Electronic Poster Session - Cardiovascular
  Myocardial Tissue Characterization & Spectroscopy 3765-3788
  Cardiovascular Function: Experimental Models & Humans 3789-3812
  Coronary MRA & Vessel Wall Imaging 3813-3836
  Cardiovascular Technology, Image Processing, Other 3837-3860
  MRA- Contrast & Non-Contrast 3861-3884
  Myocardial Perfusion & Non-Contrast MRA 3885-3908
  Flow: Quantification 3909-3932
  Cardiovascular MRI - General 3933-3956
     

Myocardial Tissue Characterization & Spectroscopy
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  13:30 - 14:30

  Computer #  
3765.   
1 Is ribose and creatine supplementation beneficial in chronic heart failure? An in vivo 1H-MRS / 31P-MRS / cine-MRI study in murine hearts
Kiterie M.E. Faller1, Craig A. Lygate1, Mahon L. Maguire1, Debra J. Medway1, Victoria L. Thornton1, Stefan Neubauer1, and Jurgen E. Schneider1
1Cardiovascular medicine, University of Oxford, Oxford, Oxfordshire, United Kingdom

 
The failing heart is characterised by a decrease in myocardial creatine, adenine nucleotides, and high-energy phosphate metabolites. In a mouse model of permanent coronary artery ligation, we tested the hypothesis whether simultaneous elevation of myocardial creatine and ribose would be beneficial by increasing cardiac energy availability. Using a combination of 1H-MRS, 31P-MRS, cine-MRI to measure total creatine, phosphocreatine (PCr)/ATP ratio, cardiac function/mass and infarct size, we did not observe any beneficial or deleterious effect of this therapeutic approach in post-infarct left ventricular remodelling or function.

 
3766.   2 In Vivo Delineation of Myocardial Infarction Using the Tractographic Propagation Angle Correlates Strongly with Delayed Gadolinium Enhancement
Choukri Mekkaoui1, Shuning Huang2, Guangping Dai2, Timothy G Reese2, Aravinda Thiagalingam3, Pal Horvat-Maurovich3, Jeremy Ruskin3, Udo Hoffmann3, Marcel P Jackowski4, and David E Sosnovik2
1Harvard Medical School, Boston, MA, United States, 2Harvard Medical School - Massachusetts General Hospital, 3Massachusetts General Hospital,4University of São Paulo

 
Gadolinium cannot be given to patients with renal disease. An urgent need thus exists to develop techniques to image myocardial infarcts without the need for exogenous contrast agents. Here we describe the use of the tractographic propagation angle (PA) to detect infarcted myocardium in vivo. We show in infarcted mice and sheep that a PA threshold of 10 degrees robustly detects infarcted myocardium. We further show that infarct size derived from the in vivo PA maps correlates extremely strongly with delayed gadolinium enhancement. Hence, tractographic PA has the potential to become a powerful tool in the cardiovascular MRI armamentarium.

 
3767.   3 Cardiac Magnetic resonance in clinical diagnosis of left left dominant phenotypes of of arrhythmogenic cardiomyopathy
Begoña Igual-Muñoz1, Esther Zorio-Grima2, Vicente Martinez-Sanjuan3, JORDI ESTORNELL4, JOSE MONMENEU4, PILAR LOPEZ-LEREU4, and ALICIA MACEIRA4
1Cardiac image unit, ERESA, valencia, valencia, Spain, 2cardiologia, Unidad de muerte subita .Hospital la Fe . Valencia, valencia, Spain, 3radiology, ERESA, valencia, valencia, 4TAC-RM, ERESA-HGUV, VALENCIA, VALENCIA, Spain

 
Recently, the spectrum of arrythmogenic miocardiopathy (AC) has been expanded with newly described biventricular (BVAC) and left-dominant (LDAC) forms. Cardiac magnetic resonance (CMR) with its superb tisular discrimination abilities, and high reproducibility for ventricular volume calculation,offers potentially relevant information for their diagnosis.

 
3768.   4 Ex-vivo Study of the Human Heart with Diffusion Tensor Imaging: Sensitivity to Cardiovascular Risk Factors
Neville D Gai1, Evrim Turkbey1, and David A Bluemke1,2
1Radiology & Imaging Sciences, National Institutes of Health, Bethesda, MD, United States, 2NIBIB, Bethesda, MD, United States

 
Diffusion tensor studies of the human heart have shown differences in certain measured DTI parameters between normal and infracted myocardium or in heart failure patients. Sensitivity of DTI to cardiac disease using a graded approach has not hitherto been undertaken. In this study of the ex-vivo human heart, global diffusion tensor and tractography related measurements were correlated with the probability of cardiac disease based on the Framingham risk score. Fiber length showed marginal correlation with cardiac disease risk while FA, ADC and eigenvalues showed poor correlation.

 
3769.   5 Myocardial T2 mapping, a Quantitative tool for evaluation of myoarditis
Darshit Thakrar1, Jeremy Collins1, Rahul Rustogi1, Asad A Usman1, Aya Kino1, and James Carr1
1Cardiovascular imaging, Northwestern memorial hospital, Chicago, IL, United States

 

3770.   6 EFFECT OF SYSTEMATIC T1 ERRORS ON LAMBDA CALCULATIONS: COMPARISON OF DIFFERENT T1 MAPPING TECHNIQUES
Jacqueline A Flewitt1, Kelvin Chow2, Joseph J Pagano2, Jordin D Green3, Matthias G Friedrich1, and Richard B Thompson2
1Stephenson CMR Centre, University of Calgary, Calgary, Alberta, Canada, 2Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada,3Siemens Healthcare, Calgary, Alberta, Canada

 
Quantitative myocardial T1 mapping is the technique of choice for fibrosis and has been combined with blood T1 measurements (pre and post gadolinium) to calculate the less time and dose sensitive blood-tissue partition coefficient (lambda). However, systematic errors have been reported in the popular MOLLI T1 mapping techniques and the effects on lambda have not been explored. In a study of 10 healthy volunteers, blood and myocardial T1 values were compared using MOLLI and a SAturation-recovery single-SHot Acquisition (SASHA) method. Systematic T1 measurement differences were found between the techniques, resulting in MOLLI-derived lambdas that are 22% greater than those calculated using SASHA.

 
3771.   7 Diffusion Tensor Imaging of Normal and Ablated Cardiac Left Atrial Specimens
Osama M Abdullah1, Ashvin K George2, Nassir F Marrouche2, and Edward W Hsu1
1Department of Bioengineering, University of Utah, Salt Lake City, UT, United States, 2CARMA Center and Division of Cardiology, University of Utah, Salt Lake City, UT, United States

 
The structure of the left atrium (LA) plays an important role in its electrophysiological dynamics, and has been implicated in diseases such as atrial fibrillation (AF). Detailed dissections of the atrial wall transmurally have revealed a complex architecture of overlapping myofibers of different orientations. Diffusion tensor imaging (DTI) has emerged as a non-destructive alternative to histology to study highly ordered tissue structures including the myocardium. The goals of the current study are to determine (a) if DTI is sensitive to the heterogeneous and anisotropic microstructure of the LA, and (b) if DTI can detect alterations of the microstructure following RF ablation procedures, which is commonly used in the treatment of AF.

 
3772.   8 Heterogeneous Distributions of Myocardial Steatosis – An Ex-Vivo Evaluation
Chia-Ying Liu1, Yuan Chang Liu1, Bharath Ambale Venkatesh1, Joao A.C. Lima1, David A Bluemke2, and Charles Steenbergen1
1Johns Hopkins University, Baltimore, MD, United States, 2National Institutes of Health (NIH), Bethesda, MD, United States

 
The purpose of this study was to characterize the distribution of intramyocellular lipid content and to determine its association with disease characteristics. 1H-MRS was performed on formalin-fixed slices of human hearts at various circumferential locations (N=55). We found fat content increases with age and fat distribution may be heterogeneous when associated with cardiovascular disease.

 
3773.   9 Validation of a Faster Modified Look-Locker Inversion-recovery (MOLLI) method for myocardial T1 mapping on 3T MRI
Yoshiaki Morita1, Naoaki Yamada1, Teruo Noguchi2, Hiromi Hashimura1, Suzu Kanzaki1, Masahiro Higashi1, Hiroaki Naito1, Katsutoshi Murata3, and Andreas Greiser4
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 3Siemens Japan K.K., Tokyo, Japan, 4Siemens AG, Erlangen, Germany

 
Modified Look-Locker Inversion-recovery (MOLLI) sequence provides high resolution T1 map of myocardium. However, long breath holds often limit clinical application in patients due to motion artifact and heart rate variability. In this study, we proposed a faster MOLLI method that decreased by about one-third the acquisition time compared with the original-MOLLI, on 3T clinical machine. The proposed fast-MOLLI sequence is a rapid and reliable method for T1 estimation, with results very close to the original-MOLLI (mean T1 : fast-MOLLI 1140}43msec , original-MOLLI 1142}50msec). The fast-MOLLI will be of great help to understand the myocardial tissue characterization in various heart diseases.

 
3774.   10 ONSET OF CARDIAC IRON LOADING IN A LARGE AND HOMOGENOUS COHORT OF THALASSEMIA MAJOR PEDIATRIC PATIENTS
Antonella Meloni1, Aldo Filosa2, Vincenzo Positano1, Daniele De Marchi1, Letizia Gulino1, Claudio Ascioti3, Massimo Midiri4, Gianluca Valeri5, Massimo Lombardi1, and Alessia Pepe1
1Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2UOC Pediatria - DH Talassemia, AORNA. Cardarelli, Napoli, Italy, 3Struttura Complessa di Cardioradiologia-UTIC, P.O. “Giovanni Paolo II”, Italy, 4Istituto di Radiologia, Policlinico "Paolo Giaccone", Palermo, Italy, 5Dipartimento di Radiologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti "Umberto I-Lancisi-Salesi", Ancona, Italy

 
The MRI screening for both cardiac iron overload and function assessment can be started for thalassemia major patients at the age of 7 years. At this age not sedation is generally needed. If the availability of cardiac MRI is low, the serum ferritin levels could be used as a discriminating factor.

 
3775.   11 Biexponential diffusion tensor analysis of myocardial structural alteration in rabbit models with myocardium infarction
Yin Wu1,2, Chao Zou1,2, Wei Liu1,2, Wei Yang1,2, Ke Jiang1,2, and Ed X. Wu3,4
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 2Key Lab of Health Informatics, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pukfulam, Hong Kong, 4Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong

 
Water diffusion behavior in some tissues was found to not comply with Gaussian manner, leading to diffusion strength dependence of DTI index characterization. In this study, infarcted myocardial structural alteration was investigated using biexponential model, which was proved to better fit of diffusion signal decay. DTI results showed that in both infarct and adjacent regions fast radial diffusivity increased due to extracellular and microvascular compartment augmentation along radial direction, leading to enhancement of fast mean diffusivity. Meanwhile, decrease of both fast and slow FA was observed as result of fiber integrity loss and fast radial diffusivity enhancement. These findings were validated by histological observations. The current study suggested that biexponential diffusion function could be utilized as a tool to monitor and detect myocardial morphological alteration and structural degradation by probing multi-compartment diffusion behavior compared to conventional used monoexponential diffusion model.

 
3776.   12 Feasibility of Dynamic 4D Whole Heart Viability Imaging Within a Single Breath-Hold Using Highly Accelerated Parallel Imaging and Compressed Sensing
Jian Xu1,2, Li Feng1, Ricardo Otazo1, Barbara Srichai1, Ruth Lim1, Bhat Himanshu3, Kelly Anne Mcgorty1, Joseph Reaume1, and Daniel Sodickson1
1Center for Biomedical Imaging, Radiology,New York University, New York, NY, United States, 2PolyTechnic Institute of New York University and Siemens Medical Solutions USA Inc., New York, NY, United States, 3Siemens Medical Solutions USA Inc., Charlestown, MA, United States

 
Myocardium viability imaging via late gadolinium hyper-enhancement (LGE) is usually imaged with an inversion recovery sequence. A multi-slice multi-planar 2D approach with an additional TI scout is commonly used in routine clinical practice. Highly accelerated whole volume LGE enables acquisition of all data at the same time point of contrast kinetics is desired. We evaluated the feasibility of whole heart dynamic 4D LGE imaging utilizing different TIs at different phases throughout the entire cardiac cycle within a single BH using 4D stack-of-star radial acquisition and k-t RASPS without the use of a precise TI scout.

 
3777.   13 Magnetic Field Dependence of Myocardial R2* Values and Segmental Myocardial Field Inhomogeneity Assessed at 1.5 T, 3.0 T and 7.0 T.
Antonella Meloni1, Fabian Hezel2, Vincenzo Positano1, Petra Keilberg1, Alessia Pepe1, Thoralf Niendorf2,3, and Massimo Lombardi1
1Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Pisa, Italy, 2Berlin Ultrahigh Field Facility B.U.F.F, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 3Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany

 
Although R2* relaxation is a complicated process, our results suggest a nearly linear field dependence of cardiac R2*. Admittedly, at 7T the pronounced propensity to macroscopic susceptibility artefacts is challenging and it seemed to spare only the septal regions. The most severe artifact source was the heart-lung interface.

 
3778.   14 Myocardial infarct heterogeneity and papillary muscle involvement correlated with appropriate ICD therapy in patients with ischemic heart disease
Yuesong Yang1, Kim A. Connelly2, Subodh B. Joshi2, Tawfiq Zeidan-Shwiri3, Gideon A. Paul3, John J. Graham2, Rhonda Walcarius1, Alexander J. Dick4, Eugene Crystal3, and Graham A. Wright1
1Imaging Research and IRCCI, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 2Cardiology, St.Michael's Hospital, Toronto, ON, Canada,3Cardiology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 4Cardiology, Ottawa Heart Institute, Ottawa, ON, Canada

 
Recent studies indicated that myocardial infarct heterogeneity measured on cardiac MRI might predict the appropriate ICD therapy in patients with ischemic heart disease (IHD). However, it is unknown whether papillary muscle involvement (PM-MI) in these patients may play a role in the prediction of appropriate ICD therapy. In this study, we investigated the correlation of myocardial infarct heterogeneity and PM-MI evaluated by cardiac MRI with the appropriate ICD therapy in patients with IHD after ICD implantation.

 
3779.   15 3D, Free Breathing Late Gadolinium Enhanced Myocardial Imaging with Retrospective TI Selection and Isotropic Resolution
Steven Kecskemeti1, Kevin Johnson1, Mark Schiebler1, Chris Francois1, and Orhan Unal1
1University of Wisconsin, Madison, Wisconsin, United States

 
A free breathing, respiratory gated 3D radial inversion recovery acquisition with retrospective inversion time (TI) and isotropic resolution is used for late gadolinium enhanced imaging of myocardium.

 
3780.   16 Human cardiac T1 mapping in vivo at 7T: quantifying and correcting for partial inversion
C. T. Rodgers1, S. K. Piechnik1, L. DelaBarre2, P.-F. Van de Moortele2, C. J. Snyder2, S. Neubauer1, M. D Robson1, and J. T. Vaughan2
1University of Oxford, Oxford, United Kingdom, 2University of Minnesota, United States

 
Quantitative mapping of myocardial T1 has proved valuable at 1.5 and 3T. In a pilot study, we began to adapt the ShMOLLI T1 mapping sequence for 7T. We now quantify the achievable magnetization inversion in the heart at 7T and to optimize T1 measurements there. To achieve this, we make further improvements to the pulse sequence and post-processing, validating these with phantom experiments. Scans on 6 volunteers measure the human myocardial T1 at 7T as 1926 ± 22ms. Our data suggest that future measurements may be feasible on scanners with 8kW RF output, in a single reasonably short breath hold.

 
3781.   17 Evaluation of Cardiac Amyloidosis with T1 Mapping
Michael Salerno1,2, and Christopher M Kramer3,4
1Internal Medicine, University of Virginia, Charlottesville, Va, United States, 2Radiology, Univeristy of Virginia, Charlottesville, VA, United States,3Radiology, University of Virginia, Charlottesville, VA, United States, 4Internal Medicine, Cardiology, Univeristy of Virginia, Charlottesville, VA, United States

 
Cardiac Amyloidosis is characterized by extracellular deposition of amyloid protein within the myocardium. We use T1 mapping techniques to demonstrate an increase in the volume of distribution and partition coefficient of gadolinium in patients with cardiac amyloidosis as compared to normal volunteers.

 
3782.   18 Toward Assessment of Iron Overload Diseases at 7.0 T: Myocardial T2* Mapping To Derive Global and Segmental T2* Norm Values For Healthy Subjects at 7.0 T
Fabian Hezel1, Antonella Meloni2, Jeanette Schulz-Menger1,3, Petra Keilberg2, Peter Kellman4, Massimo Lombardi2, and Thoralf Niendorf1,3
1Berlin Ultrahigh Field Facility, MDC Berlin, Berlin, Germany, 2Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 3Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany,4Laboratory of Cardiac Energetics, National Institutes of Health/NHLBI, Bethesda, MD, United States

 
Myocardial T2* mapping is of proven clinical value for the detection of iron overload. Ultrahigh field (>7T) offer a gain in susceptibility sensitivity, however T2* relaxation rates of healthy myocardium obtained at 1.5T and 3.0T need to be revised. This study aims to determine T2* relaxation times for normal myocardium (global and segmental) in healthy subjects with the ultimate goal to establish a lower limit of normal T2* at 7.0T.

 
3783.   19 Myocardial T1 mapping using a faster Modified Look-Locker Inversion-recovery (fast-MOLLI) method on 3T MRI : Quantification of myocardial fibrosis in dilated cardiomyopathy (DCM)
Yoshiaki Morita1, Naoaki Yamada1, Teruo Noguchi2, Hiromi Hashimura1, Suzu Kanzaki1, Masahiro Higashi1, Hiroaki Naito1, Katsutoshi Murata3, and Andreas Greiser4
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 3Siemens Japan K.K., Tokyo, Japan, 4Siemens AG, Erlangen, Germany

 
Late gadolinium enhancement (LGE) is the widely used method to evaluate the myocardial fibrosis in various heart diseases. However, the standard LGE using null-point method has a limitation in diagnosis of diffuse interstitial fibrosis. This study demonstrated that pre-contrast and post-contrast myocardial T1 mapping using a faster MOLLI method enable direct myocardial signal quantification and can help to evaluate the diffuse fibrotic change even that show apparently unenhanced myocardium on LGE images, in patients with dilated cardiomyopathy (DCM).

 
3784.   20 Assessment of cardiac iron deposition in sickle cell disease using 3.0 Tesla MRI
El-Sayed H Ibrahim1, Fauzia Rana2, Kevin Johnson1, and Richard White1
1Department of Radiology, University of Florida, Jacksonville, FL, United States, 2Department of Medicine, University of Florida, Jacksonville, FL, United States

 
Cardiac iron overload in sickle-cell disease (SCD) leads to heart-failure and death. This study investigates the potential role of 3.0T-MRI for assessing cardiac iron content by measuring R2*. R2* was measured in calibrated phantoms at 3.0T and 1.5T using optimized sequences. Myocardial R2* was measured in SCD patients at 3.0T,and results were compared to serum ferritin and hepatic R2*. The phantoms R2* at 3.0T were double those at 1.5T. R2* showed linear relationships with iron concentration. 3.0T-R2* was more sensitive than 1.5T in detecting low iron concentrations. Myocardial R2* had weak and good correlations with hepatic R2* and ferritin level,respectively.

 
3785.   21 Phase Sensitive Fat Darkening by TI-Minimized Double SPAIR (PHATTI DeSPAIR) for Robust and Highly Effective Fat Suppression in Clinical T1-Weighted Imaging of Ischemic and Non-Ischemic Heart Disease
Elizabeth R Jenista1, David C Wendell1, Deneen M Spatz1, Christoph Jensen1, Lowie MR Van Assche1, Enn-Ling Chen1, Stephen S Darty1, Raymond J Kim1, and Wolfgang G Rehwald2
1Duke Cardiovascular MR Center, Duke University, Durham, NC, United States, 2Cardiovascular MR R&D, Siemens Healthcare, Chapel Hill, NC, United States

 
We present a highly effective and robust fat suppression technique for T1-weighted inversion recovery (IR) imaging such as delayed enhancement, that is compatible with phase sensitive IR (PSIR) imaging. It combines a double-SPAIR (Spectral Selection Attenuated Inversion Recovery) module with a fat-TI minimization and a phase sensitive readout. It is called phase sensitive fat darkening by TI-minimized double SPAIR, PHATTI DeSPAIR. We compared its performance to standard chemically selective fat saturation in 13 patients with ischemic and non-ischemic heart disease, at 1.5T and 3T. Fat suppression efficiency was extremely strong compared to the standard technique, without affecting signal to noise.

 
3786.   22 Evaluation of Diffuse Myocardial Fibrosis in Hypertensive Left Ventricular Hypertrophy
Michael Salerno1,2, Rajesh Janardhanan3, Nebiyu Adenaw3, Ronny S Jiji3, Frederick H Epstein2,4, and Christopher M Kramer2,5
1Internal Medicine, Cardiology, University of Virginia, Charlottesville, Va, United States, 2Radiology, University of Virginia, Charlottesville, VA, United States, 3Internal Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States, 4Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 5Internal Medicine, Cardiology, University of Virgina, Charlottesville, VA, United States

 
Diffuse myocardial fibrosis can occur in hypertensive left ventricular hypertrophy (LVH) and is not detectable by conventional late gadolinium enhanced imaging. We utilized T1 mapping techniques to quantify myocardial fibrosis by determining the partition coefficient and volume of distribution of Gd-DTPA. We demonstrate a significant increase in these parameters in hypertensive patients with LVH as compared to age matched normal controls.

 
3787.   
23 Are the preferential patterns of myocardial iron overload preserved at the CMR follow-up?
Antonella Meloni1, Vincenzo Positano1, Daniele De Marchi1, Elisabetta Chiodi2, Massimiliano Missere3, Antonino Vallone4, Massimo Midiri5, Letizia Gulino1, Roberta Renni6, Massimo Lombardi1, and Alessia Pepe1
1Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2Servizio Radiologia Ospedaliera-Universitaria, Arcispedale “S. Anna”, Ferrara, Italy, 3Centro di Ricerca e Formazione ad Alta Tecnologia nelle Scienze Biomediche "Giovanni Paolo II", Università Cattolica del Sacro Cuore, Campobasso, Italy, 4Istituto di Radiologia, Az. Osp. "Garibaldi" Presidio Ospedaliero Nesima, Catania, Italy, 5Istituto di Radiologia, Policlinico "Paolo Giaccone", Palermo, Italy, 6Day Hospital, Ospedale Civile “F. Ferrari”, Casarano, Lecce, Italy

 
In thalassemia major patients a preferential pattern of iron store in anterior and inferior regions was present at both basal and FU CMRs, with an increment of T2* values at FU due to a basal CMR-guided chelation therapy.

