ELECTRONIC POSTER - ismrm

Tuesday 13:30-15:30 Computer 83
13:30 4426. 3D MRA with Dynamic Sequence Switching: Improved Imaging of the Arterial and
Venous Phases
Petrice M. Mostardi 1 , Clifton R. Haider 1 , Norbert G. Campeau 1 , Stephen J. Riederer 1
1 Radiology, Mayo Clinic, Rochester, MN, United States
Time-resolved CE-MRA is widely used for imaging the intracranial arterial system, while a single high spatial resolution acquisition
is generally used for the intracranial venous system. The goal of this work was to combine these two studies into a single contrastenhanced
acquisition. A time-resolved CAPR sequence was played out for about 50 sec for arterial phase imaging, providing images
every 3.57 sec. Then, by seamlessly switching to a high spatial resolution, 38 sec long scan, data for a venogram was acquired. High
speed reconstruction further allows the time of switching to be done in real time on a patient-specific basis.
14:00 4427. High-Resolution Non-Contrast Enhanced Dark Blood Brain Vessel Imaging Using a
Balanced Steady State 3D Projection Reconstruction Sequence
Aiming Lu 1 , Keith R. Thulborn 1
1 Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States
Balanced steady-state free precession (SSFP) sequences have been used for non-contrast enhanced vessel imaging due to its high SNR
efficiency and bright blood signal. However, as cerebrospinal fluid (CSF) signal is also bright in SSFP images, the application of these
techniques to brain has been limited. In this work, we demonstrate that instead of appearing as bright signal, the vessels in the brain
have low signal intensity in high-resolution 3T images. Using a dual-half-echo 3D projection reconstruction based SSFP sequence, our
results show that non-contrast enhanced high-resolution vessel imaging can be obtained rapidly along with high quality T2-contrast
images.
14:30 4428. Automated Calculation of Wall Shear Stress in the Middle Cerebral Arteries of
Healthy Volunteers Using PC-VIPR and Spline Interpolation
Warren Chang 1 , Yijing Wu, Kevin Johnson, Andrew Wentland 2 , Steven Kecskemeti 3 ,
Charles Mistretta 1 , Patrick Turski 1
1 Radiology/Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI,
United States; 2 Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison , WI,
United States; 3 Physics/Medical Physics, University of Wisconsin School of Medicine and Public Health,
Madison, WI, United States
Time-average wall shear stress in the M1 segment of the middle cerebral arteries of 10 healthy volunteers was calculated using
automated spline interpolation. The velocity measurements were acquired using PC-VIPR, a fast undersampled phase-contrast MRA
technique that allows whole-brain imaging in 5 minutes with sub-millimeter spatial resolution. The calculated average WSS for the
proximal MCA was 0.20 Pa (S.D. 0.016 Pa) consistent with published values for PC-MRA. This report shows that fast, automated,
non-invasive estimation of wall shear stress can be obtained in middle and large-sized intracranial arteries that are prone to the
development of atherosclerosis and other cerebrovascular disorders.
15:00 4429. Low Dose, Supraortic 3D Time-Resolved MR Angiography at 3T: Comparison with
High Spatial Resolution 3D Contrast-Enhanced MR Angiography
Yoon-joo Lee 1 , Jae-young Byun 1 , So-lyung Jung 1 , Won-jong Yoo 1 , Young-joo Kim 1 , Kookjin
Ahn 1 , Bum-soo KIM 1
1 Department of Radiology, The Catholic University of Korea, Seoul, Korea, Republic of
This study evaluates feasibility and effectiveness of low-dose TR-CEMRA (with injection of 1cc of Gadobutrol followed by 20cc of
saline) performed in the assessment of supraaortic vessel, acquired with combination of parallel imaging (GRAPA) and view-sharing
technique (TWIST) at 3T. Retrospective evaluation of image quality and stenosis grade by two neuroradiologist was done, and
compared with the results from high-resolution single-phase CEMRA. The overall image quality for low-dose TR-CEMRA was in
diagnostic range, comparable to HR-CEMRA. In grading of stenosis, TR-CEMRA showed concordant results with HR-CEMRA in
90.8%, with relatively more number of overestimation than underestimation.
Wednesday 13:30-15:30 Computer 83
13:30 4430. Non-Contrast Dynamic MRA Using TrueFISP Based Spin Tagging with Alternating
Radiofrequency (TrueSTAR) in Cerebral Arteriovenous Malformation
Sumei Wang 1 , Lirong Yan 2 , Yan Zhuo 2 , Ronald L. Wolf 1 , Michael F. Stiefel 1 , Jing An 3 ,
Elias R. Melhem 1 , Jiongjiong Wang 1
1 Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2 State Key Laboratory of Brain and
Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; 3 Siemens Mindit
Magnetic Resonance Ltd., Shenzhen, China
Five patients with arteriovenous malformations (AVMs) were evaluated using a novel dynamic MRA (dMRA) technique termed
TrueFISP based Spin Tagging with Alternating Radiofrequency (TrueSTAR). The results are compatible with time-of-flight (TOF)
MRA results. Dynamic MRA demonstrated the blood flow pattern through feeding arteries, nidus and draining veins with high
temporal resolution (