Traditional Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Unenhanced MRA

Tuesday May 10th
Exhibition Hall  13:30 - 15:30

1276.   A Comparison Between Ankle-Brachial Index and Quiescent-Interval Single Shot Non-Enhanced MRA for the Evaluation of Hemodynamically-Significant Peripheral Arterial Disease  
Emily V.M Ward1,2, Asad A Usman2, Philip A Hodnett3, James C Carr2, and Robert R Edelman1
1Department of Radiology, Northshore University HealthSystem, Evanston Hospital, Chicago, Illinois, United States, 2Department of Radiology, Northwestern Memorial Hospital, Chicago, Illinois, United States, 3Department of Radiology, NYU Langone Center, New York, New York, United States

Our objective was to determine whether a rapid, non-contrast MRA technique might provide superior accuracy to ABI and reduce the need for additional imaging procedures prior to a revascularization procedure. Using CE-MRA as the reference standard, the sensitivity and specificity of ABI and non contrast QISS MRA for 50% or greater stenosis or occlusion was determined. Compared with ABI, QISS MRA provides higher accuracy for clinically relevant PAD and substantially reduces the requirement for additional imaging prior to a revascularization procedure. It has the potential to be an alternative screening examination to ABI for selected patients with PAD.

1277.   Non Contrast Enhanced (NCE)-MRA of the Renal Transplant Vessels: A comparison between IFIR and VIPR-SSFP 
Eric M Bultman1, Jessica Klaers2, Christopher J François3, Mark L Schiebler3, Scott B Reeder1,3, and Walter F Block1,2
1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Radiology, University of Wisconsin-Madison, Madison, WI, United States

The development of NCE-MRA methods to visualize the renal transplant vessels remains of tremendous clinical importance. In this retrospective study, we investigated the MR angiographic performance of a 3D radial sequence (VIPR-SSFP) compared to an inflow-weighted technique (IFIR) known to provide excellent visualization of the renal arteries. After identifying 21 renal transplant patients who received VIPR-SSFP and IFIR scans, two practicing radiologists scored these patients’ images on several criteria reflecting angiographic quality. Results demonstrate that VIPR-SSFP provides superior visualization of the renal veins and improved fat suppression, while IFIR provides somewhat superior visualization of the renal arteries.

1278.   Peripheral angiography using non-contrast enhanced NATIVE SPACE MRI at 3T. A feasibility study in a clinical setting 
Elise Bannier1,2, Isabelle Corouge1,2, Nicolas Wiest-Daesslé1,2, Delphine Pelletier3, Pierre-Axel Lentz3, Antoine Larralde3, Bernard Langella3, Nashiely Pineda Alonso4, Jean-François Heautot3, and Valérie Croisé-Laurent3,5
1Neurinfo Platform, University Hospital of Rennes, Rennes, France, 2INRIA, VisAGeS Project-Team, Rennes, France, 3Radiology Dept., University Hospital of Rennes, Rennes, France, 4Siemens Healthcare, Paris, France, 5Laboratoire IADI INSERM 947, CIC IT INSERM 807, University Henri Poincaré, Nancy, France

The aim of the study was to assess and quantify the ability of non contrast enhanced MRI to image peripheral vasculature and detect vascular abnormalities using an ECG-gated 3D T2 TSE NATIVE SPACE sequence in a 3T clinical setting.

1279.   Diagnostic Quality Assessment of the bSSFP Dixon Method for NCE MRA 
Randall B. Stafford1,2, M. Louis Lauzon2,3, Mohammad Sabati4, Linda B Andersen2,3, Houman Mahallati2,5, and Richard Frayne2,3
1Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada, 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada,3Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada, 4Department of Radiology, University of Miami, Miami, Florida, United States,5Department of Radiology, University of Calgary, Calgary, Alberta, Canada

This study compares the diagnostic quality of angiograms produced with traditional contrast-enhanced (CE) MRA and the bSSFP Dixon method for non-contrast-enhanced (NCE) MRA. Eight patients with clinically indicated CE renal MRA underwent the NCE examination a week later. A vascular radiologist scored the image quality from various renal artery segments from both examinations.

1280.   Non-contrast-enhanced Flow-independent Peripheral Angiography using a 3D Concentric Cylinders Trajectory 
Kie Tae Kwon1, Holden H Wu1,2, Taehoon Shin1, Tolga Çukur3, and Dwight G Nishimura1
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Cardiovascular Medicine, Stanford University, Stanford, CA, United States, 3Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA, United States

Non-contrast-enhanced flow-independent angiography (FIA) exploits intrinsic tissue parameters such as T1, T2 and chemical shift to generate vessel contrast. FIA can generate stable vessel contrast even with slow flow potentially in the diseased leg. Magnetization-prepared 3D SSFP sequences have been of interest for FIA, but an important issue with these sequences is artery-vein contrast. Recently, an efficient and robust 3D SSFP imaging sequence using a concentric cylinders k-space trajectory was developed. In this work, the 3D concentric cylinders trajectory was incorporated into a T2-prepared SSFP FIA sequence for scan-time reduction that can be traded off to improve the artery- vein contrast in the lower extremities.

1281.   3D-Rotational Phase-Contrast MR Angiography 
Axel Bornstedt1, Eberhard Hansis2, Michael Grass3, Wolfgang Rottbauer1, and Volker Rasche1
1Internal Medicine II, University Hospital Ulm, Ulm, Germany, 2Philips Healthcare, 3Philips Research Europe

The acquisition of high resolution phase-contrast angiography is still limited by the long acquisition times. Considering the sparseness of the vascular structures, three-dimensional reconstruction techniques applied to X-ray angiography may be translated to MRI images. In this contribution, the acquisition of few projection images (thick-slab) of the vascular structures by phase-contrast MRI in combination with an iterative algorithm optimized for the reconstructing of sparse objects from few projection data by minimizing of the L1 norm of the reconstruction was tested for high-resolution phase-contrast MRA.

1282.   High-Contrast and High-SNR SWI Venography with Multiple Echo datasets 
Tae han Kim1, ung Jang1, and Dosik Hwang1
1Electrical & Electronic Engineering, Yonsei University, Seoul, Korea, Republic of

Susceptibility Weighted Imaging (SWI) method is commonly used for Magnetic Resonance (MR) venography. The difference between SWI and conventional GRE imaging is that phase information of signal is incorporated to enhance contrast of image. The phase can provide excellent contrast between venous blood vessels and other tissues with susceptibilities that are different from the background tissue. Although SWI is very powerful technique, SWI technique still has some weaknesses, regarding a trade-off between the gain of venous contrast and the loss of SNR. In this study, we propose a new approach to obtain high-contrast and high-SNR SWI venography with multiple echo datasets.

1283.   High-Field MR Venography using Adiabatic T2 Magnetization Preparation 
Ruud B van Heeswijk1,2, Simone Coppo1,2, Tobias Kober2,3, and Matthias Stuber1,2
1Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, VD, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland,3Advanced Clinical Imaging Technology, Siemens Suisse SA - CIBM, Lausanne, Switzerland

While successful coronary vein imaging approaches using magnetization transfer contrast have been reported at 1.5 T, these techniques cannot easily be adopted at higher magnetic field strength because of specific absorption rate constraints. For these reasons, we have implemented a method that exploits T2 shortening in deoxygenated blood. The hypothesis was tested whether this method enables contrast generation between the venous blood-pool and the surrounding structures at 3 T.

1284.   Hybrid Reconstruction Method for Flow-Sensitive Dephasing Non-contrast MRA 
Andrew J Wheaton1, and Mitsue Miyazaki2
1Toshiba Medical Research Institute USA, Mayfield, OH, United States, 2Toshiba Medical Research Institute USA, Vernon Hills, IL, United States

Flow-sensitive dephasing (FSD) is a subtraction-based non-contrast MRA technique. Conventional FSD acquires two data sets at different flow-dephasing first moments (m1) and phases in the cardiac cycle. The m1 value must be carefully calibrated to avoid losing arterial signal or allowing venous contamination in the subtracted image. This study proposes a hybrid reconstruction method which incorporates a priori knowledge of the relationship between signal intensity and m1 / cardiac cycle in arteries and veins. Using multiple data sets (N=3) as input, the hybrid method improves arterial signal up to 100% while avoiding venous contamination as demonstrated in the lower leg.

1285.   Continuously moving table vessel scout imaging using variable flip angles and autocorrelation analysis 
Sandra Baumann1, Michael Markl1, and Ute Ludwig1
1Dept. of Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany

The planning of bolus chase MR angiography (MRA) can be supported by the application of a vessel scout. Recently, the concept of a time-of-flight (TOF) vessel scout was presented which is based on the continuously moving table (CMT) acquisition and post processing of projection data. This study presents new acquisition and data processing strategies for CMT TOF vessel scout imaging which allow for improved vessel background contrast. A variable flip angle scheme was implemented to compensate for signal saturation caused by the repeated rf-excitation. Vessel contrast in scout images could further be increased by an autocorrelation analysis of acquired data.

1286.   Quiescent-Interval Single-Shot Unenhanced Magnetic Resonance Angiography featuring Continuous Table Movement 
Michael O. Zenge1, Christopher Glielmi2, Peter Weale2, Ioannis Koktzoglou3, Robert R. Edelman3, Manuela Rick1, Peter Schmitt1, and Xiaoming Bi2
1MR Applications Development, Siemens AG, Erlangen, Germany, 2Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States, 3Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States

Recently, quiescent-interval single-shot (QISS) peripheral MRA was introduced as a fast and robust approach for unenhanced MRA. Like any other multi-step MR imaging method QISS suffers from boundary artifacts at successive stations. Furthermore, the acquisition of adjustment and shimming parameters can be accelerated significantly in the moving table regime. Thus, continuous table movement was enabled for QISS and was compared to multi-step imaging in 5 healthy volunteers. In addition to comparable image quality as the multi-step approach, continuous table movement QISS reduces exam duration and complexity justifying further evaluation in patients.

1287.   Improving TOF angiography contrast homogeneity with B1+ shimming at 7 Tesla: benefits and challenges 
Sebastian Schmitter1, Edward J Auerbach1, Gregor Adriany1, Kamil Ugurbil1, and Pierre-Francois Van de Moortele1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

In Time-of-flight (TOF) angiography a contrast is generated between static tissues, partially saturated due to a high flip angle (&alpha=20-30º) with short TR<
1288.   Non-contrast-enhanced MR angiography of the renal arteries with inversion-prepared b-SSFP: A comparison of different imaging protocols 
Peter Schmitt1, Michaela Schmidt1, Manuela Rick1, Michael O Zenge1, Peter Weale2, Xiaoming Bi2, and Edgar Müller1
1MR Application & Workflow Development, Siemens AG, Healthcare Sector, Erlangen, Germany, 2Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States

This work evaluates four different protocol approaches for IR-prepared b-SSFP non-CE MR angiography of the renal arteries: A standard labeling method with a single transverse inversion slab is compared versus a targeted V-shaped scheme, and an ECG-triggered, navigator-based approach with shorter TI versus a respiratory triggered strategy with longer TI. Image quality was found to improve from transverse to targeted labeling, and from shorter TI to longer TI, in particular in critical subjects with diminished blood flow conditions. The assessment of such problematic cases and optimizations towards a generic, robust and time-efficient solution will be the focus of further investigations.

1289.   MR Leg Venography: Improved methodology & impact of subject positioning 
Andew Nicholas Priest1, Martin J Graves1, and David J Lomas1
1Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom

Recent non-contrast-enhanced vascular imaging methods use velocity-sensitised preparation to suppress vascular signal, combined with subtraction of bright- and dark-blood images to generate angiograms and/or venograms; however separation of arteries and veins is imperfect. In this work, acceleration-dependent preparation was used to suppress arteries, leading to venograms with no apparent arterial contamination. Additionally, the influence of subject position on the quality of vein depiction was evaluated in the lower legs of 7 healthy volunteers. Prone orientation gave better image quality than supine orientation, possibly because it avoids compression of the veins, and was also better than ‘supported supine’ orientation. Additionally, the influence of subject position on vein image quality was evaluated in the lower legs of 7 healthy volunteers. Prone orientation gave better image quality than supine orientation, possibly because it avoids compression of the veins, and was also better than ‘supported supine’ orientation.