 
3788.   24 Creatine Kinase-Overexpression Improves Adriamycin-induced Dysfunction and in vivo ATP kinetics in Murine Hearts
Ashish Gupta1, Cory Rohlfsen1, Missy Leppo1, Vadappuram P Chacko2, Yibin Wang3, and Robert G Weiss1
1Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, United States, 2Department of Radiology, Division of Magnetic Resonance Research, The Johns Hopkins University, Baltimore, MD, United States, 3University of California, Los Angeles, CA, United States

 
Adriamycin (ADR) is a commonly used life-saving antineoplastic agent that also causes dose-dependent cardiotoxicity. Impaired energy metabolism may contribute to contractile dysfunction in human heart failure and may play a role in ADR-induced cardiotoxicity. We overexpressed the myofibrillar isoform of creatine kinase (CK-M), the major cardiac energy reserve reaction, to test the hypothesis that increasing CK-M expression would improve energy metabolism and, in turn, improve contractile function in dysfunctional ADR hearts. 1H MRI and 31P MRS results reveal that CK-M overexpression improves depressed CK energetics and cardiac dysfunction in ADR hearts.
 
Electronic Poster Session - Cardiovascular

Cardiovascular Function: Experimental Models & Humans
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  14:30 - 15:30

  Computer #  
3789.   1 Progressive Alteration of Regional Principal Strain Magnitude and Orientation during Post-Infarct Left Ventricular Remodeling
Kevin J Koomalsingh1, Jeremy R McGarvey1, Chun Xu1, Gerald A Zsido1, Kristen Dillard1, Christina Lau1, Gabrielle Pilla1, Norihiro Kondo1, Manabu Takebe1, Walter RT Witschey1, Melissa M Levack1, Larry Dougherty1, Joseph H Gorman III1, Robert C Gorman1, and James J Pilla1
1University of Pennsylvania, Philadelphia, PA, United States

 
Cardiac function after infarction is impaired due to deceased contracting myocardium and mechanical effects on the normal myocardium. Following myocardial infarction changes in infarct material properties alter regional wall strain during left ventricular remodeling. Results show a significant decrease in strain magnitude for all regions acutely post infarct with strain increasing in the border zone and infarct chronically. Strain angle for all regions at baseline are aligned with the radial direction signifying wall thickening while as the infarct heals the infarct and border zone angles become less radial indicating stretch. This stretch is potentially the stimulus for remodeling.

 
3790.   2 Regional analysis of 3-directional myocardial velocities acquired in a breath-hold with efficient retrogated spiral phase velocity mapping
Robin Simpson1, Jennifer Keegan1, Peter Gatehouse1, and David Firmin1
1Imperial College, London, England, United Kingdom

 
Myocardial phase velocity mapping is capable of determining regional myocardial motion. We have developed a sequence which uses spiral k-space coverage and retrospective cardiac gating to allow the determination of 3-directional velocities over the entire cardiac cycle in a slice within a breath-hold. The acquired spatial and temporal resolution is sufficient to identify all the main features of motion and because of the retrospective gating the end diastolic atrial kick is clearly seen. The presented results demonstrate the regional variations in motion both within a slice and between different slices. Inter subject variability is also demonstrated.

 
3791.   
3 Cine DENSE for Assessment of Diastolic function: Pulse Sequence Development and Initial Results.
Bhairav Bipin Mehta1, Andrew D. Gilliam2, Frederick H. Epstein1,3, and Michael Salerno3,4
1Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States, 2A.D. Gilliam Consulting, Providence, Rhode Island, United States, 3Department of Radiology, University of Virginia, Charlottesville, Virginia, United States, 4Department of Medicine, Cardiology Division University of Virginia, Charlottesville, Virginia, United States

 
Heart failure with preserved ejection fraction (HF-PEF) resulting primarily from diastolic dysfunction accounts for more than half of all heart failure cases. Echocardiography is commonly used to assess diastolic function but has limitations affecting its measurement accuracy. Strain and strain rate measurement using cine DENSE MRI has advantages over echocardiographic techniques and could improve the diagnosis of diastolic dysfunction. Previous cine DENSE sequences have primarily imaged systole. With these sequences, SNR has degraded by mid-diastole, yielding inaccurate displacement measurements and strains. Here we modified a systolic cine DENSE sequence to image diastole with sufficient SNR to compute accurate diastolic displacements, strains, and strain rates.

 
3792.   
4 The Effect of Left Bundle Branch Block and Heart Failure on Circumferential Right Ventricular Dyssynchrony and Function: Assessment with MR Cine DENSE
Daniel A. Auger1, Bruce S. Spottiswoode1,2, Loren P. Budge3, Xiaodong Zhong4, Frederick H. Epstein5, and Kenneth C. Bilchick3
1MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa, 2Division of Radiology, University of Stellenbosch, Cape Town, Western Cape, South Africa, 3Department of Medicine/Cardiovascular Division, University of Virginia, Charlottesville, Virginia, United States, 4MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia, United States, 5Departments of Radiology and Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States

 

3793.   5 Early diastolic function observed in canine model of reperfused transmural myocardial infarction using high temporal resolution MR imaging
Ziheng Zhang1, Donald P Dione2, Ben A Lin2, James S Duncan3, Albert J Sinusas2, and Smita Sampath1
1Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, 2Department of Medicine, Section of Cardiovascular Medicine, Yale University School of Medicine, 3Department of Biomedical Engineering and Diagnostic Radiology, Yale University

 
The functional mechanisms involved in adverse left ventricular remodeling caused by reperfusion injury are unclear. We have developed a new high temporal resolution MR imaging technique, SPAMM-PAV (SPAtially Modulated Magnetization with Polarity Alternated Velocity encoding) that provides regional assessment of early diastolic flow velocity and myocardial strain. This method was applied in a canine animal model with prolonged occlusion followed by reperfusion. We examine the diastolic strain-rates, elastic modulus and viscosity of infarct regions relative to remote regions 3 days post reperfusion to provide insight into early diastolic function in these animals.

 
3794.   6 Measuring the Radial Component of Left Ventricular Strain with Circular Tagging: Feasibility and Initial Results.
Maryam Haftekhanaki1, Abbas N Moghaddam1,2, Khaled Abd-Elmoniem3, and J. Paul Finn2
1Biomedical Engineering, Tehran Polytechnic, Tehran, Tehran, Iran, 2Radiology, UCLA, Los Angeles, CA, United States, 3Biomedical and Metabolic Imaging Branch, NIDDK, NIH

 
LV wall thickening, the main factor of systolic ejection, is reflected in radial strain. This strain was locally measured in this study, from the circularly tagged images, through a K-space based compression encoding method. The results were compared to the strain measurement from HARP and general agreement was confirmed. The proposed method does not need to any tracking or differentiation for strain measurement and therefoere, it has potential advantages over other methods in practicality, computational cost and accuracy.

 
3795.   7 Magnetic Resonance Elastography Derived Stiffness as a Method to Estimate Myocardial Contractility.
Arunark Kolipaka1, Shivani R Aggarwal2, Kiaran P McGee3, Nandan Anavekar4, Armando Manduca3, Richard Ehman3, and Philip Araoz3
1Radiology, The Ohio State University Medical Center, Columbus, Ohio, United States, 2Medicine, Medical University of South Carolina, Charleston, SC, United States, 3Radiology, Mayo Clinic, Rochester, MN, United States, 4Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States

 
Contractility is the intrinsic ability of the heart to contract independent of preload and afterload. Recently, MR elastography (MRE) has been adapted to measure stiffness in the myocardium. The purpose of this study is to determine whether increasing left ventricular (LV) myocardial contractility by epinephrine infusion in an in vivo pig model is associated with increase in end-systolic (E-S) MRE-derived effective myocardial stiffness. MRE was performed on 5 pigs with incremental infusion of epinephrine to increase the heart rate by 20% from baseline. E-S MRE-derived effective myocardial stiffness increased linearly with increasing heart rate with epinephrine infusion.

 
3796.   8 Tissue phase mapping analysis of myocarial function after heart transplantation
Marius Menza1, Bernd Andre Jung1, Adriana Komancsek1, Tobias Wengenmayer2, Anna Lena Stroh2, and Daniela Föll2
1Radiology, Medical Physics, Univesity Medical Center, Freiburg, Germany, 2Cardiology and Angiology, Univesity Medical Center, Freiburg

 
MR tissue phase mapping (TPM) was used to quantify segmental myocardial velocities including rotation in stable patients after heart transplantation (HTX, n=14) without signs of rejection. Reduced regional long-axis velocities in systole and diastole were revealed in most left ventricular segments compared to healthy volunteers (n=18). HTX patients demonstrated a slightly lower apical rotation and a lower peak of early systolic counterclockwise rotation at the base. A comprehensive description of rotation and twist in the transplanted heart is essential for further studies of HTX rejection and TPM might therefore help to improve the follow-up of these patients in future.

 
3797.   9 Albiglutide, a long lasting glucagon-like peptide-1 receptor agonist, protects the rat heart against ischemia/reperfusion injury: Evidence for improving cardiac metabolic efficiency
Hasan Alsaid1, Weike Bao2, Thimmaiah Chendrimada2, Matthew Szapacs3, David R Citerone3, Mark R Harpel2, Robert N Willette2, John J Lepore2, and Beat M Jucker1
1Preclinical & Translational Imaging, GlaxoSmithKline, King of Prussia, PA, United States, 2Heart Failure DPU, GlaxoSmithKline, King of Prussia, PA, United States, 3Platform Technology and Science, GlaxoSmithKline, King of Prussia, PA, United States

 
Albiglutide is a novel GLP-1 analog in clinical development for Type 2 diabetes. In the present study, albiglutide was shown to reduce myocardial infarct size and improved post-ischemic cardiac function and energetics by combined in vivo MRI/MRS following myocardial I/R injury. The observed benefits were associated with enhanced myocardial glucose uptake and shift toward a more energetically favorable substrate metabolism profile by increasing both glucose and lactate oxidation as assessed by ex vivo MRS. These findings suggest that in addition to providing peripheral glycemic control, albiglutide may have direct therapeutic potential for improving cardiac energetic and function in the setting of myocardial ischemic injury.

 
3798.   10 Quantitative Assessment of Highly Accelerated Real Time Cardiac Cine MRI Using Compressed Sensing and Parallel Imaging
Li Feng1,2, Monvadi Barbara Srichai-Parsia1, Ruth P Lim1, Alexis Harrison3, Wilson King4, Ganesh Adluru5, Edward Dibella5, Daniel Sodickson1, Ricardo Otazo1, and Daniel Kim5
1Radiology, New York University School of Medicine, New York, New York, United States, 2Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, United States, 3Internal Medicine, University of Utah, Salt Lake City, Utah, United States, 4Division of Pediatric Cardiology, University of Utah, Salt Lake City, Utah, United States, 5Radiology, University of Utah, Salt Lake City, Utah, United States

 
Accurate assessment of cardiac size and function plays an important role in diagnosis and management of various heart diseases. For patients with impaired breath-hold capacity or arrhythmias, real time cine imaging may be more useful. Recently, highly accelerated real time cine imaging using a combination of compressed sensing and parallel imaging has been proposed with eight-fold acceleration. While this technique is promising for clinical applications, it has not been validated. The purpose of this study was to validate the relative accuracy of accelerated real time cine MRI for quantitative assessment of ventricular volumes and function in healthy human volunteers.

 
3799.   11 SAR-efficient 3D Cardiac CINE with Respiratory-Triggered RF Gating
Markus Henningsson1, Beth Goddu2, Lois Goepfert2, Kraig V Kissinger2, Raymond H Chan2, Reza Razavi1, Rene M Botnar1, Tobias Schaeffter1, and Reza Nezafat2
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachussets, United States

 
3D CINE MRI provides functional volumetric coverage of the heart, however problems associated with this approach are poor contrast-to-noise ratio (CNR) and high specific absorption rate (SAR). Therefore, 2D CINE is preferred in clinical practice. Here we address the problems associated with 3D CINE by gating the radiofrequency pulses using an external respiratory sensor (bellows) to coincide with the image data acquisition. We evaluate this approach in 5 healthy volunteers. The results show a 50% lower SAR and higher CNR and signal-to-noise ratio, comparable to 2D CINE, as switching off the RF allows for T1 recovery of the tissue.

 
3800.   12 Left Ventricular Asynchrony Quantification by Means of Myocardial Displacement Derived from Velocity Encoded MRI
Jan Paul1, Anja Lutz1, Peter Bernhardt1, Patrick Etyngier2, Wolfgang Rottbauer1, and Volker Rasche1
1Department of Internal Medicine II, University Hospital of Ulm, Ulm, Baden-Württemberg, Germany, 2Medisys Research Lab, Philips Healthcare, Sureness, France

 
Many motion parameters obtained from tagged MRI data have been applied previously to quantify motion abnormalities, for decreasing the non-responder rate of about 30 % in Cardiac Resynchronization Therapy (CRT). In the study presented here, segment-wise wall motion is tracked from velocity encoded MRI and displacement is computed. Parameters based on displacement are then analyzed for the distinction between healthy volunteers and patients with abnormal motion patterns.

 
3801.   13 Free breathing measurement of ventricular volumes from magnitude data of 4D flow-sensitive MRI in a canine model of acute pulmonary arterial hypertension
Alejandro Roldan-Alzate1, Leif Jensen1, Alex Frydrychowicz2, Scott K Nagle1, Heidi Kellihan3, Naomi Chesler4, Oliver Wieben1,5, and Christopher J François1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Radiology, Universitatsklinikum Schleswig-Holstein, Lubeck, Germany, 3Veterinary Medicine, University of Wisconsin, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 5Medical Physics, University of Wisconsin, Madison, WI, United States

 
4D flow-sensitive MRI is increasingly being used for hemodynamic analyses of cardiovascular diseases, including pulmonary arterial hypertension. PC VIPR is a time-efficient 4D flow-sensitive MRI technique, using radial undersampling, to obtain high spatial resolution data with a large volume of coverage. In this study we validated the use of PC VIPR magnitude data for the quantification of right and left ventricular volumes in a canine model of acute pulmonary arterial hypertension.

 
3802.   14 Rapid T2 mapping of mouse heart using CPMG sequence and compressed sensing reconstruction
Yong Chen1, Wen Li1, Kai Jiang1, and Xin Yu1,2
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Case Center for Imaging Research, Case Western Reserve University

 
In this study, we developed a novel method for rapid T2 mapping of mouse heart in vivo. Our results demonstrate that a high temporal resolution of one minute can be achieved by combining a fast multi-echo spin-echo sequence with compressed sensing reconstruction.

 
3803.   15 Early signs of cardiomyopathy in delta-sarcoglycan null mice
Anne-Cecile Huby1, Sumeda Abeykoon2, Scott Dunn2, and Janaka Wansapura2
1The Heart Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States, 2Imaging Research Center, Cincinnati Children's Hospital, Cincinnati, OH, United States

 
Delta-sarcoglycan null mice (DSG) develop cardiac and skeletal muscle histopathological alterations similar to those in humans with limb girdle muscular dystrophy. In this study we performed cardiac MRI on 12 week old mice compared to wild type (WT). There was no difference in the ejection fraction between DSG and WT. However the circumferential strain of DSG mice was significantly less than that of the WT. There was an increase in the gene expression of collagen markers. No delayed enhancement was observed but ex vivo T1 and T2 maps showed decreased relaxation times that correlated with mild diffused fibrosis in histopathology.

 
3804.   16 Validation of Myocardial Motion Parameter Extraction from Cine Cardiac MR Against Tissue Doppler Echocardiography
Christoph Guetter1, Paaladinesh Thavendiranathan2,3, Marie-Pierre Jolly1, Xiaoguang Lu1, Hui Xue1, and Orlando P. Simonetti2
1Siemens Corporate Research, Princeton, New Jersey, United States, 2The Ohio State University, Columbus, Ohio, United States, 3Cleveland Clinic Foundation, Cleveland, Ohio, United States

 
The assessment of mitral annular tissue velocity plays an essential role in the evaluation of diastolic dysfunction. We have previously shown that mitral annular velocities can be derived from standard four-chamber cine SSFP images by automatically detecting and tracking the mitral valve insertion points. However, this method has not been validated against Tissue Doppler echocardiography, the standard clinical method for evaluating diastolic function. The objective of this study was to assess the accuracy of early and late diastolic (e’ and a’) mitral annular velocities derived from high temporal resolution SSFP cine by correlating with tissue Doppler echocardiography.

 
3805.   17 Right ventricular strain imaging with single-acquisition simultaneous 3-D SPAMM
Hazel D Sarah Rovno1, Chun Xu2, Lawrence Dougherty1, James J Pilla1,2, Jeremy McGarvey2, Robert C Gorman2, Joseph H Gorman, III2, Walter R. T. Witschey1,2, Kevin Koomalsingh2, Gerald A Zsido2, Norihiro Kondo2, Manabu Takebe2, Kristen Dillard2, Christina Lau2, and Harold I Litt1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Surgery, University of Pennsylvania, Philadelphia, PA, United States

 
Single-acquisition, simultaneous 3-D SPAMM strain imaging of the right ventricle permits assessment of direction and magnitude of regional strains in the right ventricle, at different levels base to apex, and along the wall. 4 swine, 2 healthy, 2 post-infarction were imaged with this sequence. An optical flow method was used for tag tracking, and principal systolic strain was calculated from these displacements using a custom program. Maximal 3-D strain over systole was assessed on multiple regions of interest in both ventricles. Trends in strain data were consistent with theoretical expectations, validating this method.

 
3806.   18 Quantitative Assessment of Atrioventricular Junction Motion in Patients with Hypertrophic Cardiomyopathy-A Cine MRI Study
Sohae Chung1, Shahryar Saba2, Robert Donnino2, Monvadi B. Srichai1, Stuart D. Katz2, and Leon Axel1
1Radiology Department, NYU Langone Medical Center, New York, NY, United States, 2Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States

 
Assessment of diastolic function involves consideration of its dynamics, which are determined by a combination of pressures and myocardial relaxation. In our previous study, we demonstrated a method for assessing diastolic function with MRI in patients with heart failure, using cine MRI to track the motion of the atrioventricular junction (AVJ). Since the AVJ is clearly defined in long-axis cine MRI, its position can be readily tracked, allowing us to measure its longitudinal motion. In this work, we measured the AVJ motion in patients with hypertrophic cardiomyopathy, a group known to have altered LV relaxation, to assess their diastolic function.

 
3807.   19 Imaging intramyocardial hemorrhage following ischemia-reperfusion injury: A Translation Study
Avinash Kali1,2, Andreas Kumar3, Richard Tang2, James Min2, and Rohan Dharmakumar2,4
1University of California, Los Angeles, CA, United States, 2Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Laval University, Laval, QC, Canada, 4Northwestern University, Chicago, IL, United States

 
The effectiveness of T2* maps, T2 maps and T2-STIR images for detecting acute reperfusion myocardial hemorrhage was evaluated in a surgically controlled canine model and a pilot patient population. Relative to remote myocardium, T2* decreased significantly in the presence of reperfusion hemorrhage, while T2-STIR signal intensity and T2 remained significantly elevated. T2* of non-hemorrhagic infarctions was not significantly different from the remote myocardium. T2-STIR signal intensity and T2 were significantly higher than those of both remote and hemorrhagic myocardium. We conclude that T2* is a more effective approach to detect acute reperfusion hemorrhage.

 
3808.   20 Carnitine supplementation in long-chain acyl-CoA dehydrogenase knock-out mice is not detrimental for cardiac function
Adrianus J. Bakermans1, Michel van Weeghel2, Klaas Nicolay1, Jeanine J. Prompers1, and Sander M. Houten2
1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands, 2Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, Netherlands

 
Elevation of long-chain acylcarnitine levels is a hallmark of long-chain fatty acid lower case Greek beta-oxidation disorders, and is accompanied by low free carnitine levels. To normalize carnitine concentration, carnitine supplementation has been proposed. However, this could provoke lipotoxic accumulation of long-chain acylcarnitines. Myocardial function, morphology and triglyceride (TG) levels were quantified using in vivo MRI and 1H-MRS in long-chain acyl-CoA dehydrogenase knock-out (LCAD KO) and wild-type (WT) control mice on carnitine supplementation. Carnitine supplementation did not affect cardiac function, but normalized TG content in LCAD KO myocardium. No evidence for lipotoxic effects of supplementation-induced long-chain acylcarnitine accumulation was found.

 
3809.   21 Quantitative Assessment of L-type Calcium Channel Activity by Manganese-Enhanced MRI
Kai Jiang1,2, Ya Chen1,2, Raymond F. Muzic, Jr.1,3, and 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 mathematical model was developed for quantitative assessment of the L-type calcium channel activity with manganese-enhanced MRI. Dynamic changes in R1 during manganese perfusion and wash-out were followed with rapid T1 mapping at 3 min temporal resolution. Manganese uptake via the L-type calcium channel and efflux via the NCX were estimated by least-squares fitting of the model to experimental MEMRI data.

 
3810.   22 Evaluation of Strain and Torsion in Physiologic and Pathologic Left Ventricular Hypertrophy
Candida Laura Desjardins1, Yong Chen2, Julian Stelzer2, Monica Montano2, Michiko Watanabe1, and Xin Yu2,3
1Case Western Reserve University, Cleveland, OH, United States, 2Case Western Reserve University, 3Case Center for Imaging Research, Cleveland, OH

 
Cardiac responses to increased workload and environmental stresses may result in physiologic or pathologic remodeling of cardiomyocyte size and vascularization. Distinguishing pathologic from physiologic hypertrophy at an early stage could be critical for clinical management of patients. The discriminating factor between the physiologic and pathologic models of LVH lies in the timing of strain development. When faced with LVH in the presence of preserved function in a young patient, the difference in timing of strain development may be of clinical utility to discriminate between a benign athlete’s heart and HCM.

 
3811.   23 High spatial resolution functional cardiac MRI in mice using a cryogenic RF probe
Babette Wagenhaus1, Andreas Pohlmann1, Matthias Alexander Dieringer1,2, and 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

 
Rapid phenotyping, assessment of gender effects and evaluation of novel therapeutics in longitudinal studies using high spatial resolution cardiac MRI (CMR) is of increasing interest for a variety of mouse models of cardiovascular diseases. SNR constraints can be offset by use of a cryogenic RF probe. This study examines the feasibility and potential benefit of high spatial resolution functional cardiac MRI employing a cryogenic transceive RF surface coil compared to a conventional mouse heart receiver array/body resonator combination. Our results suggest that use of a cryogenic coil could not only improve the accuracy of left ventricular function and morphology assessment, but also affords chamber quantification of the right ventricle.

