High-Density Barium-Sulfate Suspensions: An Improved Diagnostic Medium

Since barium sulfate was first employed as a diagnostic contrast medium, radiologists, pharmacists, and others have sought to improve aqueous barium suspensions and their mucosal coating properties. Recently, Finkelstein (1) stressed the need for “contrast media of optimum particle size, in mixtures of optimum density, with superior coating ability” in the early detection of colonic neoplasms. It is the object of this paper to report a further development in this field and some resulting advantages. Heretofore, in an attempt to improve barium-sulfate suspensions, research studies have been directed in one direction or another, notably toward control of pH, addition of various thickening and suspending agents, and variations in particle size. Optimum results have not been attained, however, as these and other factors are interdependent. Any thorough study requires the combined evaluation and consideration of (a) particle size, (b) ionic charge on suspended particles, (c) pH, (d) suspending aids, (e) osmoti...