Cholecystokinin Cholangiography

To the Editor.—  While numerous reasons could be listed for the differences in results, including differences in patient selection and the astoundingly large number of patients found suitable for study by Dunn's group over such a short period of time, one overriding difference makes all such comparisons irrelevant. The study deals with a response of the gallbladder to cholecystokinin different from those responses with which comparisons are made. A glance at the abnormal radiologic gallbladder response after cholecystokinin illustrated in Dunn's paper, and their description of the rapid (45-second) intravenous injection of cholecystokinin, make it apparent that these authors accurately reproduced the spasm of the gallbladder infundibulum first described by Torsoli et al¹ in 1961 with 30-second injections. Torsoli et al carefully differentiated between gallbladder contraction consistently obtained with rapid (30-second) cholecystokinin injections and gallbladder emptying obtained with slow (three-minute) injections. We and our colleagues^2,3 have repeatedly emphasized