 
3812.   24 Analysis of left ventricular functional parameters of the mouse heart during prolonged hyperthyroidism and recovery
Neele S. Hübner1,2, Annette Merkle1, Bernd Jung1, Dominik von Elverfeldt1, and Laura-Adela Harsan1
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Faculty of Biology, University of Freiburg, Freiburg, Germany

 
Thyroid hormones (TH) have various modes of action and their beneficial effects for treatment of different diseases are focus of recent studies. One example is their pro-remyelinating effect in animal models of multiple sclerosis. However enhanced TH levels result in undesired side effects like cardiovascular impairment. Cardiovascular Magnetic Resonance Imaging is used to assess left ventricular performance in mice after prolonged hyperthyroidism and during recovery. Significant reduction of ejection fraction and global wall thickening account for a decline in the left ventricular performance induced by long-term hyperthyroidism. Recovery of the cardiac function is seen after periods of TH treatment arrest.
 
Electronic Poster Session - Cardiovascular

Coronary MRA & Vessel Wall Imaging
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  13:30 - 14:30

  Computer #  
3813.   25 Direct Coronary Artery Motion Tracking from Cartesian 2D Fat Image Navigator for Motion Corrected Coronary MRA
Keigo Kawaji1,2, Pascal Spincemaille2, Thanh D. Nguyen2, Nandadeepa Thimmappa2, Mitchell A. Cooper1,2, Martin R. Prince2, and Yi Wang1,2
1Biomedical Engineering, Cornell University, Ithaca, NY, United States, 2Radiology, Weill Cornell Medical College, New York, NY, United States

 
Direct measurement of coronary artery motion can be determined from a Cartesian 2D fat image navigator, which uses a spatial-spectral selective excitation to excite the epicardial fat surrounding the coronary arteries. In this study, we demonstrate the feasibility of motion correction on all acquired data in a 3D SSFP CMRA sequence without respiratory gating using coronary artery displacements derived from the 2D Fat image navigator.

 
3814.   26 Cartesian Whole-Heart Coronary MRA Using Interleaved Auxiliary Image Acquisition and 3D Affine Motion Correction
Markus Henningsson1, Claudia Prieto1, and Rene M Botnar1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

 
We developed a novel respiratory motion correction technique for Cartesian whole-heart coronary MRA (CMRA) using 3D affine transformation which allows for data acquisition with 100% efficiency. Fully sampled, low resolution auxiliary images are acquired for different respiratory bins, interleaved with high resolution CMRA images. Correction is performed in image space by registering each auxiliary image (bin 2-4) to the end-expiratory image (bin1), thereafter applying the calculated transformation to the corresponding CMRA images which have been similarly binned. The proposed method, with 100% gating efficiency, shows comparable image quality to a 7mm gated scan with 1D FH correction (average gating efficiency=55%).

 
3815.   27 Whole-heart Coronary MR Angiography with 2D Parallel Imaging: Comparison of Two Cartesian Sampling Schemes with and without CAIPIRINHA Reordering
Xiaoming Bi1, Randall Kroeker2, Johannes Breuer3, Sven Zuehlsdorff1, and Peter Kellman4
1Siemens Healthcare, Chicago, IL, United States, 2Siemens Healthcare, Winnipeg, Canada, 3Siemens AG Healthcare, Erlangen, Germany, 4National Institute of Health, Bethesda, MD, United States

 
The goal of this work was to: 1) investigate the feasibility of whole-heart coronary MRA in consecutive volunteers using 2D CAIPIRINHA sampling strategy; 2) compare the efficacy of 2D CAIPIRINHA to conventional reordering with total acceleration of 8 (PE x PA = 4 x 2) and matched protocol. Preliminary results from five consecutive volunteer studies showed improved parallel imaging g-factor with CAIPIRINHA reordering as compared to conventional reordering (CAIPIRINHA: 1.52 ± 0.05; Conventional: 1.85 ± 0.17, p = 0.038).

 
3816.   28 Self-Gate Free-Breathing Coronary Artery Vessel Wall Imaging by Combining Water and Fat Images
Jing Liu1, Thanh D Nguyen2, David Saloner1, and Yi Wang2
1University of California San Francisco, San Francisco, CA, United States, 2Weill Cornell Medical College, New York, NY, United States

 
In this abstract, we proposed a novel technique for imaging coronary vessel wall. A self-gated free-breathing multi-echo radial imaging technique was used to generate 3D coronary cine images. No external respiratory, cardiac gating or dedicated preparation pulses were required. Simultaneous water and fat visualization was achieved, and the combination of the two images has been demonstrated to not only improve the coronary artery contrast but provide depiction of the coronary artery vessel wall.

 
3817.   29 Black-blood Steady State Free Precession (SSFP) coronary wall MRI for cardiac allografts: A feasibility study
Kai Lin1, Xiaoming Bi2, Ying Liu1, Kirsi Taimen1, Biao Lu1, Debiao Li1, and James C Carr1
1Radiology, Northwestern University, Chicago, Illinois, United States, 2Siemens Healthcare, Chicago, Illinois, United States

 
Black-blood SSFP coronary wall MRI provides higher image quality, SNR and CNR than traditional TSE does in HTx recipients. It has the potential to become an alternative means to noninvasive imaging of cardiac allografts.

 
3818.   30 ADC mapping for carotid plaque characterisation
Victoria Young1, Andrew J Patterson2, Umar Sadat3, Andrew N Priest2, Robert van de Geest4, Martin J Graves1,2, and Jonathan H Gillard1
1Radiology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 2Medical Physics and Engineering, Addenbrooke's Hopsital, Cambridge, United Kingdom, 3Vascular Surgery, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 4Radiology, Leiden University Medical Center, Leiden, Netherlands

 
High resolution MRI is an option in the assessment of carotid atherosclerosis but there are limitations of unenhanced imaging in complex plaque and evaluation is subjective. DWI through ADC mapping has been applied both in vivo and ex vivo to quantitatively differentiate lipid core and fibrous tissue. This study evaluated a larger patient population to demonstate this separation could still be seen in a broad range of stenoses and to show plaque thrombus also demonstrated a different ADC value which varied with thrombus age. This evidence increases the value of ADC mappingin demonstrating vulnerable plaque characteristics.

 
3819.   
31 Detection of vascular remodeling using an elastin contrast agent in a rabbit model of atherosclerosis
Alkystis Phinikaridou1, Marcelo E Andia2, Andreas Indermuehle2, David C Onthank3, Rick R Cesati3, Simon P Robinson3, Prakash Saha2, and Rene M Botnar2
1Imaging Sciences, King's College London, London, United Kingdom, 2King's College London, 3Lantheus Medical Imaging

 
The extracellular matrix protein (ECM) elastin contributes to 30% of the dry weight of the vascular wall. Studies have shown that dysregulation of the balance between elastogenesis and elastolysis leads to the de novo accumulation of elastin fibers in the pathologically altered vessel wall and accompanies the development of atherosclerosis and may contribute to plaque instability. In this study, we employed in vivo MRI in a rabbit model of atherosclerosis and controlled plaque disruption to investigate the merits of an elastin-targeted gadolinium-based contrast agent for the detection of vessel wall remodeling and its association with plaque vulnerability.

 
3820.   32 Value of improved motion sensitized driven equilibrium(iMSDE) sequence in preoperative evaluation for carotid endarterectomy and carotid artery stenting in cases of atherosclerosis: compared with digital subtraction angiography
Huilin Zhao1, Xihai Zhao2, Jinnan Wang3,4, Niranjan Balu4, Ye Cao1, Xiaosheng Liu1, Xiangyang Ma5, Chun Yuan4, and Jianrong Xu1
1Radiology, Renji hospital, Shanghai Jiaotong Univesity, Shanghai, China, 2Center for Biomedical Imaging Research, Tsinghua University School of Medicine, Beijing, China, 3Philips Research North America, Briarcliff Manor, NY, United States, 4Radiology, University of Washington, Seattle, WA, United States, 5Philips Research Asia, Shanghai, China

 
The iMSDE sequence provides outstanding blood suppression efficiency and time efficiency. Thus, this new pulse sequence has the potential to become a noninvasive alternative to DSA for quantitative carotid vascular morphology evaluation. This study sought to evaluate the clinical value of the iMSDE techniques in atherosclerotic carotid artery assessment in 29 subjects before carotid endarterectomy (CEA) and carotid artery stenting(CAS), by comparing with DSA. It was found that the iMSDE sequence demonstrated a good consistency with DSA in defining the location and shape of the advanced plaques. Additionally, the iMSDE sequence has the advantage of accurately depicting early atherosclerotic lesions, which can be beneficial for clinical treatment planning.

 
3821.   33 Gadofosveset monitors the effects of different interventions on endothelial permeability and plaque progression
Alkystis Phinikaridou1, Marcelo E Andia2, and Rene M Botnar2
1Imaging Sciences, King's College London, London, United Kingdom, 2King's College London

 
Studies have demonstrated that endothelial dysfunction precedes and promotes atherosclerosis development because of increased endothelial permeability, circulating lipoproteins, inflammatory cells and molecules. We have previously shown that contrast enhanced MRI using gadofosveset, an albumin binding gadolinium contrast agent, can detect endothelial damage associated with atherosclerotic plaque formation and progression in high-fat fed apoE -/- mice. In this study, we explored whether imaging with gadofosveset could be used to monitor the effects of different interventions on endothelial permeability and plaque progression.

 
3822.   34 Time-Resolved Contrast-Enhanced Black-Blood Carotid Vessel Wall Imaging with SRDIR
Zhaoyang Fan1,2, Jingsi Xie1,3, Xiaoming Bi4, James Carr3, Troy Labounty1, James Min1, Daniel Berman1, and Debiao Li1,2
1Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2University of California, Los Angeles, CA, United States, 3Northwestern University, Chicago, IL, United States, 4Siemens Cardiovascular R&D, Chicago, IL, United States

 
Inflammation plays a critical role in various stages of the atherosclerotic plaque development. Dynamic contrast-enhanced vessel wall imaging has been used to link the enhancement pattern to the extent of inflammation of carotid plaque. However, the previous work used a bright blood technique, making it difficult to clearly draw the contour of the vessel wall. In this work, we developed a T1-insensitve 2D black blood imaging technique, SRDIR-prepared gradient-echo, to acquire time-resolved contrast-enhanced vessel wall images which is interleaved by a bright-blood acquisition. Separate signal measurements of blood and vessel wall allowed accurate determination of Ktrans and fractional plasma volume.

 
3823.   35 Optimisation of the Measurement of the Arterial Input Function During High-Dose Administration for Dual Imaging Dynamic Contrast Enhanced (DCE) Magnetic Resonance Imaging (MRI) Applications in the Human Carotid Arteries
Philip M Robson1, Claudia Calcagno1, Sarayu Ramachandran1, Venkatesh Mani1, Melanie Kotys-Traughber2, and Zahi A Fayad1
1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States, 2Philips Healthcare, Cleveland, OH, United States

 
Investigation of simultaneous imaging of the arterial input function and the vessel wall response in quantitative DCE of the carotid arteries in atherosclerosis requires acquisition of signal in the presence of highly concentrated contrast agent in the first-pass of the bolus. We employ a saturation-prepared segmented GRE acquisition and a signal model that accounts for inflow and non-steady-state conditions during acquisition. This strategy is assessed quantitatively in three subjects using the Stewart-Hamilton dilution principle, showing no significant difference (p=0.52) between the integral of the first pass of the concentration-time curve and the ratio of known dose and measured cardiac output.

 
3824.   36 Comparison of DANTE Prepared Black Blood (BB) -TSE with Conventional BB Methods
Linqing Li1, and Peter Jezzard1
1FMRIB, Clinical Neurology Department, University of Oxford, Oxford, United Kingdom

 
We have previously demonstrated that the DANTE (a rapid series of low flip angle RF pulses interspersed with gradients) preparation is a very promising black blood technique. In this work, a comprehensive comparison of T1, T2 weighted and proton density imaging was performed. In addition, further application to a DANTE-prepared multi-slab 3D GRASE sequence was investigated. The improvement of the DANTE method over the existing methods is considerable in T1, T2 and Pd weighted 2D imaging. DANTE may be adapted as a BB module for 3D BB acquisition.

 
3825.   37 Atherosclerotic Plaque Imaging with Integrated PET/MR: Preliminary Results in a Rabbit Model
Isabel Dregely1, Christine Baumgartner2, Eliane Weidl1, Stephan G Nekolla1, Carl Ganter3, Jaroslav Pelisek4, Markus Schwaiger1, and Iina Laitinen1
1Department of Nuclear Medicine, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany, 2Centre of Preclinical Research, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany, 3Department of Radiology, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany, 4Clinic for Vascular Surgery, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany

 
In atherosclerosis characterization of the so-called “vulnerable” plaque, which is at risk for disruption, is critical to predict acute adverse events. In this study we demonstrate the ability to identify complex, vulnerable atherosclerotic plaques in a rabbit model of carotid artery atherosclerosis combining morphological and functional information in simultaneous PET/MR imaging.

 
3826.   38 Prospective Multicenter Cohort Study of High Resolution MRI in Giant Cell Arteritis: initial results
Thorsten Alexander Bley1, Julia Geiger2, Markus Both3, Thomas Ness2, Peter Vaith2, Michael Markl4, Bernhard Nölle3, and Thorsten Klink5
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 2University Hospital Freiburg,3University Hospital Kiel, 4Northwestern University, 5University Medical Center Hamburg-Eppendorf

 
Giant cell arteritis (GCA) is a diagnostic challenge. Single center studies have demonstrates the value of high resolution MRI to visualize mural inflammatory changes in GCA. This multicenter cohort study compares high resolution MRI with the diagnostic gold standard temporal artery biopsy in a rather large cohort of GCA patients form 3 academic medical centers. Two blinded reader achieved high sensitivities (95% and 89%) and specificities (73% and 80%) in detection of mural inflammatory changes in GCA with substantial inter-observer-agreement (kappa = 0.657).

 
3827.   39 Compressed sensing (CS) for dynamic contrast enhanced (DCE) MRI of atherosclerosis: preliminary experience in a rabbit model of disease
Claudia Calcagno1, Hadrien Dyvorne1, Ricardo Otazo2, Philip M Robson1, Mark E Lobatto1, Sarayu Ramachandran1, Venkatesh Mani1, and Zahi A Fayad1
1Mount Sinai School of Medicine, New York, NY, United States, 2New York University, New York, NY, United States

 
Dynamic contrast enhanced (DCE) MRI of atherosclerosis is gaining increasing interest for the characterization of vulnerable atherosclerotic plaques. In this study we present our preliminary experience in applying compressed sensing reconstruction to DCE-MRI of atherosclerosis, with the aim of accelerating tissue acquisition to achive higher in-plane spatial resolution and tissue coverage.

 
3828.   40 A New Approach for Noncontrast MR Imaging of Carotid Artery Disease
Na Zhang1,2, Anqi Pei3, Lei Zhang1,2, Xiaoxin Tong3, Xin Liu1,2, and Yiu-Cho Chung1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 2Key Laboratory of Health Informatics, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Department of Neurology, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China

 
Carotid plaque imaging by MRI can characterize plaque components and allow assessment of plaque vulnerability. However, current technique requires Gd-based contrast and long examination time, making it inferior to color Doppler. We propose here a multi-contrast three dimensional (3D) carotid vessel wall imaging protocol without the use of Gd-based contrast. The protocol, consisting of T1w-SPACE, T2w-SPACE and MPRAGE, can be finished within 20 minutes including localization. Preliminary evaluation on volunteers and patients showed that total examination time was about 13 minutes excluding patient setup. The approach reduces operator dependency, provides more diagnostic information and better coverage compared to color Doppler.

 
3829.   41 MRI of carotid atherosclerosis to identify TIA and stroke patients who are at risk of a recurrence
Robert Kwee1, Robert van Oostenbrugge2, Werner Mess2, Rob van der Geest3, Jos van Engelshoven2, Joachim Wildberger2, and Eline Kooi2
1Maastricht University Medical Center, Maastricht, Limburg, Netherlands, 2Maastricht University Medical Center, Netherlands, 3Leiden University Medical Center, Netherlands

 
The results of the present study indicate that the presence of a LRNC, a thin and/or ruptured FC, and IPH are associated with the recurrence of clinical cerebrovascular ischemic events. Our study confirms findings of previous studies and shows that assessment of carotid plaque characteristics by MRI may help improving patient selection for carotid endarterectomy.

 
3830.   42 Ruptured Carotid Plaques as a Feature in Patients with Acute Lower Limb Arterial Thrombosis
Qingjun Wang1, Yong Guo2, Jianming Cai3, and Minghua Huang4
1Department of Radiology, Chinese Navy General Hospital, Beijing, Beijing, China, 2Department of Radiology, Chinese Navy General Hospital, China,3Chinese PLA General Hospital, 4Chinese Navy General Hospital

 
By using multi-contrast high-resolution MRI, we prospectively studied whether carotid plaque characteristics can predict acute lower limb arterial thrombosis (ALLAT). In the present study, each carotid atherosclerotic patient with and without ALLAT underwent a carotid MRI examination on a 3.0-T MRI scanner. Our findings showed that the presence of fibrous cap rupture was the strongest independent predictor for ALLAT.

 
3831.   43 A Motion Monitorred SPACE Sequence for Isotropic Cardotid Wall Imaging
Qiong Zhang1, Cong Zhao1, and Jing An1
1Siemens ShenZhen Magnetic Resonance, ShenZhen, GuangDong, China

 
In this work, a self-navigated 3D measurement paradigm is proposed and tested with a three-dimensional turbo spin-echo (SPACE) sequence. Compared with conventional cross-paired navigator [4], sequence of this work requires no navigation bar, skips the manual positioning and leaves no dark-band on final image. With volunteer test, this work makes motion blurring reduced and definition of vessel wall increased.

 
3832.   44 Non-invasive visualization of basilar artery wall and branches ostium with high-resolution 3D black blood sequence at 3.0T
Xin Lou1, Ning Ma2, and Hao Shen3
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, 2Department of Neurology, Beijing Tiantan Hospital, Beijing, China, 3GE healthcare, Beijing, China

 
3D fast magnetic resonance black blood sequence flow-dephasing-prepared spoiled gradient recalled echo was performed to screen basilar artery wall and the ostia of the adjacent branch arteries. Our data suggest that the sequence can be used for high-resolution and large coverage of the basilar artery wall and the ostia of branches including superior cerebral artery, anterior inferior cerebral artery, and posterior inferior cerebral artery.

 
3833.   45 Contrast-Enhanced 3D Brain Black-Blood Imaging for Detection of Intracranial Arterial Unstable Plaque in Acute Ischemic Stroke Patients
Chul-Ho Sohn1, JiHoon Kim2, Jaeseok Park3, Kee-Hyun Chang2, Seunghong Choi2, and InSeong Kim4
1Radiology, Seoul National University Hospital, Seoul, Korea, 2Seoul National University Hospital, Korea, 3Korea University, Korea, 4Siemens Healthcare, Seoul, Korea

 
Contrast-enhanced 3D fast spin echo black-blood images at the 3 T may be able to differentiate enhancement patterns of intracranial atherosclerotic plaques (eccentric), especially in the non-significant intracranial artery stenosis patients. High-resolution 3D black-blood images could help precise stroke subtyping.

 
3834.   46 High Spatial Resolution MR Imaging of the Carotid Arteries at 7.0 T Using an 8 Channel Transceiver Coil Array
Abdullah Ok1, Jan Rieger1,2, Andreas Gräßl1, Vince Istvan Madai3,4, Jan Sobesky3,4, and Thoralf Niendorf1,5
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück-Center for Molecular Medicine, Berlin, Germany, 2MRI.TOOLS GmbH, Berlin, Germany, 3Center for Stroke Research Berlin (CSB), Charite Universitätsmedizin, Berlin, Germany, 4Department of Neurology, Charite Universitätsmedizin, Berlin, Germany, 5Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Berlin, Germany

 
A dedicated 8 channel transmit/receive coil was proposed, simulated and designed to address the challenges of carotid MRI at 7 T. The coil was tested on volunteers and found to meet the needs of isotropic, sub-millimeter in-plane spatial resolution imaging of the carotid arteries.

 
3835.   47 Detection of Carotid Intraplaque Hemorrhage by In Vivo Black Blood Imaging Using Spatial Labeling with Multiple Inversion Pulses Prepared Spoiled Gradient Recalled Sequence
Qingjun Wang1, Yong Guo2, Jianming Cai3, and Minghua Huang4
1Department of Radiology, Chinese Navy General Hospital, Beijing, Beijing, China, 2Department of Radiology, Chinese Navy General Hospital, China,3Chinese PLA General Hospital, 4Chinese Navy General Hospital

 
Black blood imaging based on Spatial LabEling with multiple invErsion pulses prepared SPoiled Gradient Recalled sequence (SLEEK-SPGR) is thought to be a potentially promising tool in imaging carotid IPH. However, so far no study has evaluated its accuracy in diagnosis of IPH by histological assessment. In this study, with the help of excised specimens from carotid endarterectomy (CEA), we evaluated the sensitivity and efficacy of SLEEK-SPGR in detecting carotid IPH. Our findings showed SLEEK-SPGR has very high sensitivity and specificity in detecting carotid IPH, and can provide a better visualization of carotid IPH than traditional 3D-TOF and QIR images.

 
3836.   48 Clot Lysis Dynamics in an Experimental Rat Venous Thrombosis Model During 4 Weeks of Fibrinolytic Inhibition
Abdel Wahad Bidar1, Anna Ravnefjord2, Frank Risse1, Edvin Johansson1, Margareta Elg2, and Paul Hockings1
1R&D PHB, Imaging, AstraZeneca, Mölndal, Sweden, 2CVGI, Bioscience, AstraZeneca, Mölndal, Sweden

 
Understanding the dynamic process following clot formation and lysis in relevant animal models is of interest in order to understand the mechanism underlying human disease and to develop therapeutic approaches. The results demonstrate for the first time by means of MRI the dynamics of clot lysis in vivo in a rat model of venous thrombosis in the presence of an antifibrinolytic agent. Delayed thrombus lysis rate was measured in treated animals compared to controls. This model could be useful for translation between in vitro and in vivo results and for bridging to clinical results when evaluating thrombolytic and fibrinolytic agents.
 
