DIAGNOSTIC ACCURACY OF CONTRAST-ENHANCED COMPUTED TOMOGRAPHY VERSUS ULTRASOUND IN THE DETECTION OF GANGRENOUS CHOLECYSTITIS

Abstract

Background: Gangrenous cholecystitis (GC) is a severe complication of acute cholecystitis characterized by ischemia, necrosis, and potential perforation of the gallbladder wall. Delayed preoperative diagnosis significantly increases morbidity and mortality. Ultrasonography (USG) is the standard first-line imaging modality, while contrast-enhanced computed tomography (CECT) offers superior visualization of gangrenous changes.

Objective: To compare the diagnostic accuracy of CECT versus ultrasonography in the detection of gangrenous cholecystitis using histopathological findings as the reference standard.

Methodology: A cross-sectional analytical study was conducted at Sheikh Zaid Hospital, Lahore over four months. A total of 70 patients with clinical and histopathological features of cholecystitis were enrolled via convenient sampling. All patients underwent both USG and CECT. Data were analyzed using descriptive statistics, chi-square test, independent samples t-test, Mann–Whitney U test, and diagnostic accuracy measures including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy.

Results: The majority of patients were male (54.3%) and above 60 years of age (48.6%). Diabetes mellitus was present in 48.6% of cases. All patients presented with right upper quadrant pain and vomiting. USG detected gallbladder distension in 55.7%, wall irregularity in 51.4%, pericholecystic fluid in 40%, and gallstones in 60% of patients. A significant association was observed between biliary sludge on USG and histopathologically confirmed gangrenous change (p = 0.017). CECT identified abscess in 47.1% and perforation in 51.4% of cases. CECT demonstrated significantly higher sensitivity and specificity compared to USG in detecting gangrenous cholecystitis.

 Conclusion: CECT is significantly more accurate than ultrasonography in the preoperative detection of gangrenous cholecystitis. Sequential imaging approach USG as the initial modality followed by CECT when findings are inconclusive or complicated disease is suspected is recommended to improve early diagnosis and patient outcomes