Scintigraphic estimation of arterial and portal blood supplies to the liver.

A technique is described for the measurement of the relative magnitudes of the hepatic-artery and portal-vein components of liver perfusion, using a gamma camera and on-line computer system. This ratio is obtained from analysis of the time variation in liver activity on the first pass following bolus intravenous injection of a Tc-99m-labeled radiocolloid. The arterial and portal components are separated by their times of arrival at the liver. These arrival times are evaluated from activity time variations for spleen, left ventricle, and left kidney. Physiological validation of the technique was provided in a digestion study in which normal volunteers showed a significant increase in the portal-vein component 1 hr after a meal relative to the fasting situation. These results are compared with those from studies by other workers. The uncertainties and limitations of the technique are discussed and potential clinical uses suggested.