Electronic Poster Session - Cardiovascular

Cardiovascular Technology, Image Processing, Other
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  14:30 - 15:30

  Computer #  
3837.   25 Highly-accelerated, single breath-hold 3D Cine b-SSFP MRI with a combination of compressed sensing and parallel imaging
Daniel Kim1, Alexis Harrison2, Wilson King3, Li Feng4, Elwin Bassett5, Christopher J McGann2, Nassir F Marrouche2, and Ricardo Otazo6
1Radiology, University of Utah, Salt Lake City, Utah, United States, 2Internal Medicine, University of Utah, 3Division of Pediatric Cardiology, University of Utah, 4Sackler Institute of Graduate Biomedical Sciences, New York University, 5Physics, University of Utah, 6Radiology, New York University

 
Breath-hold cine b-SSFP MRI is the gold standard for imaging myocardial function. The need for multiple breath-holds, however, increases the examination time and likelihood for patient exhaustion from repeated breath-holds. We sought to develop a single breath-hold 3D b-SSFP cine MRI pulse sequence with 12-fold acceleration using a standard coil array, by employing a combination of compressed sensing and parallel imaging that exploits joint sparsity among all coil datasets, and compare its performance against multi-slice 2D b-SSFP cine MRI for LV function quantification. All four global function measurements (EDV,ESV,SV,EF) were in good agreement, with coefficient of variation ranging from 6-12%.

 
3838.   26 3D Cardiac CINE Imaging using 3D Through-Time Radial GRAPPA
Nicole Seiberlich1, Katherine L Wright1, Philipp Ehses2,3, Vikas Gulani1,4, and Mark A Griswold1,4
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3Neuroimaging, University Hospital Tübingen, Tübingen, Germany, 4Radiology, University Hospitals of Cleveland, Cleveland, OH, United States

 
Performing 3D cardiac CINE imaging in a single breathhold is challenging due to the long acquisition times required to collect the necessary data. By employing 3D through-time radial GRAPPA, a method similar to the 2D radial GRAPPA method introduced for real-time cardiac imaging, highly accelerated 3D CINE stack-of-stars radial data can be reconstructed. This abstract demonstrates that by using 3D through-time radial GRAPPA, data for 3D cardiac CINE images that cover the entire heart can acquired within a 15 second breathhold with a temporal resolution of 45 ms per 3D volume and a spatial resolution of 2.3x2.3x6 mm3.

 
3839.   27 Different patterns of myocardial iron overload by T2* Cardiovascular MR as markers of risk for cardiac complication in thalassemia major.
Antonella Meloni1, Vincenzo Positano1, Petra Keilberg1, Brunella Favilli1, Cristina Salvatori2, Letizia Gulino1, Gennaro Restaino3, Gianluca Valeri4, Massimo Midiri5, Angelo Zuccarelli6, Massimo Lombardi1, and Alessia Pepe1
1Cardiovascular MR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 3Centro di Ricerca e Formazione ad Alta Tecnologia nelle Scienze Biomediche "Giovanni Paolo II", Università Cattolica del Sacro Cuore, Campobasso, Italy, 4Dipartimento di Radiologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti "Umberto I-Lancisi-Salesi", Ancona, Italy,5Istituto di Radiologia, Policlinico "Paolo Giaccone", Palermo, Italy, 6Centro trasfusionale e di microcitemia, Ospedale civile, Olbia, Italy

 
Homogeneous myocardial iron overload detected by multislice multiecho T2* MRI technique predicts a significantly higher risk to develop cardiac complications, especially heart failure, suggesting an intensive chelation therapy in this group of thalassemia major patients.

 
3840.   28 Cardiac Triggered B1+ mapping using Bloch Siegert in the heart at 3T
Davide Santoro1, Federico von Samson-Himmelstjerna1,2, Flavio Carinci1,3, Fabian Hezel1, Matthias Dieringer4,5, and Thoralf Niendorf1,5
1Berlin Ultra-High Field Facility (BUFF), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany, 2Center for Stroke Research, Charite Universitätsmedizin Berlin, Berlin, Germany, 3Research Center Magnetic Resonance Bavaria (M.R.B), Wuerzburg, Germany, 4Charite Universitätsmedizin Berlin, Berlin, Germany, 5Experimental and Clinical Research Center (ECRC), Charite Campus Buch, Berlin, Germany

 
There is a growing number of Cardiac MR applications which could benefit of the signal to noise ratio advantage at high magnetic fields. However the image quality in CMR may be spoiled by effects other than SNR. B1+ inhomogeneities present at high field strengths might affect quantitative CMR studies which require knowledge of the local applied flip angle. The acquisition of a FA map with standard methods in the heart is challenging for the varying heart rates and repetition times in cardiac gated imaging. This study examines the feasibility of cardiac gated 2D Bloch Siegert B1 mapping with the goal to acquire a B1+ maps of the heart at 3T in a single breath-hold. Our preliminary results do not show major changes in the calculated flip angle at the blood/myocardium interface and hence indicate that blood flow related phase contributions might be minor.

 
3841.   29 A Two-Chamber Multi-modal (MR/Ultrasound) Cardiac Phantom for Normal and Pathologic Hearts
Vahid Tavakoli1,2, Michael Kendrick2, Motaz Alshaher2,3, and Amir A Amini1
1Electrical and Computer Engineering, University of Louisville, Louisville, ky, United States, 2Veteran's Affairs Medical Center, Louisville, ky, United States,3Department of Cardiology, University of Louisville, Louisville, ky, United States

 
A non-ferromagnetic, multimodal two chamber moving heart phantom with applications to cardiac MR, echocardiography and Doppler imaging is presented. A biventricular structure is able to simulate the asymmetric LV motion and inter-ventricular displacements. A 10% solution of Poly Vinyl alcohol (PVA) was used as the main material. Freeze-thaw cycles were used to produce different elasticity, ultrasound attenuation and T1/T2 properties. An additional pathologic heart was made to model aneurysm. Three infarct mimicking inclusions of different elastic properties were added to simulate infarcted regions. Image series were acquired with Philips iE33 echocadriography workstation and 1.5 T Philips Achieva scanner.

 
3842.   30 3D Cine MRI of Mouse Heart with Concurrent Dephasing and Excitation
Naoharu Kobayashi1, Qiang Xiong2, Joseph Ippolito2, Jianyi Zhang2, and Michael Garwood1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States, 2Cardiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States

 
3D magnetic resonance cine imaging of the mouse heart is highly challenging due to limited spatial and temporal resolution and cardiac and respiratory motion. We demonstrate CODE 3D cine MRI of mouse heart with prospective electrocardiogram gating, where the matrix size was cut down to reduce TR while keeping preferable spatial resolution by using a small surface coil and oversampled acquisition. And we applied sliding window reconstruction in order to increase the nominal temporal frame rate of the cine images. This method enabled high resolution 3D cine imaging with ~23 min at 9.4T.

 
3843.   31 Dual breath-hold 3D whole heart cine cardiac MRI: feasibility and initial experience
Marijn van Stralen1, Jesse Habets2, Mieke M.P. Driessen3,4, Hamza El Aïdi2,3, Josien P.W. Pluim1, and Tim Leiner2
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 3Cardiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 4The interuniversity cardiology institute of the Netherlands, Utrecht, Utrecht, Netherlands

 
We demonstrate the feasibility of dual breath-hold whole heart 3D cine bSSFP cardiac MR with retrospective reconstruction of any desired viewing plane. The proposed method allowed fast and accurate assessment of global LV functional parameters in comparison with standard 2D bSSFP cine imaging acquired in dedicated predefined cardiac axis orientations. This method saves costly scan time by eliminating planning and reducing acquisition time and may be of value in subjects that are unable to undergo a complete cardiac evaluation with conventional 2D cine bSSFP methods.

 
3844.   32 Free-Breathing Quantitative T2-mapping of the Heart Designed for Longitudinal Studies at 3T
Ruud B van Heeswijk1,2, Hélène Feliciano1,2, Gabriele Bonanno1,2, Simone Coppo1,2, Nathalie Lauriers3, Didier Locca3, Juerg Schwitter3, and Matthias Stuber1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Center for Cardiac Magnetic Resonance and Cardiology Service, University Hospital of Lausanne (CHUV), Lausanne, Switzerland

 
A novel navigator-gated and -corrected free-breathing cardiac T2-mapping methodology for longitudinal studies at 3T was developed and optimized using numerical simulations and phantom studies. A reference phantom with a known T2 is placed in the field-of-view while the T2 fitting procedure was optimized empirically for improved accuracy and reproducibility of the T2 measurements. The performance of this methodology was ascertained quantitatively in healthy adult human volunteers before a small cohort of myocardial infarction patients was investigated.

 
3845.   33 Active Frequency Stabilisation for Prolonged bSSFP Imaging: Application to Neonatal Cardiac MRI
Anthony N Price1, Shaihan J Malik1, Kathryn M Broadhouse1, Anna Finnemore1, Giuliana Durighel1, David J Cox1, David Edwards1, Alan M Groves1, and Jo V Hajnal1
1Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom

 
Balanced-SSFP has become a key tool for assessing cardiac function. However, the characteristic dark bands are a major problem, especially in the blood-pool. Reliable and accurate shimming is essential: as is optimum and stable frequency selection. In adult CMR, these issues are rarely a prohibitive problem. In neonatal CMR increased resolution demands, faster heart rates, low SNR, and the need to allow free-breathing, lead to longer acquisition times. Consequently, scanner frequency can no longer be assumed stable. Here we present methods for reliable B0 shimming and also active stabilisation of the scanner frequency drift during bSSFP scanning in neonatal CMR.

 
3846.   34 Self Consistent Parallel Imaging with Temporal Sensitivity Estimation (TSPIRIT): Application to improve Real-time Exercise Stress Cardiac Cine and Perfusion Imaging
Hui Xue1, Yu Ding2, Ti-Chiun Chang1, Christoph Guetter1, Subha V. Raman2, Marie-Pierre Jolly1, and Orlando P. Simonetti2
1Siemens Corporate Research, Princeton, New Jersey, United States, 2Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio, United States

 
To improve the image quality of real-time exercise stress cardiac cine and perfusion imaging, we extended the recently proposed SPIRIT image reconstruction by incorporating temporal coil sensitivity estimation on GRAPPA reconstructed kspace and spatial regularization. The proposed method was applied to 17 volunteers for cine imaging with an averaged SNR gain of 28.5% and 10 volunteers for perfusion with a 19.7% SNR gain. The level of ghosting artifacts was statistically unchanged while the SNR increase was significant.

 
3847.   35 Accelerated mouse cardiac imaging using threefold undersampling and kt-BLAST reconstruction
Ian Marshall1,2, Maurits A Jansen1,2, Yuehui Tao1,3, Gavin D Merrifield1,4, and Gillian A Gray2
1Medical Physics, University of Edinburgh, Edinburgh, United Kingdom, 2Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom, 3Brain Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom, 4SINAPSE consortium, www.sinapse.ac.uk, United Kingdom

 
Conventional “cine” cardiac scans were compared with threefold undersampled kt-BLAST acquisition in 6 healthy mice and one with myocardial infarct. Cardiological indices determined from the kt-BLAST acquisition agreed well with those from the standard cine sequence. End-diastolic LV volume was underestimated by 5%, end-systolic volume overestimated by 5% and ejection fraction underestimated by 4%. These differences are within the intra- and inter-observer variation expected in cardiac studies of mice. We conclude that accelerated mouse cardiac imaging is possible with acceptable accuracy for an acceleration factor of 3 times. The subsequent reduction in exposure to anaesthesia will contribute to animal welfare.

 
3848.   36 Respiration-Resolved Ventricular Function Evaluation Using a 5D Cardiac MRI Technique
Holden H Wu1,2, Dwight G Nishimura2, Michael V McConnell1,2, and Bob S Hu2,3
1Cardiovascular Medicine, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Palo Alto Medical Foundation, Palo Alto, CA, United States

 
Conventional MRI methods for evaluating cardiac function seek to suspend or counteract respiratory motion to avoid artifacts. However, in many disease states, including pericardial constriction and heart failure with preserved ejection fraction (HFpEF), it is precisely the changes in cardiac function associated with changes in respiration-induced intra-thoracic pressure that can reflect the pathophysiology. In this work, we employ a respiration-resolved 5D cardiac MRI technique in combination with controllable modulation of the intra-thoracic pressure to provide a more comprehensive assessment of ventricular function.

 
3849.   37 Cardiac function assessment without ECG using image-based navigation
Christoph Kolbitsch1, Daniel Giese1, Jouke Smink2, Claudia Prieto1, and Tobias Schaeffter1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Philips Healthcare, Best, Netherlands

 
Retrospectively cardiac-gated cine imaging is commonly used to analyse cardiac function. Self-navigation techniques exploiting signal amplitude changes due to blood flow in the acquired data avoid external ECGs. Nevertheless, they require detectable signals correlated to blood flow in each slice and synchronisation between different slices cannot be guaranteed. Here we propose to overcome this limitation by obtaining a navigator from 2D real-time images using a simultaneously excited second navigator slice. This yielded a cardiac gating signal used to resort data for cine imaging with an accuracy of 16ms compared to an external ECG and a variation of 8ms between slices.

 
3850.   38 Linking Myocardial Function and Structure through Tagged MRI and Diffusion Tensor Imaging
Carla S Gil1, Stephen D Meredith1, Adrianus J Bakermans2, Baastian J Nierop2, Gustav J Strijkers2, Hans C van Assen3, Niall C Colgan4, and Kathleen M Curran1
1School of Medicine & Medical Science, University College Dublin, Dublin, Ireland, 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 3Biomedical Image Analysis, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 4College of Medicine, Swansea University, Wales, United Kingdom

 
The aim of this study is to link cardiac functional and structural properties. Diffusion tensor imaging (DTI) is the best method to study myocardial fiber architecture, while tagged MRI is the best tool to measure local deformation of the myocardium. Here, we report for the first time, a preliminary study that aims at combining information of the myocardial fiber structure and its mechanical properties, such as circumferential, radial, shear and principal strains. Our analysis shows a correlation between left ventricular deformation and fiber architecture for normal datasets.

 
3851.   39 Cardiac Motion-Corrected Inversion Prepared Real-Time (“TIRT”) Cine TrueFISP Imaging for Rapid Myocardial T1 Estimation
Andreas Greiser1, Hui Xue2, Peter Schmitt1, Matthias Dieringer3,4, Florian von Knobelsdorff-Brenkhoff3,4, Thoralf Niendorf3,4, Jeanette Schulz-Menger3,4, and Edgar Mueller1
1Siemens AG, Healthcare Sector, Erlangen, Germany, 2Siemens Corporate Research, Princeton, New Jersey, United States, 3Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 4Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany

 
T1 mapping is promising for quantifying myocardial integrity. We propose a new method to rapidly (in 5 sec) map T1 in the heart based on an IR-prepared real-time Cine TrueFISP sequence combined with an elaborate motion correction. The method was validated against the established MOLLI technique in T1 phantom measurements as well as in vivo (n=10) and one myocardial infarction patient. Phantom results showed good match between methods. In vivo at 3T TIRT overestimated T1 by 12.9% pre and 17.7% post contrast, but with M0 and improved motion correction the method may become a valid alternative for myocardial T1 quantification.

 
3852.   40 Efficient 3D late gadolinium enhancement imaging using the CLAWS respiratory motion control algorithm
Jennifer Keegan1, Permi Jhooti2, Peter Drivas1, Sonya Babu-Narayan1, and David Firmin1,3
1Cardiovascular Magnetic Resonance, Royal Brompton Hospital, London, United Kingdom, 2Radiological Physics, University Hospital Basel, Basel, Switzerland, 3Imperial College, London, United Kingdom

 
Free-breathing late gadolium enhancement (LGE) studies are generally performed with diaphragmatic navigator gating which is inherently inefficient, particularly in the presence of respiratory drift. While the continuously adaptive windowing strategy (CLAWS) is highly efficient, changing the order of k-space coverage in response to the diaphragm position during gadolinium wash-out may potentially result in artefacts. We acquired CLAWS and end-expiratory accept/reject (EE-ARA) navigator gated 3D LGE studies in six patients. The respiratory efficiency was significantly higher for the CLAWS acquisitions and no k-space order related artefacts were seen. CLAWS is a suitable method of respiratory motion control free-breathing 3D LGE acquisitions.

 
3853.   41 Improved Method for Retrograde Gating for Cardiac Magnetic Resonance Imaging
Sohae Chung1, Pippa Storey1, and Leon Axel1
1Center for Biomedical Imaging, Radiology Department, NYU Langone Medical Center, New York, NY, United States

 
In the conventional retrospective gating method, the acquired data are typically interpolated onto equivalent equally spaced intervals by linearly scaling the data to fit into the average cycle. However, in the presence of R-R variation which largely reflects differences in the duration of diastasis, the usual linear time scaling used in conventional retrospective gating method will result in some temporal blurring and degradation of the image quality. In this work, we proposed a 'retrograde gating' method, which allows for retrospectively including the late diastolic events preceding each QRS detection in a fixed relation with the interval following it.

 
3854.   42 Cardiac MRI in Pediatric Patients with Congenital Heart Disease: Comparison at 1.5T and at 3.0T
Kim-Lien Nguyen1,2, Sarah N Khan3, John Moriarty3, Kiyarash Mohajer3, Pierangelo Renella3, Gary Satou4, Swati Patel5, Ines Boechat3, and Paul J Finn3
1Laboratory of Cardiac Energetics, NHLBI, Bethesda, MD, United States, 2Division of Cardiology, David Geffen School of Medicine at UCLA, United States,3Department of Radiology, David Geffen School of Medicine at UCLA, United States, 4Division of Pediatric Cardiology, David Geffen School of Medicine at UCLA, United States, 5Department of Anesthesiology, David Geffen School of Medicine at UCLA, United States

 
Widespread adoption of cardiac MR at 3.0T in the clinical setting has been slow. To the best of our knowledge, there have been no published reports on the use of 3.0T for the imaging in pediatric congenital heart disease. Our study demonstrates that cardiac MRI at 3.0T in pediatric patients with congenital heart disease and vascular abnormalities is feasible and compares the technical and diagnostic performance with an age-matched and clinically comparable control group at 1.5 T.

 
3855.   43 Isotropic whole-heart cine imaging with atlas-based segmentation
Declan P O'Regan1, Wenjia Bai2, Wenzhe Shi2, Giuliana Durighel1, Tamara Diamond1, Daniel Rueckert2, and Stuart A Cook1
1Robert Steiner MRI Unit, Imperial College London, London, London, United Kingdom, 2Department of Computing, Imperial College London, United Kingdom


 
3856.   44 Method for Investigating Respiratory Influence on Flow with Radial Trajectories
Ashley Gould Anderson III1, Eric Schrauben1, Kevin Johnson1, and Oliver Wieben1,2
1Medical Physics, University of Wisconsin, Madison, Wisconsin, United States, 2Radiology, University of Wisconsin, Madison, Wisconsin, United States

 
A flexible technique for evaluation of respiratory impact on cardiac-gated phase contrast flow acquisitions is proposed. The method is demonstrated for the case of 2D CSF flow imaging during free breathing in the spinal canal.

 
3857.   45 Left Atrial Volume Measurements Before and After Left Atrial Ablation for the Treatment of Atrial Fibrillation
Jerry Dale Walker, Jr.1, Sathya Vijayakumar2, Eugene Kholmovski2, Chris McGann1, Nathan Burgon3, Joshua Cates3, Alan Morris3, and Nassir Marrouche1
1Cardiovascular Division, University of Utah School of Medicine, Salt Lake City, Utah, United States, 2UCAIR Radiology, University of Utah, Salt Lake City, Utah, United States, 3CARMA Center, University of Utah, Salt Lake City, Utah, United States

 
This study evaluated left atrial (LA) volume measurements using cardiac magnetic resonance (CMR) based angiography before and after LA radio frequency (RF) ablation therapy as a treatment strategy for atrial fibrillation. This study employs the use of a novel software program ( Corview ) to accurately calculate left atrial volumes in patients who underwent CMR enhanced MR angiography. The Corview software program allows for segmentation and single slice analysis of individual MRA images. The segmentations were then used to compute the three-dimensional volume of the LA. LA volumes were then recorded at different time intervals to track for changes.

 
3858.   46 Simultaneous Evaluation of Blood and Tissue Velocities From Single VENC Phase-contrast MR Imaging
Junmin Liu1, James White1,2, and Maria Drangova1,3
1Imaging Research Laboratories, Robarts research Institution, The University of Western Ontario, London, Ontario, Canada, 2Division of Cardiology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada, 3Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

 
In this study we offer a unique approach to achieve simultaneous evaluation of tissue and blood flow velocities from a single low-VENC phase-contrast dataset (i.e. prescribed for measurement of tissue velocities). A novel phase unwrapping algorithm (PUROR) is tested for this purpose. The in vivo results demonstrate that the presented technique allows for simultaneous quantification of cardiac tissue and blood flow velocities within a single image acquisition.

 
3859.   47 Free Breathing Real-Time Functional Cardiac Imaging at 3 Tesla
Felix Schwab1, Florian Schwarz1, Olaf Dietrich1, Konstantin Nikolaou1, Carmel Hayes2, Maximilian Reiser1, and Daniel Theisen1
1Department of Clinical Radiology, University Hospital Grosshadern, Munich, Bavaria, Germany, 2Siemens Healthcare, Erlangen, Germany

 
Free breathing single-shot real-time protocols can be used for for functional cardiac imaging in cases of arrhythmia and when patients do not tolerate breath hold. This work investigate a volunteer study of several such protocols at 3 Tesla. Consistency with the gold standard cine protocols is found and SNR studies reveal significantly improved image quality as compared to 1.5 Tesla.

 
3860.   48 McKinnon-Bates Sparsification for Accelerated Phase Contrast Imaging
Andrew L Wentland1,2, Oliver Wieben1, Thomas M Grist2, and Kevin M Johnson1
1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States

 
Numerous procedures have been proposed in the literature to accelerate the acquisition of phase contrast (PC) data. However, these techniques require substantial reconstruction times and can have unpredictable artifacts and/or performance. We have explored sparsifying preprocessing techniques to provide relatively quick reconstruction of 2DPC data with very few projections. Initial results produced magnitude and velocity images of good quality with acceleration factors up to 30. Flow measurements in the processed images had good temporal fidelity and were consistent with measurements from unprocessed images. This algorithm may be useful for reducing the acquisition time of 2DPC data or improving temporal resolution.
 
Electronic Poster Session - Cardiovascular

MRA- Contrast & Non-Contrast
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  13:30 - 14:30

  Computer #  
3861.   
49 High Temporal and Spatial Resolution Imaging of Vascular Malformations of the Extremities
Petrice Marie Mostardi1, Phillip M Young2, Michael A McKusick2, and Stephen J Riederer1
1MR Research Laboratory, Mayo Clinic, Rochester, MN, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States

 
Choice of treatment and treatment planning for vascular malformations require accurate characterization of the vascular lesion including its structure, extent, and hemodynamics. The purpose of this work is to apply a recently developed time-resolved CE-MRA technique, CAPR, to perform high spatial and temporal resolution imaging of peripheral vascular malformations that allows for accurate lesion characterization and treatment planning. Twelve patients studies have been performed and imaging evaluation done, which show excellent diagnostic quality time-resolved imaging of vascular malformations of the upper and lower extremity.