1290.   Magnetic Resonance Angiography (MRA) of the Calf Station at 3T: Intraindividual Comparison between Non-enhanced ECG-gated flow-dependent MRA, Continuous Table Movement MRA and Time-Resolved MRA 
Stefan Haneder1, Ulrike I Attenberger1, Philipp Riffel1, Thomas Henzler1, Stefan O Schönberg1, and Henrik J Michaely1
1Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany

The purpose was to compare 3D non-enhanced ECG-gated inflow-dependent MRA (NE-MRA) vs. continuous table movement MR-angiography and time-resolved TWIST-MRA in the calf station at 3.0T in a clinical patient collective. Image qualities (IQ) and degree of stenoses were rated on a four point scale. Positive and negative predictive values, sensitivity and specificity for stenoses detection were calculated for overall graduation and severe stenoses. The results suggest that contrast-enhanced MRA techniques are superior to NE-MRA in terms of IQ and detection of stenoses. If technically successful, NE-MRA is characterized by a high NPV and overestimation of the degree of stenoses.

1291.   Non-Contrast-Enhanced 4D MRA Using Compressed Sensing Reconstruction 
Ti-chiun Chang1, Mariappan S. Nadar1, Jens Guehring2, Michael O. Zenge2, Kai Tobias Block2, Peter Schmitt2, and Edgar Mueller2
1Siemens Corporate Research, Princeton, NJ, United States, 2MR Applications Development, Siemens AG, Erlangen, Germany

: In the recent years, non-contrast magnetic resonance angiography (NCE MRA) has been an emerging tool in the diagnosis of degenerative vascular disease. Desired improvements include a reduction of the total scan time to reduce the impact of unintentional motion as well as an increase of the spatial and/or temporal resolution. Thus, the compressed sensing (CS) technique, which aims at reconstructing high quality signal from largely undersampled acquisitions, is a natural fit to further enhance time-resolved NCE-MRA applications

1292.   High-Quality Venography from Multi-echo MR Dataset using T2* Relaxation Model 
Ung Jang1, and Dosik Hwang1
1School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of

MR venography (MRv) has an important role in diagnosis of venous diseases. Unlike x-ray or CT venography, MRv produces venographic images without any ionizing radiation. Obtaining venographic image with low noise and high contrast is clinically important for diagnosis of vascular diseases based on MRv. It has been reported that the best venography can be acquired at TE=28ms for veins in parallel to the static field of 3T while much longer TE is needed for the veins not parallel to the static field. However, such a long TE would result in lower signal-to-noise ratio (SNR) in MRv image since the signals from veins and other tissues drastically decay with time. Therefore, reducing noise at longer TE is important in order to acquire a clinically meaningful venography. Employing conventional spatial filters such as low-pass filter, median filter, and anisotropic diffusion filter are typical denosing methods. Although such spatial filters reduce noise, they also smooth out the details of images such as small structures and edges, or introduce an artificial appearance such as stair-casing artifact due to nonlinear process. These degradations of image quality resulted from interference of neighbor pixels. The aim of this study is to obtain high-quality venography at longer TE without introducing blurring effects or any artificial appearance, by reducing noise on temporal domain of 3D multi-echo datasets.

Traditional Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Contrast Enhanced MRA (Non Coronary)

Wednesday May 11th
Exhibition Hall  13:30 - 15:30

1293.   Magnetic Resonance T1 Mapping Predicts Successful Venous Thrombolysis 
Prakash Saha1, Marcelo E Andia2, Ulrike Blume2, Andrea J Wiethoff2,3, Tobias Schaeffter2, Colin Evans1, Anwar Ahmad1, Ashish Patel1, Bijan Modarai1, Rene M Botnar2, Albert Smith1, and Matthew Waltham1
1Academic Department of Surgery, Cardiovascular Division, Kings College London, London, United Kingdom, 2Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, United Kingdom, 3Philips Healthcare, Guildford, United Kingdom


1294.   MRI pulmonary perfusion imaging as a quantitative predictor of regional pulmonary vascular resistance in pulmonary hypertension 
Adam Telfer1, Robin Condliffe2, David Capener1, Andrew Swift1, Smitha Rajaram1, Helen Marshall1, Judith Hurdman2, Charles Elliot2, David Kiely2, and Jim Wild1
1Academic Radiology Unit, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, 2Pulmonary Vascular Diseases Unit, Sheffield Teaching Hospitals, Sheffield, South Yorkshire, United Kingdom

This abstract describes a potential method for the non invasive estimation of Pulmonary Vascular Resistance in Pulmonary Hypertension by the use of gadolinium contrast enhanced MRI of the pulmonary vasculature. The key variable is the Time to Peak Signal Intensity (TTP) in the lung fields from initial detection of contrast in the Superior Vena Cava, Right Atrium, Right Ventricle and Pulmonary Artery. The method presented uses perfusion data from a standard contrast enhanced imaging sequence and involves only relatively quick additional calculations which may give it an advantage as a potential clinical tool.

1295.   Method for High Spatial Resolution of Proximal Stations in 3D Time-Resolved Fluoroscopically-Triggered Bolus Chase MRA 
Thomas W. Polley1, Casey P. Johnson2, and Stephen J Riederer2
1Electrical Engineering, Brigham Young University, Provo, UT, United States, 2MR Research Laboratory, Mayo Clinic, Rochester, MN, United States

A CAPR-based fluoroscopic acquisition is described which achieves both high spatial (1.0 mm isotropic) and high temporal (2.5 sec frame time) resolution for application to 3D bolus chase MRA with real-time triggering of table motion. Compared to a prior strategy that used a high degree of view sharing, the described method significantly reduces the temporal footprint, allowing sharper imaging of proximal stations with limited acquisition time windows. The benefit of the new technique is demonstrated in CE-MRA studies of the calves.

1296.   Assessment of Glenn-Fontan Shunts in Congenital Heart Disease using Low-Dose Time-Resolved and Multi-Phase High Spatial Resolution CEMRA 
Moritz Wagner1,2, Saeed Mirsadraee3, Pierangelo Renella4, Gary M Satou4, Jamil Aboulhosn4, John S Child4, Carissa Fonseca2, Roya Saleh2, and Paul Finn2
1Radiology, Charite - University Hospital, Berlin, Germany, 2Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, United States,3Clinical Research Imaging Centre, University of Edinburgh, Edinburg, United Kingdom, 4Division of Pediatric Cardiology, Mattel Children's Hospital, University of California, Los Angeles, California, United States

Low-dose time-resolved contrast-enhanced magnetic resonance angiography (time-resolved CEMRA) and multi-phase high spatial resolution CEMRA (conventional CEMRA) often provide complementary information in patients with congenital heart disease (CHD). The aim of the present study was to evaluate the diagnostic role of time-resolved and conventional CEMRA in the assessment of Glenn-Fontan shunts in CHD patients. In our retrospectively selected patient group, the combination of time-resolved and conventional CEMRA allowed for comprehensive assessment of Glenn-Fontan shunts. Moreover, time-resolved CEMRA substantially increased the diagnostic confidence in the assessment of pulmonary perfusion via the shunts.

1297.   In Vivo Fluorine-19 MR angiography in a mouse model 
Ruud B van Heeswijk1,2, Yves Pilloud2,3, Ulrich Flögel4, Juerg Schwitter5, and Matthias Stuber1,2
1Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, VD, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland,3Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 4Institute for Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, Germany, 5Center for Cardiac Magnetic Resonance and Cardiology Service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland

Fluorine-19 (19F) as part of perfluorocarbons in the blood-pool has a different frequency relative to that of protons. In theory, this can be exploited for angiography with a high contrast between the vessel lumen and the surrounding tissue. Therefore, the hypothesis was tested whether intravenously administered perfluorocarbons enables a selective and exclusive visualization of the vasculature in vivo.

1298.   A Universal Timing Strategy for Moving Table Peripheral MRA 
Jeffrey Harold Maki1,2, George Rachid Oliveira2, and Gregory J Wilson3
1Radiology, Puget Sound VAHCS, Seattle, WA, United States, 2Radiology, University of Washington, Seattle, WA, United States, 3MR Clinical Science, Philips Healthcare, Cleveland, OH, United States

Timing data from 71 peripheral MRA (pMRA) studies was analyzed to determine a universally applicable, simple algorithm for successfully performing pMRA. The algorithm requires only knowledge of the antecubital-foot contrast transit time, obtained from a time-resolved study of the lower extremity. Utilizing this data, good success can be achieved in terms of not outrunning the bolus and minimizing venous contamination. Testing of the proposed technique was successful, with a slightly greater than expected 20% venous rate (most mild - none rendering the examination non-diagnostic). Further refinements examining the arterio-venous window can apparently predict those who will demonstrate venous contamination.

1299.   Accuracy of MRI for the Assessment of the Geometry of Thoracic Stent Grafts 
Volker Rasche1, Stephan Trumpp1,2, Alexander Oberhuber2, Nico Merkle1, Karl Heinz Orend2, Martin Hoffmann3, Wolfgang Rottbauer1, and Axel Bornstedt1
1Internal Medicine II, University Hospital Ulm, Ulm, Germany, 2Thorax and Vascular Surgery, University Hospital Ulm, Ulm, Germany, 3Radiology, University Hospital Ulm, Ulm, Germany

Thoracic Endovascular Aortic Repair (TEVAR) has become an attractive alternative to open chest surgery especially in hemodynamic unstable patients. The possible, mostly graft related, associated complications, however require lifelong monitoring of the patients after treatment. The current gold standard for imaging is CT, which requires a rather high X-ray dose and the use of nephrotoxic contrast agents. It is the objective of this study to investigate the applicability of MRI for the assessment of stent graft geometry and smooth attachment to the vessel wall in direct comparison with CT.

1300.   Improved Spatial and Temporal Resolution using Parallel Imaging and SOS Trajectory for HYPR Reconstruction 
Lauren Ashley Keith1, Kang Wang1, James H Holmes2, Philip Beatty2, and Frank Korosec3
1Medical Physics, UW - Madison, Madison, WI, United States, 2Global Applied Science Laboratory, GE Healthcare, 3Radiology, UW - Madison, Madison, WI, United States

Synopsis: The stack-of-stars (SOS) trajectory has been previously used with HYPR reconstruction for time-resolved contrast enhanced angiography, particularly of the peripheral vasculature. One limitation of this trajectory has been the through plane resolution; in order to fulfill temporal resolution requirements, slice thickness has typically been larger than the in-plane resolution. In this work, we apply a data-driven, coil-by-coil parallel imaging technique to our SOS-HYPR protocol. This allows an increase in both through-plane spatial resolution and temporal resolution compared to previously presented results without parallel imaging.

1301.   Time-Resolved Calf-Foot Bolus Chase MRA with Sub-Millimeter Resolution and Real-Time Table Motion Triggering Using 3D MR Fluoroscopy 
Casey P Johnson1, Eric A Borisch1, James F Glockner1, Petrice M Mostardi1, Thomas W Polley2, Paul T Weavers1, Phillip M Young1, and Stephen J Riederer1
1MR Research Laboratory, Mayo Clinic, Rochester, MN, United States, 2Electrical Engineering, Brigham Young University, Provo, UT, United States

Dual-station calf-foot bolus chase MRA with high spatial (<1.0 mm isotropic) and high temporal (2.4-6.6 sec) resolution is demonstrated in volunteers. Real-time reconstruction of diagnostic 3D calf arteriograms is used to precisely trigger table motion to the foot station. High quality arteriograms without confounding venous contamination can be acquired over the extended field-of-view with resolution competitive with single-station methods.

1302.   Total Atherosclerotic burden by Whole Body Magnetic Resonance Angiography predicts future Major Adverse Cardiovascular Events 
Christina Lundberg1, Lars Johansson1, Charlotte Ebeling Barbier1, Lars Lind2, Håkan Ahlström1, and Tomas Hansen1
1Radiology, Uppsala University, Uppsala, Sweden, 2Medicine, Uppsala University, Uppsala, Sweden

We evaluated the atherosclerotic burden by whole-body MRA using the total atherosclerotic score (TAS). We found that TAS predicted the outcome of major adverse cardiovascular events.

1303.   A Magnetic Resonance Imaging Contrast Agent Targeted Towards Activated Platelets Allows Detection Of Platelets On Symptomatic Human Carotid Plaques 
Fabian Meixner1, Constantin von zur Mühlen2, Dominik Paul1, Irene Neudorfer2, Annette Merkle1, Mirko Meissner1, Christoph Bode2, Jürgen Hennig1, and Dominik von Elverfeldt1
1Department of Radiology, University Medical Center Freiburg, Freiburg, Baden-Württemberg, Germany, 2Department of Cardiology and Angiology, University Medical Center Freiburg

Platelets play an important role in the rupture of atherosclerotic plaques. So far with imaging techniques like MRI/CT and coronary angiography, only the degree of atherosclerotic narrowing, but not the stage, and thus the potential risk of arterial wall changes can be observed. It would be an important advance in the diagnosis, to identify late stages of atherosclerosis to initiate early treatment measures. In this study, the imaging of activated platelets in symptomatic human atherosclerotic carotid plaques with a 9.4 Tesla MRI is under investigation. The contrast agent is a single-chain antibody (LIBS) to the activated form of GPIIb/IIIa receptor which is coupled to a micro-particle of iron oxide (MPIO). The contrast agent (LIBS-MPIO) binds to activated platelets attached to the endothelium of the carotid interna plaques and results in signal loss on MRI.

