Christopher Nguyen¹, Minjie Liu^2,3, Zhaoyang Fan¹, Xiaoming Bi⁴, Peter Kellman⁵, Debiao Li¹, and Shihua Zhao^2,3
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.

Christian Torben Stoeck^1,2, Constantin von Deuster^1,2, Thea Fleischmann³, Nikola Cesarovic³, Martin Genet¹, Maximilian Y. Emmert^3,4, and Sebastian Kozerke^1,2
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.

Tamer Basha¹, Mehmet Akçakaya¹, Sébastien Roujol¹, and Reza Nezafat^1
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.

Choukri Mekkaoui¹, Howard H Chen², Yin-Ching Iris Chen², William J Kostis², Marcel P Jackowski³, Timothy G Reese², and David E Sosnovik^2
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.

Giulia Ginami¹, Simone Coppo¹, Gabriele Bonanno¹, Tobias Rutz², Juerg Schwitter², Matthias Stuber¹, and Davide Piccini^1,3
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.

Mehmet Akçakaya¹, Sebastian Weingärtner^1,2, Tamer A. Basha¹, Sebastien Roujol¹, and Reza Nezafat^1
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.

Helene Feliciano^1,2, Wajiha Bano^1,2, Matthias Stuber^1,2, and Ruud B. van Heeswijk^1,2
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.

Ronald John Beyers¹, Christopher Ballmann², Joshua Selsby³, Nouha Salibi^1,4, John Quindry², and Thomas S Denney^1
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.

Joep van Oorschot¹, Hamza El Aidi¹, Fredy Visser², Pieter Doevendans¹, Peter Luijten¹, Tim Leiner¹, and Jaco Zwanenburg^1
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.

Sagar Mandava¹, Mahesh Bharath Keerthivasan¹, Diego R. Martin², Ali Bilgin^1,3, and Maria I. Altbach^2
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.