Electronic Posters: Cardiovascular

Wednesday 13:30-15:30 Computer 30

13:30 3592. Association Between Left Ventricle Sympathetic Innervation and Torsion in Patients with Type 1 Diabetes

Scott David Swanson¹, Gisela C. Mueller¹, David Raffel¹, Dorthea Happ¹, Claire S. Duvernoy^2,3, Rodica Pop-Busui<sup>4

1</sup>Department of Radiology, University of Michigan, Ann Arbor, MI, United States; ²Cardiology Section, VA Ann Arbor Health Care System, United States; ³Department of Internal Medicine, University of Michigan; ⁴Department of Internal Medicine; Division of Metabolism, Endocrinology and Diabetes, , University of Michigan

We compare left ventricular torsion as measured by cardiac MR tagging with sympathetic denervation as measure by PET and find that increased torsion is correlated with denervation.

14:00 3593. Myofiber Developmental Plasticity in Fetal and Adult Pig Hearts Delineated with Diffusion Tensor MRI

Lei Zhang¹, Huiying Zhang¹, Gregory M. Lanza¹, Samuel A. Wickline¹, Junjie Chen<sup>1

1</sup>Washington University School of Medicine, St. Louis, MO, United States

Cardiac function in pre and post-natal stages are different because of reduced workload of right ventricle relative to left ventricle after birth. We hypothesize that myocardial fiber structure in fetal hearts differs from that of adult hearts as a response to the change of cardiac function. Diffusion tensor MRI was used to quantitatively evaluate myofiber structure in mid-gestation, pre-born and adult pig hearts. Helix angle and transverse angle in septum and LV/RV fusion sites were compared between the three groups. Our results showed that contributions of RV myofibers to septum was higher in fetal pig hearts than adult pig hearts. The current observations were in agree with change of cardiac function and reflect the plasticity of myocardial fiber development in response to programmed differential contractile functions before and after birth.

14:30 3594. Accelerated Simultaneous Multi-Slice Cardiac Cine Imaging Using a Combination of CAIPIRINHA and Compressed Sensing

Daniel Stäb¹, Tobias Wech¹, Christian Ritter¹, Dietbert Hahn¹, Herbert Köstler<sup>1

1</sup>Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany

A combination of CAIPIRINHA simultaneous multi-slice imaging with Compressed Sensing is presented. A technique is generated, effectively accelerating the imaging procedure in slice and phase encoding direction. Several slices are excited simultaneously and shifted with respect to each other in the FOV using RF phase cycles, while k-space is undersampled randomly in incoherent fashion. In the reconstruction process, Compressed Sensing is used to eliminate incoherent artifacts, while a parallel imaging reconstruction separates the simultaneously excited slices. The method shows potential for high quality multi-slice imaging with high acceleration factor.

15:00 3595. SNR Evaluation of 32 Channel Cardiac Coils in DENSE MRI at 1.5 and 3T

Andreas Sigfridsson^1,2, Henrik Haraldsson^1,2, Tino Ebbers^1,2, Hans Knutsson, ²³, Hajime Sakuma<sup>4

1</sup>Clinical Physiology, Linköping University, Linköping, Sweden; ²CMIV, Linköping University, Linköping, Sweden; ³Biomedical Engineering, Linköping University, Linköping, Sweden; ⁴Radiology, Mie University, Tsu, Mie, Japan

The in-vivo SNR for DENSE MRI was evaluated for 32 channel cardiac coils compared to standard 5 and 6 channel coils at 1.5 and 3T. On average, the 32 channel coils provided 50% higher SNR. The SNR improvement was more pronounced at 3T than at 1.5T, and closest to the chest wall. The higher SNR provides the opportunity for DENSE imaging in a longer portion of the cardiac cycle.

Thursday 13:30-15:30 Computer 30

13:30 3596. Clinical Cardiac Imaging at 7 Tesla: A Validation Study.

