Electronic Posters: Cardiovascular

Wednesday 13:30-15:30 Computer 33

13:30 3640. Triethylenetetramine Treatment in Diabetic Heart Failure: An Animal Trial

Jun Lu^1,2, Beau Pontre³, Stephen Pickup⁴, Bernard SY Choong¹, Mingming Li¹, Hong Xu⁵, Anthony RJ Phillips¹, Garth JS Cooper⁶, Alistair A. Young<sup>7

1</sup>School of Biological Sciences, University of Auckland, Auckland, New Zealand; ²NCIECP, Auckland University of Technology, Auckland, New Zealand; ³Centre for Advance MRI, University of Auckland, Auckland, New Zealand; ⁴Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; ⁵Chemistry & Chemical Engineering, Shenzhen University, Shenzhen, Guangdong, China; ⁶Department of Pharmacology, Oxford University, Oxford, United Kingdom; ⁷Department of Physiology, University of Auckland, Auckland, New Zealand

End stage diabetes is often associated with heart failure, which is the leading cause of death. We are the first to investigate the heart function in STZ-induced diabetic rats longitudinally with and without triethylenetetramine (TETA) treatment using High Field MRI. Gradient echo cine method was used to determine cardiac function. We found that the cardiac ejection fraction decreased with prolonged diabetic status and oral TETA treatment improves ejection fraction in diabetic rats. The results suggest that TETA treatment is beneficial to diabetic heart failure and warrant further clinical investigation.

14:00 3641. Manganese-Enhanced MRI Combined with Delayed Enhancement MRI Detects Injured Border Zone Myocardium in a Pig Ischemia-Reperfusion Model

Rajesh Dash¹, Jaehoon Chung¹, Yuka Matsuura¹, Fumiaki Ikeno¹, Jennifer Lyons¹, Tomohiko Teramoto¹, Alan C.Y. Yeung¹, Michael V. McConnell^1,2, Todd J. Brinton¹, Phillip Harnish³, Phillip C. Yang<sup>1

1</sup>Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, CA, United States; ²Department of Electrical Engineering, Stanford University , Stanford, CA, United States; ³Eagle Vision Pharmaceutical Corporation, Exton, PA, United States

Manganese-enhanced MRI (MEMRI) detects Mn²⁺ uptake into viable cells, a distinct mechanism from gadolinium delayed enhancement MRI (DE-MRI). We tested whether combined DE-MRI plus MEMRI would delineate peri-infarct border zone injury in a pig ischemia-reperfusion (IR). Pigs were imaged by cardiac MRI 3 weeks post-IR. 3D DE-MRI scar volume correlated with histopathologic scar volume, but MEMRI scar volume was significantly smaller than DE-MRI scar volume. The border zones of DE-MRI scar, which were also positive by MEMRI, showed decreased SNR compared to remote zone MEMRI SNR. Combined MEMRI and DE-MRI may identify injured border zone myocardium in ischemic cardiomyopathy.

14:30 3642. Diffusion Tensor Shape Measurements of Infarcted Myocardium in Porcine Models Using Three Phase Geometric Analysis

Yin Wu^1,2, Ed Xuekui Wu<sup>2,3

1</sup>Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Shenzhen, Guangdong, China; ²Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong; ³Dept. of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong

Previous DTI studies on infarcted LV myocardium structure usually investigated diffusivity and diffusion anisotropy. In current study, diffusion tensor shape with a combination of linear, planar and spherical measures are examined and illustrated on a three-phase space in porcine models. Results show that the measurements of tensor shape have significant alteration in infarcted myocardium and are more sensitive to detect subtle change of diffusion properties than conventionally used parameters. Infarct location shows no apparent influence on myocardium structural degradation. This study gives insights into myocardium structural alteration and demonstrates potential application of DTI in detecting infarcted heart remodeling.

15:00 3643. Whole Mount Heart Histology: A New Gold Standard for Myocardial Damage Validation in Experimental Cardiac MRI Studies?

