Sonographic findings in cases of missed gallstones

Purpose. We retrospectively evaluated sonographic findings in 946 cases of gallstones to determine whether the false-negative rate for gallstone detec tion by sonography has decreased as a result of technologic advances over t he past 15 years. Methods. We reviewed preoperative sonographic reports, operative notes, and pathologic reports for 614 women and 332 men (ages 22-78 years) seen over a 2.5-year period and compared sonographic findings with surgical pathologi c findings after cholecystectomy. Sonograms for patients whose gallstones w ere missed on sonography were reviewed by 3 board-certified radiologists. Results. Preoperative sonography of the gallbladder accurately predicted th e presence of gallstones in 934 cases (98.7%). Gallstones were not identifi ed by sonography in the remaining 12 cases. In those cases, sonography reve aled polyps in 5, sludge in 5, sludge plus a polyp in 1, and neither stones nor polyps in 1. Thus, the false-negative rate was 1.3%. Conclusions. Despite improvements in sonographic technology, detection of s mall gallstones remains difficult in some cases. Adherent gallstones can mi mic gallbladder polyps. Our false-negative rate for detection of gallstones was no different from that in earlier studies. (C) 1999 John Wiley & Sons, Inc.