Bile duct measurements after ceruletide as an aid to the ultrasound diagnosis of choledocholithiasis.

Despite good results in gallbladder imaging, ultrasound (US) diagnosis of choledocholithiasis remains a challenge. The value of US before and after a provocative injection of the decapeptide ceruletide was examined in 25 patients with suspected common duct stones immediately prior to diagnostic retrograde cholangiography. An abnormal response (increase in US duct diameter) was seen in 4 of 6 patients with an obstructed duct, giving a sensitivity of 67% and predictive value of 80% for the procedure. There was a normal response (decrease in US diameter of a dilated duct or decrease/no change in a normal duct) in 14 of 19 with an unobstructed duct (specificity 79%, predictive value 93%) and an equivocal response (no change in diameter of a dilated duct) in 5 patients. In 1 patient a calculus not seen on the initial US became visible as the duct distended by ceruletide administration. Symptoms after ceruletide were few and not discriminatory. Although it added to the time and difficulty of performing biliary US, ceruletide administration proved a useful adjunct to the diagnosis of choledocholithiasis.