Current trends in imaging evaluation of acute cholecystitis

This study was designed to retrospectively determine recent clinical trends of initial radiological evaluation in patients pathologically proven to have acute cholecystitis (AC) and to assess the methodology that led to its diagnosis. Over a 28-month period, the medical records and imaging studies of 117 consecutive patients who had pathologically confirmed AC were retrospectively analyzed. The sensitivities of ultrasound (US) and hepatobiliary 99mTc-iminodiacetic acid (HIDA) were computed. The false-negative scans were retrospectively reviewed by a blinded radiologist to determine the limitations and advantages of each modality. The 117 patients were grouped into six categories based on the type of imaging examination they underwent prior to cholecystectomy: initial US evaluation only (n=80, 68.4%), initial US followed by HIDA (n=17, 14.5%), initial HIDA only (n=2, 1.7%), initial HIDA followed by US (n=3, 2.6%), initial CT (n=5, 4.3%), and no imaging evaluation (n=10, 8.6%). HIDA scan had a calculated sensitivity of 90.9% (20 true-positive, 2 false-negative) while US had a sensitivity of 62% (62 true-positive, 38 false-negative). Current practice in the initial radiological evaluation of acute cholecystitis remains outdated. The vast majority of patients in our study group were initially worked up using US, although HIDA scan has been shown to have greater sensitivity for the diagnosis of acute cholecystitis.