Quantitative evaluation of spleen haemodynamics from radiocolloidal dynamic scintigraphy.

Quantitative information on spleen perfusion may be obtained as a byproduct of liver studies using 99Tcm colloids, by means of model analysis of dynamic data collected with a large field-of-view computerized gamma camera for about 4 min after intravenous administration of the tracer. Spleen extraction efficiency, vascular transit time, and parameters related to spleen blood flow, splenic clearance and volume of distribution of the tracer were computed, the latter three being expressed in arbitrary units. Results in 14 normal subjects and 78 patients with liver cirrhosis show good agreement with known physiopathological data. Results in five splenectomised patients and one patient undergoing ligation of the splenic artery provided further confirmation of the physiopathological meaning of the estimated parameters. Accuracy was found to be poor for spleens of small (normal) size, but was acceptable for enlarged spleens. Reproducibility of the results appears to be within 20%. It is concluded that this method, when associated with the study of liver function using a single 3-4 mCi dose of radiocolloids, may provide valuable additional information for routine assessment of splanchnic haemodynamics in patients with portal hypertension and splenomegaly.