Intestinal permeability measurements - a new application for water soluble contrast media?

The detection and quantification of altered intestinal barrier function (intestinal permeability) have been addressed frequently during the last year, but the tests available for determination of intestinal permeability are both flawed and have limitations. The new water-soluble roentgen contrast media (CM) of low- and iso-osmolar type have been proposed as intestinal permeability probes. In this article this possible new application for water-soluble CM is discussed in terms of their inherent properties and the experimental and clinical results obtained so far. The 2 iso-osmolar dimers, iodixanol (Visipaque) and iotrolan (Isovist), seem to be as good as the well-documented radio-labeled permeability probe (51)Cr-EDTA in detecting injury of the intestinal mucosal barrier. The CM offer the advantage of allowing direct control of bowel wall exposure with the aid of fluoroscopy. Current permeability probes lack this quality. Iodine-containing substances may be analyzed by the rapid, simple and reliable X-ray fluorescence technique, which is suitable for application in routine clinical practice. We conclude that the new water-soluble roentgen CM have properties which may be of use in the diagnosis and quantification of altered intestinal barrier function.