Electronic Posters: Cardiovascular

Wednesday 13:30-15:30 Computer 41

13:30 3765. Ultra Low Dose 4D Contrast Enhanced MRA Using HYBRID HYPR Technique

Yijing Wu¹, Kevin M. Johnson¹, Steven R. Kecskemeti¹, Charlse A. Mistretta², Patrick Alan Turski<sup>3

1</sup>Medical Physics, University of Wisconsin, Madison, Madison, WI, United States; ²Medical Physics and Radiologly, University of Wisconsin, Madison, Madison, WI, United States; ³Radiology, University of Wisconsin, Madison, Madison, WI, United States

Time resolved contrast-enhanced magnetic resonance angiography has been widely used to evaluate vascular hemodynamics. Due to recent concern of the NSF disease, eliminating or reducing Gadolinium-based contrast agent is desirable. HYBRID HYPR decouples the high spatial resolution and SNR, which require relative long scan time, from the high temporal resolution, which demands for fast data acquisitions. It used the HYPR constrained reconstruction to obtain high temporal resolution, high spatial resolution, and high SNR image series. The hypothesis of this work is that the contrast dose can be reduced using the HYBRID HYPR technique: the SNR of the HYPR images is primarily determined by the composite, which is generated using minimal mount of contrast agent (e.g. post contrast phase-contrast images) or can be acquired before contrast injection (e.g. Time-of-Flight images). High temporal and spatial resolution time resolved contrast-enhanced MRA can be obtained by using Low Dose HYBRID HYPR method with contrast dose as low as 1ml.

14:00 3766. Congenital Heart Disease: Role of Time-Resolved MR Angiography

kambiz nael¹, Michael Fenchel¹, Stefan G. Ruehm¹, J Paul Finn<sup>1

1</sup>Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States

Advances in fast imaging tools such as parallel acquisition and sparse k-space sampling methods such as time-resolved angiography with interleaved stochastic trajectories (TWIST), have the potential to improve the performance of time-resolved MR angiography (TR-MRA). In this study we evaluated the clinical usefulness of a 3D CE-MRA protocol that encompasses both high spatial and high temporal resolution acquisition in evaluation of patients with congenital heart disease (CHD). Our objective is to investigate whether TR-MRA can unravel complex functional vascular anatomy in patients with CHD and to assess the incremental diagnostic value of TR-MRA over conventional MRA in this population.

14:30 3767. Evaluation of Non-Contrast Time-Spatial Labeling Inversion Pulse for Abdominal Angiography Compared to Contrast-Enhanced Angiography

Erin Jane Kelly¹, Steve Saeger², David E. Neal<sup>2

1</sup>Toshiba America Medical Systems, Tustin, CA, United States; ²Radiology, Central Ohio Primary Care Physicians, Columbus, OH, United States

Non-contrast angiography techniques are becoming increasingly important in the clinical setting. 3D SSFP Time-SLIP has been developed to produce bright blood angiograms for abdominal angiography, including renal MRA exams. The purpose of this study was to evaluate image quality and diagnostic confidence for Time-SLIP compared to contrast-enhanced MRA in the same group of patients. Image quality scores were 2.6±0.7 and 2.4±0.7 for Time-SLIP and CE-MRA, and Diagnostic quality scores were 2.8±0.4 and 2.4±0.8 for Time-SLIP and CE-MRA, respectively. This study indicates that Time-SLIP is a safe and effective alternative for CE-MRA and may replace CE-MRA in the clinical setting.

15:00 3768. Non-Contrast-Enhanced Renal MRA Using Inflow-Enhanced, Inversion-Recovery at 3T

Thorsten Alexander Bley^1,2, Scott Brian Reeder², Mark Schiebler², Naoyuki Takei³, Jean H. Brittain⁴, Thomas Grist², Christopher J. Francois<sup>2

1</sup>Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; ²Radiology, University of Wisconsin-Madison, Madison, WI, United States; ³Japan Applied Science Laboratory, GE Healthcare, Tokyo, Japan; ⁴Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States

This work presents validation of an inflow-enhanced, inversion-recovery (IR) balanced steady state free precession (bSSFP) based non-contrast-enhanced MRA (NCE-MRA) for assessment of renal arteries at 3T in patients with suspected renal artery stenosis or with a history of renal artery transplant. NCE-MRA with inflow-enhanced IR bSSFP produced consistent results and demonstrated moderate agreement with CE-MRA for both readers and strong inter-observer agreement for grading renal artery stenosis >50%.