Joseph J. Suttie¹, Lance DelaBarre², Greg J. Metzger², Pierre Francois van de Moortele², Carl J. Snyder², Peter Weale³, Stefan Neubauer¹, Matthew D. Robson¹, J Thomas Vaughan<sup>2

1</sup>Department of Cardiovascular Medicine, University of Oxford, Oxford Centre for Clinical Magnetic Resonance Research, Headington, Oxfordshire, United Kingdom; ²University of Minnesota, Radiology Center for Magnetic Resonance Research, Minneapolis, MN, United States; ³Cardiovascular MR Research and Development, Siemens Healthcare, Chicago, IL, United States

Clinical cardiac imaging at 7 T is attractive for spectroscopy, coronary and perfusion imaging. It offers improved signal and contrast to noise, provided technical challenges of ECG and artifacts can be overcome. This study compares SSFP and FLASH imaging at different field strengths: 1.5, 3 and 7 Tesla.

14:00 3597. Quantifying Right Ventricular Motion and Deformation Using 3D Cine DENSE MRI

Daniel Alejandro Auger¹, Xiaodong Zhong², Ernesta Meintjes¹, Fred Epstein³, Bruce Spottiswoode<sup>1,4

1</sup>MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa; ²MR R&D Collaborations, Siemens Medical Solutions, Atlanta, GA, United States; ³3Departments of Radiology and Biomedical Engineering, University of Virginia, , Charlottesville VA, United States; ⁴Radiology, University of Stellenbosch, Cape Town, South Africa.

Displacement encoding with stimulated echoes (DENSE) is a quantitative MRI technique used for measuring myocardial displacement and strain at a high spatial resolution. Studies quantifying the motion of the right ventricle (RV) have been limited by the RV’s thin wall, asymmetric geometry and complex motion. A free-breathing navigator gated spiral 3D cine DENSE sequence has recently been developed, thus providing a well suited tool for capturing the complex behavior of the RV. This study involves analyzing the RV’s 3D motion and strain at a previously unattainable spatial resolution. The results are consistent with previous studies using myocardial tagging.

14:30 3598. Diffusion Tensor Imaging of Healthy and Cryo-Injured Pig Hearts

Patricia Dreessen de Gervai¹, Victor Yang, Uta Sboto-Frankenstein, Valery Kupriyanov, Lawrence Ryner

¹National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada

Diffusion Tensor Magnetic Resonance Imaging (DTI) was used to assess myocardial architecture in healthy and in injured excised pig hearts in which cryo-ablation was used to produce targeted infarctions. Using the lesion and penumbral region as seed points, fibers were not detectable in the infarct region, FA was reduced and ADC values increased compared to healthy excised hearts. The penumbral region contained traceable fibers although FA and ADC values were affected. This work suggests that the changes in fiber architecture, FA and ADC involve not only the infarct area but also the adjacent tissue.

15:00 3599. Retrospective Self-Gated Free-Breathing Radial 3D Cine SSFP CMR Using Self-Calibrated GRAPPA: A Feasibility Study

Noel C. Codella¹, Pascal Spincemaille², Jing Liu², Martin Prince², Yi Wang<sup>2

1</sup>Physiology, Cornell Weill Medical College, New York, NY, United States; ²Radiology, Cornell Weill Medical College

In this study, a 3D free-breathing self-calibrated radial GRAPPA cine-SSFP pulse sequence was developed to overcome the limitations of 2D breath-hold imaging. Radial k-space sampling was employed to provide z-profile self-navigator to monitor respiratory motion, and to allow for GRAPPA self-calibration.

Myocardial Function: Experimental & Human Studies III

Hall B Monday 14:00-16:00 Computer 31

14:00 3600. Quantification of 3D Cardiac Motion in Mice Using Multi-Phase DENSE MRI

Yong Chen^1,2, Jia Zhong^1,2, Xin Yu<sup>1,2

1</sup>Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; ²Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States

In the current study, we developed a multi-phase DENSE imaging method for quantification of 3D myocardial motion in mice. Only five acquisitions were required to quantify both in-plane and longitudinal displacements on one slice. The results showed strong agreement with 2D DENSE methods.

