Clinical implications of hepatobiliary scintigraphy and ultrasound in the diagnosis of acute cholecystitis.

BACKGROUND We assess the performance of ultrasound (US) and hepatobiliary scintigraphy (HIDA) as confirmatory studies in acute cholecystitis (AC) and demonstrate our current imaging protocol's impact on outcomes. STUDY DESIGN Between January 2013 to July 2014, 117 patients were admitted through the emergency room with a preliminary diagnosis of AC. Overall, 106/117 (91%) of the patients received US preadmission and 34/117 (29%) received a HIDA post admission. Primary end points included: 1) diagnostic test reliability for AC, and 2) outcome and quality measures (time to surgery, LOS, costs, etc.). RESULTS Laparoscopic cholecystectomy was performed in 96/117 (82%) and open cholecystectomy in 21/117 (18%) of the patients. Overall, histopathologic features consistent with AC was present in 46/117 (39%). AC alone was present in 23/117 (20%), and AC superimposed on chronic cholecystitis was present in 23/117 (20%). For AC, US had a sensitivity and specificity of 26% and 80%, respectively. HIDA scan had a sensitivity and specificity of 87% and 79%, respectively. Time to surgery (TTS) was 4 vs 2.3 days in patients who received HIDA vs US alone (p = 0.001), and length of stay (LOS) was 6.7 vs 4.3 days, respectively (p = 0.001). Age >50 years, glucose >140 (mg/dl), and WBC count >10 (×109 /L) were statistically significant independent variables associated with AC. CONCLUSION HIDA scan is superior to US as a diagnostic study in the setting of AC. Our current protocol of delayed HIDA (post-admission) was associated with increased TTS, LOS, and overall costs. Early confirmation with HIDA in high risk patients may hasten treatment allocation and improve outcomes in the setting of AC.