute myocardial infarction can be distinguished from both subacute and chronic myocardial injury by utilizing a DNA-targeted gadolinium chelate (Gd-TO).
Rakesh Sharma1,2, Kiran Shetty, 3
1FAMU-FSU College of Engineering,, CIMAR, National High Magnetic Field Laboratory, Tallahassee, FL, United States; 2Center of Nanomagnetics and Biotechnology, Florida State University & TCC, Tallahassee, FL, United States; 3NHMFL, Florida State University, Tallahassee, FL, United States
The 21T MR microimaging by using first time troponin nanoparticles enhances the visualization of cardiac muscles fiber and offers technical advancement in future. Diffusion weighting offers the fiber tracking and functional analysis. Image processing offers heart probabilistic atlas and maps.
Ravi Teja Seethamraju1, Sonia Nielles-Vallespin2, Shuning Huang3, David E. Sosnovik3,4
1MR R and D, Siemens Medical Solutions, USA Inc., Charlestown, MA, United States; 2Cardiovascular MR, Royal Brompton Hospital, London, United Kingdom; 3Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States; 4Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
Iron oxide based USPIOs inherently exhibit T1 shortening apart from their traditional T2 properties. This property is best utilized at ultrashort echo times. We demonstrate how a single UTE sequence can produce both angiographic images as well as molecular quantitation.
Andrei Maiseyeu1, Georgeta Mihai1, Marcus A. Badgeley1, Orlando P. Simonetti1, Jeffrey A. Deiuliis1, Chandan K. Sen1, Sampath Parthasarathy1, Sanjay Rajagopalan1
1Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
Novel "peach-like" nanoparticle (NP) contrast agents were manufactured, characterized and tested. In-vitro studies showed preferential uptake of NPs by macrophages while in-vivo studies in ApoE-deficient mice revealed protracted signal enhancement of atherosclerotic plaque. Proper design and ease of fabrication of these nanostructures makes them very versatile as either T1 or T2 MRI contrast agents. These NPs loaded with fluorescein or near-infrared emitting quantum dots represent attractive tools for multimodality imaging of atherosclerosis.
Yanfeng Meng1,2, Feng Zhang1, Tiffany Blair1, Huidong Gu1, Hongqing Feng1, Jinnan Wang3, Chun Yuan1, Zhaoqi Zhang2, Bensheng Qiu1, Xiaoming Yang1
1Radiology, University of Washington, Seattle, WA, United States; 2Radiology, Beijing Anzhen Hospital, Beijing, China; 3Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, United States
This study was to validate the feasibility of using clinical 3.0T MRI to monitor the migration of auto-transplanted bone marrow cells (BMC) to the injured arteries of near-human-sized animals. BMCs were extracted endogenously, labeled with Feridex and/or PKH26, and then auto-transplanted back to the same animal. Post-cell transplantation 3.0T T2-MRI showed Feridex-created MR signal voids along the injured iliofemoral artery segments, which were not seen in the control arteries. Histology, including Prussian blue and dextran immunofluorescent staining as well as PKH26 fluorescence, confirmed the MRI findings. This study establishes groundwork for clinical 3.0T MRI of cell-based repair of injured arteries.
Philip Lee1, Johannes Riegler2, Bingwen Zheng1, Anthony Price2, Mark F. Lythgoe2, Xavier Golay3
1Singapore Bioimaging Consortium, Biomedical Sciences Institute, Singapore, Singapore; 2Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom; 3Institute of Neurology, University College London, London, United Kingdom
Migration of super-paramagnetic labeled cells critically affects the success of therapeutic cell studies. Detection with T2* weighted MRI is normally implemented. But direct association of signal voids with SPIOs-labeled cells is erroneous, as they could originate from magnetic field inhomogeneities or partial volume effects. This study highlights the use of a multiple-echo ultra-short echo time (MUTE) sequence for positive contrast visualization of injected mononuclear cells. 5x105 and 2.5x105 of MNCs were directly injected into the left myocardium wall at the apex and mid-ventricle respectively and the heart was subsequently excised for MRI. Subtraction between the UTE (TE=0.208ms) and ECHO (TE=2.56ms) images exploited the transverse relaxation effect of iron, generating contrast-to-noise ratio of 19.6 and 22.7 respectively.
Rong Zhou1, Djaudat Idiadilitum2, Curt Corum2, Hualei Zhang1, Jia Zhong1, Hui Qiao1, Steen Moeller2, Michael Garwood2
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States
We demonstrate the first in vivo cardiac image by ECG-gated SWeep Imaging with Fourier Transformation (SWIFT). Myocardium anatomies are well-visualized on 3D SWIFT magnitude images. The positive contrast on SWIFT imaginary image facilitates the detection of SPIO-containing cells while the magnitude image provides anatomical reference without requirement for additional reference image. These data suggest that SWIFT might be an alternative to currently available positive contrast methods, attractive especially in cardiovascular applications.
