A novel method for accurately diagnosing acute cholecystitis

Objectives There is a need for a rapid and direct test that is sensitive and specific for acute cholecystitis (ACC). The purpose of this study is to evaluate the ability of ¹⁸FDG PET-CT to accurately assess the status of the gallbladder(GB) in patients(pts) suspected of ACC.

Methods 9 pts with suspected ACC based on history, physical exam, lab values, abdominal ultrasound(US), and HIDA scan were studied. After obtaining consent, pts were injected with ¹⁸FDG, and 30-90 mins later underwent PET-CT. This was done within 48hrs of admission but prior to the pts undergoing operation. These pts were compared with 40 consecutive control subjects who underwent ¹⁸FDG PET/CT for reasons other than ACC.

Results 9 pts suspected of having cholecystitis were evaluated with PET-CT. PET-CT localized ¹⁸FDG accumulation in the GB wall in 7 pts with a pattern of high GB wall activity relative to hepatic activity. 6 pts underwent cholecystectomy and had pathology confirmed ACC. One PET(+) pt was(+)on CT, HIDA and US was treated medically for ACC. 2 pts had (+)HIDA, (-)PET-CT and US with final Dx of non-ACC. There was no detection of ¹⁸FDG in the GB region in any of the controls.

Conclusions ¹⁸FDG-PET/CT detected inflammation of the GB in all pts with ACC. All controls and 2 pts later found not to have ACC had no activity in the GB wall. In this pilot study, PET/CT appears to be a promising rapid, direct and accurate test in diagnosing ACC. Further study of this method is warranted as it may have a role when the diagnosis of ACC is in question, possibly replacing HIDA as a more accurate test.