ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Scientific Session • Myocardial Tissue Characterization - Relaxometry & Diffusion

Wednesday 3 June 2015

Room 716 A/B

16:00 - 18:00


Martin J. Graves, Ph.D., T.B.A.

16:00 0711.   
In Vivo Diffusion-Weighted MRI: Contrast-Free Detection of Myocardial Fibrosis in Hypertrophic Cardiomyopathy Patients
Christopher Nguyen1, Minjie Liu2,3, Zhaoyang Fan1, Xiaoming Bi4, Peter Kellman5, Debiao Li1, and Shihua Zhao2,3
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, 2State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, China, 3National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 4Siemens Healthcare, Los Angeles, CA, United States, 5National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States

In 23 hypertrophic cardiomyopathy (HCM) patients, we applied a recently developed 3D motion compensated diffusion-prepared balanced steady-state free precession technique to detect diffuse myocardial fibrosis and compared it against extracellular volume (ECV) mapping and late gadolinium enhanced (LGE) imaging. The proposed technique quantitatively had excellent agreement with ECV (sensitivity, specificity, PPV, NPV, and accuracy: 0.80, 0.85, 0.81, 0.85, and 0.83 with Kappa > 0.66) and yielded increased apparent diffusion coefficient values in regions with elevated ECV (>30%). The proposed cardiac diffusion technique is a contrast-free approach that can detect diffuse myocardial fibrosis in HCM patients comparable to ECV.

16:12 0712.   Second order motion compensated cardiac DTI: direct comparison in-vivo and post-mortem
Christian Torben Stoeck1,2, Constantin von Deuster1,2, Thea Fleischmann3, Nikola Cesarovic3, Martin Genet1, Maximilian Y. Emmert3,4, and Sebastian Kozerke1,2
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 3Department of Surgical Research, University Hospital Zurich, Zurich, Switzerland, 4Clinic for Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

Spin echo based cardiac diffusion tensor imaging is highly sensitive to cardiac motion. Second order motion compensated diffusion encoding gradients are implemented to reduce sensitivity to cardiac motion. In this study the helix elevation angle in-vivo is compared to the post mortem condition in the same pig. Good correlation between in-vivo and post-mortem imaging was found indicating, that bulk motion is sufficiently suppressed by second order motion compensated diffusion encoding.

16:24 0713.   
Effect of the Number of Echoes and Reconstruction model on the Precision and Reproducibility of T2 Measurments in Myocardial T2Mapping - permission withheld
Tamer Basha1, Mehmet Akçakaya1, Sébastien Roujol1, and Reza Nezafat1
1Department of Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, Massachusetts, United States

Quantitative myocardial T2 mapping allows non-invasive assessment of myocardial inflammation/edema. Recent implementations use T2-prepared (T2prep) SSFP sequences to acquire multiple T2 weighted images at different echo times, then generate the T2 maps based on a 2-parameter fitting (2P-fit) model of T2 decay. Recently, a 3-parameter fitting (3P-fit) model was found superior to the conventional 2P-fit model, as it compensates for T1 relaxation effect, and results in more accurate T2 measurements. In this work, we sought to characterize the 3P-fit approach in terms of precision and reproducibility and to evaluate the influence of the number of employed T2prep echo times on these two metrics.

16:36 0714.   Detection of Diffuse Myocardial Fibrosis In Vivo Using Diffusion Tensor Imaging with the Supertoroidal Model
Choukri Mekkaoui1, Howard H Chen2, Yin-Ching Iris Chen2, William J Kostis2, Marcel P Jackowski3, Timothy G Reese2, and David E Sosnovik2
1Harvard Medical School - Massachussetts General Hospital, Boston, MA, United States, 2Harvard Medical School-Massachusetts General Hospital, Boston, MA, United States, 3University of São Paulo, São Paulo, Brazil

Left ventricular hypertrophy (LVH) is accompanied by a diffuse pattern of myocardial fibrosis. The ability of conventional DTI metrics to detect diffuse fibrosis, however, remains unclear. Here we show that the toroidal volume (TV), derived from the supertoroidal model of the diffusion tensor, provides a sensitive metric of local diffusivity. DTI was performed in mice with LVH due to aortic banding. Despite the presence of marked fibrosis, mean diffusivity (MD) and fractional anisotropy (FA) remained normal. In contrast, TV was significantly reduced in the banded mice, demonstrating its sensitivity and the value of the supertoroidal model in detecting microstructural changes.

