The Value of Magnetic Resonance Cholangio-Pancreatography (MRCP) in the Detection of Choledocholithiasis

Magnetic Resonance Cholangio-Pancreatography (MRCP) is a non-invasive radiological investigation which can be performed rapidly and which does not expose the patients to ionised radiations or iodinated contrast material. The present study was conducted to evaluate the role of MRCP in detection of Common Bile Duct (CBD) stones in patients with suspected choledocholithiasis. This prospective study included 30 patients with a suspicion of choledocholithiasis which was based on clinical evaluation, biochemical or radiological investigations. Ultrasonography and MRCP were performed in all patients. All patients underwent open surgery. CBD exploration was performed in all patients, either due to presence of palpable stones or due to the presence of dilated CBD (> 7 mm). Demonstration of CBD stones intra-operatively was considered the 'gold standard' for their presence, defined as stones visualised and extracted or attempted for extraction during surgical CBD exploration. Intra-operatively, 21 (70%) out of 30 patients had cholelithiasis. 26 (86.67%) out of 30 patients had dilated CBD stones intra-operatively. In 20 (66.67%) out of 30 patients, choledocholithiasis was detected intra-operatively. The sensitivity, specificity, positive and negative predictive value of ultrasonography in detecting CBD stones in the present study was 65%, 60%, 76.47% and 46.15% respectively. The sensitivity, specificity, positive and negative predictive value of MRCP in diagnosis of CBD stones in the present study was 95%, 90%, 95% and 90% respectively. MRCP is a non-invasive investigation without complications and it has high sensitivity, specificity and positive and negative predictive values in detection of CBD stones. MRCP should be done in all cases with a suspicion of CBD stones, where facilities and expertise are available.