Experimental and clinical studies of hepatic blood flow evaluation by dynamic CT

Dynamic CT of the liver were applied to a method of hepatic blood flow evaluation. The timedensity curve of the liver and the aorta after intravenous bolus injection of contrast medium were evaluated, devising a new potential index for a relative liver blood flow from the aorta (Aorto-Hepatic (A-H) ratio); hepatic peak density was expressed as percentage to aortic peak density and was divided by the peak time difference between the aorta and the liver. In experimental studies, two animal models for decreased hepatic blood flow were prepared, one with hepatic arterial embolization and the other with superior mesenteric vein ligation. The A-H ratios in both groups were well correlated to the decrease of blood flow of the liver, indicating that the A-H ratio could express not only the arterial but also the portal blood flow. In clinical studies, dynamic CT scans were performed in 69 patients, including 50 cases of the liver cirrhosis with hepatoma, 10 cases of liver cirrhosis and 9 cases of normal liver. The A-H ratio of normal liver was 0.63 ± 0.11, while in cirrhosis the ratio was 0.21 ± 0.06 and cirrhosis with hepatoma the ratio was 0.27 ± 0.09. The ratio was well correlated to the degrees of the diseases, and also the ratio was correlated to the hepatic function reserve in some degrees. From this results, it was strongly suggested that the A-H ratio would become an useful index of blood perfusion to the liver parenchyma, providing adjunctive parameter to determine resectability of the liver, indication for hepatic arterial embolization, or evaluation of the course of chronic liver diseases. (author)