Qi Yang¹, Kuncheng Li¹, Xiangying Du¹, Xiaoming Bi², Yu Zhang³, Jing An³, and Debiao Li^4
1Xuanwu Hospital, Beijing, China, ²Siemens Medical Solutions USA, ³Siemens Healthcare, MR Collaboration NE Asia, ⁴Cedars-Sinai Medical Center and UCLA

The major advantage of 3.0T whole-heart coronary MRA (CMRA) using a continuous gadolinium infusion is to combine lumenographic information and 3D myocardial viability in the same settings with patterns similar to those obtained by 2D-LGE (late Gd-enhanced) techinique. This suggests a potential of this technique to assist in recognizing the etiology of patients with left ventricular dysfunction (LVD) which is essential for the risk stratification and treatment selection.

Peter Börnert¹, Peter Koken¹, Kay Nehrke¹, Holger Eggers¹, and Peter Ostendorf^2
1Philips Research Laboratories, Hamburg, Germany, ²Centre of Preventive Medicine, Marienkrankenhaus, Hamburg, Germany

To improve coronary vessel visualization in whole heart CMRA, fat suppression is typically applied. However, recent studies showed that cardiac fat can also have diagnostic value. To address also the fat information two-point Dixon protocols have been proposed to replace fat-sat based protocols for CMRA with no scan time penalty. In this pilot study water / fat-separated Dixon protocols are compared to conventional whole heart CMRA imaging protocols used in clinical practice. It has been found in this patient study that two-point Dixon protocols can potentially replace conventional fat-sat-based protocols for CMRA.

Sahar Soleimanifard¹, Michael Schär^1,2, Allison G. Hays¹, Jerry L. Prince¹, Robert G. Weiss¹, and Matthias Stuber^1,3
1Johns Hopkins University, Baltimore, MD, United States, ²Philips Healthcare, Cleveland, OH, United States, ³University of Lausanne, Lausanne, Switzerland

In non-contrast coronary MRA, the T₂Prep sequence has been widely used for contrast enhancement between the coronary blood-pool and the myocardium. This non-selective sequence, however, results in a reduced steady-state magnetization of the inflowing blood, and consequently a penalty in SNR. We hypothesize that a slice-selective variant of this pre-pulse would leave the magnetization of blood outside the imaged volume unaffected, and thereby minimize SNR penalty for inflowing blood. In this work, we implemented a slice-selective T₂Prep and assessed the SNR gain and vessel conspicuity quantitatively using an automatic framework for vessel centerline tracking and boundary segmentation.

Marcelo E Andia¹, Markus Henningsson¹, Tarique Hussain¹, Alkystis Phinikaridou¹, Gerald Greil¹, and Rene M Botnar^1
1Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, London, United Kingdom

We present a novel technique for flow-independent vessel wall imaging based on the differences in T2-relaxation time of arterial blood and surrounding tissues using a T2prep prepulse. The technique is based on the acquisition and subtraction of two datasets, one obtained with and one without T2prep. The subtraction step allows nulling the signal of arterial blood while maintaining signal of muscle and vessel wall. In order to minimize the motion sensitivity we developed an interleaved acquisition for the T2prep and non-T2prep images, which allows obtaining coronary vessel wall images from a whole heart acquisition with minimal misregistration artefacts.

Zhaoyang Fan¹, Petter Dyverfeldt², Xin Liu³, Sven Zuehlsdorff⁴, Vibhas Deshpande⁵, David Saloner², and Debiao Li^1
1Cedars-Sinai Medical Center and University of California, Los Angeles, CA, United States, ²Departments of Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States, ³Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ⁴Siemens Cardiovascular R&D, Chicago, IL, United States, ⁵Siemens Healthcare, San Francisco, CA, United States

3D black-blood MRI is a promising technique for carotid artery wall assessment but is inherently susceptible to motion, such as swallowing. A self-gating (SG) method in combination with a 3D variable-flip-angle TSE sequence, SPACE, has been proposed for prospectively gating swallowing motion. This work aimed to test the utility of the SG-SPACE technique on healthy volunteers and patients. Results showed that the SG approach significantly mitigates the swallowing-induced artifacts, including blurred wall boundary and reduced wall-to-background contrast. Significant improvement in image quality and vessel wall delineation was obtained, indicating its potential to enhance the performance of 3D vessel wall MRI.

