Part 1. Fundament Study on ICG Test

Abstract

Using the single injection method with a dosis of 0.5mg/kg ICG and the technique ofhepatic venous catheterization, a series of observations were conducted on ICG disappearancerate, ratio of ICG concentration in th peripheral arteries versus that in the hepatic vein, aswell as the curves of ICG disappearance level in peripheral arteries.
The results were briefly summarized in the following.
1) The disappearance rate of ICG in the three cases of chronic hepatitis without intrahepaticshunt flow proved to be 76.1-89.5%, in one case with intrahepatic shunt flow it was 53.1%and in one case of precirrhosis of liver it was 78.0%. The rate in the four cases of liver cirrhosiswas 29.0-62.5%.
When the actual blood flow that is in contact with liver cells, is calculated by subtractingthe quantity of intrahepatic shunt flow as computed from the galactose disappearance rateobtained by means of Nakamura's method, it amounted to 53.9-96.8% in the entire nine casescovering chronic hepatitis to liver cirrhosis.
2) When the ratio of ICG concentration between the peripheral artery and hepatic veinis studied from the ICG plasma disappearance curves, the curve is found to fall with the lapseof time and the concentration ratio likewise diminishes at the same time. The curves ofconcentration ratio are studied case by case at the lapse of 3 min, 5 min, and 10 min. In twocases out of the seven chronic hepatitis the inclination of the curve to the base line shows aslight fall, and after 15 minutes six cases out of the seven demonstrate the decline of this inclination.On the contrary, among the cases of liver cirrhosis three out of the four cases showedan appreciable fall of the inclination and the remaining one also showed only an extremelyslight fall between 3 to 15 minutes. In addition, the cases of precirrhosis of liver as well aschronic hepatitis revealed values intermediate between these two groups.
3) The ICG disappearance curve of peripheral artery showed a linear descent at the intervalsof 3 min, 5 min and 10 min in all the cases when it was expressed on semilogarithmic scale.However, the curves of all seven cases of chronic hepatitis deviated from the straight line anddeclined in drawing a slow arch after 15 minutes. The curves in liver cirrhosis had no deviationfrom the stright line and was paralled to the horizontal axis (time). In the comparisonof the values of ICG plasma disappearance rate calculated at the intervals of 3 min, 5 min and 10 min with those calculated at 5 min, 10 min, and 15 min, respectively, those chronic hepatitiscases without portal hypertension revealed considerably high values in the former as comparedwith the latter, however, the cases of liver cirrhosis showed only a slight difference in thevalues between the two groups.
From these findings it was assumed that for the calculation of the plasma disappearancerate after the administration of ICG (0.5mg/kg) the most appropriate time is within 10 min.
The author wishes to express his profound thanks to Professor K. Kosaka for kind guidanceand proof reading of this paper, and acknowledgement is also due to Dr. Y. Shimada for hiskind supervision and advices throughout this work.