14:30 3601. Analysis of Cardio-Respiratory Motion of the Heart Using GRICS (First Insights)

Pierre-André Vuissoz^1,2, Freddy Odille³, Brice Fernandez, ^1,4, Maelene Lohezic, ^1,4, Adnane Benhadid^1,2, Damien Mandry^2,5, Jacques Felblinger<sup>1,6

1</sup>Imagerie Adaptative Diagnostique et Interventionnelle, Nancy-Université, Nancy, France; ²U947, INSERM, Nancy, France; ³Centre for Medical Image Computing, University College London, London, United Kingdom; ⁴Global Applied Science Lab., GE healthcare, Nancy, France; ⁵Departments of Radiology, University Hospital Nancy, Nancy, France; ⁶CIC801, INSERM, Nancy, France

Clinical assessment of MRI data (e.g. myocardium function) is usually performed with breath-hold acquisitions. However, cardiac functional parameters are affected by breath-hold. The generalized reconstruction technique GRICS allows free-breathing acquisition protocols, and corrects for motion artifacts by inherently establishing a motion model. Here we show how this model can be used to decouple cardiac and respiratory motion, based on the available ECG and respiratory sensors. In 5 healthy volunteers, we analyzed the respective cardiac and respiratory contribution, in terms of motion vectors, in various regions of interest from the heart, enabling new insights in thoracic motion analysis.

15:00 3602. Highly-Accelerated Real-Time Cine MRI Using Compressed Sensing and Parallel Imaging

Li Feng¹, Ricardo Otazo², Monvadi B. Srichai^2,3, Ruth P. Lim², Ding Xia², Daniel K. Sodickson², Daniel Kim<sup>2

1</sup>Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States; ²Radiology, New York University School of Medicine, New York, NY, United States; ³Medicine, New York University School of Medicine, New York, NY, United States

Real-time cine MRI is a necessary cardiac MRI pulse sequence for patients with reduced breath-hold capacity and/or arrhythmia. Currently, dynamic parallel imaging methods, such as TSENSE and TGRAPPA, can be used to achieve an acceleration rate (R) of 2-3, which typically yields relatively low spatial and temporal resolution. We propose to use a joint acceleration technique that combines compressed sensing (CS) and parallel imaging (PI) to exploit joint sparsity for randomly undersampled multicoil data. This study describes highly-accelerated (R>4) real-time cine MRI using the joint CS-PI technology and shows encouraging results using this technology.

15:30 3603. Quantitative Comparison of Left Ventricular Cardiac Volume, Mass and Function Obtained at 7 Tesla with “gold Standard” Values at 1.5 Tesla.

Anne Brants¹, Maarten Versluis¹, Albert de Roos¹, Jos Westenberg¹, Andrew Webb<sup>1

1</sup>Radiology, Leiden University Medical Center, Leiden, Netherlands

Recent advances in coil technology have enabled cardiac imaging to be performed at 7T, with high spatial resolution cine-imaging showing particular promise. However, there has been no quantitative assessment of clinically-relevant derived measures of cardiac mass, volume or function. In this current study, ten healthy volunteers underwent cardiac scans at both 1.5T, the gold standard for such measures, and 7T. Values of end-systolic and end-diastolic volumes, ejection fraction, stroke volume an left ventricular end diastolic mass showed no statistical difference between 1.5 and 7T, providing strong validation for the continuing development of high-field cardiac imaging.

Tuesday 13:30-15:30 Computer 31

13:30 3604. Evaluating Left Ventricular Wall Motion Abnormalities Using Centerline Trajectory Mapping

Ting Song^1,2, Alexander I. Bustamante³, Jeffrey A. Stainsby⁴, Maureen N. Hood^2,5, Vincent B. Ho<sup>2,5

1</sup>GE Healthcare Applied Science Laboratory, Bethesda, MD, United States; ²Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; ³Cardiology, National Navy Medical Center, Bethesda, MD, United States; ⁴GE Healthcare Applied Science Laboratory, Toronto, ON, Canada; ⁵Radiology, National Navy Medical Center, Bethesda, MD, United States

This paper presents Centerline Trajectory Mapping (CTM) method as a quantitative tool for characterization of focal and global wall motion abnormalities using long axis views of the left ventricle. Evaluation of CTM with myocardial delayed enhancement imaging and echocardiography with great consistency in wall motion abnormality detection. The proposed method does not add any extra scans to existing clinical cardiac MR routine and can be utilized in retrospective studies.

