Liver Scintigraphy in Veterinary Medicine

The most common veterinary application of liver scintigraphy is for the diagnosis of portosystemic shunts (PSSs). There has been a continual evolution of nuclear medicine techniques for diagnosis of PSS, starting in the early 1980s. Currently, transplenic portal scintigraphy using pertechnetate or 99mTc-mebrofenin is the technique of choice. This technique provides both anatomical and functional information about the nature of the PSS, with high sensitivity and specificity. Hepatobiliary scintigraphy has also been used in veterinary medicine for the evaluation of liver function and biliary patency. Hepatobiliary scintigraphy provides information about biliary patency that complements finding in ultrasound, which may not be able to differentiate between biliary ductal dilation from previous obstruction vs current obstruction. Hepatocellular function can also be determined by deconvolutional analysis of hepatic uptake or by measuring the clearance of the radiopharmaceutical from the plasma. Plasma clearance of the radiopharmaceutical can be directly measured from serial plasma samples, as in the horse, or by measuring changes in cardiac blood pool activity by region of interest analysis of images. The objective of this paper is to present a summary of the reported applications of hepatobiliary scintigraphy in veterinary medicine.