Lipid soluble contrast agents for computed tomography of the liver: results with cholesteryl iopanoate.
A new class of compounds, polyiodinated sterol esters, has recently been synthesized and found to have characteristics suggesting potential value as site-specific hepatic computed tomographic (CT) contrast agents. A prototype compound, cholesteryl iopanoate, was administered intravenously to rabbits in doses of 65 mg I/kg. The compound was found to significantly enhance hepatic parenchyma to a maximal level of 65 Hounsfield units (HU) above base-line values without observable splenic enhancement. A subsequent study comparing the administered dose with the change in CT attenuation values of liver demonstrated that near-maximum enhancement reaching 22 HU was achieved at a dose of 30 mg I/kg within 24 h after injection. The enhancement characteristics suggest the mechanism of hepatic accumulation may not be mediated solely by the reticuloendothelial system. Administration of cholesteryl iopanoate (30 mg I/kg) to rabbits with hepatic tumors (V x 2 adenocarcinoma) resulted in the CT imaging of tumors as small as 2 mm in diameter. Further investigation of this new class of lipid-soluble contrast agents seems warranted.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002788:Cholesterol Esters / Q000378:metabolism; D003287:Contrast Media / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D011817:Rabbits; D012995:Solubility; D014057:Tomography, X-Ray Computed / Q000379:methods*
D002788:Cholesterol Esters; D003287:Contrast Media; C039133:cholesteryl iopanoate