Dipanjan Pan1, Anne Schmieder1, Angana Senpan1, Shelton D. Caruthers1, Samuel A. Wickline1, Gregory M. Lanza1
1C-TRAIN and Division of Cardiology, Washington University in St. Louis, Saint Louis, MO, United States
High-resolution MR Angiogenesis Mapping with Integrin-targeted Ultralow Gadolinium-Manganese Nanocolloids
Lisette Helene Deddens1, Peter A. Jarzyna2, Arjan W. Griffioen3, Zahi A. Fayad2, Rick Michiel Dijkhuizen1, Willem JM Mulder2
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Imaging Science Laboratories, Mount Sinai School of Medicine, New York, United States; 3Angiogenesis Laboratory Amsterdam, VU Medical Center, Amsterdam, Netherlands
Nanoemulsions represent an attractive delivery platform for hydrophobic compounds since they improve their bioavailability and make their intravenous administration possible. This abstract demonstrates that the nanoemulsion platform, developed for passive delivery of hydrophobic compounds to tumor tissue, is also very suitable for targeted applications. Data show the applicability of αvβ3-specific RGD nanoemulsions in targeting tumor angiogenesis visualized by MRI, fluorescence microscopy and immunohistochemistry.
14:00 3750. Angiogenesis and Cell Tracking with Iron Oxide-Labeled Tumor Cells: Correlation Between Cell Growth and the Formation of the Tumor Vascular Bed Using High Resolution Magnetic Resonance (MR) Angiography, T1, T2 and T2* Mapping and Histology
Piotr A. Wielopolski1, Gyula Kotek1, Sandra van Tiel1, Gabriela Doeswijk1, Lejla Alic2, Gabriel P. Krestin1, Bernsen Monique1
1Radiology, Erasmus Medical Center, Rotterdam, zuid-holland, Netherlands; 2Informatics and Radiology, Erasmus Medical Center, Rotterdam, zuid-holland, Netherlands
To correlate super paramagnetic iron oxide (SPIO) labeled tumor cell growth and distribution with high resolution magnetic resonance (MR) angiography, T1, T2 and T2* parametric mapping and histology
Ming-Hung Chen1, Gin-Chung Liu2,3, Twei-Shiun Jaw2,4, Yu-Ting Kuo2,3, Chiao-Yun Chen2,3, Yun-Ming Wang1
1Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan; 2Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 3Department of Radiology,Faculty of Medicine,College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 4Department of Radiology,Faculty of Medicine,College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
In this study, the various core sizes of manganese ferrite nanoparticles (MnFe2O4) conjugated with D4 peptide (MnFe2O4-PEG-D4) were synthesized. The high relaxivity MnFe2O4 nanoparticles were obtained by thermal decomposition of Iron acetylacetonate and manganese acetylacetonate in hydrophobic solution at high boiling process. The surface of MnFe2O4 nanoparticles were coated with polyethylene glycol (PEG) and EGFR peptide ligand (D4: Leu-Ala-Arg-Leu-Leu-Thr) to improve their dispersion and ability to target EGFR. The negative signal enhancement of EGFR expressing cancer cells (SKBR-3 and PC-3) were significantly higher than that of low EGFR expressing cells (HEK-293).
Alex Xuexin Li1, Mojmir Suchy2, Chunhui Li1, Claire Poppe1, Joseph Gati1, Susan Meakin1, Robert H.E. Hudson2, Ravi S. Menon1, Robert Bartha1
1Robarts Research Institute, London, ON, Canada; 2The University of Western Ontario
A methodology to detect the on-resonance paramagnetic chemical exchange effects (OPARACHEE) of a PARACEST contrast agent: Tm3+-DOTAM-Glycine (Gly)-Lysine (Lys) in a mouse brain tumor model was developed. The OPARACHEE effect was isolated from the relaxation effects induced by the PARACEST agent using a control image and an OPARACHEE image. Isolated OPARACHEE contrast (1-3%) was observed in all animals. Immediately after contrast agent injection OPARACHEE contrast was observed and maintained at 1~2% in the hour following injection.
13:30 3753. A Targeted Nanoglobular Manganese(II) Chelate Conjugate for Magnetic Resonance Cancer Molecular Imaging - not available
Mingqian Tan1, Eun-Kee Jeong2, Zheng-Rong Lu1
1Case Western Reserve University, Cleveland, OH, United States; 2University of Utah, Salt Lake City, UT, United States
A peptide targeted nanoglobular Mn(II)-DOTA conjugate was designed and synthesized as MRI contrast agent for cancer molecular imaging. The target specific contrast agent comprised of 2 peptides and 42 Mn(II) chelates on the surface of the G3 nanoglobule with a defined structure. The T1 and T2 relaxivities at room temperature are 3.13 and 8.14 mM-1sec-1 per Mn(II) chelate at 3T, respectively. The targeted nanoglobular contrast agent specifically bound to tumor tissue and resulted in significant tumor contrast enhancement in tumor-bearing mice as compared to a non-targeted control at a dose as low as 0.03 mmol-Mn/kg .