1304.   Improved Reconstruction of Highly Under-sampled MR angiography Images Using Modified Nonlocal Means 
Yanqiu Feng1, Yingjie Mei1, Cong Wang1, and Wufan Chen1
1School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China, People's Republic of

In this paper, a novel compromise between spatial and temporal resolution is proposed based a modified nonlocal-means (NLM) filtering. Temp images are reconstructed using gridding algorithm from data being combined along temporal direction with the rectangle window function. Narrow window will produce HSR image and wide window will produce HTR image. Then, high spatio-temporal resolution is accomplished through a novel combining of the HTR image and the HTR image based on the modified NLM method. Preliminary experiments of simulated data demonstrate that the proposed method is of great potential for the reconstruction of highly under-sampled MR Angiography.

1305.   Technical Feasibility of Three-Station Time-Resolved Bolus Chase MRA 
Casey P Johnson1, Eric A Borisch1, James F Glockner1, Thomas W Polley2, Phillip M Young1, and Stephen J Riederer1
1MR Research Laboratory, Mayo Clinic, Rochester, MN, United States, 2Electrical Engineering, Brigham Young University, Provo, UT, United States

Time-resolved bolus chase MRA of the thighs, calves, and feet is demonstrated using a single injection of contrast material. Diagnostic quality 3D time frames were reconstructed in real-time for visually-guided triggering of table motion to the calf and foot stations. A CAPR acquisition was used in combination with 2D SENSE acceleration to image with both high spatial (1.0-1.2 mm) and high temporal (2.4-7.6 sec) resolution at each station. This method allows imaging of high quality arteriograms of the peripheral vasculature devoid of venous signal without use of a timing bolus or other estimates of bolus transit time.

1306.   Detection of Renal Dysfunction by Point of Care Creatinine Testing in Patients undergoing Peripheral MR Angiography 
Kevin Kalisz1, Amir H Davarpanah1, Asad A Usman1, Jeremy Collins1, Timothy J Carroll1, and James C Carr1
1Department of Radiology, Northwestern University, Chicago, IL, United States

Based on a retrospective review of patient charts, we sought to analyze the effectiveness of pre-MRA study questionnaires in identifying patients at risk for developing nephrogenic systemic fibrosis. Only 6.9% of stage 3 patients were aware of any history of renal dysfunction, whereas 50% of stage 4 and 100% of stage 5 patients admitted any history of renal dysfunction via questionnaires. It is concluded that a pre-study questionnaire alone cannot be relied upon in screening at-risk patients, and point of care creatinine testing can more reliably detect at-risk patients scheduled to undergo lower extremity MRA studies.

Traditional Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Myocardial Function: Experimental Models & Human Studies

Thursday May 12th
Exhibition Hall  13:30 - 15:30

1307.   Detecting Myocardial Hemorrhage in the Setting of Ischemia-Reperfusion Injury: T2 vs T2* 
Avinash Kali1, Andreas Kumar2, Xiangzhi Zhou3, Veronica L M Rundell3, Ying Liu3, Rachel A Klein3, Richard L Q Tang3, and Rohan Dharmakumar3
1Biomedical Engineering, Northwestern University, Chicago, IL, United States, 2Department of Medicine, Laval University, Quebec, QC, United States, 3Radiology, Northwestern University, Chicago, IL, United States

T2 and T2* changes associated with myocardial hemorrhage in the setting of ischemia-reperfusion injury were examined and the effectiveness of the two mapping techniques in discriminating hemorrhage was evaluated using a canine model. T2* of hemorrhagic infarctions were significantly lower than those of non-hemorrhagic infarctions and remote myocardium. T2s of both hemorrhagic and non-hemorrhagic infarctions were significantly elevated with respect to remote myocardium, likely due to the high sensitivity of T2 to myocardial edema. We conclude that T2* maps are more effective at discriminating hemorrhage, while T2 maps are more effective at detecting myocardial edema post ischemia-reperfusion injury.

1308.   Cardiac MR Elastography reveals increased stiffness of the left ventricular myocardium in age and pathology. 
Thomas Elgeti1, Mark Beling2, Sebastian Hirsch1, Bernd Hamm1, Jürgen Braun3, and Ingolf Sack1
1Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany, 2Department of Cardiology, Angiology, Pulmonology, Charité Universitätsmedizin Berlin, Berlin, Germany,3Institute of Medical Informatics, Charité Universitätsmedizin Berlin, Berlin, Germany

MR Elastography (MRE) relies on excitation and measurement of shear-waves in soft tissue. Cardiac MRE was performed in 4 groups: young and old healthy volunteers and patients with mild and severe diastolic dysfunction. Several elasticity-based parameters were measured. In diastolic dysfunction the amplitudes of externally induced shear waves were lower than in healthy controls. Furthermore, elasticity determined cardiac time intervals were altered similar to echocardiographic derived time intervals. Cardiac MRE allows measuring elasticity parameters of the left ventricular myocardium associated with physiological aging and relaxation abnormalities.

1309.   Inhibition of the Sodium-Calcium Exchanger by SEA0400 Inhibits Manganese Efflux from Isolated Hearts 
Ya Chen1, Kevin Payne1, Bharath Atthe1, Akemichi Baba2, Toshio Matsuda2, and Xin Yu1
1Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States, 2Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan

The present study aimed at investigating whether manganese-enhanced MRI (MEMRI) is also sensitive to changes in Na+-Ca2+ exchanger (NCX) activity. Using a rapid T1-mapping method, we investigated the dynamics of R1 changes in manganese-perfused rat hearts with and without NCX inhibition by SEA0400.

1310.   Three Dimensional Digital Polyhedral Phantom Framework with Analytical Fourier Transform and Application in Cardiac Imaging 
Tri Minh Ngo1, George S. K. Fung2, Benjamin M.W. Tsui1,2, Elliot McVeigh1, and Daniel A. Herzka1
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, 2Division of Medical Imaging Physics, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States

We present a framework which enables realistic 3-D digital phantoms of organs such as the brain and heart to be constructed from polyhedra which have an analytical Fourier transform. Using this framework and data provided by the 4-D eXtended CArdiac Torso (XCAT) phantom, we constructed an anatomically realistic 4-D phantom of the beating heart represented analytically in the k-space and image domains. We used the phantom to simulate motion artifacts observed in 3-D cine acquisitions at different temporal resolutions. This phantom provides a physiologically realistic gold standard permitting the exploration and optimization of acquisition, motion compensation, and reconstruction strategies.

1311.   Navigator Gated Volumetric Spiral Cine DENSE MRI using Outer Volume Suppression 
Bhairav Bipin Mehta1, Xiaodong Zhong2, and Frederick H Epstein1
1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia, United States

Quantitative imaging of myocardial motion and strain is growing importance. 3D cine DENSE MRI can be advantageous for complete assessment of myocardium. One of the drawbacks of 3D cine DENSE MRI is a long acquisition time. Using the outer volume suppression property of stimulated echoes the scan time was reduced approximately by one third.

1312.   A comprehensive quantitative comparison of regional cardiac motion in mice and humans 
Bernd André Jung1, Erica Dall'Armellina2, Stefan Neubauer2, Michael Markl1, and Jurgen E Schneider2
1Dept. of Radiology, Medical Physics, University Medical Center, Freiburg, Germany, 2Dept. of Cardiovascular Medicine, University of Oxford, United Kingdom

Tissue Phase Mapping is a well-established technique to assess regional cardiac function in humans. In mice, regional time course of the radial, rotational and longitudinal velocity components of the myocardium have not been systematically analyzed to date. The aim of our study was to perform a comprehensive quantitative analysis of myocardial wall motion in normal mice compared to velocity patterns in human hearts. Motion patterns of normal mouse hearts were similar to the human heart; however, distinct differences in regional myocardial motion were observed that might have to be considered when adapting myocardial mouse models to humans.

1313.   AAV6-mediated delivery of a U7 exon skipping construct improves regional cardiac function in Golden Retriever muscular dystrophy dogs 
Sean C Forbes1, Larry T Bish2, Meg M Sleeper3, Wil Mai4, H Sweeney2, and Glenn A Walter5
1Department of Physical Therapy, University of Florida, Gainesville, FL, United States, 2Department of Physiology, University of Pennsylvania, Philadelphia, PA, 3Department of clinical studies, University of Pennsylvania, Philadelphia, PA, 4School of Veterinary Medicine, University of Florida, Philadelphia, PA, 5Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL

Cardiac dysfunction is prevalent in Duchenne’s muscular dystrophy (DMD), with heart failure a common cause of death. Unfortunately, there is presently no cure or effective treatment for DMD. This study implements a novel approach of exon skipping by using viral mediated delivery of a modified U7 snRNA carrying antisense sequence to correct the disrupted reading frame in Golden Retriever muscular dystrophy (GRMD) dogs. The results indicate increased dystrophin expression and improved regional left ventricular strain values. Thus, AAV-mediated delivery of a U7 exon skipping construct shows promise as a cardiac therapeutic intervention for DMD.

1314.   MR imaging of Hypertrophy and Cardiac Recovery in the Mouse Aorta and Heart 
Bernd Jung1, Nadine Beetz2, Michael Markl1, Annette Merkle1, Lutz Hein2, and Dominik von Elverfeldt1
1Dept. of Radiology Medical Physics, University Medical Center, Freiburg, Germany, 2Dept. Phamacology 2, Institute for Pharmacology, Freiburg, Germany

Cardiac loading can initiate hypertrophy. The factors identifying patients benefiting from a load removal are still not fully understood. Therefore, the mechanisms of remodeling after cardiac unloading are of high interest for therapeutic intervention. Mouse models of experimentally increased cardiac loading/unloading can provide an important tool to investigate cardiac remodeling and recovery. Small animal MRI has proven to be a useful tool for the evaluation of cardiac functional parameters. The aim of this work was to monitor changes in aortic diameter and regional cardiac function during remodeling and recovery after experimental myocardial loading by aortic stenosis using MRI and ultrasound.

1315.   Three-dimensional Principal Strain Patterns in Acute Myocardial Infarction 
Sahar Soleimanifard1, Khaled Z. Abd-Elmoniem2, Emi Z. Murano1, M. R. Abraham1, Theodore P. Abraham1, and Jerry L. Prince1
1The Johns Hopkins University, Baltimore, MD, United States, 2National Institute of Diabetes and Digestive and Kidney Disease, Bethesda, MD, United States

Assessment of viability in myocardial disease continues to be of interest to clinicians. Principal strain patterns have been shown to change with ischemic injury, and can provide a sensitive index of viability. However, clinical use of principal orientations is extremely rare due to the existing noise in current measurements of angles. In this work, a reliable method of measuring principal strain angles was proposed. Consistency of the angles in the normal myocardium, combined with the results in the dysfunctional tissue in a porcine model, confirms the potential of principal strain orientations in assessment of viability.

1316.   Estimate of global radial, circumferential, and longitudinal strain from SSFP cines: a study in controls and patients with low to normal ejection fraction 
June Cheng-Baron1, Michael D Nelson2, Corey R Tomczak3, Kelvin Chow1, Justin A Ezekowitz4, Mark J Haykowsky3, D Ian Paterson4, and Richard B Thompson1
1Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, 2Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada,3Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada, 4Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada

We propose surrogates for global longitudinal, circumferential, and radial strains that can be measured from SSFP images based on the change in endocardial and epicardial borders over the entire left ventricle, with minimal additional post-processing. These metrics are compared in controls and patients with a wide range of ejection fractions and with literature values for each strain component. In controls, these metrics agree with literature values. In the patients with preserved ejection fractions, longitudinal function was lower than controls despite no measured difference in EF, circumferential, or radial function. The fractional longitudinal contribution to EF declines with impaired EF.

1317.   Left ventricular concentric hypertrophy and strain redirection in m.3243A>G mutation carriers: cardiomyopathy correlates with mutation load 
Kieren G Hollingsworth1, Grainne S Gorman2, Michael I Trenell1, Robert McFarland2, Robert W Taylor2, Douglass M Turnbull2, Guy A MacGowan3, Patrick F Chinnery4, and Andrew M Blamire1
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, 2Mitochondrial Research Group, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, 3Department of Cardiology, Freeman Hospital, Newcastle upon Tyne, Tyne and Wear, United Kingdom, 4Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Cardiomyopathy causes morbidity and mortality in m3243A>G mutation carriers. It remains controversial how early cardiac hypertrophy and dysfunction occur. 10 m3243A>G mutation carriers and 16 age- and gender-matched control subjects were recruited: anatomical MRI allowed assessment of left ventricular size and systolic function: cardiac tagging was used to assess torsion and regional myocardial strains. Mutant mtDNA load was measured by muscle biopsy. Concentric left ventricular hypertrophy was found in the absence of systemic hypertension, and LV index was found to discriminate hypertrophy better than LV mass. Mutation carriers had a re-orientation of myocardial strains which correlated with mutation load.

