Ultrasound measurement of contraction response of the gallbladder: comparison with the radionuclide test for cystic duct patency.

Two tests of cystic duct patency were compared in 37 patients with suspected acute cholecystitis. Ultrasound (US) measurement of gallbladder contraction induced by 40 Ivy dog units of cholecystokinin (CCK) was followed by the radionuclide (RN) test for cystic duct patency. In all 13 patients in whom US showed significant gallbladder contraction after CCK, the cystic duct was proved to be patent by the RN test. The gallbladder did not contract significantly in 24 patients. Eleven of these patients had acute cholecystitis, with evidence of cystic duct obstruction, and 12 had patent cystic ducts and final diagnoses other than acute cholecystitis. The measurement of contraction of the gallbladder in response to CCK is a valuable improvement over simple US when cystic duct obstruction is excluded; failure of contraction is not specific, and independent evaluation of cystic duct patency is required.