Ching-Tang Chen1, Chia-Hao Su2, Yi-Chien Lu1, Ang Yuan3, Jyh-Horng Chen1
1Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Taiwan; 2Center for Translational Research in Biomedical Science, Chang Gung Memorial Hospital, Kaohsiung, Taiwan; 3Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
Molecular imaging has become an indispensable technology in cancer research and clinical use. The goal of this study is to combine magnetic resonance imaging and optical imaging system with multifunctional contrast agent to detect xenograft non-small cell lung cancer (NSCLC) murine model.
High temperature solution phase reaction led to 8 nm ultrasmall superparamagnetic iron oxide (USPIO, Fe3O4), and the CdS-capped CdTexSe1-x alloyed quantum dot was synthesized to near-IR emitting nanoparticles. Aqueous iron oxide and near-IR quantum dot nanoparticles were conjugated with anti-epideremal growth factor receptor (EGFR) antibody as the biomedical probe to detect the NSCLC tumor. Variation of T2 relaxation time was obtained from MRI for nano-contrast agent quantification. Prussian blue staining imaging showed different targeting efficiency in A549 and CL1-0 in vitro. T2 and T2* MR imaging showed significant signal decrease (>30%) in vivo. It was proved caused by nano-probe targeting by using both histological cytochemistry staining. Multifunctional nanocontrast agent could hopefully not only serves as cancer detection and treatment but also used to predict disease prognosis in the future.
Emeline Julie Ribot1, Carmen Simedrea2, Patricia McGowan2, Ann Chambers2, Paula J. Foster1
1Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, University of Western Ontario, London, Ontario, Canada
In this abstract, we describe technology developed in our labs for tracking stem-like cancer cells (CSC), in a mouse model of breast cancer metastasis to the brain, using MRI and magnetic particles. A human breast cancer cell line was sorted by flow cytometry into two distinct populations: CD44high/CD24low and CD44low/CD24high, representing the CSC-like and non-CSC cells, respectively. The sorted cell populations can be labeled efficiently and without toxicity with the iron agent MoldayION Rhodamine B. Labeled CSC can be detected in vivo in images of the mouse brain after injection into the left ventricle of the heart in nude mice.
Chang-Tong Yang1, Cai-Xian Yong1, Chew-Yuan Tuang2, Young-Tae Chang2, Kai-Hsiang Chuang1
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Agency for Science,Technology and Research, Singapore, Singapore; 2Laboratory of Bioimaging Probe Development, Singapore Bioimaging Consortium, Agency for Science,Technology and Research, Singapore, Singapore
We developed a new Gd(III) chelate by conjugating GdDO3A with 2-(diphenylphosphoryl)ethyldiphenylphosphonium cation -- Gd(DO3A-xy-TPEP)+ to form a cationic MRI contrast agent. This contrast agent has been synthesized and characterized in vitro and in vivo. In vitro cell viability showed insignificant cytotoxicity at low [Gd] concentrations up to 0.2 mM. The in vitro T1 relaxivity measured at 7.0 T is about 50% higher than that of clinically used Gd-DTPA and Gd-DOTA. In vivo imaging study in mice demonstrated longer tissue retention especially in the liver. It indicated that Gd(DO3A-xy-TPEP)+ could potentially be used to detect tumor which generally has larger negative mitochondrial transmembrane potential.
Philip Anthony Hodnett1,2, Ioannis Kokztzoglou3, Timothy Scanlon, Jeremy Collins4, John Sheehan, Eugene Dunkle, James C. Carr, Robert Edelman
1Northwestern University, Chicago, IL, United States; 2Northshore University Healthcare System, Chicago, IL, United States; 3Northshore University Healthcare System, United States; 4Northwestern University, United States
Imtroduction:The purpose of this study was to test the hypothesis that a hybrid technique employing a new unenhanced MRA technique, quiescent interval single shot (QISS) in combination with a low-dose time resolved (TWIST)of the calf provides comparable diagnostic accuracy to the standard hybrid approach using low-dose TWIST of the calf and high-dose stepping table CE-MRA. Materials and Methods:20 prospective patients referred for evaluation of peripheral arterial disease underwent unenhanced and combined low-dose time-resolved (TWIST)evaluation followed by standard hybrid stepping table bolus chase MRA. Results:The combined unenhanced QISS technique and low-dose time resolved (TWIST ) calf study resulted in an overall sensitivity of 97.4%, specificity of 98.3%, a negative predictive value of 98.7% and a positive predictive value of 96.7% using CE-MRA as the reference standard. Cohen kappa analysis for inter-rater indicates almost perfect agreement (©§= 0.86) between the hybrid approach of unenhanced QISS and TWIST and standard hybrid CE-MRA. Conclusion: This hybrid strategy permits a dramatic reduction in contrast agent dosage with no loss of diagnostic accuracy.