1318.   Spiral DENSE with short breath hold duration 
Shinichi Takase1, Andreas Sigfridsson2, and Hajime Sakuma3
1Department of Radiology, Mie University Hospital, Tsu, Mie, Japan, 2IMH/Cardiovascular Medicine, Linkoping University, Linkoping, Sweden, 3Department of Radiology, Mie University, Tsu, Mie, Japan

DENSE MR images were acquired in 10 volunteers within reduced scan time of 9 RR intervals by using spiral acquisition. The image quality with this approach was comparable to that by conventional 18 RR acquisitions, with peak Lagrangian strain of -0.20+/-0.03 for both methods. The bias between two methods for quantifying strain was 0.000, with 95% limits of agreement of }0.04. Spiral DENSE MRI acquired in 9 RR intervals is useful for patients who cannot hold their breath for 18 RR intervals, and may enable to use DENSE for stress imaging which is especially demanding for short breath holding time.

1319.   Mechanically Altering Infarct Properties Improves Regional and Global Function Secondary to Acute Myocardial Infarction 
Kevin J Koomalsingh1, Chun Xu1, Larry Dougherty2, Masahito Minakawa1, Takashi Shuto1, Joseph H Gorman, III1, Robert C Gorman1, and James J Pilla1
1Surgery, University of Pennsylvania, Glenolden, PA, United States, 2Radiology, University of Pennsylvania, Philadelphia, PA, United States

We evaluated the effect of an adjustable pressure device in a well developed large animal myocardial infarction model using 3D SPAMM tagging and optical flow mapping for data analysis.

1320.   The Second Generation (2G) k-t GRAPPA: Faster and More Accurate 
Feng Huang1, Wei Lin1, George Randy Duensing1, and Arne Reykowski1
1Invivo Corporation, Gainesville, Florida, United States

k-t GRAPPA has been proposed for dynamic imaging with high reduction factors. In this work, GRAPPA operator and narrow window data sharing are used to significantly improve the accuracy and reconstruction speed of k-t GRAPPA. The enhanced version is called the second generation (2G) k-t GRAPPA. Experiments with cardiac cine data set shows that the 2G k-t GRAPPA can produce images with lower error using shorter reconstruction time than k-t GRAPPA, and a compressed sensing technique in k-t space (k-t FOCUSS).

1321.   Quantification of In Vivo Left Ventricular Torsion and Principal Strains in Mouse Models of Hypertrophic and Dilated Cardiomyopathy 
Candida Laura Desjardins1, Yong Chen2, Julian Stelzer1, and Xin Yu2,3
1Physiology, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Case Center for Imaging Research, University Hospitals, Cleveland, OH, United States

This study investigated the biomechanical consequences of altering the contractile properties and structural stability of cardiac myocytes. Myocardial wall strain and torsion were quantified in mouse models of hypertrophic and dilated cardiomyopathy using DENSE MRI. The amplitude and time course of strain and torsion development was severely altered in mice with complete deletion of myosin binding protein-C (cMyBP-C) or muscle LIM protein (MLP). In addition, the heterozygous cMyBP-C mice showed normal global function but decreased strain and torsion, suggesting the sensitivity of DENSE MRI in detecting subtle changes in contractility at an early stage of disease progression.

1322.   7 Tesla Cardiac Imaging with a Phonocardiogram Trigger Device 
Stefan Maderwald1, Stephan Orzada1,2, Zimin Lin3, Lena C. Schäfer1,2, Andreas K. Bitz1,2, Oliver Kraff1, Irina Brote1,2, Lars Häring3, Andreas Czylwik3, Michael O. Zenge4, Susanne C. Ladd1,2, Mark E. Ladd1,2, and Kai Nassenstein1,2
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany, 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, 3Department of Communication Systems, University of Duisburg-Essen, Essen, Germany, 4MR Application Developement, Siemens AG, Erlangen, Germany

The inherently higher signal-to-noise ratio and certain enhanced soft tissue contrasts at 7T compared to 1.5T or even 3T MRI might improve image quality in selected imaging applications such as high-resolution cardiac MRI in humans. A number of artifacts and imaging constraints related to 7T transmit/receive problems have been addressed in previous work. However, a major issue is still the generation of a strong, reliable trigger signal. In this study we use an optoacoustic microphone and a DSP card for signal detection and trigger generation. Volunteers and a patient with known chronic myocarditis, pericardial effusion, and mild arrhythmia were scanned and evaluated.

1323.   Right Ventricular Geometric Shortening in Pulmonary Arterial Hypertension: Follow-up in Survivors and Non-survivors 
J. Tim Marcus1, Gert Jan Mauritz2, T. Kind2, Marielle van de Veerdonk2, Nico Westerhof2, and Anton Vonk-Noordegraaf2
1Physics & Medical Technology, VU University Medical Center, Amsterdam, Netherlands, 2Pulmonary Diseases, VU University Medical Center, Amsterdam, Netherlands

The changes of right ventricular (RV) geometric shortening in surviving (n=26) and non-surviving (n=16) Pulmonary Arterial Hypertension (PAH) patients were studied. RV longitudinal shortening, transverse shortening and RV fractional area change (RVFAC) were measured on 4-chamber cardiac MRI cine images. These values remained the same in the survivors, but transverse shortening and RVFAC decreased further in the non-survivors at 1 year follow-up (p<0.05). This decrease in RVFAC was associated with loss of RV ejection fraction (p=0.005). Thus, non-surviving PAH patients are characterized by a continued decline in RV transverse shortening and in RVFAC, while RV longitudinal shortening remains the same.

1324.   A Left Ventricular Motion Phantom for Cardiac MRI 
Mehmet Ersoy1,2, Melanie S Kotys3, Xiaopeng Zhou1,2, George P Chatzimavroudis2, and Randolph M Setser1
1Imaging Institute, Cleveland Clinic, Cleveland, Ohio, United States, 2Cleveland State University, Cleveland, Ohio, United States, 3Philips Healthcare, Cleveland, Ohio, United States

The purpose of this study was to design and build a low-cost, non-ferromagnetic LV motion phantom for use with cardiac MRI that is able to produce physiologically realistic LV wall thickening and rotation. Wall motion and rotation are modeled using separate phantoms housed within a common enclosure. The phantoms are easy to assemble and are constructed entirely of non-ferromagnetic materials, Results were physiologically realistic and reproducible, with standard deviations below 1.7% for strain and 1.1° for rotation. These phantoms could be of benefit when developing new cardiac MRI techniques and could potentially reduce development costs.

1325.   Accelerating global cardiac function assessment in mice using compressed sensing 
Tobias Wech1, Angela Lemke2, Debra Medway2, Lee-Anne Stork2, Craig A Lygate2, Stefan Neubauer2, Herbert Köstler1, and Jürgen E Schneider2
1Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany, 2Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom

Cine-MRI is a well-established tool to assess global cardiac function in rodent models of cardiovascular disease. The aim of this study was to validate compressed sensing as an approach to accelerate cine-MRI in mice at 9.4T. Fully sampled data cine sets acquired in normal and chronically infarcted mice were 2-, 2.5-, 3- and 4-fold undersampled in post-processing and subjected to compressed sensing reconstruction. Blinded segmentation of all data showed that 3-fold acceleration is possible without impairing accuracy of left-ventricular volume and mass measurements.

1326.   4D MR Velocity Mapping using PC VIPR to Investigate the Hemodynamics of Acute Pulmonary Hypertension in a Dog Model 
Alejandro Roldán-Alzate1, Heidi B Kellihan2, Daniel W Consigny1, Eric J Niespodzany1, Christopher J François1, Oliver Wieben1,3, Naomi C Chesler4, and Alex Frydrychowicz1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Veterinary Medicine, University of Wisconsin, Madison, WI, United States, 3Medical Physics, University of Wisconsin, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin, Madison, WI, United States

The hemodynamics in pulmonary arterial hypertension (PAH) and mechanisms of associated heart failure are not well understood. Non-invasive imaging techniques enable qualitative and quantitative assessment ofcardiopulmonary status during PAH progression. We hypothesized that large that 4D velocity (MRI) could be effectively used to visualize hemodynamics in a dog model of acute PAH and assess right ventricular (RV) function. In addition, we hypothesized that pulmonary artery stiffening with PAH would alter blood flow patterns. Results demonstrate a significant increase in PA stiffness as determined by relative area change measurements and altered hemodynamics that provide a potential mechanism for RV dysfunction.

1327.   Complementary Radial Tagging for the Assessment of Left Ventricular Function 
Zhe Wang1,2, Abbas N Moghadam2,3, Meral Reyhan2,4, J Paul Finn2,4, and Daniel B Ennis1,2
1Biomedical Engineering Interdepartmental Program, University of California, Los Angeles, CA, United States, 2Department of Radiological Sciences, Diagnostic Cardiovascular Imaging Section, University of California, Los Angeles, CA, United States, 3Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran, 4Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States

Radial tags have advantage for the measurement of left ventricle (LV) contraction and myocardial torsion compared with conventional line or grid SPAtial Modulation of Magnetization (SPAMM) tags due to the gross annular geometry of left ventricles. Complementary SPAMM (CSPAMM) with ramped imaging flip angles provides a way to maintain relatively uniform tag contrast throughout the whole cardiac phase. We combine the CSPAMM technique with radial tag encoding and demonstrate the sequence in simulations, images in phantoms, and a normal healthy subject. Complementary radial tags obviously increases the apparent contrast of the tags in late phases of the cardiac cycle and enables estimates of circumferential and radial strain. LV torsion and radial-circumferential shear strain with a pattern that is better matched to the LV geometry and may enable more facile assessment of LV regional function

1328.   Cardiac magnetic resonance imaging in peripartum cardiomyopathy: A comprehensive imaging approach 
Thomas Elgeti1, Dietmar E. Kivelitz2, Dirk Habedank3, Bernd Hamm1, Rainer Röttgen1, and Diane Miriam Renz1
1Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany, 2Albers-Schönberg-Institut für Strahlendiagnostik, AK St. Georg, Hamburg, Germany, 3Department of Cardiology, Charité Universitätsmedizin Berlin, Berlin, Germany

A comprehensive cardiac magnetic resonance imaging (CMRI) approach was evaluated retrospectively in 6 patients with peripartum cardiomyopathy (PPCM). This is a rare, possible life-threatening cardiac disorder, which affects previously healthy women in the last month of pregnancy or within five months after birth. The MR-protocol included SSFP images (functional analysis), T2 weighted images (edema), early (reflecting increased capillary leakage) and late gadolinium enhancement (LGE; irreversible myocardial injury). Using this protocol, myocardial inflammation is detected the acute phase of the disease. In most patients, these changes are transient. If LGE is found, the patient’s clinical course may not be favourable.

1329.   Assessment of Cardiac Functions and Inflammation Burden of Ischemic Injury with Integrated Functional and Cellular MRI 
Yijen Lin Wu1, Qing Ye1, Fang-Cheng Yeh1,2, Brent D Barbe1, Lesley M Foley1, Li Liu1, T Kevin Hitchens1, and Chien Ho1,3
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, 2Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States, 3Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

The aim of this study to investigate the potential of integrated cardiac MRI (CMR) protocols for better assessment and diagnosis of coronary artery disease (CAD), especially for acute coronary syndrome (ACS). Our data indicate that integrated CMR with tagging and perfusion to assess myocardial perfusion and regional wall motion simultaneously might be valuable for better assessment of myocardial status after myocardial infarction, and can better assist early evaluation of ACS. In addition, we observed macrophage infiltration shortly after ischemic injury, suggesting inflammation plays a role in ischemia-reperfusion injury.

1330.   Cardiac magnetic resonance imaging of the Ts65Dn murine model of Down Syndrome 
Lucas Abraham Citro1, Sarah E. Sansom2, Mahmood Khan2,3, Mickey Mizzell Martin2, Periannan Kuppusamy1,2, and Terry S. Elton.2,4
1Internal Medicine, The Ohio State University, Columbus, Ohio, United States, 2Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio, United States, 3Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, Ohio, United States, 4College of Medicine, Department of Pathology, The Ohio State University, Columbus, Ohio, United States

We have utilized cardiac magnetic resonance imaging, for the first time, to assess the cardiac functional defects of the left (LV) and right ventricles (RV) of Ts65Dn mice, the most-studied murine model of Down syndrome. Using a vertical-bore 11.7T MRI system, T1-weighted gradient echo FLASH-cine images were acquired to examine ventricular function and interventricular septal volume. The Ts65Dn mice showed significant decreases in LV ES and ED mass, EDV, ESV, SV, ED RV mass, and ED IVS volume. These results suggest that the extensive cardiac functional abnormalities present in Ts65Dn mice can be detected using high-field cardiac magnetic resonance imaging.

