The Double-Contrast Study of the Colon

Abstract

Since the description of the technic for double-contrast examination of the colon by Fischer (1) in 1923, barium sulfate, with or without the addition of various other agents, has been the chief medium used in such studies. Other substances, such as “Umbrathor,” a colloidal suspension of thorium dioxide, have appeared from time to time but have not gained wide acceptance. It is our feeling that the unsatisfactory results of the double-contrast procedure which can be traced to the medium are in many instances attributable to a poor selection of the material to be used or to its inconstant composition due to (a) difficulties in mixing the ingredients and (b) the necessity of preparing it in amounts sufficient only for immediate use. Because of our own experience and that of other radiologists in various parts of the country, we have conducted the study to be reported here, chiefly with the idea of determining the possibilities of the ready-prepared media now on the open market. As a working basis we have set up the following criteria for comparison of the available media: 1. Radiopacity: The medium must have sufficient opacity to roentgen rays to give a low-grade contrast to soft tissues when it is spread in a thin layer over the mucosa of the colon. It must not be opaque enough, in a thin layer, to obscure mucosal detail and intraluminal lesions. 2. Adherence: The medium must adhere to the intestinal mucosa as a thin layer and not form lumps in the intestinal canal. 3. Suspension: The medium must stay in suspension for a sufficient length of time for completion of the study, without “drying out.” 4. Preparation: A minimum of time and effort should be required to make a uniform preparation for immediate and subsequent examinations. The possibility of using “left-over” solutions by addition of freshly made solutions would be desirable to avoid waste. Absence of staining qualities and of other objectionable characteristics is necessary. 5. Toxicity: The medium must, of course, be non-toxic and free of adverse reactions for the patient. 6. Cost: The cost should be within a reasonable range to make use of the medium feasible. 7. End-Results: The final approval of any medium used for double-contrast studies must rest upon consistently good diagnostic roentgenograms, all other factors being equal. We know of only two commercial ready-prepared special barium sulfate mixtures for colon study on the open market at the present time. This study is a comparison of these two products and two barium sulfate U.S.P. products which are distributed by different companies. Characteristics Preparation I: Barium Sulfate U.S.P. (3): This preparation is a white, finely granular, uniform powder with no tendency to cohesion of particles. It forms practically no clumps on the stirring apparatus and requires very little stirring to complete its suspension.