Yuesong Yang¹, Kela Liu¹, Dan Wang¹, Mihaela Pop¹, Jay Detsky¹, Yingli Lu¹, Alexander J. Dick¹, Martin J. Yaffe¹, Graham A. Wright<sup>1

1</sup>Imaging Research, Sunnybrook Health Sciences Centre, University Of Toronto, Toronto, Ontario, Canada

Triphenyltetrazolium chloride (TTC) stain is commonly used for the validation of myocardial damage in experimental cardiac MRI studies using various animal species such as mice, dogs and pigs. However, subtle myocardial damage, border zone or infarct heterogeneity associated with myocardial infarction (MI) is difficult to recognize on TTC stains. In this study, we investigated the feasibility of whole-mount heart histology that preserved the 3D morphology with a digital display at the microscopic level as a new alternative in the validation of myocardial damage in a porcine model of MI in experimental cardiac late-enhancement (LE) MRI studies.

Thursday 13:30-15:30 Computer 33

13:30 3644. Comparison of Scar Morphology by 3D Multi-Contrast Late Enhancement MRI, 3D DW-MRI and Histology in a Pig Model of Chronic Infarct

Mihaela Pop¹, Venkat Ramanan, Yuesong Yang, Nilesh Ghugre, Beiping Qiang, Elliot R. McVeigh², Alexander J. Dick³, Graham A. Wright

¹Medical Biophysics, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada; ²Biomedical Engineering, Johns Hopkins University, United States; ³Cardiology, Sunnybrook Research Institute

Accurate assessment of the scar extent and tissue remodeling during healing is very important. To better understand the scar morphology associated with chronic infarct in a porcine model, we have developed and tested (ex vivo) a 3D pulse sequence based on multi-contrast late enhancement (MCLE) and a non-contrast 3D diffusion-weighted DW sequence, and compare the results against histopathology. We have found that 3D MCLE identifies fine heterogeneity of scar, and compares well the classification of pathology to that from apparent diffusion coeficient maps using DW-MRI.

14:00 3645. Respiratory Self-Gated 2D Cine Balanced SSFP Myocardial Edema Imaging: Preliminary Study in Canines

Swati Gupta¹, Xiangzhi Zhou², Xiaoming Bi³, Saurabh Shah³, Sven Zuehlsdorff³, Andrew Larson², Debiao Li², Rohan Dharmakumar<sup>2

1</sup>Department of Biomedical Engineeering, Northwestern University, Chicago, IL, United States; ²Department of Radiology, Northwestern University, Chicago, IL, United States; ³Siemens Medical Solutions, Chicago, IL, United States

Myocardial edema imaging with bSSFP approaches have been recently demonstrated. In this work, we investigated the utility of respiratory self-gated (RSG) 2D cine bSSFP for acquiring free-breathing myocardial edema images using a canine model subjected to ischemia-reperfusion injury. Early results show that RSG bSSFP imaging is capable of generating edema contrast similar to breath-held bSSFP imaging.

14:30 3646. Repair of Cardiac Damage Using Intrapericardial Drug Delivery by Means of MR-Trackable Alginate Beads

Yamin Yang¹, Marco L.H. Gruwel², Patricia Gervai³, Jiankang Sun³, Olga Jilkina¹, Eugene Gussakovsky¹, Valery Kupriyanov<sup>1

1</sup>Cardiac, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada; ²MRTechnology, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada; ³MRRD, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada

Re-establishment of a vascular network is an important step in the repair of damaged myocardium. For this purpose vascular growth factors were applied at the site of injury. To prolong action of these peptides, growth factors were incorporated in alginate beads. However, visualization of the beads is not an easy task.

15:00 3647. Comprehensive and Serial Evaluation of Myocardial Structure, Function and Perfusion in Reperfused Infarct

Maythem Saeed¹, Alastair J. Martin¹, Loi Do¹, David Saloner¹, Mark Wilson<sup>1

1</sup>Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, Ca, United States

MR imaging was used to 1) assess the changes in LV volumes, ejection fraction, LV mass, regional wall thickness, and 3D wall strain as well as myocardial structure, edema, microvascular obstruction and intramyocardial haemorrhage in reperfused infarct in a single imaging session, to ensure image co-registration and 2) compare LV changes over 10 weeks. MR imaging provides comprehensive and serial characterization of evolved infarct. Myocardial edema, microvascular obstruction and hemorrhage are transient features of reperfusion injury. Based on the MR pulse sequences used it appears five weeks is enough time to arrest fibrosis, but not LV dilation, in reperfused infarct.