14:00 3605. Orientation and Magnitude of the Left Ventricular Principal Strains Are Sensitive to Ischemic Injury

Chun Xu¹, Kevin Koomalsingh¹, Gamaliel Isaac², Joseph H. Gorman², Robert C. Gorman², Lawrence Dougherty², James Pilla<sup>2

1</sup>University of Pennsylvania , Philadelphia, PA, United States; ²University of Pennsylvania, Philadelphia, PA, United States

Accurate assessment of regional and global left ventricular (LV) functions is critical for ischemic heart disease. The orientation and the magnitude of the myocardial principal strains have been shown to be sensitive to ischemic development. This study presents a method to fully characterize the alterations in the magnitude and orientations of principal strains in a pig left ventricle. The computaed decreases in principal strains due to introduced infarct are confirmed by implanted markers and perfusion image, indicating impaired transmural thickening and circumferential shortening. Characterization of the remote, border zone and infarct 3D strain is paramount in understanding infarct expansion and in the development of therapies to mitigate remodeling.

14:30 3606. Cardiac Valve Position Prediction in CINE-BSSFP Images Using SURF

Hendrikus Joseph Alphons Crooijmans¹, Philippe C. Cattin², Oliver M. Weber^1,3, Klaus Scheffler<sup>1

1</sup>Division of Radiological Physics, Department of Medical Radiology, University of Basel Hospital, Basel, Switzerland; ²Medical Image Analysis Center (MIAC), University of Basel, Basel, Switzerland; ³Siemens Healthcare, Zürich, Switzerland

The interest point detector and region descriptor SURF finds features in every image/phase of a series of CINE-bSSFP images. By the help of user input, the best feature is selected in a Matlab program and corresponding features are automatically detected. If no feature is found within preset limits, it is created by linear interpolation. User indicated points of interest are described as a function of the position and diameter of the feature (all in the first image/phase), and can therefore be repositioned based on the corresponding features in the succeeding images/phases. This method provides reliable fast online valve position detection.

15:00 3607. Comparison of Left Function Assessment Using Phonocardiogram and Electrocardiogram Triggered 2D SSFP CINE MR Imaging at 1.5 T and 3.0 T

Tobias Frauenrath¹, Meike Becker^2,3, Fabian Hezel¹, Gabriele A. Krombach², Ute Kremer², Jeanette Schulz-Menger^1,3, Thoralf Niendorf<sup>1,3

1</sup>Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, 13125 Berlin, Germany; ²Department of Radiology, University Hospital, RWTH, 52074 Aachen, Germany; ³Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, 13125 Berlin, Germany

As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to distortions and mistriggering increases and with it the motivation for a cardiac triggering alternative. Hence, this study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects at 1.5T and 3.0T.

Wednesday 13:30-15:30 Computer 31

13:30 3608. Improved Myocardial Mechanics as Assessed by MRI Generated Pressure-Volume Loops Following AAV6-Mediated βARKct Gene Delivery.

James J. Pilla¹, Jabaris D. Swain, Michael G. Katz, Anthony Fargnoli, Marina Sumaroka, Catherine Tomasulo, Mihail Petrov, Rose Nolen-Walston, JanLee Jensen, Hansell Stedman, Walter J. Koch², Joseph Rabinowitz², Charles R. Bridges

¹University of Pennsylvania, Philadelphia, PA, United States; ²Thomas Jefferson University

Genetic modulation of ventricular function and remodeling may offer a novel therapeutic strategy for patients with acute ischemic left ventricular (LV) dysfunction. We hypothesize that âARKct gene therapy will amplify the cardiac response to a beta-adrenergic agonist resulting in improved function and efficiency as measured by MRI. MRI generated PV loops demonstrated that âARKct expression improves global LV systolic performance and efficiency relative to controls. These results in a normal ovine subject, using a novel, cardiac-specific gene delivery platform (MCARDTM) are predictive of long term efficacy in a clinically relevant large animal HF model.

