Room 255 EF

16:00 - 18:00

Moderators:

J. Paul Finn, Stefan O. Schönberg

Lirong Yan¹, Noriko Salamon², and Danny J.J. Wang^1
1Neurology, UCLA, Los Angeles, CA, United States, ²Radiology, UCLA, Los Angeles, CA, United States

The purpose of this study is to introduce a new non-contrast dynamic MRA (dMRA) technique termed multi-bolus TrueSTAR, by combining the benefits of pulsed ASL, including short RF duration and low SAR, and pseudo-continuous ASL (pCASL), including higher SNR and prolonged labeling bolus. Multi-bolus dMRA offered a prolonged tagging bolus compared to the standard single-bolus dMRA, and allowed improved visualization of the draining veins in arteriovenous malformation. Compared to pCASL based dMRA, multi-bolus dMRA provided visualization of the full passage of the labeled blood with the flexibility for both static and dynamic MRA.

Masanobu Nakamura¹, Masami Yoneyama¹, Takashi Tabuchi¹, Atsushi Takemura², Makoto Obara², and Taro Takahara^3
1Yaesu clinic, Tokyo, Japan, ²Philips Electronics Japan, Tokyo, Japan, ³Tokai University School of Engineering, Kanagawa, Japan

A new technique was presented for non-contrast volumetric time-resolved MRA (Contrast inherent INflow Enhanced Multi phase Angiography using pseudo-continuous arterial spin labeling; CINEMA-PCASL) [4]. This technique requires no catheter insertion or contrast agent and provides useful qualitative information on the morphologic and dynamic filling of intracranial vessels. The feasibility study of CINEMA-PCASL sequence has been reported recently on healthy volunteers, but its clinical application in patients with AVMs has not been conducted. The purpose of this study was to evaluate the diagnostic use of non-contrast time-resolved MRA with time-of-arrival map in patients with cerebral AVM.

Rola Saouaf¹, Zhaoyang Fan², Mariko L. Ishimori³, Lindsy J. Forbess³, Emmanuil Smorodinsky¹, Daniel J. Wallace³, Michael H. Weisman³, and Debiao Li^2
1Imaging, Cedars-Sinai Medical Center, Los Angeles, California, United States, ²Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States,³Rheumatology, Cedars-Sinai Medical Center, Los Angeles, California, United States

Systemic Lupus Erythematosus (SLE) is an autoimmune disease which can affect hand vasculature. Noncontrast FSD MRA was compared to contrast enhanced (CE) Time resolve (TWIST) and high resolution MRA. Vascular pathology was compared to clinical findings. Preliminary data shows FSD MRA was superior to CE MRA in all segments evaluated. Vascular pathology had variable concordance with clinical presentation which will warrant further investigation.

Stanislas Rapacchi¹, Fei Han¹, Yutaka Natsuaki², Randall Kroeker³, Adam Plotnik¹, Evan Lehrman¹, James Sayre¹, Gerhard Laub⁴, J. Paul Finn⁵, and Peng Hu^5
1Departement of Radiology, UCLA, Los Angeles, CA, United States, ²Cardiovascular, Siemens Healthcare, Los Angeles, CA, United States, ³Siemens Healthcare, Winnipeg, MB, Canada, ⁴Siemens Healthcare, Los Angeles, CA, United States, ⁵Departement of Radiology, University of California Los Angeles, Los Angeles, CA, United States

We propose a compressed sensing technique based on magnitude image subtraction for high spatial and temporal resolution dynamic contrast-enhanced MR angiography (CE-MRA). In a breath-held CE-MRA acquisition, the subtraction of a pre-contrast mask to a post-contrast image promotes sparsity of the difference image. This "subtraction-sparsity" has been previously reported and our proposed magnitude subtraction-based technique takes advantage of this sparsity while avoiding a number of issues with direct k-space subtraction. Full-sampled Cartesian 3D CE-MRA datasets were retrospectively under-sampled and different strategies of reconstruction were evaluated. Our technique was tested with a prospectively under-sampled CE-MRA sequence achieving an acceleration of 12.5x.

Taehoon Shin¹, Bob S. Hu^1,2, and Dwight G. Nishimura^1
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²Palo Alto Foundation, Palo Alto, CA, United States

Velocity-selective (VS) excitation is a promising magnetization preparation for non-contrast-enhanced (NCE) MRA as it can generate positive angiographic contrast directly without subtraction. This work aims to develop a new version of the VS excitation pulse sequence that is robust to off-resonance and demonstrate its application to NCE peripheral MRA. The proposed VS pulse design modifies a reference k-space-based design by incorporating 180° refocusing pulses and tailoring sequence parameters in a limited velocity region-of-interest. The improved off-resonance immunity and clinical feasibility of NCE peripheral MRA using the proposed VS preparation are shown in healthy and patient subjects.