 
3862.   50 Early corticosteroid treatment effects on MRI and Ultrasonography findings in Giant Cell Arteritis
Thorsten Alexander Bley1, Matthias Reinhardt2, Julia Geiger2, Michael Markl3, Andreas Hetzel2, Andrasz Treszl4, and Carolin Hauenstein2
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2University Hospital Freiburg,3Northwestern University, 4University Medical Center Hamburg-Eppendorf

 
Corticosteroids are the mainstay of treatment in Giant cell arteritis (GCA). High resolution MRI and color-coded duplex ultrasonography (CCDS) have proven feasible for non-invasive diagnosis of mural inflammatory changes in active GCA. This study indicates that for first-time diagnostic imaging in GCA the sensitive period of detecting univocal changes of inflammation is very short, potentially as short as one day. Therefore, CCDS or MRI examination of patients with suspected GCA should be performed as soon as possible, preferentially within the first day after onset of steroid treatment.

 
3863.   51 High Temporal Frame Rate 3D Spiral Head and Neck Magnetic Resonance Angiography: Initial Experience
Bo Xu1,2, Pascal Spincemaille2, Nanda Deepa Thimmappa2, Martin Prince2, and Yi Wang1,2
1Biomedical Engineering, Cornell University, Ithaca, New York, United States, 2Radiology, Weill Cornell Medical College, New York, New York, United States

 
Time resolved contrast enhanced intracranial MR angiography is particularly challenging because of the short arterial-venous time interval. In this work, a 3D spiral Temporal Resolution Acceleration with Constrained Evolution Reconstruction (TRACER) acquisition is presented resulting in a very high temporal frame rate head and neck MR angiogram.

 
3864.   52 Non-invasive planning of endovascular procedures in patients with peripheral arterial occlusive disease: value of 125 µm³ spatial resolution steady state MRA with a blood pool contrast agent
Winfried Albert Willinek1, Jack Boschewitz1, Dariusch Reza Hadizadeh1, Guido Matthias Kukuk1, Ute L Fahlenkamp1, Jürgen Gieseke1,2, Carsten Meyer1, Kai Wilhelm1, and Hans Heinz Schild1
1Radiology, University of Bonn, Bonn, NRW, Germany, 2Clinical Scientist, Philips Healthcare, Best, Netherlands

 
Steady state MRA (SSMRA) with blood pool contrast agents (BPCA) overcomes the limited spatial resolution in first pass imaging by offering a prolonged time window that allows for increased spatial resolution with improved sensitivity and specificity of stenosis grading in patients with peripheral arterial occlusive disease (PAOD). We investigated the usefulness of 125 µm³ spatial resolution SSMRA for non-invasive planning of endovascular procedures in critical limb ischemia (PAOD III-IV). 125 µm³ spatial resolution SSMRA improved the pre-interventional planning of endovascular procedures by allowing to correctly predict stent size and location of the intervention and, thus may influence therapeutic decision making.

 
3865.   53 Evolution of Image Quality in View-Shared Time-Resolved 3D CE-MRA
Casey P. Johnson1, Thomas W. Polley1, James F. Glockner1, Phillip M. Young1, and Stephen J. Riederer1
1MR Research Laboratory, Mayo Clinic, Rochester, MN, United States

 
In time-resolved 3D CE-MRA, incomplete view sharing will result in degradation of image quality. This has been observed in traditional imaging and new applications. The loss of image quality is dependent on the specific time-resolved sequence parameters used. In this work, the evolution of image quality as view sharing progresses is quantitatively assessed in phantoms and in vivo CE-MRA calf studies for various sequence parameters. A fundamental tradeoff between vessel signal and sharpness and its relation to the sequence temporal footprint is investigated. Implications for various applications are discussed.

 
3866.   54 Time-Resolved 3D Dynamic Contrast-Enhanced MR Angiography with Optimized Separate Auto Calibration Signal Lines
Yutaka Natsuaki1, Randall Kroeker2, Peter Schmitt3, J. Paul Finn4, and Gerhard Laub5
1Siemens Healthcare, Los Angeles, CA, United States, 2Siemens Healthcare, Winnipeg, Canada, 3Siemens Healthcare, Erlangen, Germany, 4Radiology, UCLA, Los Angeles, CA, United States, 5Siemens Healthcare, San Francisco, CA, United States

 
Time-resolved 3D (“4D”) dynamic contrast-enhanced MR angiography (DCE-MRA) offers combined anatomic and hemodynamic information with fractional Gd contrast doses. Time-resolved imaging with stochastic trajectories (TWIST) is a view-sharing technique that acquires the peripheral k-space region with lower density while acquiring central data with full sampling. With a conventional TWIST, auto-calibration signal (ACS) lines for the parallel MRI are integrated in every central data acquisition. In the current work, we propose to modify the conventional TWIST by using an optimized separate ACS lines to improve the image quality of the peak carotid artery enhancements.

 
3867.   55 Combined MRA and DCE perfusion imaging of the liver using an IVD acquisition and HYCR reconstruction with a single contrast injection
James H Holmes1, Kang Wang1, Mahdi S Rahimi2, Frank R Korosec3,4, Lauren A Keith4, Jens-Peter Kühn3,5, Scott B Reeder3,4, and Jean H Brittain1
1Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States, 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 3Radiology, University of Wisconsin-Madison, Madison, WI, United States, 4Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 5Department of Diagnostic Radiology, University Greifswald, Greifswald, MV, Germany

 
The current clinical standard of care currently requires separate DCE and MRA acquisitions to evaluate liver lesions and vasculature. New time-resolved imaging methods can produce a series of dynamic images with high temporal and spatial resolution. In this work we present a novel contrast enhanced imaging method to acquire both high resolution angiograms and high temporal resolution perfusion images of the liver in a single acquisition. This approach could eliminate the need for separate MRA and DCE injections and produces co-registered MRA and perfusion images to facilitate surgical and treatment planning.

 
3868.   56 Comparison of Diagnostic Image Quality of HYPR and TRICKS for Peripheral MRA Exams in Patients
Lauren Keith1, Mark Schiebler2, Chris Francois2, Scott Reeder2,3, and Frank Korosec1,2
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States

 
Peripheral vascular disease (PVD) is a prevalent condition and an important cause of morbidity. Non-invasive diagnostic imaging is used to plan for both surgical and percutaneous treatment of this disease. Challenges for MRA of the peripheral vasculature include the need for high spatial and temporal resolution. In this clinical investigation, we compare the diagnostic image quality of a method with high spatial and temporal resolution (VIPR-HYPR) with current clinical MRA techniques using DSA as reference standard. We hypothesize that VIPR-HYPR will provide similar or better image quality and that the improved temporal and spatial resolution will provide increased diagnostic confidence.

 
3869.   57 Dynamical evaluation of the longitudinal relaxation rate of blood after administration of gadobenate dimeglumine for optimzed SS-MRA
Fabio Tedoldi1, Cristina Neira1, Michele Anzidei2, Alessandro Napoli2, Miles Kirchin3, Fulvio Uggeri1, Beatrice Cavallo Marincola2, Fulvio Zaccagna2, Carlo Catalano2, and Roberto Passariello2
1Centro Ricerche Bracco, Bracco Imaging Spa, Colleretto Giacosa, Torino, Italy, 2Department of Radiological Science, University of Rome ‘la Sapienza’, Rome, Italy, 3Bracco Imaging SpA, Global Medical and Regulatory Affairs, Milan, Italy

 
Steady state magnetic resonance angiography (SS-MRA) following gadobenate dimeglumine administration has been shown to be feasible, but still not fully optimized. In this work we have first validated, in vitro, an inversion recovery gradient echo sequence for monitoring fast evolving phenomena and then use it to determine the longitudinal relaxation rate of blood after gadobenate dimeglumine injection in human subjects and to derive a tailored flip angle for SS-MRA with said gadolinium based agent. The benefits of using a calibrated flip angle in SS-MRA have been thus demonstrated in contrast enhanced imaging of carotid arteries.

 
3870.   58 Effect on Image Quality of Carotid Three-Dimensional MR-Angiography: 1.0 M Gadobutrol versus 0.5 M Gadoterate Meglumine at 3 Tesla scanner
RAYMOND LEE1, Gladys Lo Goh1, Kai Ming Paul Au Yeung1, CHI WAI LIU1, KA MAN CHAN1, and MEI LEE BETTY HUNG1
1Department of Diagnostic and Interventional Radiology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, China

 
Improvements in 3D CEMRA image quality are needed to achieve high diagnostic confidence. One approach to overcoming the limitations of CEMRA is the introduction of contrast agents with increased T1 relaxivity, which leads to higher vessel signal intensity. Previous studies showed contradictory results whether 1.0 M gadobutrol could improve image quality over 0.5 M gadolinium-based contrast, possibly because different anatomic regions were examined and study design. As far as the author knows, no previous study has compared the effect of 1.0M Gadobutrol versus 0.5 M Gadoterate Geglumine in carotid angiography by using a 3 Tesla MRI scanner. Current study may give an insight whether 1.0M Gadolinium-based contrast would improve the image quality in carotid MR angiography.

 
3871.   59 Steady-State Magnetic Resonance Angiography of the Thoracic Vasculature in Congenital Heart Disease using a Blood-Pool Contrast Agent: Evaluation of Two Different Techniques
Jennifer A Febbo1, Mauricio S Galizia1,2, Andrada R Popescu3, Xiaoming Bi4, Jeremy Collins1, Michael Markl1, Robert R Edelman2, and James C Carr1
1Department of Radiology, Northwestern University-Feinberg School of Medicine, Chicago, IL, United States, 2Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 3Department of Medical Imaging, Children's Memorial Hospital, Chicago, IL, United States,4Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States

 
Twenty-three adult patients with congenital heart disease were imaged with contrast-enhanced MRA using a blood-pool contrast agent. The protocol consisted of a first-pass (FP) MRA and two MRA sequences at the steady-state (SS) contrast phase (5-10 min after injection): inversion-recovery (IR) FLASH and IR-SSFP. Image quality, the presence of pathology, and aortic measurements in several vessels was recorded by two observers. There was no significant difference in aortic dimensions at all anatomic locations between FP-MRA and SS-MRA. Image quality scores were higher for SS-MRA compared to FP-MRA. More pathological abnormalities were seen with SS-MRA than FP-MRA.

 
3872.   60 Non-contrast-enhanced peripheral MRA using velocity-selective saturation preparation
Taehoon Shin1, Bob S Hu2, and Dwight G Nishimura1
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Palo Alto Medical Foundation, Palo Alto, CA, United States

 
We propose a new non-contrast-enhanced (NCE) lower leg MRA method which allows high artery-background contrast from a single 3D acquisition. The key component of the proposed method is a velocity-selective magnetization preparation at systole which saturates all tissues except arterial blood using high velocity selectivity. Unlike existing subtractive 3D methods, this new method removes the need for two acquisitions and is insensitive to elevated diastolic flow or arrhythmia unlike existing subtractive 3D methods. In-vivo tests on healthy volunteers show excellent depiction of arteries over a wide range of velocity-saturation bandwidths.

 
3873.   61 Non-contrast Enhanced Time-Resolved 4D MRA using Multi-bolus TrueSTAR
Lirong Yan1, and Danny JJ Wang1
1Neurology, UCLA, Los Angeles, CA, United States

 
Non-contrast time-resolved 4-D MR angiography (MRA) has been proposed recently by combining pulsed ASL with a segmented multi-phase trueFISP sequence (TrueSTAR). However, the SNR of dynamic MRA signal is limited and the labeled blood relaxes within a short duration following the labeling pulse. The present study proposes a novel multi-bolus TrueSTAR technique that employs a train of intermittent inversion pulses interleaved with multi-phase trueFISP acquisitions. The experimental data show that this technique can provide an enhanced and prolonged labeling bolus for dynamic MRA without sacrificing imaging speed or temporal resolution.

 
3874.   62 Clinical Validation of Non-Contrast Abdominal MRA with Quadruple Inversion-Recovery Prepared 3D b-SSFP
Iliyana Atanasova1,2, Ruth Lim2, Hersh Chandarana2, David Stoffel2, Mary Bruno2, Daniel Kim3, and Vivian Lee3
1Columbia University, New York, New York, United States, 2New York University, New York, NY, United States, 3The University of Utah, Salt Lake City, UT

 
An inflow-based non-contrast angiography sequence with quadruple inversion-recovery preconditioning and 3D b-SSFP readout (NC-MRA) has been developed for abdominopelvic MRA. We evaluate the diagnostic accuracy of this method for detection of aortoiliac disease in 21 patients using gadolinium-enhanced MRA (CE-MRA) as a reference standard. Two blinded radiologists rated image quality, disease severity, and artifacts on a per-segment basis. Image quality of CE-MRA was superior to NC-MRA; however, 97% of all evaluated non-contrast segments were judged diagnostic. Of all evaluable segments with CE-MRA available, overall accuracy/sensitivity/specificity of NC-MRA was 93%/75%/95% respectively, indicating good diagnostic accuracy of the non-contrast technique.

 
3875.   63 High Resolution Non Contrast-Enhanced MRA of the Hand and Forearm Arteries Using ECG-triggered Quiescent-Interval Single-Shot (QISS) Technique
Ning Jin1, Christopher Glielmi1, Xiaoming Bi1, Georgeta Mihai2, Eugene Dunkle3, Robert R Edelman3, Sven Zuehlsdorff1, Orlando P Simonetti2, and Sanjay Rajagopalan2
1Cardiovascular R&D, Siemens Healthcare, Chicago, IL, United States, 2Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States, 3Department of Radiology, NorthShore University Health System, Evanston, IL, United States

 
MRA of the forearms and hands is particularly challenging. There is a renewed interest in non contrast-enhanced (NCE) MRA techniques given the concerns of nephrogenic systemic fibrosis in patients with chronic kidney disease. Recently, QISS MRA technique has been implemented for imaging of the lower extremities and demonstrated to be rapid, easy to use, and insensitive to patient motion, heart rate and flow patterns. The purpose of this study was to investigate the feasibility of high resolution NCE-MRA of the hand and forearm arteries using the QISS technique.

 
3876.   64 High Acceleration Quiescent-Interval Single Shot Magnetic Resonance Angiography at 1.5 and 3T
Christopher Glielmi1, Maria Carr2, Xiaoming Bi1, Peter Schmitt3, Mauricio Galizia2,4, Judith Wood2, Robert R. Edelman4, Michael Markl2, James Carr2, and Jeremy Collins2
1Cardiovascular MR R&D, Siemens Healthcare, Chicago, Illinois, United States, 2Northwestern Memorial Hospital and Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States, 3MR Application & Workflow Development, Siemens AG, Erlangen, Germany, 4NorthShore University HealthSystem, Evanston, Illinois, United States

 
Quiescent-Interval Single Shot (QISS) is a non-contrast MRA technique with proven clinical utility as an alternative to contrast-enhanced MRA (CE-MRA) at 1.5T. 3T QISS can potentially provide improved image quality and enable higher acceleration factors. This study compares QISS at 1.5 and 3T with high acceleration factors in healthy volunteers. In addition, the diagnostic quality of QISS at 3T in patients with peripheral artery disease (PAD) was evaluated. Results show improved image quality at 3T, maintained vessel conspicuity at high acceleration factors, and clinical utility of 3T QISS in patients with peripheral artery disease.

 
3877.   65 Vessel-selective non-contrast enhanced time-resolved MR angiography using PULSER prepared 4D T1TFE in intracranial arteries
Masanobu Nakamura1, Masami Yoneyama1, Tomoyuki Okuaki1, Takashi Tabuchi1, Atsushi Takemura2, Makoto Obara2, Thomas Kwee3, Taro Takahara4, and Satoshi Tsutsumi5
1Yaesu clinic, Tokyo, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3University Medical Center Utrecht, Utrecht, Netherlands, 4Tokai University School of Engineering, Kanagawa, Japan, 5Juntendo University Urayasu Hospital, Chiba, Japan

 
We have proposed vessel - selective 3D volumetric non -contrast time- resolved MRA technique termed Contrast inherent inflow enhanced multi phase angiography ( v-sel CINEMA ). In this study the vessel selective PULSER preparation module was combined with a 4D T1 TFE readout that has previously been shown to generate time resolved MRA in healthy volunteers as well as in patients carrying cerebrovascular abnormalities. vsCINEMA could extract the blood flow in the whole brain at an interval of about 200 ms with a high degree of vessel specificity and showed good agreement compared to TOF-MRA and MR-DSA . vsCINEMA allows visualizing the dynamics of cerebral blood flow with high spatial and temporal resolutions. Patients carrying cerebrovascular pathologies such as AVM and moyamoya disease are good candidates for further investigations.

 
3878.   66 Non contrast enhanced 3D volumetric time-resolved MRA combining multiple phase pCASL(CINEMA-pCASL)
Masanobu Nakamura1, Masami Yoneyama1, Tomoyuki Okuaki1, Takashi Tabuchi1, Atsushi Takemura2, Makoto Obara2, and Taro Takahara3
1Yaesu clinic, Tokyo, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Tokai University School of Engineering, Kanagawa, Japan

 
Recently we have proposed 3D volumetric non -contrast time -resolved MRA technique termed Contrast inherent inflow enhanced multi phase angiography combining multiple phases pseudo -continuous arterial spin labeling (CINEMA -pCASL). CINEMA-pCASL was developed as a technique that enables diachronic observation of hemodynamic as in DSA and extensive 3D volume acquisition with the whole brain as a target. We present a preliminary study of CINEMA-pCASL sequence and discuss its clinical relevance.

 
3879.   67 Dynamic non-contrast enhanced Angiography based on Superselective Arterial Spin Labeling and Compressed Sensing
Michael Helle1, Mariya Doneva1, Matthias JP van Osch2, and Peter Börnert1
1Research Laboratories, Philips Technologie GmbH, Innovative Technologies, Hamburg, Hamburg, Germany, 2C.J. Gorter Center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

 
In the diagnosis of many cerebrovascular diseases highly resolved spatial and temporal images as well as vessel-selective information are required. Existing MR angiography techniques lack at least one of these demanded properties so that digital subtraction angiography (DSA) is still considered the gold-standard for cerebral angiography although the procedure is invasive and bears the risk of severe complications. In this study, superselective arterial spin labeling in combination with compressed sensing is employed to provide vessel-selective, temporally and spatially highly resolved angiograms with the potential to overcome limitations of existing MR methods and potentially provide the same information as with DSA.

 
3880.   68 Unenhanced MR Liver Circulation Imaging using a Triple Inversion Recovery ASL Technique
Marcelo E Andia1, and Rene M Botnar1
1Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, London, United Kingdom

 
Recently we have developed a new Arterial Spin Labeling technique without the need of subtraction based on the use of a triple inversion recovery pre-pulse. In this work we investigated the feasibility of selectively visualizing the portal vein, hepatic artery and hepatic vein in healthy subjects.

 
3881.   69 Intracranial microvascular imaging at 7T MRI : A comparison of the different RF coils
Myung-Kyun Woo1, Chang-Ki Kang1, Suk-Min Hong1, Kyoung-Nam Kim1, Joshua Park1, Hongbae Jeong1, Hongbae Jeong1, Hongbae Jeong1, Young-Bo Kim1, and Zang-Hee Cho1
1Neuroscience Research Institute, Gachon University, Incheon, Korea

 
The RF coil could contribute significantly to the quality of the intracranial microvascular imaging in ultra-high-field MRI. We have investigated several different types of RF coils and analyzed their relative performance in terms of SNR profiles and resolutions. The overlapped 6-channel coil exhibited highest performance, especially for angiographic imaging, due to its improved penetration depth, i.e., overall improved SNR.

 
3882.   70 Non-Contrast MRA of Pedal Arteries in Type II Diabetes: Effect of Disease Load on Vessel Visibility
Lijuan Zhang1, Na Zhang1, Weiqi Liao1, Xin Liu1, Yang Liu1, Dehe Weng2, Renate Jerecic3, Fei Feng4, Zhaoyang Fan5, and Debiao Li5
1SIAT, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 2Siemens Healthcare, China, 3Siemens Healthcare, 4Peking University Shenzhen Hospital, 5Cedars Sinai Medical Center, LA, USA

 
Non-contrast magnetic resonance imaging (NC-MRA) have attracted rising interest in peripheral artery imaging with the benefit of avoiding the risk of contrast induced nephropathy. However, it remains challenging to image the diseased peripheral arteries with NC-MRA especially in diabetic patients whose local and/or systemic disease load intrinsic to the diabetes may substantially complicated the overall vessel visibility. Exploration the effect of intrinsic disease load on the image quality of NC-MRA would help optimize candidate selection and disease management of diabetes in the clinical practice.

 
3883.   71 Evaluation of 3D Non-Rigid Algorithms for the Registration of the Lower Legs in MRA
Daniel Foley1, Barry Sheane1, Mark Knox1, Dearbhail O’Driscoll1, Niall Sheehy1, James F. Meaney1,2, and Andrew J. Fagan1,2
1Centre for Advanced Medical Imaging (CAMI), St. James's Hospital, Dublin, Ireland, 2School of Medicine, Trinity College, University of Dublin, Ireland

 
The use of a simple registration procedure has been shown to improve image quality in MR angiography images of the lower legs. The aim of this study was to investigate the use of more sophisticated registration algorithms designed specifically to deal with pre- and post-contrast signal intensity differences. Significant improvements using these algorithms were noted in a clinical evaluation of the diagnostic image quality, while contrast-to-noise ratios of the blood vessels were also significantly improved. Of concern was the observation that simple algorithms degraded the vessel integrity in the registered images, which could lead to mis-diagnoses of apparent stenoses.

 
3884.   72 Comparison between Breath-hold and Navigator-gated Magnetization-Prepared 3D Steady-State Free Precession for Nonenhanced Renal Magnetic Resonance Angiography
Huan Tan1, Ioannis Koktzoglou1,2, Christopher Glielmi3, Mauricio Galizia4, and Robert Edelman1,4
1NorthShore University HealthSystem, Evanston, IL, United States, 2The University of Chicago Pritzker School of Medicine, Chicago, IL, United States,3Siemens Healthcare, Chicago, IL, 4Northwestern University Feinberg School of Medicine, Chicago, IL

 
Nonenhanced, navigator-gated, inversion-prepared MR angiography technique (Nav SSFP) has proven accurate for evaluating the patency of renal arteries. However, the scan time of Nav SSFP can be excessive depending on breathing patterns. A highly efficient single-shot 3D SSFP technique was implemented to allow the full extent of the renal arteries to be depicted in a single breath-hold (BH SSFP). Overall, BH SSFP demonstrated comparable image quality, SNR and CNR in volunteers and patients despite a mean eight-fold reduction in scan time. The initial results suggested a potential supplementary clinical role for BH SSFP in the evaluation of suspected renal artery disease.
 
