4[4]Yin XY, Lu MD, Huang JF, et al.Color Doppler velocity profile assessment of portal hemodynamics in cirrhotic patients with portal hypertension:correlation with esophageal variceal bleeding. J Clin Ultrasound, 2001,29(1):7.
5[5]Sabba C,Merkel C,Zoli M,et al. Interobserver and interequipment variability of echo-Doppler examination of the portal vein:effect of a cooperative training program.Hepatology,1995,21(2):428.