1331.   Cardiac function in an experimental model of the metabolic syndrome through pressure conductance analysis and cine MRI 
Wouter Oosterlinck1, Tom Dresselaers2, Vincent Geldhof1, Uwe Himmelreich2, and Paul Herijgers1
1Experimental Cardiac Surgery, K.U.Leuven, Leuven, Belgium, 2Biomedical NMR unit - MoSAIC, K.U.Leuven, Leuven, Belgium

The prevalence and consequences of diabetes mellitus type 2 and the metabolic syndrome contribute to the increasing morbidity and mortality from ischemic heart disease. Experimental animal models allow us to evaluate disease progression and new treatment options. We used cardiac cine MRI (cMRI) and left ventricular (LV) pressure conductance (PC) analysis to study cardiac function in an experimental model of the metabolic syndrome (DKO mice [1], both leptine and LDL receptor deficient, leading to obesity, diabetes mellitus type 2 and dyslipidemia). The aims of our study were: (1) to compare PC and MRI volumetric information and (2) to determine which contractility parameters were altered in the DKO mice at 24 weeks.

1332.   Non-invasive Evaluation of Allograft Rejection after Heart Transplantation with Integrated Cellular and Functional MRI 
Yijen Lin Wu1, Qing Ye1, Brent D Barbe1, Fang-Cheng Yeh1,2, Lesley M Foley1, Li Liu1, T Kevin Hitchens1, and Chien Ho1,3
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, 2Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States, 3Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

The aim of this study is to establish integrated cellular and functional MRI parameters for various stages of acute and chronic rejection, in searching for possible non-invasive surrogate indicators with MRI that could potentially translate to clinical arena. Our data indicated that the allograft rejection, both acute and chronic forms, appears to be highly heterogeneous. Regions with compromised functions also show more macrophage infiltration. Multiple MRI parameters provide further accuracy in rejection evaluation. Detailed profiling and modeling of the temporal and spatial relationship of the integrated multi-parameter MRI may be useful in establishing surrogate markers for detecting rejection.

Traditional Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Myocardial Perfusion: Experimental Models & Human Studies

Monday May 9th
Exhibition Hall  14:00 - 16:00

1333.   Quantification of Myocardial Blood Flow and Flow Reserve in Rats Using Arterial Spin Labeling MRI, Comparison with a Fluorescent Microsphere Technique 
Frank Kober1, Alexis Jacquier1, Soksithikun Bun1, Patrick J Cozzone1, and Monique Bernard1
1Centre de Resonance Magnetique Biologique et Medicale, Faculte de Medecine, Universite de la Mediterraneee, Marseille, Provence, France

In earlier studies, myocardial blood flow reserve was assessed using ASL in rats under pentobarbital, known to depress cardiac function. Here, MBF reserve was quantified in isoflurane-anesthetized rats using Look-Locker FAIR gradient-echo (LLFAIRGE) ASL. Results were compared with fluorescent microspheres (FM). Myocardial ASL was performed at rest and during adenosine infusion (140µg/kg/min). MBF reserve measured using LLFAIRGE-ASL was 2.5±0.6 and not significantly different from FM (2.4±0.9). MBF reserve was significantly higher than that earlier obtained under pentobarbital. The finding of significant MBF reserve using isoflurane is important, since this anesthetic is commonly used in imaging experiments.

1334.   The effect of myocardial contour errors on myocardial blood flow estimates in cardiac DCE-MRI perfusion. 
John David Biglands1, Abdulghani Larghat2, Sven Plein2, Derek R Magee3, Roger D Boyle3, and Aleksandra Radjenovic4,5
1Division of Medical Physics, University of Leeds, LEEDS, Yorkshire, United Kingdom, 2Division of Cardiovascular & Neuronal Remodelling, University of Leeds, LEEDS, Yorkshire, United Kingdom,3School of Computing, University of Leeds, LEEDS, Yorkshire, United Kingdom, 4School of Medicine, University of Leeds, LEEDS, Yorkshire, United Kingdom, 5Academic Section of Musculoskeletal Disease, University of Leeds, LEEDS, Yorkshire, United Kingdom

Estimating myocardial blood flow (MBF) from DCE-MRI cardiac perfusion datasets requires contouring of the myocardium. This study aimed to investigate the effect of myocardial contour error on estimated MBF with a view to defining a suitable target accuracy level. MBF values were estimated from concentration vs. time curves from 16 volunteers using manually drawn contours. Erroneous contours were simulated by allowing the manual contours to deviate by up to half the mean myocardial width from the ‘true’ manual reference. Statistically significant errors weren’t induced in MBF with contour errors allowed to deviate up to 0.4 of the mean myocardial width.

1335.   Myocardial contour error distance metrics do not correlate with myocardial blood flow estimate errors in DCE-MRI cardiac perfusion. 
John David Biglands1, Abdulghani Larghat2, Sven Plein2, Derek R Magee3, Roger D Boyle3, and Aleksandra Radjenovic4,5
1Division of Medical Physics, University of Leeds, LEEDS, Yorkshire, United Kingdom, 2Division of Cardiovascular & Neuronal Remodelling, University of Leeds, LEEDS, Yorkshire, United Kingdom,3School of Computing, University of Leeds, LEEDS, Yorkshire, United Kingdom, 4School of Medicine, University of Leeds, LEEDS, Yorkshire, United Kingdom, 5Academic Section of Musculoskeletal Disease, University of Leeds, LEEDS, Yorkshire, United Kingdom

Estimating myocardial blood flow (MBF) from DCE-MRI datasets requires contours to be drawn outlining the myocardium. Manual contouring is time consuming and numerous automated contouring algorithms have been developed. A variety of metrics are employed to evaluate such algorithms in terms of either geometric contour errors or errors in the estimated MBF. This study aimed to establish the relationship between a selection of geometric distance metrics and MBF error and found that these measures did not correlate. Future automated myocardial contouring algorithms should be evaluated in terms of both geometric distance metrics and MBF to enable objective cross-comparison.

1336.   Myocardial blood flow measurement using DCE-MRI: comparison of region-of-interest and voxelwise analysis 
Steven Sourbron1, William Morton1, David L Buckley1, John P Greenwood2, and Sven Plein2
1Division of Medical Physics, University of Leeds, Leeds, United Kingdom, 2Division of Cardiovascular and Neuronal Remodelling, University of Leeds, Leeds, United Kingdom

Measurement of myocardial blood flow (MBF) with DCE-MRI is conventionally performed on a region-of-interest (ROI) basis. In principle a voxelwise analysis is more attractive, but the lower SNR of single-voxel curves may reduce the accuracy or precision. This study aimed to investigate in patient data (n=25) whether voxelwise MBF values are significantly different from an analysis on ROI basis. Results show that both are in very good agreement, with a systematic difference of 4%. Since a voxelwise analysis offers additional information on the heterogeneity of myocardial perfusion, these results provide a strong case for the voxelwise approach in clinical applications.

1337.   Comparison of 3D Stress Cardiac Magnetic Resonance PerfusionImaging and Invasive Fractional Flow Reserve Measurements for the Detection of Coronary Artery Disease 
Robert Manka1,2, Cosima Jahnke3, Peter Boesiger1, Thomas F. Lüscher2, Ingo Paetsch3, and Sebastian Kozerke1
1Institute for Biomedical Engineering University and ETH Zürich, Zürich, Switzerland, 2Cardiology, Unispital Zürich, Zürich, Switzerland, 3Cardiology, University Hospital RWTH Aachen, Aachen, Germany

3D-CMR stress perfusion offers high quality and high diagnostic accuracy for the detection myocardial ischemia.

1338.   Myocardial microvascular function at rest and under adenosine stress measured with dynamic contrast-enhanced MRI 
David L Buckley1, John D Biglands1, Abdulghani Larghat2, Steven P Sourbron1, Aleksandra Radjenovic3, John P Greenwood2, and Sven Plein2
1Division of Medical Physics, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, West Yorkshire, United Kingdom, 2Division Cardiovascular & Neuronal Remodelling, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, West Yorkshire, United Kingdom, 3Section of Musculoskeletal Disease, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, West Yorkshire, United Kingdom

The purpose of this study was to estimate microvascular function in the myocardium at rest and under adenosine stress using dynamic contrast-enhanced MRI and to establish whether transport of Gd-DTPA was perfusion-limited. 16 healthy volunteers underwent myocardial perfusion imaging at stress and rest. Data were analyzed to provide estimates of myocardial perfusion, blood volume, capillary permeability-surface area product (PS) and interstitial volume. Delivery of Gd-DTPA at rest was close to perfusion-limited while this was not the case under stress. In addition to a 3-fold increase in perfusion, the effect of adenosine was to increase blood volume and PS.

1339.   Mapping of Myocardial ASL Perfusion and Perfusion Reserve Data 
Terrence Jao1, Zungho Zun2, Padmini Varadarajan3, Ramdas Pai3, and Krishna Nayak2
1Keck School of Medicine, University of Southern California, Los Angeles, California, United States, 2Electrical Engineering, University of Southern California, Los Angeles, California, United States, 3Division of Cardiology, Loma Linda University Medical Center, Loma Linda, California, United States

Arterial spin labeled MRI is an emerging approach for measuring myocardial perfusion and perfusion reserve in humans. The technique requires acquisition and registration of multiple tagged and control images and suffers from low signal-to-noise ratio. In this work, we address these two challenges by spatially aligning and spatio-temporally filtering myocardial ASL data in a polar coordinate frame. We demonstrate that this approach facilitates assessment of regional perfusion and perfusion reserve in patients.

1340.   High Resolution Whole Heart Cardiac Perfusion Imaging Using CAIPIRINHA 
Daniel Stäb1, Felix A. Breuer2, Christian Oliver Ritter1, Dietbert Hahn1, and Herbert Köstler1
1Institute of Radiology, University of Würzburg, Würzburg, Bavaria, Germany, 2Research Center Magnetic Resonance Bavaria, Würzburg, Germany

Applying CAIPIRINHA with an acceleration factor higher than the number of simultaneously acquired slices allows accelerating the imaging procedure in slice and phase encoding direction. With this Parallel Imaging approach myocardial perfusion imaging can be performed with whole heart coverage and high spatial resolution. 12 slice first pass in-vivo examinations are demonstrated, showing excellent image quality at a high spatial resolution of 2.0 x 2.0 mm2. Being easy to implement and providing short reconstruction times, the technique is suitable for application in clinical routine.

1341.   AIF Determination for Quantitative Myocardial Perfusion Imaging Using a Model Based Reconstruction of Radially Acquired Data 
Daniel Stäb1, Johannes Tran-Gia1, Christian Oliver Ritter1, Dietbert Hahn1, and Herbert Köstler1
1Institute of Radiology, University of Würzburg, Würzburg, Bavaria, Germany

Saturation prepared quantitative myocardial perfusion imaging particularly depends on an exact determination of the arterial input function (AIF). However, for typical contrast agent doses and recovery times TI between magnetization preparation and image acquisition, this is hampered by saturation effects. Utilizing a model constrained image reconstruction algorithm in conjunction with radial data acquisition, one complete image can be reconstructed for every single acquired radial projection; i.e. every corresponding TI. Hence, the technique allows determining a non-saturated AIF (short TI) and the conventional images (long TI) within one single scan.

1342.   Myocardial blood flow estimates depend on the location of the arterial input function within the cardiac cycle in first-pass DCE-MRI studies of myocardial perfusion 
Aleksandra Radjenovic1,2, John Biglands1, Abdulghani Larghat1, John Ridgway1, John Greenwood1, and Sven Plein1
1School of Medicine, University of Leeds, Leeds, United Kingdom, 2Academic Section of Musculoskeletal Disease, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, United Kingdom

In this study, we analysed the systematic differences between left ventricular arterial input function (AIF) curves acquired in different parts of the cardiac cycle, and assessed the impact of these differences on the estimated values of myocardial blood flow (MBF) in 17 healthy volunteers. Diastolic AIF precedes the systolic AIF at rest and stress, and diastolic AIF is more compact (with higher amplitude and shorter time to peak). Consequently, there is a significant variation between MBFs estimated using diastolic or systolic AIF: the use of diastolic AIF yields consistently lower MBF values. When reporting MBF values in the literature, the details of the AIF used for deconvolution should be reported too, to enable direct cross-study comparisons.

