Liposomes loaded with contrast material for image enhancement in computed tomography. Work in progress.

Large unilamellar phospholipid vesicles were prepared and loaded with various radiographic contrast media. Body CT following in vivo administration of these vesicles in the rat demonstrated opacification of organs associated with the reticuloendothelial system. Image enhancement in the spleen and liver was dose dependent and was linearly related within the dose range investigated. Contrast enhancement was observed within five minutes of intravenous administration, was maximal 60 minutes after injection, and declined during the second hour. Clearance of the radiographic contrast material was complete within 24 hours. Diffuse splenic lymphoma following intraperitoneal or intrasplenic injection of lymphoma cells, and solitary lymphoma nodules following intrahepatic injection were readily detected as nonenhanced areas following injection of liposomes.