14:30 3758. "Does Higher R1 Relaxivity Transfer in Improved Vessel Enhancement of the Run-Off Vasculature?" - Evaluation of Macrocylic Gadolinium Chelates for Peripheral MR-Angiography at 3 T by an Inter-Individual Comparison of Gadobutrol Vs Gadoterate Meglumine, Bo
Ulrike I. Attenberger1, Matthias Voth2, Andre Luckscheiter3, Stefan Haneder1, Stefan O. Schoenberg4, Henrik J. Michaely1
1Department of Clinical Radiology and Nuclear Medicine, University Medical Center Manheim, Mannheim, Germany; 2Bayer Schering AG, Berlin, Germany; 3University of Heidelberg, Heidelberg, Germany; 4Department of Clinical Radiology and Nuclear Medicine, University Medical Center Manheim , Mannheim, Germany
Since nephrogenic systemic fibrosis (NSF) has been linked to gadolinium-chelate administration in patients with impaired renal function, contrast agent dose and chelate stability have attracted broad attention. Numerous studies have demonstrated linear compounds to be the least stable, whereas the macrocyclic compounds are the most stable. With the approval of gadobutrol, a double concentrated macrocyclic gadolinium chelate became available, characterized by the highest R1-relaxivity among the macrocyclic gadolinium chelates. The aim of this study was to evaluate the enhancement characteristics of gadobutrol and gadoterate meglumine, both injected at a dose level of 0.07 mmol/kg BW, for peripheral MR-angiography.
Takayuki Masui1, Motoyuki Katayama1, Kimihiko Sato1, Hiroki Ikuma1, M Sugimura1, M Ishii1, Naoyuki Takei2, Mitsuharu Miyoshi2
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan; 2Japan Applied Science Laboratory, GE Healthcare Japan, Hino, Japan
Non-contrast (NC) MRAs including inflow inversion recovery (IFIR) FIESTA have shown promising results for demonstration of the renal arteries but might show irregularity in the most peripheral parts of the renal arteries. The purpose was to evaluate effect of autovoice guiding respiratory cycle with ECG gating (IFIR with autovoice) on the quality of NC MRA for demonstration of renal arteries in comparison with contrast MRA. MRA using IFIR with autovoice could provide best image quality of the peripheral renal arteries when autovoice successfully guided respiration. Contrast MRA might miss the optimal timing for selective visualization of the renal arteries.
Casey Peter Johnson1, Clifton R. Haider1, Eric A. Borisch1, Roger C. Grimm1, Phillip J. Rossman1, Thomas C. Hulshizer1, Jake C. Snell1, James F. Glockner1, Stephen J. Riederer1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States
The purpose of this work was to improve bolus-chase MRA techniques by imaging multiple stations with both high spatial and temporal resolution. A highly-accelerated (14x) CAPR acquisition, previously demonstrated for single-station MRA of the calves, was adapted for this purpose. As part of the implementation, a system was developed to reconstruct the CAPR images in real time and allow for visually-guided station switching. Vasculature of the thighs and calves of volunteers was imaged with 1.0 mm isotropic resolution and frame times as low as 2.5 seconds. High-quality arterial frames were consistently acquired in both stations while avoiding venous contamination.
Satoru Morita1, Shinya Kojima1, Masami Hirata1, Masaru Suzuki1, Kazufumi Suzuki1, Ai Masukawa1, Eiko Ueno1
1Department of Radiology, Tokyo Women's Medical University Medical Center East, Arakawa-ku, Tokyo, Japan
Unenhanced electrocardiographically-gated fast spin-echo-based magnetic resonance digital subtraction angiography (MRDSA) can obtain hemodynamic information of pulse wave transmission. We prospectively compared the image quality of MRDSA using sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) with constant flip angle mode and conventional half-Fourier single-shot turbo spin-echo (HASTE) sequence of femoral arteries in 10 healthy volunteers at 1.5T MRI. All quantitative and qualitative analyses of the SPACE were significantly better than those of the HASTE. We show that unenhanced electrocardiographically-gated fast spin-echo MRDSA using SPACE with constant flip angle mode provides good visual hemodynamic information of arteries.
14:00 3762. Nonenhanced Time-Resolved MR Angiography for the Arteriovenous Malformation/Fistula of the Pelvis and the Lower Extremity. - not available
Masaaki Akahane1, Jiro Sato1, Shuhei Komatsu1, Yasushi Watanabe2, Yoshiro Satake2, Kuni Ohtomo1
1Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan; 2Clinical Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan
Nonenhanced MRA by spin-labeling technique with subtraction between labeled and non-labeled images was applied to the time-resolved study for better background suppression in any inversion time. Seven patients having arteriovenous malformations or fistulas of the pelvis or lower extremity underwent nonenhanced time-resolved MRA using respiratory-gated balanced steady state free precession (SSFP) sequence with 1.5-T scanner (Toshiba EXCELART Vantage, Japan). Inversion times (TI) were assigned as 300, 800, 1300 and 1800 ms. Nonenhanced time-resolved MRA was useful for the evaluation of hemodynamics of the arteriovenous malformation or fistula and the distinction of feeding arteries.
Florian Knoll1, Christian Clason2, Manuela Aschauer3, Franz Ebner3, Rudolf Stollberger1
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria; 3Department of Radiology, Medical University Graz, Graz, Austria
Variable density 3D random sampling trajectories have great potential for subsampled CE-MR angiography techniques which deliver data sets with high contrast to noise ratio. The goal of this work was to present a parameter-free method to construct variable density sampling patterns which are tailored to angiography. Sampling patterns are generated with the use of a probability density function that is constructed by using measured k-space data as a reference, which automatically ensures an appropriate distribution of sample points.
