Comperative study of diagnostic accuracy of mrcp with ultrasonography in choledocolithiasis with post ercp correlation

Sajad Ahmed and Keshav Kumar ADT

Introduction: Choledocholithiasis is an important and curable cause of obstructive jaundice. Besides jaundice it causes many complications as pancreatitis, ascending cholangitis etc. Clinical and haematological findings can raise the suspicion of choledocholithiasis in patients of obstructive jaundice but the clinician have to rely on imaging findings for final diagnosis. Multiple non-invasive & invasive methods have been used for the diagnosis of calculi in the bile duct including ultrasonography, MRCP and ERCP. All the test have their own advantages and disadvantages. Sensitivity, specificity and other statistical parameters for performance varies from test to test. The aim of the study was to review USG & MRCP, then correlate the results with ERCP and finally to assess the accuracy, sensitivity and specificity of USG, MRCP and ERCP in detecting choledocholithiasis.

Material And Methods: The study was conducted in the Department of Radio Diagnosis and Imaging, Sagar Hospitals, Bangalore. Patients admitted or attending OPD in Sagar Hospitals with suspected obstructive jaundice or as a known case of obstructive jaundice. Every patient suspicious of choledocholithiasis was investigated with USG & MRCP. Final correlation was done with ERCP/ post-intervention findings. The study was performed on all patients after written informed consent. The study was carried out over a period of 26 months from October 2010 to December 2012. Total number of 70 Consecutive patients fulfilling all the criteria of the study population were selected.

Results: Out of 70 patients 40 (57%) patients were female and 30 (43%) patients were male. Age of the patients were between 11 to 87 yrs with mean age 49 yrs. Ultrasound could not identify Common bile duct calculus in 26 patients (26 false negative patients). The sensitivity, specificity, positive and negative predictive values of ultrasonography in detecting CBD stones in the present study were 48%, 90%, 92% and 40.9% respectively. The sensitivity, specificity, positive and negative predictive values of MRCP in detecting CBD stones in the present study were 97.8%, 82.8%, 92% and 95% respectively. The sensitivity and specificity values of ERCP in detecting CBD stones in the present study were 100%, 100%, 100% and 100% respectively.

Conclusion: This study shows that MRCP has a diagnostic accuracy which is almost similar to ERCP in the diagnosis of choledocholithiasis. Hence MRCP can be used as a primary tool for detecting or excluding CBD stones non invasively and without use of contrast media and ionizing radiation.

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