The response of the portal vein to an oral glucose load.

Changes of total blood flow, velocities, and cross-sectional area in the portal vein before and after oral glucose administration were studied using image-directed Doppler ultrasonography. Portal vein cross-sectional area, flow velocity, and total blood flow increased significantly compared with baseline studies. Relative increase in these values compared with baseline studies (95% confidence intervals) are presented, and future applications of this method are discussed.