15:00 3764. Imaging of Pulmonary Artery and Vein Using ASL Based Non-Contrast MRA Technique - not available
Tomoyuki Okuaki1,2, Takeshi Ishimoto3, Momoe Kawakami3, Masaru Ishihara4, Tetsuro Ogino1, Ivan Zimine1, Marc Van Cauteren5, Toshiaki Miyati6
1Clinical Science, Philips Electronics Japan, Minato-ku, Tokyo, Japan; 2Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan; 3Hyogo Brain and Heart Center, Japan; 4Kakogawa Medical Center, Japan; 5Philips Healthcare, Netherlands; 6Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan
For lung imaging, depiction of pulmonary artery (PA) and vein (PV) can be done using ASL based technique. However, visualization of PV using conventional ASL approach is challenging because tagged blood in the pulmonary artery requires several seconds to reach the vein. In this work we evaluated the possibility of simultaneous visualization of PA and PV using ASL based technique at multiple inversion times (TI). For PA, high scores were observed at TI=800ms and 1100ms respectively; For PV, highest score was observed at TI=300ms. Expected clinical application is imaging of patients with pulmonary infarction.
Yijing Wu1, Kevin M. Johnson1, Steven R. Kecskemeti1, Charlse A. Mistretta2, Patrick Alan Turski3
1Medical Physics, University of Wisconsin, Madison, Madison, WI, United States; 2Medical Physics and Radiologly, University of Wisconsin, Madison, Madison, WI, United States; 3Radiology, University of Wisconsin, Madison, Madison, WI, United States
Time resolved contrast-enhanced magnetic resonance angiography has been widely used to evaluate vascular hemodynamics. Due to recent concern of the NSF disease, eliminating or reducing Gadolinium-based contrast agent is desirable. HYBRID HYPR decouples the high spatial resolution and SNR, which require relative long scan time, from the high temporal resolution, which demands for fast data acquisitions. It used the HYPR constrained reconstruction to obtain high temporal resolution, high spatial resolution, and high SNR image series. The hypothesis of this work is that the contrast dose can be reduced using the HYBRID HYPR technique: the SNR of the HYPR images is primarily determined by the composite, which is generated using minimal mount of contrast agent (e.g. post contrast phase-contrast images) or can be acquired before contrast injection (e.g. Time-of-Flight images). High temporal and spatial resolution time resolved contrast-enhanced MRA can be obtained by using Low Dose HYBRID HYPR method with contrast dose as low as 1ml.
kambiz nael1, Michael Fenchel1, Stefan G. Ruehm1, J Paul Finn1
1Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
Advances in fast imaging tools such as parallel acquisition and sparse k-space sampling methods such as time-resolved angiography with interleaved stochastic trajectories (TWIST), have the potential to improve the performance of time-resolved MR angiography (TR-MRA). In this study we evaluated the clinical usefulness of a 3D CE-MRA protocol that encompasses both high spatial and high temporal resolution acquisition in evaluation of patients with congenital heart disease (CHD). Our objective is to investigate whether TR-MRA can unravel complex functional vascular anatomy in patients with CHD and to assess the incremental diagnostic value of TR-MRA over conventional MRA in this population.
Erin Jane Kelly1, Steve Saeger2, David E. Neal2
1Toshiba America Medical Systems, Tustin, CA, United States; 2Radiology, Central Ohio Primary Care Physicians, Columbus, OH, United States
Non-contrast angiography techniques are becoming increasingly important in the clinical setting. 3D SSFP Time-SLIP has been developed to produce bright blood angiograms for abdominal angiography, including renal MRA exams. The purpose of this study was to evaluate image quality and diagnostic confidence for Time-SLIP compared to contrast-enhanced MRA in the same group of patients. Image quality scores were 2.6±0.7 and 2.4±0.7 for Time-SLIP and CE-MRA, and Diagnostic quality scores were 2.8±0.4 and 2.4±0.8 for Time-SLIP and CE-MRA, respectively. This study indicates that Time-SLIP is a safe and effective alternative for CE-MRA and may replace CE-MRA in the clinical setting.
15:00 3768. Non-Contrast-Enhanced Renal MRA Using Inflow-Enhanced, Inversion-Recovery at 3T - not available
Thorsten Alexander Bley1,2, Scott Brian Reeder2, Mark Schiebler2, Naoyuki Takei3, Jean H. Brittain4, Thomas Grist2, Christopher J. Francois2
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 2Radiology, University of Wisconsin-Madison, Madison, WI, United States; 3Japan Applied Science Laboratory, GE Healthcare, Tokyo, Japan; 4Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States
This work presents validation of an inflow-enhanced, inversion-recovery (IR) balanced steady state free precession (bSSFP) based non-contrast-enhanced MRA (NCE-MRA) for assessment of renal arteries at 3T in patients with suspected renal artery stenosis or with a history of renal artery transplant. NCE-MRA with inflow-enhanced IR bSSFP produced consistent results and demonstrated moderate agreement with CE-MRA for both readers and strong inter-observer agreement for grading renal artery stenosis >50%.