Myocardial Viability: Human Models

Hall B Monday 14:00-16:00 Computer 34

14:00 3648. Incremental Benefit of Cardiovascular MRI in the Evaluation of Patients with Systemic Embolism

Monvadi B. Srichai¹, Amelia M. Wnorowski¹, Itzhak Kronzon¹, Leon Axel¹, Ambika Nayar¹, Gila Perk¹, Allison G. Hays², Mark Fisch¹, Vivian S. Lee<sup>1

1</sup>NYU School of Medicine, New York, NY, United States; ²Johns Hopkins, Baltimore, MD, United States

Echocardiography is often the sole imaging technique used for evaluation cardiac sources of embolism. However, studies have demonstrated that up to 40% of patients with ischemic strokes often have no identifiable etiology. Contrast enhanced MRI with MRA identified a cardiovascular source of embolism in an additional 20% of patient in this cohort that was undetected by echocardiography, and hence provides a valuable adjunctive diagnostic imaging method for evaluation of patients with a potential cardiovascular source of embolism, particularly in patients with a negative echocardiography study or who are unable to undergo transesophageal echocardiography.

14:30 3649. Rapid Quantification of Systolic and Diastolic Transverse T1ρ Relaxation Times in the Human Left Ventricle

Gerald A. Zsido II¹, Julio Chirinos², Larry Dougherty³, Kevin Koomalsingh⁴, James J. Pilla^2,4, Walter RT Witschey^1,4, Hee Kwon Song², Joseph H. Gorman III⁴, Robert C. Gorman⁴, Ravinder Reddy<sup>1

1</sup>Radiology, University of Pennsylvania, Center for Magnetic Resonance and Optical Imaging, Philadelphia, PA, United States; ²University of Pennsylvania, Division of Cardiovascular Medicine, Philadelphia, PA, United States; ³Radiology, University of Pennsylvania, Philadelphia, PA, United States; ⁴Surgery, University of Pennsylvania, Philadelphia, PA, United States

A technique for rapid quantification of 1H relaxation times in the human myocardium during systole and diastole was developed. The technique makes use of a T1ρ spin locking pulse cluster, followed by a short, multiecho, radial acquisition, from which k-space-weighted image contrast reconstruction is performed. An 8-fold acceleration of data acquisition was obtained in vivo, compared to a similar set of fully sampled data. In 3 subjects, each scanned 4 times; a significant difference between left ventricular systolic and diastolic relaxation times was measured.

15:00 3650. Three Dimensional Black Blood MRI with Extensive Cardiothoracic Coverage: A Feasibility Study in Healthy Volunteers

Thanh D. Nguyen¹, Keigo Kawaji², Pascal Spincemaille¹, Beatriu Reig¹, Matthew D. Cham¹, Martin R. Prince¹, Yi Wang<sup>1

1</sup>Radiology, Weill Cornell Medical College, New York, NY, United States; ²Biomedical Engineering, Cornell University, Ithaca, NY, United States

Black blood (BB) MRI is useful for morphologic assessment in cardiovascular diseases. While a 3D BB imaging sequence of the whole heart and chest similar to the whole-heart coronary artery imaging approach is highly desirable, commonly used BB preparation techniques rely on blood washout and do not work well in large imaging volumes. The purpose of this study is to develop a free-breathing balanced SSFP sequence for BB imaging of the whole chest using flow-independent T2prep inversion recovery preparation. This sequence was found to provide excellent blood suppression and good BB image quality within a large cardiothoracic volume.

