RUQ pain

Clinical history, physical examination, and routine laboratory tests often not specific. By far ultrasound is best first imaging. US showing stones, gallbladder wall thickening and Murphy's sign is diagnostic of acute cholecystitis with > 85% likelihood.

CT and HIDA scan helpful additional tests. Positive HIDA confirms diagnosis of cholecystitis. CT helpful if atypical (? Other etiologies of pain), long duration of syptoms (?abscess) or preoperative planning (duct dilation, perforation)