Ioannis Koktzoglou^1,2, Charles A. Mistretta³, Shivraman Giri⁴, Parag Amin⁵, and Robert R. Edelman^1,6
1Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States, ²The University of Chicago Pritzker School of Medicine, Chicago, IL, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States, ⁴Siemens Healthcare, Chicago, IL, United States, ⁵Radiology, Northwestern University, Chicago, IL, United States, ⁶Northwestern University Feinberg School of Medicine, Chicago, IL, United States

A time-resolved variation of nonenhanced quiescent interval single-shot (QISS) MRA using a golden angle radial trajectory and highly constrained back projection (HYPR) reconstruction is presented. The method permits rapid display of peripheral arterial anatomy and flow with high spatial and temporal resolution.

Jonathan Powell¹, Markus Henningsson¹, Claudia Prieto¹, and Rene M. Botnar^1
1Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, London, United Kingdom

We achieve 100% navigator efficiency for free breathing 3D coronary magnetic resonance angiography, using radial self navigation to retrospectively correct for motion artefacts. Compared to 1D navigator gated scans we achieve equivalent image quality with substantially reduced scan time.

Claudia Prieto^1,2, Mariya Doneva³, Muhammad Usman¹, Rene M. Botnar¹, and Tobias Schaeffter^1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, ²Escuela de Ingenieria, Pontificia Universidad Catolica de Chile, Santiago, Chile, ³Philips Research Europe, Hamburg, Germany

A 3D respiratory motion-corrected reconstruction approach for whole-heart coronary MRA is proposed. This approach achieves 100% scan efficiency by correcting all acquired data directly in the reconstruction after image-based registration of high-resolution undersampled reconstructed data. This is achieved by using a golden-step spiral-like Cartesian acquisition. This phase-encoding scheme ensures a quasi-uniform sampling for any respiratory window and at any breathing position. Motion parameters are estimated from undersampled respiratory-resolved images reconstructed with iterative SENSE and 3D motion correction is performed directly in the reconstruction using a multiple-coils generalized matrix formulation approach. The proposed approach achieves high image quality comparable to that of an 8mm navigator-gated acquisition, which is less efficient.

Davide Piccini^1,2, Christophe Sierro³, Juerg Schwitter³, Pierre Monney³, Gabriella Vincenti³, Simon C. Koestner³, Didier Locca³, Tobias Rutz³, Arne Littmann⁴, Michael O. Zenge⁴, Gunnar Krueger^1,5, and Matthias Stuber^2
1Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ²Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, ⁴MR Application and Workflow Development, Healthcare Sector, Siemens AG, Erlangen, Germany, ⁵CIBM-AIT, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland

While self-navigated (SN) whole heart coronary MRA data have successfully been acquired in healthy adult subjects, the performance of this technique remains to be ascertained in patients with suspected or established coronary artery disease (CAD). In this work our 3D radial SN whole-heart technique was optionally integrated in clinical examinations of 60 patients with suspected or confirmed CAD. All coronary segments were graded by experts and compared with x-ray angiography, when available, for detection of stenoses. The SN technique was also tested for identification of congenital anomalies of the coronary arteries.

Kuncheng Li¹, Qi Yang², Bin Sun³, Hong Yun⁴, Lijun Tang⁵, Junling Xu⁶, Shurong Li⁷, Mengqi Wei⁸, Zhenbin Cao⁹, Lixin Jin¹⁰, Mengsu Zeng⁴, Qing Duan³, Yi Huan⁸, Quanfei Meng⁷, Xiangquan Kong⁹, and Dehang Wang^5
1Radiology Department, Xuanwu Hospital, Beijing, China, ²Xuanwu Hospital, Beijing, China, ³Fujian Union Hospital, Fuzhou, China, ⁴Zhongshan hospital, Fudan University, Shanghai, China, ⁵Jiangsu Province Hospital, Nanjing Medical University, Nanjing, China, ⁶Henan Provincial Hospital, Zhengzhou, China, ⁷First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China, ⁸Xijing Hospital, Fourth Military Medical University, Xian, China, ⁹Wuhan Union Hospital, Huazhong University of Science, Wuhan, China, ¹⁰Siemens Healthcare, MR Collaboration NE Asia, Shanghai, China

Among patients who were scheduled to conventional x-ray coronary angiography, coronary MRA at 3.0T demonstrates high accuracy for detection of significant coronary artery stenosis. With contemporary techniques, 3.0T whole heart coronary MRA can be performed efficiently, and warrants greater consideration as a suitable noninvasive method to exclude obstructive coronary artery disease.