1343.   Cardiac Perfusion MRI at 3T for the Assessment of Endothelial Dysfunction in Diabetic Patients 
Alessia Tognolini1, Wanda Marfori1, Cesar Arellano1, Golnaz Heidari1, Christine Darwin2, Yutaka Natsuaki1,3, Gerhard Laub1,3, Mayil Krishnam4, and Stefan Ruehm1
1Diagnostic Cardiovascular Imaging, UCLA, Los Angeles, CA, United States, 2Medicine, Endocrinology, UCLA, Los Angeles, CA, United States, 3Siemens Medical Solution, Los Angeles, CA, United States, 4Cardiovascular and Thoracic Imaging, UCI, Irvine, CA, United States

Cardiovascular risk factors can lead to endothelial dysfunction, known precursor of atherosclerosis, which can manifest with impaired arterial vasodilation/paradoxical constriction in response to an appropriate stimulus. Cold pressor test (CPT) can be utilized to assess the endothelium dependent coronary vasomotor function. We utilized 3T cardiac perfusion MRI to detect changes in myocardial signal slope after CPT (immersion of the foot in ice water) in 10 diabetic patients and 10 healthy volunteers. Patients with diabetes showed stable/decreased perfusion after CPT vs. two-fold increase of perfusion in healthy control (p=0.0009). Perfusion MRI with CPT is a promising tool for early imaging of atherosclerosis.

1344.   An Area-Based Imaging Biomarker for the Characterization of Coronary Artery Stenosis with Blood Oxygen-Sensitive MRI 
Sotirios Athanasios Tsaftaris1,2, Richard Tang2, Xiangzhi Zhou2, Debiao Li2, and Rohan Dharmakumar2
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States

Current approaches for analyzing myocardial BOLD changes are suboptimal for detecting critical stenosis. This study proposes, ARREAS (Area-based biomaRker for chaRactErizing coronAry Stenosis), a statistical approach relying on the differences between rest and stress images, to characterize BOLD changes with exquisite sensitivity and specificity. Findings are validated with microsphere perfusion measurements. The method has the potential to rapidly determine the presence of oxygenation anomalies in the myocardium due to coronary artery disease, and provide an unbiased and quantitative imaging biomarker that can enable the assessment of the critical states of stenosis on the basis of BOLD MRI.

1345.   Quantitative Myocardial Perfusion Using Conventional Single-Bolus Contrast Imaging Overestimates Absolute Myocardial Blood Flow Compared with Dual-Bolus or Dual-Sequence Cardiac MR Methods 
Li-Yueh Hsu1, Peter Kellman1, Peter Gatehouse2, Sven Zuehlsdorff3, Christopher B Glielmi3, and Andrew E Arai1
1National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 2CMR Unit, Royal Brompton Hospital, London, United Kingdom, 3CMR Research and Development, Siemens Medical Solutions, Chicago, IL, United States

While it has been previously shown that myocardial perfusion reserve (MPR) is less sensitive to the nonlinearity of the arterial input function (AIF), using a single-bolus method to quantify myocardial blood flow (MBF) substantially overestimates MBF compared with either dual-bolus or dual-sequence methods.

1346.   Quantification of Myocardial Blood Volume and Water Exchange with Intravascular Contrast Agent 
Octavia Biris1,2, Neil Chatterjee3, Daniel C Lee3,4, and James Carr1,3
1Radiology, Northwestern University, Chicago, IL, United States, 2Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 4Cardiology, Northwestern University, Chicago, IL, United States

Absolute quantification of myocardial perfusion with MRI has the potential to reduce patient mortality from myocardial infarction by detecting coronary stenosis and coronary artery disease in patients with more accuracy than the current state-of-the-art semi-quantitative or qualitative analysis of perfusion images. In order to achieve absolute quantification of myocardial perfusion, we have measured myocardial blood volume and described myocardium-vessel water exchange in an animal model by a new MRI protocol using intra-vascular contrast agent. Myocardial blood volume will be used to calibrate the relative first-pass perfusion images to obtain absolute quantification of myocardial perfusion and cardiac perfusion reserve.

1347.   Myocardial Perfusion Study of Heart Failure Swine with Semi-quantitative Analysis 
Ting Song1,2, Maureen N Hood2,3, Jeffrey A Stainsby4, and Vincent B Ho2,3
1Global Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States, 2Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Radiology, National Naval Medical Center, Bethesda, MD, United States, 4Global Applied Science Laboratory, GE Healthcare, Toronto, ON, Canada

Cardiac perfusion imaging is a recognized method for non-invasive evaluation for myocardial ischemia. There is currently limited report of myocardial perfusion applied in heart failure. In this study of tachycardia-induced heart failure in swine, perfusion shows delayed arrival time, delayed peak time, and reduced slope of enhancement in myocardium.

1348.   Improved Clinical Performance of A New Myocardial Adenosine Stress Perfusion Technique with SW-CG-HYPR at 3.0T: A Comparison to Conventional IR-Turbo-FLASH Perfusion MRI and X-Ray Angiography in Patients with Suspected Coronary Artery Disease 
Heng Ma1, Lan Ge2, Jing An3, David Chen2, Lixin Jin4, Xiaoming Bi5, Renate Jerecic4, Kuncheng Li1, and Debiao Li2,6
1Xuanwu Hospital, Capital Medical University, Beijing, Beijing, China, People's Republic of, 2Northwestern University, 3Siemens Healthcare, MR Collaboration NE Asia, Siemens Mindit Magnetic Resonance, 4Siemens Healthcare, MR Collaboration NE Asia, Siemens Limited China, 5Siemens Healthcare, Cardiovascular MR R&D, USA, 6Cedars-Sinai Medical Center and UCLA

Conventional myocardial perfusion MRI is limited by the low spatial coverage (3 to 4 slices), temporal and spatial resolution, signal-to-noise ratio, and cardiac motion-related image artifacts. A sliding-window conjugate-gradient HYPR (SW-CG-HYPR) technique allows increased spatial coverage (whole left ventricular coverage), resolution, signal-to-noise ratio and reduced motion artifacts. This work shows that myocardial adenosine stress perfusion MRI with SW-CG-HYPR is feasible and robust in a clinical population. Compared with conventional IR-Turbo-FLASH perfusion MRI, perfusion imaging with SW-CG-HYPR allows whole left ventricular coverage and has higher diagnostic accuracy in patients with suspected CAD.

1349.   Rapid Cardiac T1 mapping within Two Heartbeats 
Elodie Breton1,2, Daniel Kim1, Sohae Chung1, and Leon Axel1
1Center for Biomedical Imaging - Radiology Research, New York University Langone Medical Center, New York, NY, United States, 2LSIIT - eAVR, University of Strasbourg, Strasbourg, France

Multi-point T1 mapping techniques, such as Modified Look-Locker inversion recovery (MOLLI), have shown quantitative changes in tissue T1 with ischemia but are sensitive to cardiac motion during data acquisition. In this work we developed a pixel-wise myocardial T1-mapping technique with reduced sensitivity to cardiac motion, adapted to perform pre-contrast and delayed-enhancement myocardial T1-mapping, with a 2-heartbeat-long acquisition. The proposed T1-mapping method was compared to a reference multi-point SR fitting method in 8 healthy volunteers before and after a gadolinium contrast injection. It was also performed in 2 patients with arrhythmia but no areas of delayed-enhanced was detected during routine contrast-enhanced clinical exam.

Traditional Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Myocardial Imaging & Spectroscopy

Tuesday May 10th
Exhibition Hall  13:30 - 15:30

1350.   Towards Quantification of Tissue Sodium Concentration in Mice with Acute Myocardial Infarction 
Mahon L Maguire1, L Stork1, Kiterie Faller1, Debra Medway1, Craig A Lygate1, Stefan Neubauer1, and Jurgen E Schneider1
1Dept Cardiovascular Medicine, University of Oxford, Oxford, Oxfordshire, United Kingdom

Myocardial sodium concentration increases rapidly following ischemic injury and is an early marker of electrophysiological disruption and myocardial injury. This study sought to measure the changes in myocardial sodium concentration in a surgical model of acute myocardial infarction in mouse 24 hours post surgery. Multi-slice high resolution 23Na chemical shift imaging was used in conjunction with late gadolinium enhanced 3D imaging to assess tissue sodium concentration as well as infarct size and location. An elevation of myocardial sodium concentration was observed in the region of the infarct compared to remote myocardium; no such elevation was observed in healthy control mice.

1351.   In Vivo Temperature Threshold for Myocardial Thermal Damage 
Peter Nabil Costandi1, Ramez Emile Necola Shehada1, Neha Bharat Butala1, Ben Anthony Coppola1, Kevin Jurkowski1, and Ali Dianaty1
1Cardiac Rhythm Management Division, St. Jude Medical, Sylmar, California, United States

Current contraindications for pacemaker patients in clinical MR systems stem primarily from RF induced tissue heating hazards. The quantified effect of elevated temperature doses on myocardial tissue remains unknown. Sixteen canines were implanted with a ventricular pacing system capable of monitoring temperature of viable myocardium. Three cumulative one-hour thermal doses to 44°C were applied to each chronic canine. Change in capture threshold relative to baseline was measured following each heating cycle and shown to increase by 68%, 81% and 83%, respectively. These findings provide data that may serve as a foundation for proof of safety of pacemaker systems in MRI.

1352.   Direct detection of postinfarction myocardial fibrosis with ultrashort TE (UTE) MRI 
Sanne de Jong1, Jaco J.M. Zwanenburg2,3, Fredy Visser2,4, Roel van der Nagel1, Harold V.M. van Rijen1, Marc A. Vos1, Jacques M.T. de Bakker1,5, and Peter R. Luijten2
1Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 4Philips Healthcare, Best, Netherlands, 5Interuniversity Cardiology Institute of the Netherlands, Utrecht

This study is aimed to detect fibrosis in infarcted and control rat hearts by using ultrashort TE (UTE) MRI. The results are compared with histology as a golden standard. For the first time it is shown that the use of UTE MRI can be used for the direct detection of postinfarction collagen formation.

1353.   23Na Chemical Shift Imaging of myocardial edema 
Eissa Aguor1, Cees W.A. van de Kolk1, Marcel G.J. Nederhoff1, Pieter A.F.M Doevendans1, Gerard Pasterkamp1, Gustav J. Strijkers2, Fatih Arslan1, and Cees J.A. van Echteld1
1Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

Assessment of myocardial viability is essential for diagnosis and treatment of patients with coronary artery disease. DCE MRI is the gold standard for chronic infarct size but may be less accurate in acute infarcts due to edema. Instead, we have explored 23Na CSI in an isolated heart model of edema with different perfusion pressures, independently characterized by 31P MRS. A perfusion pressure of 140 mmHg resulted in an increase in cross sectional area of the heart and a larger distribution volume for PPA, Nae and Gd. Unexpectedly, images of Nai also showed an small increase in signal intensity.

1354.   Sensitive MRI markers for systemic amyloidosis: amide proton transfer and equilibrium contrast 
Adrienne E Campbell1,2, Anthony N Price1,3, Simon Walker-Samuel1, Stephan Ellmerich4, Paul Simons4, Raya Al-Shawi4, Philip N Hawkins4, Xavier Golay5, James C Moon6, Roger J Ordidge2, Mark B Pepys4, and Mark F Lythgoe1
1Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London, London, United Kingdom, 2Department of Medical Physics and Bioengineering, University College London, London, United Kingdom, 3Robert Steiner MRI Unit, Imaging Science Department, Hammersmith Hostpital, Imperial College London, London, United Kingdom, 4Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, University College London, London, United Kingdom, 5Institute of Neurology, University College London, London, United Kingdom, 6Heart Hospital and Division of Medicine, University College London, London, United Kingdom

MR imaging was applied for the detection of systemic amyloidosis. Two novel MR techniques were applied to transgenic mouse models of amyloidosis: amide proton transfer (APT) in the kidney and equilibrium contrast MR (EQ-MR) in the heart and liver. Both EQ-MR and APT techniques were able to detect minor amyloid deposits and EQ-MR was demonstrated to be more sensitive to amyloid deposition in the heart than the calculation of cardiac functional parameters. These MR techniques may have applicability in early diagnosis of amyloidosis and in preclinical amyloidosis therapy studies.

