The ultrasonic determination of renal transplant volume

Four methods are described for calculating the volume of the transplanted kidney from the ultrasonic scan. The first, called an integration method, utilized measurements based on both longitudinal and transverse scans. The other three were based on measurements from a single longitudinal scan. Of the four methods tested, the “integration” procedure is clearly superior to the simpler approximations. Although extremely accurate in vitro , a moderate error is to be expected when in vivo scans are performed. A single ultrasonographer should perform all volume determinations so as to minimize subjective scanning technique differences. Correctly performed, the ultrasonic volume should be within 14% of the true volume at the 95% confidence level.