ROLE OF MRCP IN EVALUATING DILATED COMMON BILE DUCT IN PATIENTS WITH SYMPTOMATIC GALLSTONES

Background: Obstructive jaundice caused by choledocholithiasis remains a frequent clinical problem that requires timely and accurate diagnosis for effective management. Endoscopic Retrograde Cholangiopancreatography (ERCP) has traditionally been considered the diagnostic gold standard; however, its invasive nature and associated complications limit its routine use. Magnetic Resonance Cholangiopancreatography (MRCP) has gained prominence as a non-invasive, radiation-free imaging modality capable of providing high-resolution visualization of the biliary tree with excellent diagnostic performance. Objective: To determine the diagnostic accuracy of MRCP in detecting dilated common bile duct (CBD) and choledocholithiasis, using ERCP as the reference gold standard in patients presenting with obstructive jaundice. Methods: A cross-sectional validation study was conducted in the Radiology Department of Combined Military Hospital (CMH), Malir, Karachi, over a six-month period. Seventy patients aged 20–70 years who presented with clinical and biochemical evidence of obstructive jaundice were included through non-probability consecutive sampling. MRCP was performed on all participants, followed by ERCP for confirmatory diagnosis. Data were analyzed using SPSS version 22. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of MRCP were calculated through a 2×2 contingency table, with further stratification by gender and age group. Results: MRCP identified choledocholithiasis in 47 patients, whereas ERCP confirmed the diagnosis in 45 cases. When compared to ERCP, MRCP demonstrated a sensitivity of 95.6%, specificity of 84.0%, PPV of 91.5%, NPV of 91.3%, and an overall diagnostic accuracy of 91.4%. Subgroup analysis showed high diagnostic consistency across both male (accuracy 89.7%) and female (accuracy 93.5%) patients, as well as among younger (<50 years, accuracy 89.3%) and older (≥50 years, accuracy 92.3%) individuals. Conclusion: MRCP exhibits excellent diagnostic accuracy in detecting choledocholithiasis and CBD dilatation. Owing to its non-invasive nature, absence of ionizing radiation, and strong diagnostic performance, MRCP should be considered the preferred first-line imaging tool for evaluating patients with obstructive jaundice prior to proceeding with ERCP.