The present study evaluated the diagnostic efficacy of MRCP compared with USG in detecting bile duct abnormalities, using sensitivity, specificity, and predictive values as key performance indicators. Our findings reaffirm the superior diagnostic yield of MRCP in delineating the level and cause of biliary obstruction, particularly in cases of choledocholithiasis, benign strictures, and malignant biliary lesions. In our study, the distal CBD was the most frequent site of obstruction (64%), consistent with previous studies by Arjun Raju et al. [13], Goyani et al. [14], and Al-Obaidi et al. [15], who also reported distal CBD as the predominant level of obstruction. However, Upadhyaya et al. [16] observed the intrapancreatic portion of the CBD as the most common site (38%), possibly due to differing etiological spectra and imaging criteria in their study population.

The most common cause of obstruction in our cohort was CBD stones, aligning with the findings of Kaur et al. [17]. While studies by Arjun Raju et al. [13], Upadhyaya et al. [16], and Madhok et al. [18] reported pancreaticobiliary tumors as the leading cause, and Rathore et al. [19] observed choledocholithiasis as most prevalent, these variations likely reflect geographic and referral biases, as well as differences in patient selection criteria.

Regarding diagnostic performance, MRCP demonstrated high sensitivity (96.8%) and specificity (84.9%) for CBD stone detection, in concordance with previous studies by Soto et al. [20] (sensitivity 94%, specificity 100%) and Pavone et al. [21] (sensitivity 88.9%, specificity 100%). Similar accuracy rates were reported by Regan et al. [22] and Hazem et al. [23], further validating MRCP’s reliability in identifying biliary calculi. MRCP effectively visualized calculus regions as signal voids against the high T2-weighted biliary background, enhancing its diagnostic clarity. For benign biliary strictures, MRCP achieved sensitivity and specificity of 92.6% and 100%, respectively, which is comparable to the results reported by Al-Obaidi et al. [15] (sensitivity 100%, specificity 98.5%), Munir et al. [24] (sensitivity 83.3%, specificity 97.6%), and Bhatt et al. [25] (sensitivity 100%). The high-performance metrics observed reinforce MRCP’s capacity to identify and characterize benign ductal narrowing, particularly in cases where USG findings are inconclusive due to bowel gas or limited acoustic access. In evaluating benign biliary pathologies, MRCP exhibited a sensitivity of 95.6% and specificity of 78.9%, findings consistent with Kurian et al. [26] (sensitivity 94.4%, specificity 50%), Kaur et al. [17], and Singh et al. [27] (sensitivity 100%). MRCP’s ability to accurately delineate both intra- and extrahepatic biliary dilatation makes it a valuable non-invasive alternative to diagnostic ERCP. For tumor detection, MRCP showed excellent diagnostic performance with both sensitivity and specificity of 100%, corroborating the observations of Kaur et al. [17] and Kushwah et al. [28]. These results affirm MRCP’s role as a precise imaging modality for identifying malignant obstructions, while simultaneously offering superior visualization of the biliary anatomy and surrounding structures compared with USG.

MRCP has several established advantages: it is non-invasive, radiation-free, and less operator-dependent than USG, while providing better visualization of ducts proximal to the obstruction. Moreover, when combined with conventional T1- and T2-weighted sequences, MRCP can detect extraductal disease, offering a comprehensive overview of hepatobiliary pathology. Despite its benefits, MRCP’s limitations include contraindications in patients with metallic implants, pacemakers, or claustrophobia, and its inability to provide therapeutic intervention. Nonetheless, its high diagnostic accuracy, safety, and reproducibility make it a compelling first-line imaging choice for evaluating biliary and pancreatic ductal disorders, potentially reducing the need for invasive ERCP procedures.

This study has several limitations that should be acknowledged. First, the sample size was relatively small (N = 30), which may limit the statistical power and generalizability of the findings to broader populations with obstructive jaundice. Second, as a single-center study conducted in a tertiary hospital, referral bias may have influenced the spectrum of cases, particularly the proportion of malignant vs. benign etiologies. Third, although MRCP and USG findings were compared with a reference standard, not all patients underwent the same verification procedure (operative confirmation, ERCP, or histopathology), which may introduce verification bias. Fourth, operator dependency of USG, particularly variability in expertise and technique, may have affected diagnostic accuracy, but interobserver reliability was not assessed. Fifth, MRCP acquisition parameters were standardized; however, variations in patient cooperation, breath-holding ability, and motion artefacts could have influenced image quality and diagnostic interpretation. Finally, because the study focused primarily on diagnostic performance, other clinically relevant parameters such as cost-effectiveness, accessibility, and time to diagnosis were not evaluated, limiting the application of findings in resource-constrained settings.