sodium-pertechnetate-tc-99m and Liver-Cirrhosis--Biliary

Portosystemic shunt fraction estimation using transcolonic iodine-123-iodoamphetamine (IMP) has been previously validated relative to portal vein macroaggregated albumin injections using an experimental model of cirrhosis. Transcolonic technetium-99m-pertechnetate (TcO4-) has been proposed as an alternative tracer to IMP to study portal circulation in cirrhotic patients. We compared shunt fraction estimates from paired transcolonic IMP and TcO4- studies performed on a group of dogs before and after common bile duct ligation surgery. Pertechnetate over-estimated shunt fraction in 6/7 postoperative studies relative to IMP. A good correlation between the two methods was demonstrated, however, the slope of the regression line was substantially less than 1.0 with TcO4- values reaching 100% at IMP shunt values of approximately 60%. This apparent inability to accurately assess high shunt flows may limit the quantitative aspects of TcO4- studies on patients with severe portosystemic shunting.

Topics: Amphetamines; Animals; Dogs; Hypertension, Portal; Iodine Radioisotopes; Liver Cirrhosis, Biliary; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Portal circulation in patients with chronic liver diseases was evaluated by [99mTc]pertechnetate per-rectal scintigraphy. Technetium-99m pertechnetate (10 mCi) was instilled into the upper rectum, and serial scintigrams were taken. Radioactivity curves for the liver and heart were then recorded sequentially. Through analysis of these curves, the per-rectal portal shunt index (Sl) was calculated for six healthy subjects and 228 patients, 59 with chronic hepatitis, seven with idiopathic portal hypertension, six with primary biliary cirrhosis, and 156 with cirrhosis. In the healthy subjects, the Sl was 1.9-5.2% (mean 4.1%). In hepatitis, the mean Sl was 7.1%, and in cirrhosis, 52.9%. The Sl was higher in cirrhotic patients with esophageal varices than in those without (p less than 0.001), and in cirrhotic patients with encephalopathy than in those without (p less than 0.01). For some patients with portal hypertension, portal collateral circulation could be depicted, and images of changes in the portal collateral circulation after vascular anastomosis were seen.

Topics: Administration, Rectal; Adult; Chronic Disease; Collateral Circulation; Esophageal and Gastric Varices; Female; Heart; Hepatitis; Humans; Hypertension, Portal; Liver; Liver Cirrhosis; Liver Cirrhosis, Biliary; Liver Diseases; Methods; Middle Aged; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Vena Cava, Inferior