Measurement of hepatic blood flow using 111In colloid

The reduced hepatic blood flow calculated from hepatic scintigram with 198Au colloid was elucidated as the primary responsible factor for postoperative hepatic insufficiency. However 198Au colloid is no longer in use because of the high levels of radiation. Although 99mTc-phytate behaves similarly to 198Au on imaging, there were discrepancies between the hepatic blood flow index (KL) value and the severity of cirrhosis determined by laboratory data or by histology. In the measurement of hepatic blood flow using a radioactive colloid, factors like organ distribution, stability and uniformity of the colloid particles influence the values. In the present study, a 111In colloid was prepared and administered to rats to investigate the usefulness: as much as 95.4 (0.8) [Mean (+/- SD)]% of the colloid accumulated in the liver at pH 6.8. The distribution of particle diameter was within a relatively narrow range with the peak at 0.2 to 0.4 microns. Moreover, the KL values were not affected by condition of the reticuloendothelial system. The values showed a significant correlation with the measurements of the hepatic tissue blood flow obtained by the hydrogen gas clearance method (gamma = 0.83, P < 0.001). Thus, the 111In colloid can be clinically used as a substitute for 198Au colloid in the preoperative examination for estimation of the limit of resection.