Image analysis using hemodynamic computed tomography (CT) on various liver diseases

In order to study image analysis of the hepatic hemodynamics in diffuse and focal liver diseases, a method of hemodynamic computed tomography (CT) was designed. Involved in this study were 65 patients with chronic liver diseases, 53 with focal liver diseases, and 14 controls with normal liver. Scan program was made on the basis of hemodynamic assessments by the use of a method for separate measurement of blood flow through the hepatic artery and portal vein using 133Xe as reported previously. The contrast medium was 65 % meglumine amidotrizoate, which was injected into the right antecubital vein in 10 seconds in a dosage of 1 ml/kg. Scans were made serially at postinjective 18, 34, 50, 90, and 120 seconds, of which the former 3 corresponded to the afferent phase of hepatic arterial blood flow, the early and middle stages of the afferent phase of portal venous blood flow, respectively, and the latter 2 to efferent phase. Differences between pre- and postgraphic concentration of contrast medium in liver, spleen, tumor tissues, abdominal aorta, inferior vena cava and portal vein were then calculated for comparison. In liver cirrhosis, the concentrations of contrast medium at 34 and 50 seconds were significantly lower than the normal, while those in chronic hepatitis were intermediate between those in the former two conditions. In hepatocellular carcinoma, the tumor tissue was strongly stained at 18 seconds and the stainability declined gradually thereafter. On the other hand, tumor visualization was persistently low in metastatic carcinoma. Moreover, in hemangioma the tumor tissue began to stain from peripheral part and remained higher in density for several minutes. An analysis of temporal change in concentration of contrast medium in hepatocellular carcinoma suggested an disturbance in the outflow of blood from the tumor tissue. (J.P.N.)