Minimizing contrast agent dose during intraarterial gadolinium‐enhanced MR angiography: In vitro assessment

PURPOSE: To minimize contrast agent dosage for intra-arterial (IA) contrast-enhanced magnetic resonance angiography (CE-MRA) by examining the effects of encoding order (elliptical vs. sequential) and injection duration (100% to 30% of the acquisition time). MATERIALS AND METHODS: Catheter-based IA gadolinium (Gd) injections were performed in an arterial flow phantom. Blood flow rates, injection rates, and injection durations were systematically varied. Signal-to-noise (SNR) measurements were obtained in the aorta, renal artery, and common iliac artery. RESULTS: No significant SNR losses were observed for any of the vessels with 75% injection duration, or for the aorta and iliac artery with 50% injection duration. Excellent images of all vessels were obtained at 50% injection duration. There was no significant SNR difference between encoding schemes. CONCLUSION: Contrast agent dosage can be substantially reduced without loss of SNR by limiting injection to part of the imaging acquisition time.