Study to establish normal values for portal vein blood flow in children using a duplex ultrasound system.

Portal vein blood flow in healthy children was measured using a duplex ultrasound system consisting of a B mode linear scanner and a single Doppler transducer. Portal blood flow volume (PBFV) correlated with age, height, weight and body surface area. Increases in PBFV with age were greater in boys than girls. A correlation was noted between the diameter of the portal vein and PBFV (r = 0.89). However, the maximum portal blood flow velocity (Vmax) did not correlate with age, height, weight or body surface area. Increases in PBFV in accordance with physical development was thought to depend mainly on widening of the portal vein and not on acceleration of portal blood flow velocity. The formula for calculating PBFV by multivaliate statistical analysis is as follows: PBFV(ml/min) = 30.1 x age(yrs) - 1.07 x height(cm) = 3.31 x weight(kg). Portal vein flowmetry using a duplex ultrasound system may be useful for evaluation of the hepatic circulation in children.