Diagnosis of acute cholecystitis: why do patients get multiple studies?

The aim of this study is to establish factors affecting total number of imaging studies performed for acute cholecystitis (AC) prior to surgery. The study included subjects with cholecystectomy and pathologic diagnosis of AC 1/1/05-1/1/14 and imaging studies (computed tomography (CT), ultrasound (US), and/or cholescintigraphy) within 7 days of surgery. The subjects were separated into groups based on modality of the first study. For each subject, report of the first study was reviewed for report's confidence in diagnosis of AC (scored 1-5 on Likert scale: 5 = definitely AC, 1 = definitely no AC), recommendation of additional study, clinical history concerning for AC (history of right upper quadrant pain, cholelithiasis, and/or "rule out AC"). There were 219, 339, and 38 subjects in CT, US, and cholescintigraphy groups, respectively, with mean confidence scores of 3.7 (± 1.2), 3.7 (± 1.1), and 4.7 (± 0.9), respectively (p < 0.001). Prior to surgery, only one study was performed in 21.9 % (48/219) of CT group, 70.2 % (238/339) of US group, and 71.1 % (27/38) of cholescintigraphy group (p < 0.0001). Compared to the US group, the odds of undergoing additional study were 11.8 times higher (p < 0.001) in CT group and 1.7 times higher (p = 0.229) in cholescintigraphy group, adjusting for age, sex, time interval between first study and the surgery, confidence score, recommendation of follow-up study, and clinical history concerning for AC. Patients with AC and CT as the first study are more likely to undergo additional imaging studies prior to surgery as compared to US or cholescintigraphy.