1355.   Serial Quantitative MRI of Post-Infarct Macrophage Infiltration of the Mouse Heart Using Gd-Liposomes and R1-Mapping 
Nivedita K. Naresh1, Alexander L. Klibanov1,2, Moriel H. Vandsburger1,3, Jonathan Leor4, Yaqin Xu1, Brent A. French1,5, and Frederick H. Epstein1,5
1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Division of Cardiovascular Medicine, University of Virginia, Charlottesville, VA, United States,3Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, 4Tel-Aviv University, Israel, 5Department of Radiology, University of Virginia, Charlottesville, VA, United States

Macrophages play a number of critical roles in the wound healing response that follows myocardial infarction (MI). Two days prior to MI (day -2), we labeled macrophages in vivo using intravenous liposomes containing gadolinium. MRI R1-mapping of the heart and spleen was performed at days -3 (baseline) and -1 (1 day post-injection of Gd-liposomes) before MI, and at days 1, 4 and 7 post-MI. R1 mapping after monocyte labeling detected the time-course of macrophage infiltration of the infarcted anterolateral wall after MI, including their arrival, peak, and departure.

1356.   Passive targeting of paramagnetic lipid-based contrast agents to acute mouse cardiac ischemia/reperfusion injury 
Tessa Geelen1, Leonie E Paulis1, Bram F Coolen1, Klaas Nicolay1, and Gustav J Strijkers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

The aim of this study was to assess the circulation and extravasation kinetics of paramagnetic micelles and liposomes with T1-weighted MRI and evaluate their ability to report on infarct status after acute mouse cardiac ischemia/reperfusion injury. Directly after administration of micelles and liposomes, circulating contrast agents caused higher MRI signal intensities in the remote myocardium as compared to the infarct area, likely reporting on reduced perfusion of the infarcted myocardium. At later time points micelles and liposomes extravasated in the infarcted myocardium, leading to hyperenhancement of the infarction, enabling assessment of the infarct size.

1357.   Characterization of Rodent Heterotopic Heart Transplantation Models with Cellular and Functional MRI 
Qing Ye1, Yijen L Wu1, Brent D Barbe1, Fang-Cheng Yeh1, Li Liu1, Lesley M Foley1, T. Kevin Hitchens1, and Chien Ho1
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States

MRI is a powerful tool for heart transplantation research. Here, we characterized the rejection states and cardiac function of two different heterotopic transplantation models (working and nonworking hearts) in rats by cellular and functional MRI. Our data shows that the nonworking heart graft had poor cardiac function and rejected much faster than the working-heart model, even though they both showed strong palpation and normal ECG, which is not adequate for complementary graft evaluation. Cellular and functional MRI can evaluate rejection and function status of graft in real time with whole-heart information and avoid biases during investigation of the immune response.

1358.   Contrast-enhanced cardiac MRI of vascular remodeling after myocardial infarction using lipid-based nanoparticles 
Leonie E Paulis1, Tessa Geelen1, Michael Kuhlmann2, Bram F Coolen1, Klaas Nicolay1, and Gustav J Strijkers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 2European Institute for Molecular Imaging, University of Muenster, Muenster, Germany

In vivo monitoring of vascular remodeling after myocardial infarction can yield useful insights in the progression of global left ventricular (LV) remodeling. Extravascular contrast agents as Gd-DTPA have limited potential due to their nonspecific cardiac distribution. Therefore, the use of paramagnetic lipid-based nanoparticles was explored in acute and chronic phases of myocardial infarction with in vivo MRI and ex vivo CLSM. In the acute phase of myocardial infarction, nanoparticles were able to report on vascular integrity, by extravasation of nanoparticles at sites of impaired integrity. In the chronic phase, revascularized infarcted myocardium could be distinguished from necrotic or fibrotic myocardium.

1359.   Multi-channel Proton Spectroscopy of the Heart 
Nicola Martini1, Kilian Weiss2, Peter Boesiger2, Dante Chiappino1, and Sebastian Kozerke2
1Fondazione G. Monasterio CNR-Regione Toscana, Massa, Italy, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

This work investigates the use of phased array coils for navigator gated and ECG triggered cardiac 1H-MRS. A suitable reconstruction of cardiac MRS signals from multiple receiver elements is introduced with the aim of maximizing the signal-to-noise ratio (SNR) of the combined signal. In vivo experimental results with 5-element and 32-element cardiac arrays are presented. The obtained spectral quality allowed visualizing both the myocardial triglyceride peak and the creatine resonance, demonstrating the feasibility of cardiac 1H-MRS using large coil arrays.

1360.   Identification of two myocardial lipid pools in muscular dystrophy patients by 1H MRS at 3 T 
Belen Rial 1, Joseph J Suttie1, Stefan Neubauer1, Matthew D Robson1, and Jurgen E Schneider1
1Dept of Cardiovascular Medicine, University of Oxford, Oxford, Oxfordshire, United Kingdom

The excess of myocardial lipid accumulation may produce cardiomyopathy, leading to dysfunction. Myocardial lipid content can now be evaluated using 1 H magnetic resonance spectroscopy. The present study shows the ability of proton spectroscopy at 3 T to differentiate intra- from extramyocellular lipid resonances in the inter-ventricular septum of muscular dystrophy patients with impaired septal contractility. Conversely, extramyocellular lipid resonances were not visible in corresponding myocardial spectra of lean normal subjects with significantly lower intra-myocellular lipid content.Thus, cardiac proton MR spectroscopy may help to determine whether or not myocardial lipid overstorage is important in this disease process.1

1361.   In vivo assessment of the effects of pioglitazone on myocardial triglyceride content and cardiac function in diabetic mice using 1H MRS and MRI 
Desiree Abdurrachim1, Klaas Nicolay1, and Jeanine J Prompers1
1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

Myocardial triglyceride (TG) accumulation has been shown to be associated with the development of diabetic cardiomyopathy. Pioglitazone is one of the commonly prescribed anti-diabetic drugs; however, its effects on cardiac function and metabolism are not yet clear. In this study, the effects of pioglitazone on myocardial TG content and cardiac function were investigated in vivo in diabetic db/db mice using 1H MRS and MRI, respectively. Our findings show that db/db mice exhibit high myocardial TG content accompanied with the development of diastolic dysfunction, while pioglitazone treatment in an early stage of diabetes normalizes myocardial TG levels and prevents diastolic dysfunction.

1362.   Six hours of hyperglycemia and hyperinsulinemia affects cardiac function and increase myocardial lipid accumulation. 
Martin Krssak1,2, Yvonne Winhofer3, Drazenka Jankovic3, Christian Anderwald3, Gert Reiter4, Siegfried Trattnig2,5, Anton Luger3, and Michael Krebs3
1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Wien, Austria, 2Center of Exellence, HF MR, Medical University of Vienna, Wien, Austria, 3Internal Medicine III, Medical University of Vienna, Wien, Austria, 4Siemens AG Healthcare, Wien, Austria, 5Radiology, Medical University of Vienna, Wien, Austria

To mimic the effect of postprandial diabetic hyperglycemia on the heart, myocardial lipid accumulation and myocardial function were measured by 1H MR spectroscopy and imaging in a group of young, healthy, lean subjects before and after 6h of experimentally induced hyperglycemia and associated hyperinsulinemia. This experimental protocol resulted in increase in myocardial lipid content by ~ 25% and also an increase in left ventricular ejection fraction ~4%, suggesting that these metabolic alterations might be directly responsible for myocardial steatosis in type 2 diabetes.

1363.   Longitudinal assessment of T2* changes in mouse myocardium following ischemia-reperfusion injury 
Eissa Aguor1, Fatih Arslan1, Cees W.A. van de Kolk1, Marcel G.J. Nederhoff1, Pieter A.F.M Doevendans1, Cees J.A. van Echteld1, Gerard Pasterkamp1, and Gustav J. Strijkers2
1Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

Ischemic injury may lead to a progressive decline in heart performance and heart failure. Noninvasive techniques to characterize the myocardium during infarct development are essential to assess efficacy of novel therapeutics. The aim of this study was to explore the utility of quantitative T2* mapping as a noninvasive technique to characterize the myocardium in the acute and chronic phases following ischemia/reperfusion injury in the mouse. Quantitative T2* values dynamically decreased during infarct development. In the chronic phase the infarction was better distinguished on the T2* maps than by late-gadolinium-enhancement. Therefore, T2* may enable distinction between acute and chronic myocardial infarctions.

1364.   Detection of Focal Inflammation on Myocardial Disorder Using T2 Contrast Agent-based MRI: Comparison to Late-enhanced MRI with T1 contrast agent 
Hyeyoung Moon1,2, Hyo Eun Park3, Jongeun Kang1,4, Hee-Seok Kwon5, Kiyuk Chang3, and Kwan Soo Hong1,4
1MR Research, Korea Basic Science Institute, Cheongwon, Chungcheongbuk-Do, Korea, Republic of, 2University of Science and Technology, Daejeon, Korea, Republic of, 3Department of Internal Medicine, Catholic University, Seoul, Korea, Republic of, 4Graduate School of Analytical science and Technology, Chungnam National University, Daejeon, Korea, Republic of, 5Division of Electron Microscopic Research, Korea Basic Science Institute

In this study, we investigated whether T2 contrast agent-combined CMR (cardiac magnetic resonance) imaging would be feasible and effective for the detection of the inflammation in a rat model of experimental autoimmune myocarditis (EAM) in comparison between T2 and T1 contrast agents, and whether T2 contrast agent-combined CMR imaging could give a guidance where the biopsy samples should be collected.

1365.   Free Breathing Independent Respiratory Navigator-Gated Imaging: Concurrent PSIR and T2-Weighted 3D Imaging of the Left Ventricle 
Sangjune Laurence Lee1, Michael Schär2,3, M Muz Zviman4, Valeria Sena-Weltin4, Ahmed A Harouni5, Sebastian Kozerke6, Elliot R McVeigh1, Henry Halperin4, and Daniel A. Herzka1
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States, 2Philips Healthcare, Cleveland, OH, United States, 3Radiology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 4Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 5Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States, 6Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

2D breath-hold phase sensitive inversion recovery (PSIR) has been shown to provide excellent depiction of myocardial scar and other clinically relevant conditions. The transition from breath-hold 2D to respiratory navigator-gated 3D imaging should yield higher SNR and CNR, allowing whole heart coverage at higher spatial resolution. Current 3D PSIR implementations navigate only the IR-prepared volume, relying on phase reference images that may be corrupted by respiratory motion. We hypothesize that additional navigation of the reference volume will yield more robust high-resolution imaging. Here, we present an independently-navigated 3D PSIR sequence and extend its utility to include co-registered T2W imaging volumes.

1366.   High-resolution localization of fibrosis in a mouse model of viral chronic myocarditis using T2* weighted MRI 
xavier Helluy1, Martina Sauter2, Yu-xiang Ye3, Roland Jahns3, Ali Yilmaz4, Karin Klingel2, Karl-Heinz Hiller1, and Peter M Jakob1
1Magnetic Resonance Bavaria, Wuerzburg, Germany, 2Department of Molecular Pathology, University of Tuebingen, Germany, 3Department of internal medicine I, University Hospital of Wuerzburg, Germany, 4Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany

Myocarditis which is the major cause of heart failure and sudden death in young adults is most often induced by viruses, importantly by coxsackieviruses. We report a novel application of T2* weighted MRI at 7T on the murine model of coxsackievirus B3 induced chronic myocarditis. T2* weigthed images show a negative contrast correlating with fibrosis distribution within the myocardium. The observed T2* contrast might be due to local field inhomogeneities induced by fibrotic tissue. Besides the value of characterizing the disease model in vivo, this finding could be a novel technique for diagnosing chronic myocarditis in humans or some other fibrosis-related diseases.

1367.   T2 mapping of the mouse heart using segmented MLEV supercycle preparation 
Bram F Coolen1, Frank FJ Simonis1, Rik PM Moonen1, Tessa Geelen1, Leonie EM Paulis1, Klaas Nicolay1, and Gustav J Strijkers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

In this study, we present a novel method for robust T2 quantification in the mouse heart. The method makes use of an ECG-triggered non-selective T2 preparation consisting of MLEV weighted composite pulses, followed by a multi-slice k-space segmented acquisition. High quality images with different T2 weighting were obtained by segmenting the MLEV16 supercycle into different MLEV blocks, providing a broad TE range from 0.8 to 43.5 ms. Six healthy control mice were measured to assess reproducibility of the method and baseline values for myocardial T2.

1368.   Improved T2-Weighted Cardiac Imaging using Retrospective Motion Correction and Optimal Image Combination 
Hui Xue1, Xiaoming Bi2, Christoph Guetter1, Sven Zuehlsdorff2, Marie-Pierre Jolly1, Jens Guehring1, and Peter Kellman3
1Imaging and Visualization, Siemens Corporate Research, Princeton, NJ, United States, 2CMR Research and Development, Siemens Medical Solutions USA, Inc., Chicago, IL, United States,3National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States

Recent development in cardiac MR shows that improved SNR can be achieved by selectively averaging the motion-corrected free-breathing images using the non-rigid image registration. In this work we presented dedicated retrospective techniques to improve the free-breathing, single-shot T2w imaging using motion correction and optimal image combination which computes a weighting function to minimize the total deformation brought into the averaging and effectively avoids visible artifacts possibly introduced by imperfect registration. The whole process was validated on patient datasets, showing the noticeable SNR gain can be achieved without introducing smearing artifacts.

