COMPARISON OF PER‐RECTAL PORTAL SCINTIGRAPHY USING 99mTECHNETIUM PERTECHNETATE TO MESENTERIC INJECTION OF RADIOACTIVE MICROSPHERES FOR QUANTIFICATION OF PORTOSYSTEMIC SHUNTS IN AN EXPERIMENTAL DOG MODEL

Per‐rectal portal scintigraphy using tech‐netium‐99m pertechnetate ( 99m TcO 4 ‐ ) was performed in 8 normal dogs before and after surgical creation of a portacaval shunt. Shunt fractions were calculated by computer assisted analysis of dynamic images (IMG) and compared to shunt fractions determined by mesenteric venous injection of radioactive microspheres (MIC). The mean pre‐operative shunt fraction was 1.59% using IMG and 3.00% using MCI. The mean postoperative shunt fraction was 64.56% using IMG and 69.56% using MIC. There was excellent correlation between both methods (r 2 0.94). Per‐rectal portal scintigraphy is an easily performed, inexpensive method to diagnose and quantify portosystemic shunts in dogs.