Segmented 5 versus nonsegmented flow quantitation: comparison of portal vein flow measurements.

RATIONALE AND OBJECTIVES Times of acquisition, mean velocities, mean flows, and their respective standard deviations provided by segmented and nonsegmented flow quantifications (FQ) were compared in the main portal veins of ten healthy adults. METHODS The segmented FQ performed five phase-encoding lines per segment. The authors successively applied the two electrocardiogram-triggered techniques in the same slice perpendicular to the portal flow direction. Their measurements were compared in particular by means of the statistical analysis proposed by Bland and Altman. RESULTS The segmented 5 FQ reduced the acquisition time by two compared with the nonsegmented FQ. The mean velocity and mean flow values of the two techniques were not significantly different. The standard deviations were similar. CONCLUSIONS The segmented 5 FQ showed its major advantage in the portal vein: the acquisition time was reduced without any loss of accuracy or any uncertainty enhancement.