Isabelle Parienty1, Faiza Admiraal-Behloul2, Francis Jouniaux1, Michel Piotin3, Guy Rostoker3
1Centre d'Imagerie du Bois de Verrière, Antony, France; 2MRI, Toshiba Medical Systems Europe, Zoetermeer, Netherlands; 3Nephrology, Centre Hospitalier Claude Galien, Paris, France
The purpose of this study was to compare the findings in non-contrast enhanced MRA using the Time Spatial Labeling Inversion Pulse (Time-SLIP) technique to those of Digital Subtraction Angiography (DSA) in patients with significant renal artery stenosis (>60%, or >50% with post stenotic dilation).
Francis Jouniaux1, Isabelle Parienty1, Faiza Admiraal-Behloul2
1Centre d'Imagerie du Bois de Verrière, Antony, France; 2MRI, Toshiba Medical Systems Europe, Zoetermeer, Netherlands
Respiratory gated non contrast enhanced MR angiography using Time-Spatial inversion labeling pulse (Time-SLIP) is a well established technique at our institution for the exploration of renal arteries. Since 2007, we scanned more than 450 patients with age ranging for 18 to 92 year old. Patients with fast and/or irregular respiration rates (RR) can be very challenging to image. Most of the difficult patients are old (80+), or have a cardiac disease and/or a respiratory disease. A breath hold of more than 16s is intolerable for most of these patients. We describe how regulating the respiratory rate can significantly improve the image quality and the success rate of Time-SLIP.
Erin Jane Kelly1, JoEllyn L. L. Stolinski2, James Jelinek2
1Magnetic Resonance, Toshiba America Medical Systems, Tustin, CA, United States; 2Radiology, Washington Hospital Center, Washington, D.C., United States
Diabetes is highly associated with renal failure and peripheral artery disease. In light of the association between MRI contrast media and the onset of NSF/NSD, it is increasingly important to replace CE-MRA with non-contrast angiographic imaging techniques, such as Fresh Blood Imaging and Time-SLIP. In this study, diabetic patients referred for and MRA were imaged with FBI and Time-SLIP for peripheral run-offs and renal angiography. Image Quality and Diagnostic Confidence scores indicate that FBI and Time-SLIP are both safe and effective alternatives to CE-MRA in this patient group.
Rachel Clough1, Tarique Hussain1, Sergio Uribe1, Peter Taylor2, Reza Razavi1, Tobias Schaeffter1, Matthew Waltham2
1Division of Imaging Sciences, King's College London, London, United Kingdom; 2Guy’s and St Thomas’ NHS Foundation Trust, St Thomas' Hospital, London, United Kingdom
An MRI examination for evaluation of aortic dissection using a blood-pool agent is presented. The aims of this study were to investigate the use of direct thrombus MRI and quantitative flow analysis for the determination of false lumen thrombus volumes in patients with Type B aortic dissection. It is shown that blood-pool imaging together with direct thrombus MRI allows assessment of aortic anatomy and more accurate quantification of false lumen thrombosis compared with CT. Current clinical trials using false lumen thrombosis as a primary endpoint should consider multi-parametric MRI as the preferred diagnostic tool.
Teik Choon See1, Andrew Winterbottom1, Edmund Soh2, Ilse Joubert1, Martin Graves1, David Lomas1
1Radiology, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 2Singapore General Hospital, Singapore
Our prospective clinical trial authorised study aims to assess MR venography of the neck and thoracic central veinous system using Vasovist® (gadofosveset trisodium, Schering), a blood pool contrast agent, for first pass (FP) and steady state (SS) imaging. Images are assessed independently for image quality, artefacts, stenosis, and thrombosis. Sixteen participants recruited to date and 144 venous segments assessed. The result shows very favourable SS imaging quality compared to FP (although not quite statistically significant) with potential for improving diagnostic accuracy. Mild artefacts are seen in 50% of both techniques. No significant differences noted in detection of stenosis or thrombosis.
Manojkumar Saranathan1, Ersin Bayram2, James F. Glockner3
1Applied Science Lab, GE Healthcare, Rochester, MN, United States; 2GE Healthcare, Waukesha, WI, United States; 3Radiology, Mayo Clinic, Rochester, MN, United States
While contrast-enhanced MR Angiography (CEMRA) is widely used for evaluation of vascular pathology, recent nephrogenic systemic fibrosis (NSF) concerns following administration of Gadolinium based contrast agents have spurred interest in non-contrast MRA methods. Balanced steady state free precession (b-SSFP) imaging has shown great promise due to its high SNR and short scan times. We propose a balanced SSFP-Dixon technique with a novel group-encoded k-space segmentation scheme for breath-held non-contrast MRA.
