Biodistribution of a New Lipid-soluble CT Contrast Agent

Evaluation of Cholesteryl Iopanoate in the Rabbit

Abstract

Longino MA, Weichert JP, Schwendner SW, Szabo SM, Counsell RE, Glazer GM. Biodistribution of a new lipid-soluble CT contrast agent: evaluation of cholesteryl iopanoate in the rabbit. Invest Radiol 1983;18:275–278.

Cholesteryl iopanoate, the prototype for a new class of lipid-soluble, site-specific contrast agents, has undergone preliminary evaluation for organic-specific uptake. This report describes the tissue distribution profile of this radioiodinated sterol ester in the rabbit as a function of time following intravenous injection of tracer doses. Selective accumulation of this agent in the liver and adrenal was observed relative to blood and other tissues. Maximum contrast concentration was achieved between 24 and 48 hours postinjection. Analysis of lipid extracts of liver, adrenal, and plasma indicated that the compound was relatively resistant to hydrolysis and dehalogenation. The hepatic selectivity and retention of cholesteryl iopanoate support further study of this or related agents for site-specific, contrast-enhanced computed tomography.