Ultrasonic evaluation of patients with acute right upper quadrant pain.

To define the role of ultrasound in evaluating acute right upper quadrant pain, a prospective study was performed on 52 patients having clinically suspected acute cholecystitis. Ultrasonographic determination of acute or chronic cholecystitis, or diagnosis of a normal gallbladder, was based on analysis of location of tenderness, calculi, sludge, and wall thickness. The diagnosis of acute cholecystitis (34.6% of patients) was based on the highly significant observations of focal gallbladder tenderness and calculi. Sludge and wall thickening were also statistically significant, but to a lesser degree. Cholelithiasis allowed differentiation of patients with chronic cholecystitis (32.7%) from patients with normal gallbladders (32.7%). Neither of these two groups had significant focal gallbladder tenderness, sludge, or thickened walls. Because acute cholecystitis is found in the minority of patients with acute right upper quadrant pain, and because ultrasound is rapid, accurate, and noninvasive, it should be the initial modality used to evaluate these patients.