VARIABILITY OF SPLANCHNIC BLOOD-FLOW MEASUREMENTS USING MR VELOCITY MAPPING UNDER FASTING AND POSTPRANDIAL CONDITIONS - COMPARISON WITH ECHO-DOPPLER

Background/Aims: The aim was to study the reproducibility of magnetic resonance velocity mapping, when measuring portal vein and superior me senteric artery blood how under fasting and post-prandial conditions. Magnetic resonance flow measurements for the portal vein were compared with echo-Doppler measurements in the right portal vein. Methods: Eig ht healthy volunteers were studied on two occasions, separated by 1 we ek. Blood flow in the portal vein and superior mesenteric artery was m easured repeatedly under basal fasting conditions. On one occasion mea surements were also made after a meal. Every magnetic resonance measur ement was followed by an echo-Doppler measurement in the right portal vein. Correlations between flow values were calculated using Pearson's r. Variability components were assessed using ANOVA. Results: Intra-i ndividual variability was approximately 7% for portal vein flow measur ements using magnetic resonance velocity mapping. This variability did not increase after 1 h, 1 week and after a meal. Values of flow measu red in the portal vein and superior mesenteric artery using magnetic r esonance velocity mapping correlated well (r=0.80, p<0.001). Fasting p ortal flow as measured with magnetic resonance velocity mapping was 1. 2 l/min (range 0.96-1.6 l/min). Variability in echo-Doppler measuremen ts was comparable to the variability of magnetic resonance velocity ma pping, and flow measurements obtained with the two techniques correlat ed well (r=0.74; p<0.001). Conclusions: Magnetic resonance velocity ma pping accurately measures blood flow in the portal vein with low varia bility and should be preferred when absolute flow values are necessary . Echo-Doppler measurement of the right portal vein has a low variabil ity and can be used to study changes in flow.