15:30 3651. Detecting Cardiac Involvement in Systemic Sarcoidosis Using a Multi-Contrast Late-Enhancement MRI Technique: Preliminary Results

Yuesong Yang¹, Kim Connelly¹, Jay Detsky¹, Sumaya Al-helali¹, Gideon Paul¹, Rhonda Walcarius¹, Graham A. Wright¹, Alexander J. Dick<sup>1

1</sup>Imaging Research and Cardiology, Sunnybrook Health Sciences Centre, University Of Toronto, Toronto, Ontario, Canada

Sarcoidosis is a systemic disease with a predilection for pulmonary involvement. Although clinical cardiac involvement occurs only in 5-7% of patients with systemic sarcoidosis, the incidence of autopsy-proven disease ranges from 20% to 47%. The presence of cardiac involvement is important to recognize, as it can lead to conduction disturbance and ventricular arrhythmias. Early detection of cardiac involvement with suitable treatment plays a critical role in the prevention of sudden death in these patients. A newly developed multi-contrast late-enhancement (MCLE) MRI has shown the potential to identify subtle myocardial damages in myocardial infarction. In this study we investigated this MCLE technique in the determination of cardiac involvement in systemic sarcoidosis and compared it with conventional IR-FGRE imaging.

Tuesday 13:30-15:30 Computer 34

13:30 3652. Free-Breathing Delayed-Enhancement 3D MRI with and Without Phase-Sensitive Inversion-Recovery

Yasuo Amano¹, Masaki Tachi¹, Yoshio Matsumura¹, Yuriko Suzuki², Shinichiro Kumita¹, Yasutomo Katsumata<sup>2

1</sup>Radiology, Nippon Medical School, Tokyo, Japan; ²Philips Electronics Japan, Tokyo, Japan

This study demonstrated that phase-sensitive inversion-recovery technique was feasible for free-breathing 3D delayed-enhancement MRI at 3.0T, because it significantly improved the confidence for the presence of the hyperenhancing myocardium and the image contrast between the myocardium and blood. However, the 3D MRI without PSIR could not be omitted in some patients, because of its fewer image artifacts and no deterioration of the image quality.

14:00 3653. Clinical Evaluation of a Cardiac T1 Mapping Method Using a Reduced Number of Sample Times

Ting Song^1,2, Vincent B. Ho^2,3, Glenn Slavin¹, Maureen N. Hood^2,3, Jeffrey A. Stainsby<sup>4

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

A Modified Look-Locker with saturation recovery sequence was evaluated on nine patients using different data sampling schemes. The proposed sequence enables flexibility in sampling schemes and an approach comparing a typical 16 heartbeat data acquisition with 8 samples of the signal recovery is compared to an approach that samples only 4 points during the signal recovery in 8 heartbeats. T1 values in normal myocardial tissue pre- and post-contrast, and infarcted myocardial tissue post-contrast, are measured and quantified on patients and volunteers. Accurate T1 estimates can be obtained using reduced data sampling.

14:30 3654. Quantitative Detection of Myocardial Edema Using a Breath-Hold T2 Mapping Pulse Sequence

Mansi Shah¹, Monvadi B. Srichai^2,3, Robert Donnino³, Daniel Kim<sup>2

1</sup>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

Clinical evaluation of myocardial edema with conventional T2-weighted imaging is challenging because of non-uniform signal intensities associated with surface coil. We propose to quantitatively detect myocardial edema using a breath-hold T2 mapping pulse sequence. The accuracy of the T2 mapping pulse sequence was validated against qualitative T2-weighted imaging in seven patients with clinical evidence of heart disease. The T2 mapping pulse sequence was correlated against delayed contrast-enhanced imaging in a patient with acute myocardial infarction. Future research include comprehensive evaluation of T2 values with specific cardiac conditions and the clinical utility of T2 mapping for assessment of myocardial edema

15:00 3655. Triple Inversion Recovery Imaging of Myocardial Infarction

Larry Kramer¹, Catalin Loghin², Eduardo Matta, Martin Pilat, Naveen Garg, Khader Hasan

¹Diagnostic Imaging, UTHSC-Houston, Houston, TX, United States; ²Cardiology, UTHSC-Houston

Triple Inversion Recovery Imaging of the ventricular myocardium is sensitive to myocardial edema due to injury from a severe vascular event. Transmural myocardial infarcts were accurately identified relative to delayed contrast enhancement in 81% of positive cases of myocardial edema. The absence of edema in a patient with initial symptoms of chest pain and a positive electrocardiogram or coronary catheterization suggests a favorable functional outcome.