Electronic Poster Session - Cardiovascular

Myocardial Perfusion & Non-Contrast MRA
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  14:30 - 15:30

  Computer #  
3885.   49 Repeatability of quantitative first-pass perfusion MRI in the mouse myocardium
Bastiaan J. van Nierop1, Bram F. Coolen1, Wouter J.R. Dijk1, Larry de Graaf1, Klaas Nicolay1, and Gustav J. Strijkers1
1Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

 
The repeatability of quantitative, first-pass perfusion MRI in the healthy mouse heart was evaluated. A dual-bolus approach was used for accurate determination of the arterial input function (AIF). Direct experimental evidence from 28 pre-boluses showed that this approach results in an unsaturated AIF, by establishing linearity of the AIF signal intensity with Gd-DTPA concentration. Next, myocardial perfusion (ml/min/g) was quantified in 9 mice using a Fermi constraint deconvolution model. The repeatability was demonstrated by measuring perfusion at two time points. The resulting between-session coefficient of variation (11%) makes this method well-suited for longitudinal studies in mouse models of cardiac disease.

 
3886.   50 Variable-Density Spiral Adenosine Stress Perfusion Imaging Detects Coronary Artery Disease with High Diagnostic Accuracy
Michael Salerno1,2, Christopher T Sica3, Craig H Meyer4, and Christopher M Kramer5,6
1Internal Medicine, Cardiology, University of Virginia, Charlottesville, Va, United States, 2Radiology, University of Virginia, Charlottesville, VA, United States, 3Center for NMR Research, Penn State Hershey Medical Center, Hershey, PA, United States, 4Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 5Radiology, University of Virginia, Charlottesville, Va, United States, 6Internal Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States

 
We demonstrate that adenosine stress CMR using variable density spiral perfusion pulse sequences accurately detects obstructive coronary artery disease. These pulse sequences produce high quality perfusion images with minimal artifacts resulting in high diagnostic accuracy.

 
3887.   51 Quantitative Cardiac 17O MRI: Initial Validation Study
Jie Zheng1, David Muccigrosso1, Adil Bashir1, Pradeep Gupte2, and Robert J. Gropler1
1Washington University, Saint Louis, Missouri, United States, 2Rockland Technimed, Ltd, United States

 
Quantification of myocardial oxygen consumption using 17O-CMR was validated in this study using microsphere measurements and blood sampling in normal dogs. Further evaluation was performed in dogs with severe coronary artery stenosis. The oxygen consumption rates measured by 17O-CMR strongly agreed with reference values. Increases in oxygen consumption rate in severely ischemic regions reflect increased oxygen extraction to compensate substantial loss in oxygen supply, as expected.

 
3888.   52 Evaluation of semi quantitative perfusion parameter maps generated based on a fully automated non-rigid motion correction during a first pass myocardial perfusion (FPMP) MRI
Aya Kino1, Mauricio S Galizia1, Andrada R Popescu2, Rhaul Rustogi1, Darshit Thakrar1, Jeremy D Collins1, Christopher Glielmi3, Hui Xue4, Jens Guehring4, Sven Zuehlsdorff5, Daniel Lee6, and James Carr1
1Northwestern University, Chicago, IL, United States, 2Radiology, Children Memorial Hospital, Chicago, IL, United States, 3Siemens Healthcare, Siemens, 4Corporate Research USA, Siemens, Princenton, New Jersey, 5Siemens Healthcare, Siemens, Chicago, IL, 6Medicine Cardiology Division, Northwestern University, Chicago, IL

 
The purpose of this study is to evaluate semi quantitative perfusion parameter maps generated based on a fully automated non-rigid motion correction during a first pass myocardial perfusion (FPMP) MRI in patients with suspected coronary artery disease (CAD) or coronary micro vascular disease (CMVD)

 
3889.   53 Comparison of Cardiac Stress MR Perfusion Imaging With and Without Non-Rigid Motion Correction
Pamela K. Woodard1, Matthew R. Lyons2, Sven Zuehlsdorff3, Gary McNeal4, Agus Priatna4, Cylen Javidan-Nejad5, Ibrahim M. Saeed6, Hui Xue7, Christopher Glielmi4, and Robert J. Gropler5
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States, 2Cardiology, Case Western School of Medicine, Cleveland, Ohio, United States, 3Siemens Medical Solutions, Erlangen, Germany, 4Siemens Medical Systems, Malvern, PA, United States,5Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States, 6Cardiology, Saint Lukes Hospital, Kansas City, MO, United States, 7Siemens Corporate Research, Princeton, New Jersey, United States

 
A framework for non-rigid multimodal registration has been created and applied to compensate for distortions between EPI images and anatomical MRI volumes. Initially applied in brain MR imaging, this technique has now been applied to a cardiac perfusion sequence to be used with pharmacologic stress imaging. The implemented algorithm uses a key frame of the dynamic data set during the first pass of contrast agent as the reference frame. Subsequently, all other frames are registered using a nonrigid registration algorithm. Myocardial perfusion imaging was performed in patients with image reconstruction without and with motion correction. More perfusion defects were visible with motion correction than without.

 
3890.   54 Steady-state first-pass perfusion (SSFPP): A 3D "TWIST" in myocardial first-pass perfusion imaging
Shivraman Giri1, Hui Xue2, Abdul Wattar1, Yu Ding1, Randall Kroeker3, Gerhard Laub4, Peter Kellman5, Sven Zuehlsdorff6, Subha V. Raman1, and Orlando P. Simonetti1
1The Ohio State University, Columbus, OH, United States, 2Siemens Corporate Research, Princeton, NJ, United States, 3Siemens Healthcare, Winnipeg, Manitoba, Canada, 4Siemens Healthcare, San Francisco, CA, United States, 5National Institutes of Health, Bethesda, MD, United States, 6Siemens Healthcare, Chicago, Il, United States

 
We present a new approach to 3D myocardial first-pass perfusion imaging. The technique uses EKG-gated SSFP sequence such that data is acquired only during mid-diastole, whereas the magnetization is maintained in steady-state at other times. TWIST acquisition scheme is combined with GRAPPA to achieve the desired acceleration; the dynamic 3D frames were then motion-corrected using 3D non-rigid registration. Finally, pixel-wise contrast enhancement ratio (CER) images were generated to improve visualization.

 
3891.   55 Feasibility of Detecting Myocardial Ischemia Using First-Pass Contrast MRI and Regadenoson
Pamela K. Woodard1, Matthew R. Lyons2, Cylen Javidan-Nejad3, Ibrahim M. Saeed4, Donna Lesniak5, Gary McNeal6, Agus Priatna6, Sven Zuehlsdorff7, and Robert J. Gropler3
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States, 2Cardiology, Case Western School of Medicine, Cleveland, Ohio, United States, 3Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States,4Cardiology, Saint Lukes Hospital, Kansas City, MO, United States, 5Mallinckrodt Institute of Radiology, Washington University School of Medicine, St., Louis, MO, United States, 6Siemens Medical Systems, Malvern, PA, United States, 7Siemens Medical Systems, Erlangen, Germany

 
Cardiac stress MR perfusion imaging requires an MRI compatible infusion pump for the administration of adenosine or a non-MRI compatible pump housed in the control room or beyond the 10-Gauss line. This later method requires high-pressure extension tubing running for some distance across the control room and/or scan room floor. This has the potential to compromise both the quality of the examination and patient safety. Regadenoson is a recently FDA-approved A2A receptor agonist which can be given intravenously in a single 400 microgram bolus. We hypothesize that a single injection of regadenoson could be used instead of an adenosine infusion to produce coronary vasodilatation and demonstrate myocardial ischemia during first-pass perfusion cardiac MRI. Forty-four patient were imaged. All but one patient tolerated the regadenoson cardiac MR perfusion examination. Regadenoson can be used safely in cardiac MR perfusion imaging to demonstrate ischemia.

 
3892.   56 Spatiotemporal Filtering of Myocardial ASL Data: Implications in Detection and Diagnosis of Coronary Artery Disease
Terrence Jao1, Zungho Zun2, Padmini Varadarajan3, Ramdas Pai3, and Krishna Nayak4
1Biomedical Engineering, University of Southern California, Los Angeles, California, United States, 2Division of Radiology, Stanford School of Medicine, Stanford, California, United States, 3Division of Cardiology, Loma Linda University Medical Center, 4Electrical Engineering, University of Southern California

 
ASL is a promising technique for the quantification of myocardial perfusion and perfusion reserve in humans, ultimately for the diagnosis of coronary artery disease (CAD). The primary challenges are image misregistration and low signal to physiological noise ratio. Image registration and spatio-temporal filtering techniques can offset these setbacks. In this work, we evaluate how the choice of spatial filter parameters ultimately impacts the sensitivity and specificity of ASL myocardial perfusion reserve as a clinical tool for the diagnosis of CAD.

 
3893.   57 Free-breathing first-pass 3D perfusion imaging of the heart
Johannes F.M. Schmidt1, Lukas Wissmann1, Robert Manka1,2, Peter Boesiger1, and Sebastian Kozerke1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Cardiology, University Hospital Zurich, Zurich, Switzerland

 
Scan acceleration methods have proven invaluable for dynamic contrast-enhanced perfusion imaging. One practical issue, however, relates to the requirement of breathholding or shallow breathing which cannot always be ensured in clinical routine exams. An extended k-t PCA algorithm is proposed which corrects for non-rigid frame-to-frame motion based on motion operators derived from two pencil-beam navigators for feet-head and anterior-posterior motion detection and the fully sampled k-t training data. It is demonstrated that this approach successfully corrects for respiratory motion artifacts and hence enables free-breathing 3D cardiac perfusion MRI.

 
3894.   58 Uptake and Retention Maps for Myocardial Perfusion Analysis: Application in Duchenne Muscular Dystrophy
William Kerwin1, Anna Naumova1, Rainer Storb2, Stephen Tapscott2, and Zejing Wang2
1Radiology, University of Washington, Seattle, WA, United States, 2Fred Hutchinson Cancer Research Center, Seattle, WA, United States

 
The goal of this effort was to develop an intuitive, but physiologically meaningful method for quantifying myocardial perfusion by CMRI and to test the method on a dog model of Duchenne Muscular Dystrophy (DMD). The perfusion model characterized contrast kinetics using parametric maps of agent uptake and retention. Both parameters appeared to be altered in dogs with DMD compared to normal controls.

 
3895.   59 Absolute quantification of myocardial blood flow using CAMM estimation of the AIF
Jacob U Fluckiger1, Brandon C Benefield2, Kathleen R. Harris2, and Daniel C Lee2
1Radiology, Northwestern University, Chicago, Il, United States, 2Cardiology, Northwestern University, Chicago, Il, United States

 
In this work we present results using the constrained alternating minimization with model method for determining the arterial input function. This method estimates the input function directly from the myocardial tissue curves, using the LV blood pool signal as a constraint. The input function can then be used to quantify blood flow in compartmental analyses. We present preliminary work comparing this method with a dual bolus method using a microsphere validation.

 
3896.   60 Cine-ASL: new arterial spin labeling method for myocardial perfusion mapping in mice using a Cine-FLASH labeling and readout module
Thomas Troalen1, Thibaut Capron1, Monique Bernard1, Patrick Cozzone1, and Frank Kober1
1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS N°6612, Faculté de Médecine, Aix-Marseille Université, Marseille, France

 
This study presents a novel arterial spin labeling method to assess myocardial perfusion in small rodents. An ECG-gated steady-pulsed labeling approach is combined with simultaneous readout over the cardiac cycle using Cine-FLASH. Perfusion measurements were carried out on twenty mice with both techniques. Perfusion maps and values show good accordance between both experiments. This method allows shorter acquisition times than the previously used Look-Locker FAIR gradient-echo technique while preserving spatial resolution and robustness with respect to cardiac motion. In addition, the stationary regime offers the possibility to increase the signal to noise ratio by averaging over cardiac cycles.

 
3897.   
61 Comparison of Subtractive and Non-Subtractive Nonenhanced MR Angiography for Peripheral Arterial Disease: A Pilot Study
Emily Ward1, NavYash Gupta2, Eugene Dunkle1, Christopher Glielmi3, and Robert R. Edelman1,4
1Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States, 2NorthShore University HealthSystem, 3Siemens Healthcare,4Radiology, Northwestern University, Chicago, Illinois, United States

 
Nonenhanced techniques can be a useful alternative to contrast-enhanced MRA for patients with peripheral arterial disease. Both subtractive and non-subtractive approaches have been proposed. The purpose of this pilot study was to determine the relative merits and accuracy of the two types of nonenhanced approaches. Our data showed good sensitivity and excellent inter-observer agreement for PAD using either subtractive or non-subtractive nonenhanced MRA. In this pilot study, specificity and image quality were significantly better for QISS than Native SPACE, due to substantially reduced sensitivity to motion artifacts and lack of dependence on selection of trigger delays.

 
3898.   
62 Non-Contrast-Enhanced Flow-Independent 3D Peripheral Angiography with Sliding Interleaved Concentric Cylinders
Kie Tae Kwon1, Holden H. Wu1,2, Taehoon Shin1, Adam B. Kerr1, Dwight G. Nishimura1, and Jean H. Brittain3
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Cardiovascular Medicine, Stanford University, Stanford, CA, United States,3MR Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States

 
Non-contrast-enhanced flow-independent angiography (FIA) exploits intrinsic tissue parameters such as T1, T2 and chemical shift, and thereby generates stable vessel contrast even under slow-flow conditions in the lower extremities. Magnetization-prepared 3D SSFP sequences have been of interest for FIA, but an important challenge with these sequences is artery-vein contrast. In this work, a variation of SLINKY (Sliding Interleaved ky) acquisition was incorporated into a 3D concentric cylinders SSFP FIA sequence to improve artery-vein contrast in the lower extremities by suppressing the venous signal while retaining an arterial flow-independent approach.

 
3899.   63 Evaluation of a Non-Contrast-Enhanced MR Angiography method in PVD patients and comparison with TRICKS
Andrew Nicholas Priest1, Ilse Joubert1, Teik Choon See1, Andrew Philip Winterbottom1, Martin John Graves1, and David John Lomas1
1Department of Radiology, Addenbrookes Hospital and Cambridge University, Cambridge, United Kingdom

 
This study assesses the diagnostic performance of VANESSA, a new non-contrast-enhanced MRA technique, in patients with peripheral vascular disease, by comparison with our standard clinical contrast-enhanced protocol using TRICKS. The lower legs of 34 patients were imaged using both techniques, and two reviewers evaluated eight arterial segments for each dataset. The specificity and sensitivity for detection of significant disease (stenosis > 50%) were 75.6% and 91.4% when evaluated per segment, 89.7% and 72.7% when evaluated per limb and 97.6% and 44.4% when evaluated per patient. This method could be used to select patients for further investigation, reducing unnecessary Gadolinium administration.

 
3900.   64 Non-contrast enhanced 3D pulmonary MRA with vein-artery differentiation
Tzu-Cheng Chao1,2, Ming-Ting Wu3, Maria Alejandra Durán Mendicuti4, and Bruno Madore4
1Institute of Medical Informatics, National Cheng Kung University, Tainan, Taiwan, 2Department of Computer Science and Information Engineering, Naional Cheng Kung University, Tainan, Taiwan, 3Department of Radiology, Kaohsiung Veteran General Hospital, Kaohsiung, Taiwan, 4Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

 
Routinely-used pulmonary angiography methods, such as CTA and CE-MRA, require the administration of an intravenous contrast agent. These protocols are not generally suitable for subjectswith low renal function. A modified 3D slab-interleaved sequence is proposed here for non-contrast enhanced 3D pulmonary MRA. A retrospective ECG gated reconstruction with hybrid parallel imaging technique is introduced to accelerate the acquisition and to time-resolve the entire cardiac cycle. In addition to conventional vessel images, the proposed strategy can differentiate veins from arteries based on vessel pulsatility, to further facilitate the image interpretation.

 
3901.   65 Self-gated Free-breathing Non-contrast Renal MRA
Yibin Xie1,2, Zhaoyang Fan2, Rola Saouaf2, Yutaka Natsuaki3, Gerhard Laub3, and Debiao Li1,2
1University of California, Los Angeles, California, United States, 2Cedars-Sinai Medical Center, Los Angeles, California, United States, 3Siemens Healthcare, Los Angeles

 
Free-breathing bSSFP MR angiography with slab-selective inversion preparation has been successfully used in clinic to provide bright blood renal MRA without contrast. It typically uses regulated breathing, respiratory bellow, or pencil-beam navigators to alleviate breathing motion artifacts, all of which have practical issues limiting the usage of this technique. This work attempts to overcome these issues with a self-gating technique which uses the projections of the imaging volume to gate data acquisition. Preliminary results from volunteer studies showed comparable image quality versus conventional navigator-gating.

 
3902.   66 A non-linear subtraction method for MRA
Yongquan Ye1, Dongmei Wu2, and E.Mark Haacke1
1Radiology, Wayne State University, Detroit, MI, United States, 2Department of Physics, East China Normal University, Shanghai, China

 
We designed an interleaved-TR sequence for simultaneous flow rephased/dephased imaging. And by using subtraction method by self-squaring the images prior to the subtraction, not only the artery/tissue contrast is maintained or enhanced relative to linear subtraction, but also the venous signal is greatly reduced, generating MRA result with minimized venous contamination.

 
3903.   67 ECG-gated Fast Spin Echo MRA with Interleaved Acquisition of Systolic and Diastolic Data for Improved Robustness to Motion
Iliyana Atanasova1,2, Pippa Storey2, Daniel Kim3, Ruth Lim2, and Vivian Lee3
1Columbia University, New York, New York, United States, 2New York University, New York, NY, United States, 3The University of Utah, Salt Lake City, UT

 
In ECG-gated spin-echo based non-contrast MRA (FSE-MRA) bright blood angiograms are obtained by subtracting sequentially acquired systolic and diastolic images. This technique can provide excellent depiction of the arteries, but suffers from poor tolerance to patient motion. We hypothesize that interleaving the acquisition of systolic and diastolic partitions may improve robustness to motion. Our results demonstrate that it is feasible to implement FSE-MRA with systolic-diastolic interleaving. Results in one volunteer, instructed to perform controlled movements, suggest that the interleaved acquisition may be more robust to motion compared to a sequential scan.

 
3904.   68 Effect of prone vs. supine positioning and hydration on lower extremity venography
Moazzem Kazi1, Nanda Deepa Thimmappa1, Neil Khilnani1, Yi Wang1, and Martin R. Prince1
1Radiology, Weill Cornell Medical College, New York, NY, United States

 
Patients are normally imaged in the supine position and often dehydrated for MR venography of the lower extremity veins. The purpose of this study was to determine the effect of supine vs. prone positioning and hydration status on the common femoral vein luminal size. Our data indicates the importance of hydration for reducing underfilling of antedependent veins and repeating MR venography prone to distinguish physiologic underfilling from pathologic narrowing.

 
3905.   69 Non-contrast Enahanced MR angiography combined with peripheral cardiac gating at 3T: Comparison of respiratory triggered and breath held technique
Takayuki Masui1, Motoyuki Katayama1, Kimihiko Sato1, Kazuma Terauchi1, Kei Tsukamoto1, Masayoshi Sugimura1, Naoyuki Takei2, Mitsuharu Miyoshi2, Kenichi Mizuki1, and Harumi Sakahara3
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, 2Applied Science laboratory, GE Healthcare, Hino, Tokyo, Japan,3Radiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan

 
Non-contrast (NC) MRA with peripheral cardiac pulse gating (PG) using respiratory triggering (RT) or breath-held (BH) technique at 3T can be obtained in relatively short period time using ARC and fan beam k-space view ordering and well demonstrate the renal arteries and aorta due to suppression of systolic flow effects. Overall, RT NC MRA with PG provides better visualization of peripheral renal arteries with good background suppression. When image quality of RT NC MRA is not enough to evaluate arteries, BH NC MRA can be used as substitute.

 
3906.   70 A Simple Noncontrast FBI Technique for Peripheral Run-Offs: Development of Automatic Algorithm to Find Systolic and Diastolic Triggering Delays
Mitsue Miyazaki1,2, Naoyuki Furudate2, Jill S Chotiyanonta1, Akiyoshi Yamamoto3, and Katsumi Nakamura3
1MRI, Toshiba Medical Research Institute, Vernon Hills, IL, United States, 2Toshiba Medical Systems Corp., Otawara, Tochigi, Japan, 3Tobata Kyoritsu Hospital, Fukuoka, Japan

 
In noncontrast FBI run-off MRA, finding the systolic and diastolic ECG triggering delay times is an important factor to influence the resulting FBI images. A simple auto-ECG algorithm using heart rate was developed to determine the systolic and diastolic triggering delay times. The result of the auto-ECG and the manual ECG-prep method gives similar image quality in all 12 volunteers. In addition, the total operator examination time for three-station run-offs was tremendously improved using the auto-ECG.

 
3907.   71 Renal Artery MRA with Time-SLIP: Comparison Between a 3-T System Incorporating Multi-phase Transmission and a 1.5-T System
Kuninori Kobayashi1, Isao Miyazaki1, Ooto Makio1, Masamichi Imai2, Kenichi Yokoyama2, Kazuhiro Tsuchiya2, Mitsue Miyazaki3, Kenji Yodo4, Sachiko Isono4, and Toshiaki Nitatori2
1Radiology, Kyorin University Faculty of Medicine, Mitaka-shi, Tokyo, Japan, 2Department of Radiology, Kyorin University, Mitaka-shi, Tokyou, Japan,3MRI, Toshiba Medical Reser, Vernon Hills, IL, 4MRI, Toshiba Medical Systems Corp, Otawara, Tochigi

 
Non-contrast-enhanced MRA of the renal arteries with Time-SLIP using a 3-T MRI system incorporating Multi-phase Transmission was compared with that using a 1.5-T MRI system. In the 3-T system, the BBTI value at which the renal arteries were visualized out to their peripheral branches matched the BBTI at which the signal of the renal parenchyma reached the null point. The 3-T system incorporating Multi-phase Transmission was found to have superior visualization capabilities as compared to the 1.5-T system and was therefore judged to be of greater clinical usefulness.

 
3908.   72 Renal Transplant: Nonenhanced Magnetic Resonance Angiography with Quiescent-Interval Single-Shot
Pegah Entezari1, Mauricio S Galizia1, Christopher Glielmi2, Jeremy Collins1, Michael Markl1, Robert R Edelman3, and James C Carr1
1Department of Radiology, Northwestern University-Feinberg School of Medicine, Chicago, IL, United States, 2Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States, 3Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States

 
Patients with renal transplants were images with two non-enhanced MRA techniques: quiescent-interval single-shot (QISS) and steady-state free precession (SSFP) with inversion recovery. Image quality and diagnostic findings were recorded by two observers. There were no significant differences in terms of image quality between the methods. Both observers had one misdiagnosis each using the SSFP MRA as gold standard. QISS is a potential alternative for the imaging of patients with renal transplants when there is insufficient blood flow.
 
