A safe and effective intravenous Cholangiographie agent has been available to radiologists since the introduction in Europe of Biligrafin as a 20 per cent solution of sodium iodipamide in 1953 and its successor in this country, the methylglucamine salt Cholografin.2 Through the twelve-year period, 1953 to 1965, clinical investigators using the recommended 20 cc injection have published widely divergent results on the success of this contrast agent (1–6). In their review of the literature, Floch and Geffen (7) noted that the incidence of nonvisualization was as high as 34 per cent, but with improved patient selection and experience the degree of failure is generally in the 6 to 15 per cent range. The duct was satisfactorily visualized in 83.5 per cent of the 237 cases in their series. Wise (8) indicated in his monograph that, with proper patient selection based on preliminary liver function evaluation, successful visualization of the common duct in the cholecystectomized patient might be improved from his ...