Although hepatobiliary iminodiacetic acid (HIDA) scan is often used when the diagnosis of cholecystitis remains questionable after ultrasound, it carries a high false-positive rate and has other limitations. Fluorodeoxyglucose positron emission tomography–computed tomography (18FDG PET-CT) has recently gained enthusiasm for its ability to detect infection and inflammation. In this study, we evaluate the accuracy of 18FDG PET-CT in diagnosing cholecystitis. Nineteen patients with suspected cholecystitis (Group S) underwent PET-CT and 10 had positive PET-CT findings. Of these 10, nine underwent cholecystectomies, and pathology confirmed cholecystitis in all nine. One patient was managed nonoperatively as a result of multiple comorbidities. Of the nine patients with negative PET-CT, six were managed nonoperatively, safely discharged, and had no readmissions at 3-month follow-up. The other three patients with negative PET-CT underwent cholecystectomies, and two showed no cholecystitis on pathology. The third had mild to moderate cholecystitis with focal mucosal erosion/ulceration without gallbladder wall thickening on pathology. 18FDG PET-CT detected gallbladder inflammation in all but one patient with pathology-proven cholecystitis with a sensitivity and specificity of 0.90 and 1.00, respectively. 18FDG-PET-CT appears to be a promising, rapid, direct, and accurate test in diagnosing cholecystitis and could replace HIDA scan in cases that remain equivocal after ultrasound.
G59(P) The role of fluorodeoxyglucose positron emission tomography FDG-PET scan in the diagnosis of autoimmune encephalitis