1369.   Myocardial ECV imaging by MRI compared to myocardial ECV imaging by CT – validation in experimental acute myocardial infarction 
Martin Ugander1, Marcus Y Chen1, Billy Chen1, Li-Yueh Hsu1, Peter Kellman1, and Andrew E Arai1
1National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States

The myocardial extracellular volume fraction (ECV) can by quantified by MR. However, independent validation is lacking. We performed ECV imaging by MR (1.5T) and CT (320 channel) in experimental acute myocardial infarction. ECV was quantified using hematocrit and T1 or Hounsfield unit quantification in tissue and blood before and after Gd-DTPA or iodinated contrast injection for MR and CT, respectively. ECV in remote, infarcted and peri-infarction myocardium by CT and MR correlated (R2=0.76, p<0.001, y=0.92x+0.08, MR bias 4.7±8.3 percentage points, n=17 measures in 6 dogs). CT provides independent validation that MR can be used to quantitatively image myocardial ECV.

1370.   Quantitative MRI can distinguish remodeling mechanisms after acute myocardial infarction based on the severity of ischemic insult 
Nilesh R Ghugre1, Mihaela Pop1, Jennifer Barry1, Beiping Qiang1, John J Graham2, Kim Connelly2, Alexander J Dick1,3, and Graham A Wright1
1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 2Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada, 3University of Ottawa Heart Institute, Ottawa, ON, Canada

The type and extent of infarction encountered clinically [transmural, hemorrhagic, heterogeneous, with microvascular obstruction (MVO)] is primarily determined by the severity of the initial ischemic insult. The purpose of our study was to evaluate longitudinal fluctuations in edema (T2), hemorrhage (T2*) and vasodilatory function (stress-induced T2 changes) in infarcted and remote territories of porcine myocardium subjected to different ischemic durations: 45 min and 90 min followed by reperfusion. The 90 min group produced hemorrhagic transmural infarcts with MVO while infarction in the 45 min group was non-transmural, non-hemorrhagic and heterogeneous. MRI parameters revealed faster resolution of edema and earlier restoration of vasodilatory function in less severe infarcts, potentially indicating reduced adverse remodeling. Understanding the in vivo pathophysiological mechanisms after acute myocardial infarction in the clinical setting will be key in predicting functional recovery and assessing the efficacy of novel therapies.

1371.   A real-time cine late gadolinium enhancement imaging method at 3T 
Mo Kadbi1, Hui Wang1, Mohammadjavad Negahdar1, Melanie Kotys2, Stefan Fischer2, and Amir A. Amini1
1Department of Electrical and Computer Engineering, University of Louisville, Louisville, KY, United States, 2Philips Healthcare, cleveland, oh, United States

A real-time LGE MRI technique (free breathing, non-gated) is presented for detection of myocardial scars. Conventional real-time LGE imaging has long acquisition window and low temporal resolution. The goal of this study was to increase the temporal resolution of imaging, providing the possibility for better visualization of the wall motion and more accurate assessment of myocardial viability. The number of acquired images is more than twice the number in previously published methods. 12 single-shot images were acquired using an IR TFE-EPI sequence in a single heat beat. Unlike other methods, nulled-myocardium is acquired without the need to set TI value.

1372.   Free-breathing T1 Mapping MRI for Quantification of Myocardial T1 Pre and Post Contrast in Swine with Non-ischemic Heart Failure 
Maureen N Hood1,2, Ting Song1,3, Peter Bedocs4, John Capacchione4, Mark Haigney5,6, Christine E Kasper7, and Vincent B Ho1,2
1Radiology, Uniformed Services University, Bethesda, Maryland, United States, 2Radiology, National Naval Medical Center, Bethesda, Maryland, United States, 3Global Applied Science Laboratory, GE Healthcare, Bethesda, Maryland, United States, 4Anesthesiology, Uniformed Services University, Bethesda, Maryland, United States, 5Medicine, Uniformed Services University, Bethesda, Maryland, United States, 6Cardiology, National Naval Medical Center, Bethesda, Maryland, United States, 7Graduate School of Nursing, Uniformed Services University, Bethesda, Maryland, United States

MRI may offer a non-invasive tool to quantify the degree of fibrosis in patients with diffuse disease by taking advantage of the inherent T1 values of tissues. Purpose of this study is to investigate a new free-breathing pulse sequence to quantify myocardial T1 changes in tachycardia-induced heart failure in swine and to investigate T1 value changes after administration of a gadolinium-chelate. T1 mapping results were compared to traditional myocardial delayed enhancement as well as to control and heart failure histological tissue samples.

1373.   Characterization of myocardial T1 and partition coefficient as a function of time after gadolinium delivery in healthy subjects 
Kelvin Chow1, Jacqueline Flewitt2, Jordin Green3, Matthias Friedrich2,4, and Richard Thompson1
1Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, 2Stephenson CMR Centre at the Libin Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada, 3Siemens Healthcare, Calgary, Alberta, Canada, 4Department of Radiology, University of Calgary, Calgary, Alberta, Canada

Myocardial and blood T1 mapping was performed in 9 healthy subjects using a custom saturation recovery SSFP sequence on a single mid-ventricular short axis slice at 1.5T. Images were acquired at baseline and repeated at one-minute intervals following a gadolinium bolus injection and the blood-tissue partition coefficient was derived at each time point to determine the time-course relationship. At 15 min post contrast, average myocardial T1 was 719±38ms and lambda was 0.39±0.05. Over the 10–15 minute post contrast window, myocardial T1 values increased by 6% and the derived partition coefficient increased by only 1%.

1374.   Myocardial T1 mapping at 3T using variable flip angle method: a pilot study 
Hélène POINSIGNON1,2, Maelene LOHEZIC2,3, Hai-Ling Margaret CHENG4,5, Pierre-Yves MARIE6, Jacques FELBLINGER2,7, and Marine BEAUMONT1,6
1CIT 801, INSERM, Nancy, France, 2IADI, Nancy-Université, Nancy, France, 3Global Applied Science Laboratory., GE Healthcare, Nancy, France, 4Physiology & Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada, 5Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, 6CHU de Nancy, Nancy, France, 7U947, INSERM, Nancy, France

T1 mapping is a useful quantitative MR technique for cardiac tissue characterization and contrast agent concentration measurements. Because of cardiac and respiratory motion, cardiac T1mapping remains challenging. The conventional modified look locker sequence allows myocardial T1 measurement, but it is a dedicated research sequence and T1 values are interpolated from apparent T1 values. In this work, we are interested in determining T1 using standard clinical sequences. This study aims at evaluating the feasibility of variable flip angle T1 mapping integrating B1 correction on the myocardium at 3T.

1375.   Quantitative measurement of myocardial T1 with a modified cine inversion recovery pulse sequence 
Matteo Milanesi1,2, Andrea Barison3, Vincenzo Positano1, Luca Marinelli4, Pier Giorgio Masci1, Daniele De Marchi1, Christopher James Hardy4, Thomas K Foo4, Luigi Landini1, and Massimo Lombardi1
1MRI Laboratory, Fondazione “G. Monasterio” CNR – Regione Toscana, Pisa, Tuscany, Italy, 2Magnet Technology Center, Agilent Technologies UK Ltd, Oxford, Oxfordshire, United Kingdom,3Scuola Superiore Sant'Anna, Pisa, Italy, 4General Electric Global Research, Niskayuna, NY, United States

A modified version of the Cine-IR pulse sequence is herein introduced for T1 mapping of the myocardium. In the new sequence, data are acquired for a greater number of heart cycles following the inversion pulse than the original version used to do. This allows the pre-contrast myocardium to fully recover its longitudinal magnetization. The effective TR is adjusted according to the specific heart rate of the subject. In vivo results showed that the sequence is able to detect T1 differences between healthy and areas of myocardium positive to DE, both in pre and post contrast measurements

1376.   Novel pilot data - Cardiac MR Imaging Post Catheter Ablation: Does T2 and DE ratios matter in predicting clinical outcome? 
Aruna Arujuna1, Rashed Karim1, Benjamin Knowles1, Dennis Caulfield1, Mark O'Neill1, Aldo Rinaldi1, Michael Cooklin2, Jaswinder Gill1, Tobias Schaeffter1, Kawal Rhode1, and Reza Razavi1
1Imaging Sciences, King's College London, London, United Kingdom, 2Cardiothoracic Department, Guy's &St Thomas' Hospital, London, United Kingdom

The recent role of delayed enhancement (scar) MR imaging in evaluating post catheter ablation left atrial lesions has been well documented and correlated with clinical outcome. In this abstract we describe and discuss our T2-Weighted (oedema) findings alongside DE quantification post ablation and correlate this to clinical outcome.

1377.   3D Spiral LGE for reduced enhancement artifacts in PV imaging of pre- and post-ablation scar. 
Benjamin R Knowles1, Warren J Manning1, and Dana C Peters1
1Cardiovascular Research, Havard Medical School, Beth Israel Deconess Medical Center, Boston, Massachusetts, United States

The detection of late gadolinium enhancement (LGE) due to RF ablation of the pulmonary veins, or for the visualization of arrhythmic substrate is challenging due to the thickness of the left atrial myocardium. Image artifacts can be mis-interpreted as enhancement. We demonstrate how the use of a stack-of-spirals LGE sequence can be implemented to reduce the artifacts observed from incomplete fat suppression and from edge-artifacts due to profile ordering. Results are shown in simulations, phantoms and in-vivo studies. The spiral LGE sequence was found to reduce enhancement compared to Cartesian, and is more likely to reflect true enhancement.

1378.   Self-navigated 3D late gadolinium enhancement imaging of the left atrium 
Ganesh Adluru1, Liyong Chen1, Seong-Eun Kim1, Eugene Kholmovski1, Nassir Marrouche2, and Edward V.R. DiBella1
1Radiology, University of Utah, Salt Lake City, Utah, United States, 2Internal Medicine, University of Utah, Salt Lake City, Utah, United States

Late Gadolinium Enhancement imaging of the left atrium is evolving as a valuable tool in the treatment and management of atrial fibrillation using radio-frequency ablation. Current segmented Cartesian acquisition scheme with a respiratory navigator based on the diaphragm position is limited in achieving consistent image quality. Here we explore an alternative self-navigated hybrid radial scheme that can identify motion and can offer improved image quality efficiently. The method is based on a more direct measurement of motion across different segments in 3D k-space and then using compressed sensing reconstruction to further improve the image quality. Results from patient studies show the feasibility of promising method.

1379.   Patients with Histologically Abnormal Left Atrial Myocardium Demonstrate Greater Left Atrial Late Gadolinium Enhancement 
Jaime L Shaw1, Susie N Hong-Zohlman1, Robert C Hagberg1, Benjamin R Knowles1, Warren J Manning1,2, and Dana C Peters1
1Cardiology, Beth Israel Deaconess Medical Center, Boston, MA, United States, 2Radiology, Beth Israel Deaconess Medical Center

The use of late gadolinium enhancement (LGE) for detecting pre-existing scar in the LA wall of patients with atrial fibrillation is challenging, due to the widespread appearance of LA wall enhancement in all subjects. This study compares LA wall enhancement in healthy controls vs. patients prior to minimally invasive maze procedure. While the enhancement pattern was generally similar in controls vs. patients, pre-maze patients with abnormal histological findings on their resected left atrial appendage (LAA) tissue had greater LA wall enhancement compared with patients with normal LAA findings. This is a first study correlating per-ablation LGE findings with histological fibrosis/hypertrophy in the LA.

1380.   Left Atrial Scar Imaging Using 3D Dixon Late Gadolinium Enhancement 
Jaime L. Shaw1, Benjamin R Knowles1, Warren J Manning1, and Dana C. Peters1
1Beth Israel Deaconess Medical Center, Boston, MA, United States

Left atrial (LA) scar imaging using late gadolinium enhancement (LGE) is important for the assessment of post-ablation injury, fibrosis, and pre-ablation arrhythmic substrate. Common fat-saturation techniques for LGE do not always provide complete fat suppression, particularly visceral fat, and require a centric view-ordering scheme, causing misleading enhancement which may be misidentified as scar. In this study, a Dixon technique is applied to LA LGE imaging for the purpose of providing excellent fat-saturation and sequential view-ordering. Results indicate the proposed Dixon LGE technique is a highly promising method for LA scar imaging with reduced enhancement artifacts.