Zechen Zhou¹, Rui Li¹, and Chun Yuan^1,2
1Center for Biomedical Imaging Research, Tsinghua University, Beijing, China, ²Department of Radiology, University of Washington, Seattle, WA, United States

Currently, Quadruple Inversion Recovery (QIR) prepared TSE sequence is a common black blood method to image the pre- and post- contrast enhanced vessel wall which can detect the neovasculature and inflammation in atherosclerotic plaque. However, this QIR prepared TSE technique is limited by the acquisition efficiency and partial volume effect. In this work, we first explained the principle of Phase Sensitive Double Inversion Recovery (PSDIR) and then investigated a time efficient 3D isotropic high resolution PSDIR based T1 insensitive flow suppression vessel wall imaging technique. This technique can further improve the CNR between lumen and vessel wall and be potentially applied for dynamic contrast enhanced black and white blood vessel wall imaging.

Philip M Robson¹, Claudia Calcagno¹, Sarayu Ramachandran¹, Venkatesh Mani¹, Melanie Kotys-Traughber², and Zahi A Fayad^1
1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States, ²Philips Healthcare, Cleveland, OH, United States

A new sequence interleaving bright-blood GRE full-image and dark-blood SE image-segment acquisitions is investigated for application to quantitative Dynamic Contrast Enhanced imaging of the carotid arteries in atherosclerosis. Bright-blood images are acquired with 1-sec temporal and low 0.5x4-mm spatial resolutions to capture the arterial input function, while the interleaved dark-blood images have lower temporal and 0.5x0.5-mm spatial resolution to image the thin vessel wall without blooming of the bright vessel lumen. This study in three subjects demonstrates the feasibility of simultaneously-acquired combined image contrasts. Contrast agent kinetic parameters measured in the vessel wall are consistent with those in the literature.

Bo Li¹, Bin Chen², Shuangxi Ji¹, Li Dong³, Zhaoqi Zhang³, Wenchao Cai⁴, Xiaoying Wang⁴, Jue Zhang^1,2, and Jing Fang^1,2
1College of Engineering, Peking University, Beijing, China, ²Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, ³Dept. of Radiology, An Zhen Hospital, Beijing, China, ⁴Dept. of Radiology, Peking University First Hospital, Beijing, China

High-resolution 3D-MERGE technique based black-blood imaging has been reported to quantitatively measure carotid atherosclerotic plaque morphology and tissue composition. However, it brings about relative long time consuming due to the use of motion-sensitized preparation. Nevertheless, compressed sensing (CS) can improve temporal resolution by reconstructing images from a dramatically small number of data without introducing severe image artifacts. Therefore we investigate the feasibility of the fast 3D-MERGE imaging using CS reconstruction. Moreover, compared to the fully k-space sampling approach, we verified whether or not the CS based 3D MERGE images could provide appropriate blood signal suppression and comparable details.

Linqing Li¹, Karla Miller¹, Jamie Near¹, and Peter Jezzard^1
1FMRIB, Clinical Neurology Department, University of Oxford, Oxford, United Kingdom

During application of DANTE (a rapid series of low flip angle RF pulses interspersed with gradients)pulse trains, longitudinal magnetization of flowing spins is largely (or fully) attenuated. This is in contrast to static tissue, whose longitudinal magnetization is mostly preserved. DANTE may be well suited for mutilslice imaging acquisition. This work is to introduce this novel approach to fast black blood imaging. It was found that the overall improvement of the DANTE method over the existing methods is approximately factor of 2.

Isabel Dregely¹, Stephan G Nekolla¹, Carl Ganter², Tobias Koppara³, Hua-Lei Zhang¹, Sylvia Schachoff¹, Anna Winter¹, Marijana Dzijan-Horn³, Markus Schwaiger¹, and Tareq Ibrahim^3
1Department of Nuclear Medicine, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany, ²Department of Radiology, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany, ³Department of Cardiology and Angiology, Klinikum rechts der Isar der TU München, Munich, Bavaria, Germany

Non-invasive imaging techniques have the potential to identify high risk patients in atherosclerotic disease. In this study we demonstrate the feasibility of simultaneous PET/MR in peripheral artery disease (PAD) to improve characterization of atherosclerotic plaques.