Tokunori Kimura1, Masato Ikedo2
1MRI Systems Development Department, Toshiba Medical Systems , Otawara, Tochigi, Japan; 2MRI Systems Development Department, Toshiba Medical Systems, Otawara, Tochigi, Japan
We have proposed a new MR angiography technique named Hybrid of Opposite-Contrast MRA (HOP-MRA) with 3D dual-echo gradient-echo sequence combining Time-of-Flight (TOF) with a Flow-Sensitive Black-Blood (FSBB) employing flow dephasing gradients. In this study, for the purpose of decreasing flow-void appeared in major arteries, two types of gradient moment nulling (GMN) for the TOF part were compared between 1st order full 3-axis GMN and partial 2-axis GMN. We demonstrated that flow-void artifacts were decreased by using the 2-axis GMN in the TOF part and vessel misregistration due to phase-encode displacement in the TOF part was minor. The HOP technique is suitable for decreasing both flow-void and PED artifacts in MRA compared to TOF alone.
Petrice M. Mostardi1, Clifton R. Haider1, Norbert G. Campeau1, John Huston1, Stephen J. Riederer1
1Radiology, Mayo Clinic, Rochester, MN, United States
We define a comprehensive neurovascular exam (CNVE) as the high quality imaging of the aortic arch through the intracranial veins. The goal of this work is to image these territories by dynamically changing (scaling/shifting) the FOV during a contrast-enhanced acquisition. Volunteer studies were performed with an imaging protocol consisting of: (i) a large FOV, low dose (2 ml) time-resolved acquisition to provide overall diagnostic information and serve as a timing bolus and (ii) a high spatial resolution contrast-enhanced exam implementing dynamic change of the FOV to image the carotid arteries and the intracranial venous system.
Jiang Du1, Jacqueline Corbeil1, Richard Znamirowski1, Michael Peterson2, Niren Angle3, Graeme Bydder1, Andrew Kahn4
1Radiology, University of California, San Diego, CA, United States; 2Pathology, University of California, San Diego, CA, United States; 3Surgery, University of California, San Diego, CA, United States; 4Medicine, University of California, San Diego, CA, United States
Carotid plaque vulnerability is dependent upon its tissue constituents, which may include fibrous tissue, lipid core, intra-plaque plaque hemorrhage as well as calcification. Clinical MR sequences have been employed to characterize the long T2 plaque components. Carotid plaque calcification (CPC) is undetectable with conventional clinical MR sequences. Here we describe the use of a 2D ultrashort TE (UTE) sequence combined with efficient long T2 suppression to image and characterize CPC (T2, T2* and water content) using a clinical 3T scanner. High spatial resolution micro-CT images were also acquired for comparison and validation.
Robert Manzke1, Anja Lutz2, Marcel Schenderlein3, Axel Bornstedt2, Raymond C. Chan4, Klaus Dietmeyer3, Volker Rasche5
1Tomographic Imaging, Philips Research Europe, Hamburg, Germany; 2Dept. of Internal Medicine II, University Hospital Ulm, Germany; 3Inst. Measurement, Control, and Microtechnology, University Ulm, Germany; 4Philips Research North America, Briarcliff Manor, NY, United States; 5Dept. of Internal Medicine II, University Hospital Ulm, Germany
A new PVA-based dynamic cardiac MR phantom is introduced, aiming to enable cross validation of novel tagged and phase contrast MR methods specifically at 3T, aiding the development of clinically relevant functional MR techniques. Examples of phase contrast and tagged images using a 3T system with a 6 element cardiac coil are given.
Ioannis Koktzoglou1, Philip Hodnett, 1,2, Erik Offerman1, Robert Edelman1
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States; 2Northwestern University, Chicago, IL, United States
Arterial spin-labeled MRA using a balanced steady-state free precession is limited by flow artifacts in the setting of luminal narrowing. In a stenotic flow phantom, we show that these artifacts can be minimized with the use of abbreviated echo trains made possible with the use of parallel imaging acceleration and partial Fourier acquisition, and subsequently apply the technique in volunteers and patients.
Anna Lakoma1, James C. Carr1
1Department of Radiology, Northwestern University, Chicago, IL, United States
MRI derived pulmonary circulation parameters best predict need for future intervention in patients post Ross procedure.
Kevin M . Johnson1, Oliver Wieben1,2, Patrick Turski2, Charles Mistretta1
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 2Radiology, University of Wisconsin - Madison, Madison, WI, United States
Arterial spin labeling (ASL) sequences which utilize tagging schemes to images the flow of blood have emerged as effective techniques for the non-contrast angiography; however, these techniques typically suffer from long acquisition times, sensitivity to tag delay parameters, and uncertain performance in cases of complex flow . To mitigate these errors, we investigate the utilization of highly accelerated, dynamic inflow imaging utilizing efficient, short TR 3D radial bSSFP sequences.
Mehmet Akçakaya1,2, Peng Hu2, Vahid Tarokh1, Warren J. Manning2, Reza Nezafat2
1Harvard University, Cambridge, MA, United States; 2Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
Non-contrast pulmonary vein (PV) MR angiography (MRA) is an alternative to the clinical contrast-enhanced technique. We have recently developed a non-contrast PV MRA technique using a sagittal selective inversion pulse. However, the resulting acquisition time is significantly longer than breath-hold contrast-enhanced technique. In this study, we investigate the feasibility of using compressed sensing for accelerating data acquisition in non-contrast PV MRA. We use a distributed compressed sensing technique to reconstruct separate coil images simultaneously. We show that this reconstruction yields good results even at high rates (x10).
