Gallbladder nonvisualization with pericholecystic rim sign: morphine-augmentation optimizes diagnosis of acute cholecystitis.

Abstract

This study investigated the value of morphine-augmentation in patients who demonstrated gallbladder nonvisualization with a pericholecystic rim sign at 1 hr, a cholescintigraphic pattern considered highly predictive of acute cholecystitis. Retrospectively, 170 consecutive morphine-augmented cholescintigrams were analyzed for the presence of a pericholecystic rim sign, marked or mild, associated with gallbladder nonvisualization at 1 hr (before morphine); those with a pericholecystic rim sign were further evaluated for persistent gallbladder nonvisualization versus gallbladder visualization after morphine. Scintigraphic interpretations were correlated with surgical pathology or clinical diagnosis. Before morphine, 43/170 (25%) patients demonstrated gallbladder nonvisualization with a pericholecystic rim sign. Since only 31 had acute cholecystitis, a diagnosis based solely on that scintigraphic pattern would have resulted in 12 false-positives. After morphine, gallbladder visualization correctly excluded acute cholecystitis in seven; a single false-negative was encountered; five false-positives remained. Morphine-augmentation improved the positive predictive value from 72% (gallbladder nonvisualization with pericholecystic rim sign before morphine) to 86% (gallbladder nonvisualization after morphine). Of 24 patients with marked pericholecystic rim signs, 21 had acute cholecystitis. Of 31 with acute cholecystitis, however, 10 (32%) had a mild pericholecystic rim sign. Morphine-augmented cholescintigraphy optimizes the diagnosis of acute cholecystitis in patients with the suggestive, but not pathognomonic, cholescintigraphic pattern at 1 hr of gallbladder nonvisualization with a pericholecystic rim sign, regardless of its intensity.