BREATH-HOLD GADOLINIUM-ENHANCED MR-ANGIOGRAPHY OF THE MAJOR VESSELS AT 1.0 T - DOSE-RESPONSE FINDINGS AND ANGIOGRAPHIC CORRELATION

PURPOSE: To find the appropriate contrast agent dose for gadolinium-en hanced magnetic resonance (MR) angiography by using individual measure ments of contrast agent transit times in a randomized study. MATERIALS AND METHODS: A total of 34 patients with disease of the aorta or its major branches or both were randomly assigned to receive a dose of 0.1 , 0.2, or 0.3 mmol of gadopentetate dimeglumine per kilogram of body w eight. Initially, contrast agent transit times were measured with use of a turbo fast-low-angle-shot sequence. Subsequently, a three-dimensi onal fast imaging with steady-state precession sequence (7.3-msec repe tition time, 2.8-msec echo time) was used for breath-hold MR angiograp hy. Gadopentetate dimeglumine was injected with an MR-compatible power injector. Efficacy was evaluated by measurement of vessel enhancement and by clinical correlation of MR angiograms with x-ray angiograms. R ESULTS: Evaluation of contrast agent transit time was possible in all patients with the test doses, which provided contrast-enhanced MR angi ograms of constant quality. Neither vessel enhancement nor diagnostic information was significantly different across the three study groups. CONCLUSION: The clinical gadolinium dose of 0.1 mmol/kg is sufficient for diagnostic assessment of the aorta and its major branches at cont rast-enhanced MR angiography. High-dose studies appear not to tie requ ired for these large vessels.