RENAL-ARTERY BLOOD-FLOW - QUANTITATION WITH PHASE-CONTRAST MR-IMAGINGWITH AND WITHOUT BREATH-HOLDING

PURPOSE: To compare the accuracy of 16-frame cine phase-contrast (PC) magnetic resonance (MR) imaging with those of two breath-hold PC techn iques in the measurement of renal artery blood flow. MATERIALS AND MET HODS: In vitro flow measurements were performed in a segment of harves ted human artery embedded in gel. For the cine PC acquisition, respira tory motion was simulated. In eight subjects with recently obtained pa ra-amino-hippurate-clearance renal blood flow data, renal artery flow measurements were subsequently performed with two breath-hold imaging techniques and with cine PC imaging during shallow respiration. RESULT S: Breath-hold sequences were significantly more accurate than convent ional cine PC sequences both in vitro (P <.005) and in vivo (P <.05). Cine PC imaging tended to overestimate flow (in vivo mean, 24.47% +/- 9.94), reflecting artifactual enlargement of the apparent vessel size. CONCLUSION: Reliable blood flow measurements in the renal artery are possible with breath-hold PC imaging.