14:00 3609. Comparison of Magnetic Resonance Imaging and Doppler Echocardiography for the Evaluation of Diastolic Function in Patients with Hypertrophic Cardiomyopathy

Yeon Hyeon Choe¹, Eun Young Kim<sup>2

1</sup>Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; ²Radiology, Samsung Medical Center, Seoul, Korea, Republic of

Diastolic function parameters (mitral inflow velocities, deceleration time, E/A ratio) using phase contrast MRI showed good correlation with that of echocardiography in patients with hypertrophic cardiomyopathy. Analysis of pulmonary vein flow velocity was feasible on MRI and give additional information on diastolic function analysis.

14:30 3610. Evaluation of Patients with Systemic Sclerosis Prior to Hematopoietic Stem-Cell Transplantation Using Cardiac Magnetic Resonance Imaging

Amir H. Davarpanah¹, Aya Kino¹, Kirsi Taimen¹, Philip Hodnet¹, Cormac Farrelly¹, Jeremy Collins¹, Sanjiv Shah², Karin Dill¹, Richard Burt³, James Carr<sup>1

1</sup>Department of Radiology, Cardiovascular Imaging, Northwestern University, chicago, IL, United States; ²Department of Cardiology, Northwestern University, chicago, IL, United States; ³Department of Immunotherapy, Northwestern University, chicago, IL, United States

Using time to peak systole (TPS) from volumetric assessment of right ventricle, may have an important role in detecting both the presence and severity of pulmonary hypertension (PH); It may apply to patients with systemic sclerosis overall, in whom early detection of PH is of significant clinical importance.

15:00 3611. An Optimal Physiologic Model for Study of Murine Cardiac Function Under Inhalational Anesthesia

Christakis Constantinides¹, Richard Mean¹, Laurence W. Hedlund<sup>2

1</sup>Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus; ²Radiology, Duke University Medical Center, Durham, NC, United States

While cardiac mechanical functional studies initially focused on large mammals and the human, the mouse emerged as the preferred animal species for research in recent years. Albeit evidence supports that bioenergetically and hemodynamically the mouse scales linearly with larger mammals and humans, important physiological questions still remain for the appropriateness of this model for extrapolation of conclusions to man. Since the complete characterization of the mouse and human genomes in 2002 and 2003 respectively, there has been a plethora of transgenic mouse studies targeting the cardiovascular system. Equally important were non-invasive imaging studies of such animals for phenotypic and genotypic screening, often conducted under inhalational anesthesia. Anesthetics, however, are known to cause severe cardio-depression with adverse physiological effects on hormonal release, centrally to the heart and peripherally to the vasculature, at the cellular level, affecting calcium entry through L-type Ca2+ channels, the calcium binding sensitivity of the contractile proteins to calcium, and on conduction and excitability. The objective of this study was to determine the isoflurane dose in normal mice for optimal physiological status (respiration, cardiac function, and metabolism) for a period of 1-2 hours post-induction, facilitating migration of such work to the non-invasive imaging platform of MRI, with tremendous potential for future basic science towards the phenotypic screening of transgenic mice and translational research.

Thursday 13:30-15:30 Computer 31

13:30 3612. The Patho-Physiological Sensitivity of Cardiac MR Elastography: Preliminary Results.