Electronic Poster Session - Cardiovascular

Flow: Quantification
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  13:30 - 14:30

  Computer #  
3909.   
73 Acceleration techniques for phase contrast flow quantification: a deal with the Devil?
Francesco Santini1
1Division of Radiological Physics - Institute of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland

 
Spatiotemporal acceleration techniques, while allowing high acceleration factors, increase the temporal footprint of each image, because every reconstructed frame contains information from neighboring images. In particular, higher framerates can give the illusion of better accuracy, while in fact leaving the actual information content unchanged. The purpose of this work is to recall the basic concepts of signal sampling and MRI acceleration applied to flow imaging, and to provide a general guideline to compare different acquisition/reconstruction methods in order to obtain the most efficient acquisition.

 
3910.   74 Reduction of Eddy Current-Induced Velocity Offsets in Phase Contrast MRI
Matthew J. Middione1,2, and Daniel B. Ennis1,2
1Department of Radiological Sciences, University of California, Los Angeles, CA, United States, 2Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States

 
Phase contrast MRI (PC-MRI) is subject to numerous sources of error including eddy currents, which decreases both quantitative accuracy and clinical confidence in the reported measures. A recently proposed PC-MRI protocol minimizes flow measurement errors arising from chemical shift effects. Herein we demonstrate that this same protocol reduces eddy current-induced velocity offsets to clinically acceptable levels (<0.6cm/s) for the ascending aorta and right and left pulmonary arteries as demonstrated in N=10 healthy subjects. Reductions for the pulmonary artery are also seen. The proposed PC-MRI protocol improves the accuracy and robustness of PC-MRI by reducing two significant sources of error.

 
3911.   75 Accurate method for measuring pulmonary artery pulse wave velocity by magnetic resonance imaging – mathematical proof and applications
El-Sayed H Ibrahim1
1Department of Radiology, University of Florida, Jacksonville, FL, United States

 
A new method (flow-time-area’(QTA)) is introduced for accurately measuring pulse wave velocity (PWV) in the pulmonary artery (PA). The method is based on the flow area(QA) method, yet is more robust to measurement errors as mathematically proved and demonstrated in a study on PA hypertension (PAH) patients and volunteers. Statistical analysis was conducted to compare the two methods under different operating conditions. The results were validated against standard non-MRI measurements in PAH. The QTA method always results in smaller or (at most) equal PWV errors than QA. Experimental results showed significant differences between the two methods in favor of QTA.

 
3912.   76 In-vivo distortion of through-plane flow by small off-resonance error in spiral phase-contrast imaging
Iain T Pierce1,2, Peter D Gatehouse1,2, and David N Firmin1,2
1NHLI, Imperial College London, London, United Kingdom, 2CMR Unit, Royal Brompton Hospital, London, United Kingdom

 
Spiral readouts are used due to their efficient coverage of k-space, but longer durations increase sensitivity to off-resonance. For spiral through-plane flow imaging, two sources of phase curvature over the vessel cross-section, velocity encoding and frequency off-resonance, can interact in a complex manner and cause in-vivo contraction and dilation artefacts of the vessel, distorting the velocity distribution and the peak velocity measurement.

 
3913.   77 Quantification of Pulse Wave Velocity From Phase-Contrast MRI Data Using Fourier Analysis
Nikhil Jha1, Wei Zha1, Himanshu Gupta2, Steven Lloyd2, and Thomas S Denney1
1Auburn University, Auburn, AL, United States, 2University of Alabama at Birmingham, Birmingham, AL, United States

 
Currently pulse wave velocity (PWV) is measured using the transit time between two corresponding points in respective velocity profiles. The coarse temporal resolution of PC-MRI and change in waveform shape make it difficult to calculate PWV reliably. A frequency domain approach to the measurement of transit time is presented where the Fourier transform of the velocity profiles are taken. The quotient of the two transforms have a linear phase characteristic where the slope is a function of transit time. This method was implemented and found to be more robust in response to changes in the measured velocity wave.

 
3914.   78 Evaluation of Wall Shear Stress in Spontaneously Hypertensive Rats by Phase-Contrast MRI
Shin-Lei Peng1, Hsu-Hsia Peng1, Tao-Chieh Yang2, Jee-Ching Hsu3, Yi-Chun Wu4, and Fu-Nien Wang1
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, HsinChu, Taiwan, 2Department of Neurosurgy, Chang Gung Memorial Hospital, TaoYuan, Taiwan, 3Department of Anesthesiology, Chang Gung Memorial Hospital, TaoYuan, Taiwan, 4Molecular Imaging Center, Chang Gung Memorial Hospital, TaoYuan, Taiwan

 
Wall shear stress (WSS) derived from phase-contrast MRI (PC-MRI), has been used to provide insights into the blood rheology. The vessels with atherosclerosis are of low WSS, and the hypertension is one of the risk factors for developing atherosclerosis. This study demonstrated the feasibility of WSS measurements in a rat model. The lower WSS in the bifurcation of common carotid artery (CCA) of spontaneously hypertensive rats (SHR) was measured when compared to the middle level of CCA. Furthermore, higher WSS was observed in the normotensive Wistar Kyoto (WKY) rats. It could be a potential technique for longitudinal research on atherosclerosis.

 
3915.   79 Feasibility of 4D Flow MRI of the Brain with y-z Radial Sampling and k-t SENSE: Comparison with 4D Flow MRI using SENSE
Tetsuro Sekine1, Yasuo Amano1, Ryo Takagi1, Yuriko Suzuki2, and Shinichiro Kumita1
1Radiology, Nippon Medical School, Tokyo, Japan, 2Philips Electronics Japan

 
4D Flow MRI velocity mapping, generated from time-resolved 3D phase-contrast imaging data, is available for the assessment of complicated flow pattern in cerebrovascular diseases. The main disadvantage of 4D Flow MRI is its lengthy scan time. We assessed the feasibility of@4D Flow MRI combined with two acceleration techniques, y-z radial sampling and k-t SENSE, by comparing with the standard 4D Flow MRI using SENSE. Y-z radial sampling was feasible for the quantification of peak systolic velocity and flow volume, whereas k-t SENSE was feasible for the 4D flow visualization.

 
3916.   80 Evaluating portal venous hemodynamics with 4D flow: how essential is the temporal dimension?
Benjamin R Landgraf1, Kevin M Johnson2, Christopher Francois1, Alejandro Roldan1, Oliver Wieben2, and Scott Reeder1,2
1Radiology, University of Wisconsin - Madison, Madison, Wisconsin (WI), United States, 2Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin (WI), United States

 
4D flow MRI has been shown effective in the assessment of the hemodynamics and morphology in portal hypertension. Rapid imaging approaches such as PCVIPR offer complete abdominal coverage with high spatial and temporal resolution in short scan times. Further reductions in scan time may be possible by exploiting the non-pulsatile nature of portal venous blood flow by time-averaging flow. The purpose of this study was to compare the accuracy of time-averaged versus time-resolved 4D flow MRI and to determine the degree of scan time reduction that can be achieved while maintaining high quality angiograms and accurate quantification of blood flow.

 
3917.   81 Modeling and Simulation Framework for Hemodynamic Assessment of Aortic Coarctation Patients
Kristof Ralovich1,2, Viorel Mihalef2, Puneet Sharma2, Lucian Itu3, Dime Vitanovski2, Razvan Ionasec2, Michael Suehling2, Allen Everett4, Giacomo Pongiglione5, Dorin Comaniciu2, and Nassir Navab1
1Computer Aided Medical Procedures, TU Munich, Munich, Germany, 2Siemens Corporate Research, Princeton, New Jersey, United States,3Universitatea Transilvania, Brasov, Romania, 4Johns Hopkins University, 5Ospedale Pediatrico Bambino Gesu, Rome, Italy

 
We present an integrated modeling and simulation framework for hemodynamic analysis of coarctation patients (post-stenting). 3D anatomical and 2D PC-MRI images are automatically processed to obtain the patient-specific anatomy and flow measurements, which are then used for performing patient-specific Computational Fluid Dynamics (CFD) simulations. A novel coupling of axi-symmetric 1D and 3D CFD unsteady simulations provides physiological boundary conditions for the overall simulation framework. As a first validation study, we compared the simulated and PC-MRI distal aortic flow rate in six patients. The promising initial results reiterate the potential of CFD simulations to provide assessment of post operative hemodynamics.

 
3918.   82 Quantification of net vorticity evolution in the left atrium
Prasanta Pal1, Ziheng Zhang1, Ben A. Lin2, Mitchel Stacy2, Donald Dione2, Albert J. Sinusas2, and Smita Sampath1
1Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, 2Internal Medicine Cardiology, Yale University School of Medicine, New Haven, Connecticut, United States

 
We have developed an EPI-based high temporal resolution phase contrast MR imaging pulse sequence. This sequence was used to acquire LA velocity data in two orthogonal directions on a 4-chamber slice. The velocity data with the application of appropriate data filters was used to quantify vorticity patterns in the left atrium (LA). We observed significant differences between the net vorticity of normal pigs and ~8 day post myocardial infarct pigs. We hypothesize that alterations in vorticity patterns may provide a quantitative tool to assess early changes in atrial function.

 
3919.   83 Cerebral Cine PC-MRI to Investigate Brain Hemodynamic Of Neonates With Transposition Of The Great Arteries Before And After Cardiopulmonary Bypass Surgery.
Malek I Makki1, Olivier Baledent2, Hitendu Dave3, Walter Knirsch4, Bea Latal5, Ianina Scheer6, and Cornelia Hagmann7
1MRI Research Center, University Chidlren Hospital, Zurich, Switzerland, 2Imagerie Medicale, CHU Nord Amiens, France, 3Congenital Cardiovascular Surgery, University Children Hospital Zurich, 4Cardiology, University Children Hospital Zurich, 5Child Development, University Children Hospital Zurich,6Diagnostic Imaging, University Children Hospital - Zurich, 7Neonatalogy, University Hospital Zurich

 
We applied 2D cine PC-MRI to investigate brain hemodynamic of 4 term neonates with TGA before and after CPB surgery along with 4 age-matched healthy neonates. Flows were bilaterally measured in the internal carotid, vertebral arteries and jugular veins and we combined left and right measures. We observed striking differences in the shape and peak values of the pre-surgical group compared to healthy controls both in systolic and diastolic period. We also reported significant changes in the arterio-venous flows of these patients following CPB surgery where the peak values at both systole and diastole resembled that of healthy controls.

 
3920.   84 Magnetic resonance assessment of the changes associated with portal hypertension in a rat model of portal vein stenosis
Philippe Garteiser1, Pierre-Emmanuel Rautou1,2, Sabrina Doblas1, Eric Frampas3, Safi Dokmak2, Richard Moreau1, Dominique Valla1,2, Ralph Sinkus1, Valerie Vilgrain3, and Bernard E Van Beers3
1CRB3 U773 Université Paris Diderot, Sorbonne Paris Cite, INSERM, Paris, 75018, France, 2Service of Hepatology, Hopital Beaujon, Clichy, France,3Service of Radiology, Hopital Beaujon, Clichy, France

 
Portal hypertension is the most important complication of chronic liver diseases and is a leading cause of mortality and liver transplantation worldwide. Yet reliable animal models are still lacking despite an important demand for a robust method enabling pharmacological tests. Here we report the use of Fourier flow MRI in the establishment of a robust rat model of portal hypertension.

 
3921.   85 Ferumoxytol Enhanced 2D & 3D Phase Contrast MRI in dialysis fistulas
Monica Sigovan1, Gabriel Acevedo-Bolton1, Petter Dyverfeldt1, Christopher Owens2, and David Saloner1
1Radiology, UCSF, San Francisco, CA, United States, 2Vascular Surgery, UCSF, San Francisco, CA, United States

 
Ferumoxytol is a very promising MRI contrast agent for medical applications in which Gadolinium agents are contra-indicated. The quality of Phase Contrast MR acquisitions can be improved with the use of Gd. In comparison, Ferumoxytol’s higher r2* relaxivity could potentially induce strong intravoxel dephasing leading to errors in flow measurements. The objective was to evaluate ferumoxytol’s effect on 2D and 3D PC-MR flow imaging by simulations, in vitro and in vivo imaging. We showed that if administered in relatively low concentrations, ferumoxytol does not affect the PC-MRI flow measurements. However, the velocity dependent effect on SNR needs to be considered.

 
3922.   86 Assessment of Blood Flow Hemodynamics of Liver Cirrhosis Patients after Treatment with a TIPS Stent-graft using a flow-sensitive 4D MRI Imaging at 3 Tesla
Zoran Stankovic1, Zoltan Csatari1, Bernd Jung1, Peter Deibert2, Elisabeth Panther2, Wulf Euringer1, Julia Geiger1, Wolfgang Kreisel2, Mathias Langer1, and Michael Markl3
1Radiology and Medical Physics, University Medical Center Freiburg, Freiburg, Ba.-Wü., Germany, 2Gastroenterology, University Medical Center Freiburg, Freiburg, Ba.-Wü., Germany, 3Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, Illinois, United States

 
Flow-sensitive 4D MRI provides complete volumetric and temporal coverage of hepatic venous and arterial hemodynamics in liver cirrhosis patients before and after TIPS-stent-graft implantation. Flow-sensitive 4D MRI provided a complete picture of pre- and post-interventional hepatic hemodynamics with additional information compared to Doppler US in liver cirrhosis after TIPS-stent-graft implantation. TIPS-stent-graft implantation resulted in altered hemodynamics and increased velocities and flow volume in the venous as well as hepatic arterial system. Compared to Doppler Ultrasound, maximum and mean velocities and vessel area tended to be lower in MRI while flow volume, resistance and pulsatility indices were similar.

 
3923.   87 Aortic Pulse Wave Velocity Evaluation in Normals and Heart Failure Patients
Yi Wang1,2, Jie J Cao1,3, Yang Cheng1, and Nathaniel Reichek1,3
1St. Francis Hospital, Roslyn, NY, United States, 2Biomedical Engineering, SUNY Stony Brook, Stony Brook, NY, United States, 3Cardiology, SUNY Stony Brook

 
Aortic pulse wave velocity is altered by normal aging, as well as vessel wall pathology. We evaluated aortic compliance and its relationship to age in normals and patients with heart failure.

 
3924.   88 Wavelet-Based Evaluation for the Thoracic Aorta Stiffness from CINE-MR Images
Abubakr El-Tahir1, Alain Lalande1, Marie Xavier1, Alexandre Cochet1, Nicolas Vignon1, Paul M. Walker1, Jean-Eric Wolf1, and François Brunotte1
1LE2I, UMR CNRS 5158, Dijon, Burgundy, France

 
A new method is proposed to evaluate the aortic stiffness and to detect abnormalities in its condition. The methods relies on cine MR images to monitor the aortic vessel and to observe the evolution of its cross sectional area at a given site over time. The variation of the area is then analyzed using the wavelet decomposition. The wavelet spectrum is used to classify patients with aortic disorders from healthy subjects. This method was tested on patients with Marfan syndrome and MYH11 mutation. Promising results was obtained in comparison with the commonly used stiffness measurements like compliance and pulse-wave-velocity.

 
3925.   89 Pulmonary Artery 4D Flow MRI in Normal Volunteers and Pulmonary Hypertension
Pegah Entezari1, Susanne Schnell1, Octavia Biris1, Jeremy D Collins1, Maria Carr1, Marie Wasielewski1, Jennifer McDonald1, Timothy J. Carroll1,2, James Carr1, and Michael Markl1,2
1Dept. of Radiology, Northwestern University, Chicago, Illinois, United States, 2Biomedical Engineering, Northwestern University, Evanston, Illinois, United States

 
This study evaluates the feasibility of 4D flow MRI for the assessment of 3D pulmonary flow characteristics in normal and hypertensive pulmonary arteries. The results of this pilot study demonstrate the feasibility of 4D flow MRI for the assessment of pulmonary flow characteristics and the ability to detect changes in PA flow compared to normal controls. Noticeably, patients with similar clinical presentation showed markedly different pulmonary 3D flow patterns indicating the potential of the methods to detect changes in pulmonary hemodynamics that may permit an improved characterization of the individual PAH severity.

 
3926.   90 Abdominal Aortic Aneurysm Causes Hemodynamic Abnormalities in the Iliac Arteries
Mamoru Takahashi1, Yasuo Takehara2, Haruo Isoda3, Naoki Ooishi2, Masaki Terada4, Tetsuya Wakayama5, Atsushi Nozaki5, Toshiyuki Shimizu6, Marcus Alley7, Naoki Uno2, Norihiko Siiya2, Norihiro Tooyama8, Katsutoshi Ichijo8, and Harumi Sakahara2
1Seirei Mikatahara General Hospital, Hamamatsu, Shizuoka, Japan, 2Hamamatsu University School of Medicine, 3Nagoya University School of Health Sciences, 4Iwata City Hosipital, 5GE Helthcare Japan, 6R's Tech Co, 7Stanford University School of Medicine, 8Seirei Mikatahara General Hospital

 
Low wall shear stress is known to cause atherosclerosis in the arterial wall. Hemodynamic patterns of the iliac arteries were assessed in two groups (i.e. dilated and undilated abdominal aorta) in terms of the patterns of streamlines and mean values of wall shear stress (WSS). As a result, abnormal flow dynamics such as vortex and/or turbulent flow occur in the abdominal aortic aneurysm (AAA) also affected the hemodynamics in the downstream iliac arteries, which reduced their WSSs.

 
3927.   91 Hemodynamic changes during arterio-venous fistula maturation. An MRI follow-up
Monica Sigovan1, Vitaliy Rayz1, Warren Gasper2, Christopher Owens2, and David Saloner1
1Radiology, UCSF, San Francisco, CA, United States, 2Vascular Surgery, UCSF, San Francisco, CA, United States

 

3928.   92 Quantification of 3D hemodynamics in large and giant intracranial aneurysms
Susanne Schnell1, Sameer A. Ansari2, Parmede Vakil1, Michael C. Hurley1, Bernard R. Bendok2, Hunt Batjer2, Timothy J. Carroll1,3, James Carr1, and Michael Markl1,3
1Dept. of Radiology, Northwestern University, Chicago, Illinois, United States, 2Dept. of Neurological Surgery, Northwestern University, Chicago, Illinois, United States, 3Biomedical Engineering, Northwestern University, Evanston, Illinois, United States

 
In patients with large and giant intracranial aneurysms, 4D-Flow-MRI was employed to characterize hemodynamics, WSS and vorticity patterns and their association with aneurysm location and morphology. Two distinct groups could be identified by comparing mean WSS and vorticity. Group 1 was characterized by saccular/spherical aneurysms with narrow high-flow channels, high and heterogeneous WSS and vorticity. Group 2 consisted of fusiform aneurysms with slow-flow regions and hardly defined flow channels as well as with low more homogeneous WSS and vorticity. Future longitudinal studies based on the measurement, analysis and visualization of intracranial aneurysms using 4D-Flow-MRI have the potential to correlate disease progression with regional hemodynamics; and may thus; improve risk stratification and interventional or surgical treatment planning.

 
3929.   93 Increased Growth with Eccentricity: 4D Flow evaluation of valve-related aortic disease
S. Jarrett Wrenn1, Monica Sigovan1, and Michael Hope1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, United States

 
Bicuspid aortic valve is a relatively common congenital anomaly and is associated with ascending aortic aneurysm. 4D Flow MRI has previously demonstrated unique systolic flow patterns in bicuspid valve patients. Here we examined ascending aorta growth rates in patients with bicuspid aortic valves and in tricuspid aortic valve controls, who were all studied with 4D Flow MRI. Abnormal flow patterns, assessed both qualitatively and quantitatively, correlated with more rapid ascending aortic growth. This suggests that 4D Flow MRI could be used to risk stratify bicuspid aortic valve patients with regards to the development of ascending aortic aneurysm.

 
3930.   94 Evaluation of 3D Blood Flow Patterns and Wall Shear Stress in the Normal and Dilated Thoracic Aorta using flow-sensitive 4D MRI.
Jonas Buerk1, Zoran Stankovic1, Philipp Blanke1, Alex Barker1, Maximiliam Russe1, Julia Geiger1, Mathias Langer1, and Michael Markl2
1Radiology and Medical Physics, University Hospital, Freiburg, Germany, 2Radiology and Biomedical Engineering, Northwestern University, Chicago, USA

 
Flow-sensitive 3-dimensional MRI was successfully used to visualize different flow patterns in aneurysms of the ascending aorta. 33 aneurysm patients, 15 age matched normal controls and 15 healthy volunteers were examined. The study shows that there is a significant relationship between vessel diameter in the AAo, AAo/DAo diameter ratio and the incidence and strength of irregular blood flow and altered vessel wall parameters. Our results contribute to our understanding of the mechanism involved in the development of ascending aneurysms. However, longitudinal follow-up studies are needed to correlate aneurysm growth rate or rupture risk with characteristics of flow pattern alterations noted in this study.

 
3931.   
95 In Vivo Four-Dimensional Flow Analysis of Mechanically Assisted Ischemic Cardiomyopathy
Jeremy R. McGarvey1,2, Walter R.T. Witschey2,3, Kevin J. Koomalsingh2, Norihiro Kondo2, Manabu Takebe2, Gerald A Zsido2, Melissa M. Levack2, Christen M. Dillard2, Kristina Lau2, Chun Xu2, Francisco Contijoch2, Alexander J. Barker4, Michael Markl5, Joseph H. Gorman1,2, Robert C. Gorman1,2, and James J. Pilla2,3
1Department of Surgery, University of Pennsylvania Health System, Philadelphia, PA, United States, 2Gorman Cardiovascular Research Lab, Harrison Department of Surgical Research, Glenolden, PA, United States, 3Department of Radiology, University of Pennsylvania Health System, Philadelphia, PA, United States, 4Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 5Department of Radiology, Northwestern University School of Medicine, Chicago, IL, United States

 
Development of ischemic cardiomyopathy is complex pathophysiologic process that is both challenging to describe and treat. Ischemic insult results in an increase in the zero-pressure volume (Vo) and residual volume, as defined by pressure-volume relationships and flow-sensitive 4D MRI respectively. A directed therapy that restores the V0 of the infarcted area has yet to be introduced or evaluated. We describe the flow changes associated with a novel epicardial active assist device. Using 4D flow-sensitive MRI, we have found that both systolic and diastolic flow is increased in the area adjacent to the infarct while being assisted, when compared to baseline.