16:48 0715.   An Iterative Approach to Respiratory Self-Navigation enables 100% Scan Efficiency in 3D Free-Breathing Whole-Heart Phase Sensitive Inversion Recovery MRI
Giulia Ginami1, Simone Coppo1, Gabriele Bonanno1, Tobias Rutz2, Juerg Schwitter2, Matthias Stuber1, and Davide Piccini1,3
1Center for Biomedical Imaging (CIBM), Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland,2Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, 3Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland

The use of respiratory Self Navigation for 3D Whole Heart Phase Sensitive Inversion Recovery (PSIR) has not been exploited yet, since such acquisitions are characterized by strong contrast variations. An Iterative approach to SN showed to successfully compensate for respiratory motion and to enable 100% scan efficiency for PSIR applied to late Gadolinium enhanced imaging of the heart.

17:00 0716.   Joint Myocardial T1 and T2 Mapping Using a Saturation-Recovery Sequence
Mehmet Akçakaya1, Sebastian Weingärtner1,2, Tamer A. Basha1, Sebastien Roujol1, and Reza Nezafat1
1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 2Heidelberg University, Mannheim, Germany

In this study, we develop a saturation-recovery based sequence that exhibits no heart-rate dependence, that can be acquired in a single breath-hold and that allows for accurate simultaneous estimation of myocardial T1 and T2.

17:12 0717.   
Characterization of the Accuracy and Precision of Radial Cardiac T2 Mapping at 3T
Helene Feliciano1,2, Wajiha Bano1,2, Matthias Stuber1,2, and Ruud B. van Heeswijk1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland

In this study, the accuracy and precision of radial cardiovascular T2 mapping at 3T were evaluated as a function of influences such as the signal-to-noise ratio (SNR), acquisition in systole versus diastole, and the off-resonance frequency. Both numerical simulations and in-vivo imaging of healthy volunteers were used.

17:24 0718.   Whole-heart T2-mapping at 7T quantifies dystrophic myocardial pathology in mdx/utrn+/- mice - permission withheld
Ronald John Beyers1, Christopher Ballmann2, Joshua Selsby3, Nouha Salibi1,4, John Quindry2, and Thomas S Denney1
1MRI Research Center, Auburn University, Auburn University, AL, United States, 2Kinesiology, Auburn University, Auburn University, AL, United States,3Department of Animal Science, Iowa State University, Ames, IA, United States, 4MR R&D, Siemens Healthcare, Malvern, PA, United States

Duchenne muscular dystrophy (DMD) causes cardiac dysfunction. In a DMD mice model, we developed and applied cardiac MR as whole-heart T2-mapping sequence to quantify myocardial T2 changes and to confirm that quercetin treatment is cardio-protective in DMD mice with haploinsufficiency of the utrophin gene (mdx/utrn+/-). T2 mapping confirmed significantly higher T2 in untreated mdx/utrn+/- hearts, but normal T2 in quercetin treated hearts at age 10 months. T2-mapping in mice hearts is effective for tracking T2 changes. Quercetin treatment helps protect from DMD cardiac dysfunction.

17:36 0719.   
Endogenous assessment of chronic myocardial infarction with T1lower case Greek rho-mapping in patients
Joep van Oorschot1, Hamza El Aidi1, Fredy Visser2, Pieter Doevendans1, Peter Luijten1, Tim Leiner1, and Jaco Zwanenburg1
1University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Philips Healthcare, Best, Noord-Brabant, Netherlands

Studies in animal models have shown that cardiac T1ρ-mapping can be used to detect myocardial fibrosis without the use of a contrast agent. In this study we performed cardiac T1ρ-mapping for detection of chronic MI in 21 patients, and compared it with the LGE method. A significantly higher T1ρ relaxation time was found in the infarct region (79 ± 11 ms), compared to healthy remote myocardium (55 ± 6 ms). A sensitivity of 0.77 and a specificity of 0.73 was found for T1ρ-mapping compared to LGE imaging.

17:48 0720.   
Improved slice coverage in DBIR-FSE with multi-band encoding
Sagar Mandava1, Mahesh Bharath Keerthivasan1, Diego R. Martin2, Ali Bilgin1,3, and Maria I. Altbach2
1Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 2Medical Imaging, University of Arizona, Tucson, AZ, United States, 3Biomedical Engineering, University of Arizona, Tucson, AZ, United States

The double inversion fast spin echo (DBIR-FSE) pulse sequence is used to generate black blood images of the heart but is known to be a single slice technique due to a non-selective inversion pulse used for magnetization preparation. In this work we present a multi-band version of DBIR-FSE which can generate multiple slices acquired at the null point of blood and exhibits better SNR efficiency. A radial version of the proposed sequence can generate anatomical images of multiple slices along with individual echo images at different TE's and T2 maps in a single breath-hold.