Thomas Elgeti¹, Mark Beling², Dieter Klatt¹, Sebastian Papazoglou¹, Sebastian Hirsch¹, Kerstin Riek¹, Bernd Hamm¹, Jürgen Braun³, Ingolf Sack<sup>1

1</sup>Institut für Radiologie, Charité Universitätsmedizin , Berlin, Germany; ²Klinik und Poliklinik für Kardiologie, Charité Universitätsmedizin , Berlin, Germany; ³Institut für Medizinische Informatik und Biometrie, Charité Universitätsmedizin , Berlin, Germany

MR Elastography (MRE) is capable to directly measure tissue stiffness. This is particularly interesting for cardiac applications, since the cardiac shear modulus changes over the cardiac cycle. It is known, that increasing myocardial stiffness yields decrease of wave amplitudes in MRE. Therefore, left ventricular shear wave amplitudes were measured in 11 healthy volunteers and 11 patients with relaxation abnormalities. It is observed, that shear wave amplitudes are significantly lower in the left ventricle of patients. This result indicates the sensitivity of amplitude-based cardiac MRE to identify increased myocardial stiffness.

14:00 3613. Relationship Between Mitral Velocity and Mitral Flow Time-Profiles During Ventricular Filling

June Cheng-Baron¹, Jessica M. Scott², Ben T. Esch², Mark J. Haykowsky², John V. Tyberg³, Richard B. Thompson<sup>1

1</sup>Biomedical Engineering, University of Alberta, Edmonton, AB, Canada; ²Physical Therapy, University of Alberta, Edmonton, AB, Canada; ³Cardiac Sciences, University of Calgary, Calgary, AB, Canada

It has been shown that blood velocity waveforms measured at the conventional mitral leaflet tips location do not match mitral flow waveforms. In this study we quantify the relationship between velocity profiles at several points along the inflow path and volumetric flow, illustrating the dependence of commonly derived diastolic parameters (E/A ratio, deceleration time) on the measurement approach. Velocity profiles and derived parameters vary significantly over small (1 cm) intervals and are distinct from flow profiles. Velocity-time curves above the conventional leaflet tip location (in the atrium) are less susceptible to measurement error and are most similar to flow curves.

14:30 3614. Cine DENSE and Manganese-Enhanced Cardiac MRI Demonstrate That ENOS Does Not Play a Determining Role in Modulating the Effects of ß-Adrenergic Stimulation

Moriel H. Vandsburger¹, Brent A. French¹, Xiaodong Zhong^1,2, Christopher M. Kramer¹, Frederick H. Epstein<sup>1

1</sup>University of Virginia, Charlottesville, VA, United States; ²MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States

Dynamic manganese-enhanced MRI and cine DENSE MRI can be used to probe calcium flux and contractile function in vivo in the mouse heart. Using these methods, we sought to elucidate the role of endothelial nitric oxide synthase (eNOS) in modulating calcium flux and contractile function. Counter to the prevailing opinion, which suggests that eNOS inhibits basal calcium flux, we found that eNOS does not play a role in modulating either calcium flux or contractile function at baseline, during β-adrenergic stimulation, or during muscarinic inhibition of β-adrenergic stimulation.

15:00 3615. Adaptive Method for Black Blood Cardiac Imaging in End-Systolic Rest Improves Visualization of the Right Ventricular Wall

Brice Fernandez^1,2, Julien Oster^2,3, Maelene Lohezic^1,2, Damien Mandry^2,4, Olivier Pietquin, ^2,5, Pierre-André Vuissoz^2,3, Jacques Felblinger<sup>2,3

1</sup>Global Applied Science Lab., GE Healthcare, Nancy, France; ²IADI lab., Nancy-Université, Nancy, France; ³U947, INSERM, Nancy, France; ⁴Departement of Radiology, CHU Nancy, Nancy, France; ⁵IMS Research Group, Supelec, Metz, France

Conventional Double Inversion Recovery Fast Spin Echo (DIR-FSE) sequence provides detailed anatomical information in cardiac MRI. However, the preparation time required to cancel blood signal is too long to acquire DIR-FSE during the end-systolic rest. To overcome this constraint, two methods are described. The first one relies on the assumption that the RR intervals are constant whereas the second method is based on an adaptive RR interval prediction algorithm. These approaches were evaluated on 14 healthy volunteers; results demonstrated the robustness of the adaptive method with a better delineation of the right ventricle wall than with the conventional DIR-FSE.