 
3932.   
96 Wall Morphology, Hemodynamics and Wall Shear Stress in Peripheral Arterial Disease
Mauricio S Galizia1, Jennifer McDonald1, Marie Wasielewski1, Maria Carr1, Mary McDermott2,3, James C Carr1, and Michael Markl1,4
1Department of Radiology, Northwestern University-Feinberg School of Medicine, Chicago, IL, United States, 2Department of Preventive Medicine, Northwestern University-Feinberg School of Medicine, Chicago, IL, United States, 3Department of Internal Medicine, Northwestern University-Feinberg School of Medicine, Chicago, IL, United States, 4Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States

 
Twenty-three patients with peripheral artery disease were imaged with a multi-contrast plaque imaging protocol and with phase-contrast MRA. The plaque images were classified as normal or abnormal and divided in categories. Phase-contrast images were manually segmented and various flow parameters were calculated. Patients with plaques had lower total blood flow, peak wall shear stress (WSS), and average WSS. This technique has the potential to being able to investigate a direct connection between the presence and type of atherosclerotic plaques and changes in wall shear stress.
 
Electronic Poster Session - Cardiovascular

Cardiovascular MRI - General
Click on to view the abstract pdf and click on to view the video presentation. (Not all presentations are available.)
Wednesday 9 May 2012
Exhibition Hall  14:30 - 15:30

  Computer #  
3933.   73 Non-Contrast Enhanced Renal Artery Angiography with a Respiratory Triggered 3D balanced SSFP Sequence: Comparison of Optimized Repetitive Arterial or Vein Labeling (RAVEL) Method with and without T2prep
Kosuke Morita1, Tomohiro Namimoto2, Masanori Komi3, Masahiro Hashida3, Yasuyuki Yamashita2, and Yoshiaki Komori4
1Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, kumamoto, 1-1-1 honjo, Japan, 2Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 3Radiology, Kumamoto University, 4Philips Electronics Japan

 
The purpose of our study was to optimize imaging parameters of the respiratory-triggered Repetitive Arterial or VEin Labeling (RAVEL) method with selective inversion pulse for the renal arteries and to apply optimized non-contrast MR renal angiography for normal volunteers. Moreover, we evaluated the utility of T2prep to suppress a background signal for the RAVEL method.Non-contrast MRA using the respiratory-triggered RAVEL with 3D balanced SSFP was available to visualize renal arteries especially when the FA and TI were optimized. Furthermore, T2prep improves vessel/background contrast and image quality of the aorta and renal artery without the use of contrast media.

 
3934.   74 A New Approach for Time-Resolved Phase Contrast MRA
Jelena Bock1, Hans Burkhardt2, and Michael Markl3
1Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Computer Science, University of Freiburg, Freiburg, Germany,3Radiology and Biomedical Engineering, Northwestern University, Chicago, United States

 
In this study we present results for extraction of time-resolved 3D PC-MR angiography from PC-MRI data with 3-directional velocity encoding using fully automated feature based fuzzy clustering for dynamic aortic lumen segmentation. This approach was applied and evaluated in 11 healthy subjects and 12 patients with different cardiovascular pathologies. In all data, time-resolved PC-MRA demonstrated good vessel depiction in peak systolic time frames, with incomplete vessel extraction in early systole and diastole. Different pathologies had no influence on segmentation quality. In comparison to manual segmentation, this approach underestimated flow parameters; however, compared with rigid segmentation, flow parameters were determined more accurately.

 
3935.   75 Automated model-based assessment of the aortic root for optimal planning of TAVI procedures using CMRI – A comparison with manual measurements
Sabine Mollus1, Maximilian Pietsch1, Irina Waechter-Stehle2, Yang-Chul Boering3, Meike Schmidt3, Jason Foerst3, Sebastian Gruenig3, Mirja Neizel3, Burkhard Sievers3, Patric Kroepil4, Juergen Weese2, Jan Balzer3, and Malte Kelm3
1Philips Research, Aachen, Germany, 2Philips Research, Hamburg, Germany, 3Clinic for Cardiology, Pneumology and Angiology, University Hospital Duesseldorf, Germany, 4Department of Diagnostic and Interventional Radiology, University Hospital Duesseldorf, Germany

 
TAVI is a catheter-based intervention for high-risk patients with severe aortic valve stenosis. It is based on the replacement of the non-functioning valve by a stent-based prosthesis. Comprehensive, (MR) imaging-based planning is essential for TAVI device selection. Methods for automatic aortic valve planimetry can improve manual evaluations. For this purpose, we developed a MR-based model of the relevant anatomy. In this study, we compare model-based with manual measurements, evaluate the inter-operator variability and perform inter-modality comparisons between MR and CT. The results show that model-based automated aortic root measurements in MR correlate well with manual evaluations and with CT-based measurements. Thus, geometrical modelling proves to be an accurate and innovative technique for automatic aortic root planimetry.

 
3936.   76 Automated T2* Mapping with Susceptibility Removal for the Assessment of Cardiac Iron Content
Brian A. Taylor1, Ralf B. Loeffler1, Ruitian Song1, Mary E. McCarville1, Jane S. Hankins2, and Claudia M. Hillenbrand1
1Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States, 2Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States

 
Simultaneous T2* and field maps are calculated using an autoregressive moving average (ARMA) model on a cardiac multi-gradient echo acquisition. By using the field map, areas of high susceptibility are identified and removed for T2* quantification in the left ventricle. This can aid in precise T2* mapping for improved cardiac iron concentration assessment.

 
3937.   77 COMPARISON OF METHODS FOR THE ANALYSIS OF PHASE SENSITIVE INVERSION RECOVERY IMAGES IN THE ASSESSMENT OF MYOCARDIAL INFARCTION
Laura Fernandez-de-Manuel1,2, Haiyan Ding1,3, Maria J. Ledesma Carbayo2, Elliot McVeigh1, Andres Santos2, Aravindan Kolandaivelu4, and Daniel A. Herzka1
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States, 2Biomedical Image Technologies Lab., ETSI Telecomunicacion, Universidad Politecnica de Madrid and CIBER-BBN, Madrid, Spain, 3Department of Biomedical Engineering, Tsinghua University, Beijing, China, 4Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, MD, United States

 
Two-dimensional PSIR is a well established method of delineating scar in subjects with MI. Quantification of MI has been traditionally based on a threshold of more than 2 standard deviations (+2SD) above the mean of normal myocardial intensity. Newer alternative approaches with improved performance have yet to be applied to 3D PSIR imaging. In this work we compare different scar segmentation methods applied to a dataset of high-resolution 2D and 3D PSIR images from a swine model of MI. Proposed methods are based on Gaussian Mixture Model fitting and the Otsu algorithm, and are compared to the standard (+2SD).

 
3938.   78 Respiratory Triggered Retrospectively Cardiac Gated Cine Steady-State Free Precession (SSFP) Imaging
Amol Pednekar1, Ramkumar Krishnamurthy2, Claudio Arena3, Raja Muthupillai3, Benjamin Cheong3, and Debra Dees3
1MR Clinical Science, Philips HealthCare, Houston, TX, United States, 2BioEngineering, Rice University, Houston, Texas, United States, 3Radiology, St. Luke's Episcopal Hospital, Houston, Texas, United States

 
We propose a free breathing respiratory triggered multi-shot cardiac cine SSFP technique with a drive to steady state at each expiration phase and retrospective cardiac gating. Our initial evaluation in normal subjects shows that slice-by-slice LV volumes estimated using this free breathing technique are comparable to the LV volumes obtained using conventional, breath-hold cardiac cine SSFP techniques. The combination of respiratory triggering, multi-shot acquisition, and retrospective cardiac gating may make this approach particularly useful in patients with severely compromised breath holding capability and moderate arrhythmia. Further allowing high spatial and/or temporal resolution cardiac cine imaging.

 
3939.   79 Cardiac magnetic resonance in patients with antiarrhythmic devices .Image quality and diagnostic utility study.
Begoña Igual-Muñoz1, Vicente Martinez-Sanjuan2, JORDI ESTORNELL3, JOSE MONMENEU3, PILAR LOPEZ-LEREU3, ALICIA MACEIRA3, and Maria Jose Sancho-Tello4
1Cardiac image unit, ERESA, valencia, valencia, Spain, 2radiology, ERESA, valencia, valencia, 3TAC-RM, ERESA-HGUV, VALENCIA, VALENCIA, Spain,4Cardiology, Hospital universitari i politecnic la FE, Valencia, Valencia, Spain

 
Recent studies suggest that cardiovascular magnetic resonance (CMR) could be carried out in those patients with implanted antiarrhythmic devices (AAD), such as pacemakers (PM) or implantable cardioverter-defibrillators (ICD), with minimum risk both for the patient and for the AAD. CMR in this setting can be technically demanding and the signal loss and magnetic field inhomogeneity induced by the AAD may limit the diagnostic yield of this imaging technique. The aim of this study was 1) to assess the safety and diagnostic usefulness of CMR in patients with AAD, 2) to analyse which factors may affect image quality in these scans.

 
3940.   80 Diffusion tensor magnetic resonance imaging for the human heart with free breathing
Yuqing Huang1, Cong Zhao1, Jing An1, Zhiguo Sun1, and Dehe Weng1
1Siemens Shenzhen Magnetic Resonance Co. Ltd., Shenzhen, Guangdong, China

 
A STEAM single shot EPI sequence with two ECG triggers and respiratory motion correction was applied on the heart of a healthy volunteer to detect the cardiac fibre tracts. This method provides a useful tool to depict the myocardial structure under free breathing and may help us understand structural correlates of functional remodeling after heart disease.

 
3941.   81 Evaluation of the relationship between right ventricle mechanics and pulmonary artery vessel and flow dynamics in pulmonary artery hypertension by MRI
El-Sayed H Ibrahim1, and Abubakr A Bajwa2
1Department of Radiology, University of Florida, Jacksonville, FL, United States, 2Department of Medicine, University of Florida, Jacksonville, FL, United States

 
This study investigates the relationships between right-ventricle (RV)-related and pulmonary-artery (PA)-related parameters using MRI. A comprehensive MRI exam was developed for evaluating RV and PA, and tested on 25 PA hypertension(PAH) patients. Standard non-MRI measurements were collected. Comprehensive statistical analysis was conducted to study relationships between parameters, parameters’ significance, and data redundancy and reduction. The results showed strong correlations between most RV and PA parameters; and between most MRI parameters and PA pressure. There were redundancies between some within-group parameters. In conclusion, RV and PA are coupled and negatively affected in PAH. Both entities should be evaluated and interpreted together.

 
3942.   82 Cardiac MR Imaging and Technology Assessment: A randomized prospective comparison of Robotic Assisted versus Standard Catheter AF ablation
Aruna Arujuna1,2, Rashed Karim1, Aldo Rinaldi1,2, Michael Cooklin2, Mark O'Neill1,2, Kawal Rhode1, Tobias Schaeffter1, Jaswinder Gill1,2, and Reza Razavi1,2
1Imaging Sciences and Biomedical Engineering, King's College London, London, London, United Kingdom, 2Cardiology Department, Guy's &St Thomas' Hospital, London, London, United Kingdom

 
The recent few years has seen the emerging role of Cardiac MR Imaging in Atrial Fibrillation. In particular, delayed enhancement imaging following catheter ablation has allowed for areas within the left atrium following tissue injury to be visualized. There is a good correlation between scar quantification and clinical outcome. In this study we performed a randomized control clinical study using CMR to assess a novel robotic catheter ablating navjgation system and correlated CMR data to clinical outcomes.

 
3943.   83 Myocardial T2* Cut-Off Values Determined by Gaussian Mixtures Models
Taigang He1,2, Yanqiu Feng3, Rongrong Liu4, John-Paul Carpenter1, Andrew Jabbour1, Yongrong lai4, Dudley Pennell1, and David Firmin1,2
1CMR Unit, Royal Brompton Hospital, London, United Kingdom, 2NHLI, Imperial College, London, United Kingdom, 3School of Biomedical Engineering, Sourthern Medical University, China, 4Department of Hematology, The first affiliated Hospital of Guangxi Medical University, China

 
Cardiovascular magnetic resonance (CMR) T2* can provide a non-invasive means of measuring tissue iron in the heart. We have found that T2*< 20ms represents iron overload in the heart, and that T2*<10ms predicts risk of heart faliure in patients with thalassemia major. In this study, we aimed at clustering patients automatically into normal and abnormal groups by using Gaussian mixture models. This study confirms statistically that T2* is a reliable tool for screening patients with iron overload. The results agree well with T2* cut-off value of 20ms and 10ms commonly used in clinical practice.

 
3944.   84 Correlation Between Left Atrial Volume Changes And Percentage Scar Measured 3-months Post RF Ablation
Sathya Vijayakumar1,2, Jerry Walker2,3, Eugene Kholmovski1,2, Nathan Burgon2, Alan Morris2, Josh Cates2, Chris J McGann2,3, and Nassir F Marrouche2,3
1UCAIR, Dept. of Radiology, University of Utah, Salt Lake City, Utah, United States, 2CARMA Center, University of Utah, Salt Lake City, Utah, United States,3Dept. of Cardiology, University of Utah, Salt Lake City, Utah, United States

 
The aim of this study is to evaluate LA volume measurements using CMR based angiography before and after left atrial RF ablation therapy as a treatment strategy for atrial fibrillation (AFIB) and see how it correlates with the percentage of scar formed 3 months post ablation. We hypothesize that a greater scar percentage obtained at 3 months post procedure would lead to a greater change in volume of the LA (computed as LA volume measured at different time points, normalized by the pre-ablation LA volume).

 
3945.   85 Fluorine-19 magnetic resonance imaging in a mouse model of atherosclerosis
Ruud B van Heeswijk1,2, Maxime Pellegrin3, Lucia Mazzolai3, Ulrich Flögel4, Juerg Schwitter5, and Matthias Stuber1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Service of Angiology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, 4Institute for Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, Germany, 5Center for Cardiac Magnetic Resonance and Cardiology Service, University Hospital of Lausanne (CHUV), Lausanne, Switzerland

 
A perfluorocarbon emulsion was intravenously administered in ApoE-knockout mice. Next, fluorine-19 MRI was performed multiple times after injection in order to quantitatively determine the time course of perfluorocarbon uptake in regions where atherosclerotic plaques often occur. The signal-to-noise ratio (SNR) at these locations reached an optimum of ~10 at 6-8 days after injection.

 
3946.   86 Feasibility of 5-Minute Comprehensive Cardiac MR Examination Using Highly Accelerated Parallel Imaging and Compressed Sensing
Jian Xu1,2, Li Feng1, Ricardo Otazo1, Alicia Yang1, Kai Tobias Block1, Barbara Srichai1, Ruth Lim1, Kelly Anne Mcgorty1, Joseph Reaume1, Leon Axel1, Yao Wang3, and Daniel Sodickson1
1Center for Biomedical Imaging, Radiology,New York University, New York, NY, United States, 2PolyTechnic Institute of New York University and Siemens Medical Solutions USA Inc., New York, NY, United States, 3Polytechnic Institute of New York University, New York, NY, United States

 
The newly developed radial k-t SPARSE SENSE (RASPS) technique make it possible to further speed up the acquisition and increase the coverage with high temporal/spatial resolution without sacrificing SNR. In this study, we have incorporated dynamic 4D stack-of-star hybrid radial acquisitions with RASPS into this 5-min protocol, and the results of comparisons between RASPS and the previous approach using GRAPPA/TGRAPPA (PAT) for PERF, CINE and LGE imaging are presented.

 
3947.   87 Late gadolinium enhancement imaging with dynamic_TI in the atrial fibrillation population
Jennifer Keegan1, Peter Gatehouse1, Sonya Babu-Narayan1, Ricardo Wage1, Shouvik Haldar2, and David Firmin1,3
1Cardiovascular Magnetic Resonance, Royal Brompton Hospital, London, United Kingdom, 2Cardiology, Royal Brompton Hospital, London, United Kingdom,3Imperial College, London, United Kingdom

 
An adaptive inversion recovery preparation (dynamic_TI) was implemented to improve late gadolinium enhancement imaging in patients with variable RR intervals. Three-D data were acquired in phantoms and 2D data were acquired in 5 patients with atrial fibrillation. We demonstrate that dynamic adaptation of the inversion time for each cardiac cycle is feasible and can result in less ghosting, improved nulling of normal myocardium and increased blood-myocardium contrast-to-noise ratio. Application to 3D studies in the atrial fibrillation population should result in fewer inadequate studies.

 
3948.   88 Inflow Inversion Recovery Steady State Free Precession with Tracking Navigator
Yuji Iwadate1, Anja C.S. Brau2, Naoyuki Takei1, and Hiroyuki Kabasawa1
1Global Applied Science Laboratory, GE Healthcare Japan, Hino, Tokyo, Japan, 2Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States

 
Inflow inversion recovery steady state free precession (IFIR FIESTA) with respiratory triggering is a free-breathing 3D technique for renal MR angiography without contrast agent. We propose a new respiratory triggered IFIR FIESTA technique which adds navigator echoes dedicated for slab tracking to compensate motion at image acquisition timing. The new method improved delineation of the arteries with an inconsistent breather whose end-expiration position varied between imaging periods.

 
3949.   89 MR compatible Doppler-ultrasound device to trigger the heart frequency in Cardiac MRI: comparison to ECG
Ulrike Wedegaertner1, Jin Yamamura1, Björn Schönnagel1, Chressen Much1, Claus Valett1, and Gerhard Adam1
1Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Hamburg, Germany

 
In this study a MR compatible Doppler-ultrasound device was developed to trigger the heart frequency during cardiac MR imaging. A commercially available ultrasound transducer was modified, so that the heart beat could be recorded during the whole scanning time without any artifacts. Cardiac MRI was performed using the novel MR compatible Doppler-ultrasound and conventional ECG for triggering. There was no difference between both methods in the evaluation of anatomical structures and functional information. The MR compatible Doppler-ultrasound device might be faster and easier in the application compared to ECG.

 
3950.   90 High spatio-temporal resolution retrospectively triggered CINE imaging for measuring diastolic function in mice
Bram F Coolen1, Desiree Abdurrachim1, Abdallah GA Motaal1, Klaas Nicolay1, Gustav J Strijkers1, and Jeanine J Prompers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

 
This study presents the use of retrospectively triggered CINE MRI for high spatio-temporal resolution diastolic function measurements in mice. A temporal resolution < 2 ms could be reached allowing accurate determination of the E and A diastolic filling rates. Using this technique, subtle reductions in diastolic function were observed in diabetic db/db mice compared to non-diabetic db/+ mice.

 
3951.   91 Fat Imaging and Suppression Techniques and Applications for Cardiac MRI
Karl K. Vigen1, Christopher J. Francois1, Scott K. Nagle1,2, Mark L. Schiebler1, and Scott B. Reeder1,3
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States,3Medical Physics, Biomedical Engineering, and Medicine, University of Wisconsin-Madison, Madison, WI, United States

 
Suppression or direct imaging of fat in and around the heart is potentially useful for imaging several pathologies. Fat can be suppressed with techniques such as chemically-selective fat suppression, STIR, and triple-IR imaging. Direct fat visualization can be performed with chemically selective water suppression and chemical shift based water-fat separation methods. Applications for fat suppression and imaging include evaluation of chronic myocardial infarct and cardiac masses as well as improved visualization of structures such as the coronary arteries and pericardium.

 
3952.   92 Review and Analytical Discussion of Cardiac Segmentation
Esmeralda Ruiz Pujadas1, and Marco Reisert1
1Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, Germany

 
Segmentation of the myocardium gives valuable information for the the diagnosis and treatment in cardiac pathologies. Manual segmentation is a very tedious and time consuming task. Therefore, an automatic procedure is desirable. But the myocardium detection is very challenging due to the low heterogeneous and discontinuous myocardium, the presence of papillary muscles or the tissues surrounding the myocardium. For that reason, the problem remains open. We will make an overview of the methods applied in medical segmentation and discuss their limitations. After that, an analysis of the methods will be presented.

 
3953.   93 Pitfalls of using T2Weighted Imaging for Visualizing Myocardial Edema using CMR
Ramkumar Krishnamurthy1, Amol Pednekar2, Benjamin Cheong3, Claudio Arena3, and Raja Muthupillai3
1BioEngineering, Rice University, Houston, Texas, United States, 2Philips HealthCare, 3Radiology, St. Luke's Episcopal Hospital, Houston, Texas, United States

 
In this animal study, we study the effect of different T2 weighting on determination of the area at risk (AAR) in cardiac black-blood T2 weighted images. After LAD occlusion in five pigs, black blood images of short axis at different T2 weightings were obtained and AAR were determined as regions with signal intensity greater than ‘mean + 2,3 and 4 SD ‘ of remote myocardium. Significant differences in AAR were observed with different quantifying metrics as well as T2 weighting. A significant overlap of absolute T2 values were also observed.

 
3954.   94 Cardiac MRI in Mice @ 11.7T: Comparison of a 4-Element Array Coil and a 2-Element Cryo Coil
Volker Rasche1,2, Bornstedt Axel1, and Ina Vernikouskaya1,2
1Experimental Cardiovascular Imaging, University of Ulm, Ulm, Germany, 2Small Animal MRI, University of Ulm, Ulm, Germany

 
High-resolution imaging of the mouse heart is still limited by the SNR. In this contribution, a cryogenic 2-element coil is evaluated for possible SNR improvements in the mouse heart. It is shown that in direct comparison to measurements with a four-element cardiac array coil an SNR gain between 2.65 and 2.95 can be realized in the mouse heart.

 
3955.   95 A Local Static Magnetic Field Confines Implanted Stem Cells in Targeted Regions and Improves Their Therapeutic Efficacy for Heart Failure
Jian Wang1, Fei Wang2, Bo Xiang2, Jixian Deng2, Chris Stillwell2, Hung-Yu Lin2, Marco Gruwel2, Chun-Te Ko2, Boguslaw Tomanek2, Mike Sowa2, Tarek Kashour2, Darren Freed2, Rakesh Arora2, and Ganghong Tian2
1National Research Council, Winnipeg, Manitoba, Canada, 2National Research Council

 
Cell therapy holds a great promise for curing of various degenerative diseases, including congestive heart failure (CHF). However, both animal and human studies showed very marginal benefits of cell therapy. Lack of strategies to confine implanted stem cells in a targeted region may underlie the limited efficacy observed in cell therapy. This study was to determine whether an externally applied static magnetic field (SMF) increase the retention of superparamagnetic iron oxide (SPIO)-labeled cells in a targeted organ and then improve efficacy of cell therapy.

 
3956.   96 Evaluation of Parallel Reconstruction Techniques for First-pass Perfusion Imaging Using Spiral Trajectories
Yang Yang1, Xiao Chen1, Xue Feng1, Meihan Wang1, Frederick Epstein1,2, Craig Meyer1,2, and Micheal Salerno2,3
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

 
We evaluate the performance of the spiral PILS, SPIRiT and CS reconstruction techniques for the spiral first-pass myocardial perfusion imaging at acceleration factor 2 and 4 by downsampling the full acquired clinical data. We find that at lower acceleration factor, all the techniques work well while at the higher acceleration rate, images reconstructed by CS with finite-difference in time have similar SNR and image quality to the fully sampled images and may have a SNR advantage compared to other parallel imaging techniques.