The Utility of Hepatobiliary Scintigraphy Scans in the Tokyo Guidelines Era for Acute Cholecystitis.

BACKGROUND

Hepatobiliary Scintigraphy (HIDA) aids the diagnosis of acute cholecystitis (AC) but has limitations. We sought to design a model based on the Tokyo Guidelines 2018 (TG18) to predict HIDA results.

METHODS

A retrospective review of patients who underwent a HIDA scan during the evaluation of AC was performed. Using logistic regression techniques incorporating the TG18 criterion and additional readily available patient characteristics, a prediction model was created to identify patients likely to test negative for acute cholecystitis by HIDA scan.

RESULTS

In 235 patients with suspected AC, a HIDA scan was performed. Variables associated with positive HIDA results were male gender (RR 2.0 (CI 1.33-2.99), age (OR 1.02 (CI 1.01-1.04), right upper quadrant tenderness (RR 1.7 (CI 1.1-2.8)), clinical Murphy's sign (RR 2.2 (CI 1.5-3.4)), ultrasound findings suggestive of AC by any of its components (RR 3.2 (CI 1.6-6.5)), gallbladder wall thickening (RR 2.0 (CI 1.3-3.1)), and gallbladder distention (RR 1.9 (CI 1.3-2.9)). These variables allowed for creation of a model to predict HIDA results. The model predicted HIDA results in 36.9% of patients with an area under the curve of 0.81.

CONCLUSIONS

In the era of TG18, HIDA is probably over utilized. We developed an accurate, simple model based on TG18 that identifies a group of patients for whom a HIDA scan is unnecessary to establish the diagnosis of AC.