Improved Peripheral MRA using Multi-Velocity-Encoding Phase Contrast-Enhanced MRA Techniques

Abstract

Phase contrast MR angiography (PC-MRA) depends on phase shifts caused by blood flow. Generally, PC sequences employ one VENC (velocity-encoding) value for each encoded spatial direction to optimize the signal in major vessels during peak systolic flow. We compared a mono- (30) with a multi- (20/30/45) VENC-PC-MRA technique in 10 patients with peripheral arterial occlusive disease. In all patients, the multi-VENC-PC sequence enhanced the vascular signal in vessels with very different flow velocities in one measurement. Large fields-of-view can be measured in a relatively short examination time to obtain an overview of the peripheral arterial system of the patient when contrast-enhanced MRA is not possible.