Wednesday 13:30-15:30 Computer 34

13:30 3656. Highly Accelerated Single Breath-Hold Myocardial T₂^* Mapping Using Susceptibility Weighted Fast Spin-Echo Imaging

Fabian Hezel¹, Gabriele Krombach², Sebastian Kozerke³, Thoralf Niendorf<sup>1,4

1</sup>Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; ²Department of Diagnostic Radiology, University Hospital, RWTH Aachen, Aachen, Germany; ³Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; ⁴Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany

Myocardial T2* mapping is proven value for the assessment of myocardial iron content and tissue oxygenation. This study examines the feasibility of highly accelerated fast-spin echo based T2* mapping. Acceleration is accomplished by (i) inner volume imaging, (ii) regional saturation slab based blood suppression,(iii) partial Fourier and (iv) k-t BLAST. A four-fold acceleration is feasible without compromising image quality and the accuracy of calculated T2* values.

14:00 3657. Contrast Optimization for LGE Imaging of Left Atrium

Sathya Vijayakumar¹, Eugene G. Kholmovski¹, Nassir F. Marrouche<sup>2

1</sup>UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, United States; ²Department of Cardiology, University of Utah, Salt Lake City, UT, United States

While imaging the left atrial wall to assess procedure outcome of RF ablation therapy in the heart, it is necessary to have optimal contrast between scar and blood and scar and normal myocardium. In this work, we present a technique to get optimal contrast between scar and both blood and myocardium using phase sensitive reconstruction and an appropriate choice of inversion time TI.

14:30 3658. Reducing Motion Sensitivity in Free Breathing DWI of the Heart with Localized Principal Component Analysis

Stanislas Rapacchi¹, Pierre Croisille, ^1,2, Vinay Pai³, Denis Grenier¹, Magalie Viallon⁴, Peter Kellman³, Nathan Mewton, ^1,2, Han Wen<sup>3

1</sup>CREATIS, Université Lyon 1, INSA Lyon, Villeurbanne, France; ²Hopital Cardiologique et Pneumologique L. Pradel, Lyon, France, France; ³LCE/NHLBI/NIH, United States; ⁴Hopital Cantonal Universitaire de Genève, Switzerland

Free breathing in vivo cardiac Diffusion Weighted Imaging (DWI) is highly sensitive to physiologic motion. To cope with this issue, we designed a DWI protocol which repeats image acquisition multiple times with incremental trigger delays to cover a large time window in diastole. After registration, a localized Principal Component Analysis (PCA) is employed to reduce inter images myocardium deformation, thus improving final image quality. Then temporal Maximal Intensity Projection (tMIP) (3) is used to find the diffusion weighted intensity for each pixel. We present the benefits of our method and preliminary results in healthy and diseased volunteers.

15:00 3659. Delineating Myocardial Edema and Hemorrhage Using T2, T2*, and Diastolic Wall Thickness Post Acute Myocardial Infarction at 2 Early Time Intervals

Mohammad Imran Zia¹, Nilesh R. Ghugre¹, Gideon A. Paul¹, Jeffrey A. Stainsby¹, Venkat Ramanan¹, Kim A. Connelly¹, Graham A. Wright¹, Alexander J. Dick<sup>1

1</sup>Sunnybrook Health Sciences Centre, Toronto, ON, Canada

Our goal was to demonstrate myocardial edema using T2 spiral and diastolic wall thickness (DWT) and myocardial hemorrhage using T2* in patients post acute myocardial infarction (AMI) at 48 hours and 3 weeks. Assessing the presence and evolution of edema and myocardial hemorrhage early post AMI demonstrates distinct patterns. If myocardial hemorrhage is present, then early scans are affected by the competing effects of T2*, counteracting an increased T2 signal. This may be important in accurately quantifying AAR and identifying those patients most likely to suffer deleterious left ventricular remodeling.