In portosystemic shunt surgery, there still is a lack of correlation between various preoperative hemodynamic measurements and the postoperative clinical course of patients. The magnitude of post-shunt increment in hepatic arterial flow was found to be directly related to long term prognosis. To predict the arterial response for selecting patients for shunting, we tried to use a new non invasive method: Arterial and portal components of total liver blood flow were determined quantitatively by "Sequential hepato-splenic scintigraphy". Dilatation capability of the hepatic artery, was tested by means of the hemodynamic action of Parathyroid hormone (PH). PH has been found to induce a large and exclusive augmentation of hepatic arterial blood flow. We were able to document a statistically highly significant increase in hepatic arterial flow following i. v. applications of PH. The extent of arterial increment appears to be dependent upon the degree of entrapment of the hepatic arterioles by the fibrous tissues of cirrhosis.