Correlation and Diagnostic Agreement Between Ultrasonography and MRCP in Evaluating Obstructive Jaundice: A Prospective Study

Abstract

Background: Obstructive jaundice is a clinical condition characterized by the yellow discoloration of the skin, sclera, and mucous membranes due to elevated bilirubin levels caused by bile flow obstruction. Accurate diagnosis of the obstruction's cause and site is essential for effective management. Ultrasonography (USG) is commonly used for initial screening, but it has limitations, especially in visualizing the distal common bile duct (CBD). Magnetic resonance cholangiopancreatography (MRCP) has emerged as a superior, non-invasive imaging modality with higher accuracy in evaluating biliary obstructions. Objective: To evaluate the correlation and agreement between USG and MRCP findings in patients with obstructive jaundice and to determine the diagnostic accuracy of each modality in detecting the level and cause of biliary obstruction. Methods: This prospective cohort study was conducted over six months at a tertiary care hospital in Rawalpindi. A total of 32 patients with clinical suspicion of obstructive jaundice were included. Each patient underwent both USG and MRCP. USG was performed using a GE Logiq-e machine, followed by MRCP on a Philips Achieva 1.5 Tesla MRI scanner. Data were analyzed using SPSS version 25. Pearson's correlation coefficient and kappa statistics were used to assess the correlation and agreement between the two modalities. The diagnostic accuracy of USG and MRCP was compared based on the detection of the level of obstruction and the identification of benign and malignant etiologies. Results: The mean age of the patients was 59.53 ± 13.41 years, with 65.6% being male. MRCP showed a diagnostic accuracy of 97.2% compared to 78.1% for USG. MRCP detected distal CBD calculi with 100% accuracy, while USG missed these in 11 cases. A positive correlation was found between USG and MRCP in detecting the site of obstruction (r = 0.48, p = 0.005), the porta hepatis as the site of obstruction (r = 0.47, p = 0.006), and the ampulla as the site of obstruction (r = 0.47, p = 0.006). However, the correlation for benign etiologies was weak (r = 0.094, p = 0.607), and for malignant etiologies, it was moderate (r = 0.31, p = 0.08). Conclusion: MRCP demonstrated superior diagnostic accuracy compared to USG in evaluating patients with obstructive jaundice, particularly in detecting distal CBD calculi and malignant lesions. While USG remains useful as an initial screening tool, MRCP should be considered the preferred imaging modality when detailed evaluation is required.