Hepatic artery peak systolic velocity compared to non-Doppler ultrasound observations for predicting acute cholecystitis: diagnostic performance and impact on a risk categorization approach.

Purpose: Compare HAv to non-Doppler ultrasound observations for diagnosing acute cholecystitis in a large consecutive cohort of emergency department (ED) patients and establish a method to combine HAv assessment with non-Doppler observations for diagnosing acute cholecystitis.

Methods: Consecutive ED patients at one institution undergoing gallbladder (GB) ultrasound (US) for acute cholecystitis between 1/1/2020 and 8/31/2022 had assessments of GB diameter, GB wall thickness, GB contents, pericholecystic irregular collection, and hepatic artery peak systolic velocity (HAv). The non-Doppler observations were scored and summed. Non-Doppler risk categorization was based on rate of acute cholecystitis associated with summed scores. The impact of HAv stratification on the rate of acute cholecystitis in the non-Doppler risk categories was evaluated, with regrouping when subgroups had changes in the acute cholecystitis rate; the regrouping established the HAv-adjusted risk model. Receiver-operator curves for acute cholecystitis diagnosis for individual parameters, the non-Doppler risk categorization, and the HAv-adjusted risk model were compared using area-under-curve (AUC) calculations.

Results: Of the 885 patients in the study cohort, 117 (13.2%) had acute cholecystitis. The AUC for diagnosing acute cholecystitis using GB distention (83.8%, p < 0.001), GB wall thickness (79.1%, p < 0.001), and GB contents (75.0%, p 0.02) were higher than HAv (66.3%). HAv assessment adjusted risk for 195 patients. The non-Doppler risk categorization and the HAv-adjusted risk model had the same sensitivity (84.6%) and specificity (85.2%) for diagnosing acute cholecystitis, but the HAv-adjusted risk model showed higher AUC (91.3%, p 0.03) due to increased ability to exclude acute cholecystitis.

Conclusions: The diagnostic performance of HAv for acute cholecystitis was lower than other assessments. A categorization scheme based on summed points assigned to each non-Doppler observation was improved with HAv assessment. This risk categorization approach using formulaic integration of non-Doppler and Doppler assessments on ED patients allows radiologists to convey one of five levels of disease probability based solely on sonographic features ranging from effectively excluding acute cholecystitis to substantially elevating the chance the patient has the condition.