Abdominal ultrasound versus hepato-imino diacetic acid scan in diagnosing acute cholecystitis--what is the real benefit?

ABSTRACT

BACKGROUND: Acute cholecystitis is one of the most common surgical problems, yet substantial debate remains over the utility of simple examination, abdominal ultrasound (AUS), or advanced imaging such as hepato-imino diacetic acid (HIDA) scan to support the diagnosis. MATERIALS AND METHODS: The preoperative diagnostic workup of patients who underwent cholecystectomy with histologically confirmed acute cholecystitis was reviewed to calculate the sensitivity of AUS, HIDA scan, or both. In addition, the sensitivity of the commonly described ultrasonographic findings was assessed. RESULTS: From 2010 through 2012, 406 patients among 9087 reviewed charts presented to the emergency department with acute upper abdominal pain and met inclusion criteria. 32.5% (N = 132) of patients underwent AUS only, 11.3% (N = 46) underwent HIDA scan only, and 56.2% (N = 228) had both studies performed for workup. 52.7% (N = 214) of patients had histopathologically confirmed acute cholecystitis. The sensitivities of AUS, HIDA, and AUS combined with HIDA for acute cholecystitis were 73.3% (95% confidence interval [CI] = 66.3%-79.5%), 91.7% (95% CI = 86.2%-95.5%), and 97.7% (95% CI = 93.4%-99.5%), respectively. Although of limited sensitivity, AUS findings of sonographic Murphy sign, gallbladder distension, and gallbladder wall thickening were associated with a diagnosis of acute cholecystitis. CONCLUSIONS: The sensitivity of AUS for diagnosing acute cholecystitis in patients with acute upper abdominal pain is limited. The addition of a HIDA scan in the diagnostic workup significantly improves sensitivity and can add valuable information in the appropriate clinical setting.