Iliyana Plamenova Atanasova1,2, Ruth P. Lim1, Hua Guo1, Daniel Kim1, Pippa Storey1, Kellyanne McGorty1, Andrew Laine2, Vivian S. Lee1
1Department of Radiology, New York University, New York, United States; 2Columbia University, New York, United States
3D non-enhanced balanced steady-state free precession MRA with a slab-selective inversion (IR SSFP) has demonstrated promise for renal artery evaluation at 1.5T. With proper selection of inversion times (TI), the technique can be adopted for coronal imaging of the abdominal aorta with comprehensive superior-inferior coverage at 3T. We propose a method for subject-specific calculation of TI based on arterial blood velocities. Our results illustrate that visualization of the aortoiliac vessels using IR SSFP varies considerably across subjects depending on flow velocities. Thus, measuring aortic velocities prior to MRA enables an examination tailored to the patient’s physiology for improved arterial visualization.
Gustav Jacob Strijkers1, Glenda S. van Bochove1, Roel Straathof1, Rob Krams2, Klaas Nicolay1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Department of Bioengineering, London Imperial College, London, United Kingdom
We report here on the pre-clinical MRI characterization of an apoE-/- mouse model of stable and vulnerable carotid artery atherosclerotic plaques, which were induced by a tapered restriction (cast) around the artery. Specific focus was on the quantification of flow velocities and wall shear stress (WSS), which are considered key players in the development of the plaque phenotype.
13:30 3785. A Novel 3D Time-Of-Flight MRA with Optimized Partial Saturation Recovery 3D-FLASH - not available
Yutaka Natsuaki1, Randall Kroeker2, Gerhard Laub3
1Siemens Medical Solutions, Los Angeles, CA, United States; 2Siemens Medical Solutions, Winnipeg, Manitoba, Canada; 3Siemens Medical Solutions, San Francisco, CA, United States
One of the major drawbacks with 3DTOF is the inplane flow saturation, where the fresh inflow enters the imaging volume and gets saturated by the imaging RF pulses. This is particularly problematic when the inflow vessels are perpendicular to the slice direction (e.g. vertebral arteries), and this may result in signal loss of the blood vessels. The current work proposes a novel approach to the magnetization prepared 3D TOF MRA with the partial saturation recovery (SR) 3D-FLASH. The optimization strategies and initial results with improved visualization of vertebral arteries are presented.
Hua Guo1, Iliyana Atanasova1,2, Ruth P. Lim1, Pippa Storey1, Jian Xu3, Qun Chen1, Henry Rusinek1, Zhaoyang Fan4, Debiao Li4, Vivian S. Lee1
1Department of Radiology, New York University School of Medicine, New York, NY, United States; 2Columbia University, New York, NY, United States; 3Siemens Medical Solutions USA, Inc., MR R&D Collaboration, New York, United States; 4Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States
Flow-sensitive dephasing prepared balanced steady state free precession (FSD-bSSFP) has been proposed as a non-contrast MRA technique for the lower extremities at 1.5T. However, its application at higher magnetic fields is hindered by poor B0 and B1 homogeneities. As a result, the background signal cannot be completely suppressed. In this work, we investigated the performance of B1-insensitive adiabatic RF pulses for FSD preparation to improve non-contrast MRA with FSD-bSSFP at 3T. The results demonstrate that the approach is less B1-sensitive than with conventional hard RF pulses, thus providing better background signal suppression and more reliable MRA images at 3T.
Xiuling Qi1, Aaron Teitelbaum1, Kevan Anderson1, Nigel Munce1, Beiping Qiang1, Ronen Jaffe1, Michelle Ladouceur-Wodzak1, Bradley H. Strauss1, Graham A. Wright1
1Sunnybrook Health Sciences Center, Toronto, Ontario, Canada
Synopsis: Revascularization in an arterial chronic total occlusion (CTO) could improve the prognosis. We evaluated the effect of injecting vascular endothelial growth factor (VEGF) into a CTO in a femoral artery of rabbit using in vivo MRI and ex-vivo micro-CT. Thirteen rabbit were divided randomly into control and VEGF groups. The blood volume changes in CTO pre and post interventions were determined. Results indicated by both MRI and micro-CT that the VEGF significantly increased the formation of microvessels within CTO. Our study also demonstrated that MRI is a feasible method to assess the new blood vessel growth in CTO tissue.
Samuel W. Fielden1, Hao Tan1, John P. Mugler III1,2, Christopher M. Kramer2,3, Craig H. Meyer1,2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States; 3Medicine, University of Virginia, Charlottesville, VA, United States
rTSE hybridizes the increased signal provided by the 180° refocusing RF pulses of RARE and the better flow performance of the fully-refocused gradients and phase alternation of balanced SSFP. Here, we apply the principles of rTSE with spiral readout gradients in order to improve the data acquisition efficiency of the sequence while increasing the echo spacing to provide improved artery-vein contrast.