Clinical significance of magnetic resonance cholangiopancreatography (MRCP) compared to endoscopic retrograde cholangiopancreatography (ERCP)

Abstract

Background and study aims: The clinical importance of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic modality for investigation of the biliary tree and pancreatic duct system is under debate. Using endoscopic retrograde cholangiopancreatography (ERCP) as the gold standard, this study determined in a prospective, blinded fashion the sensitivity and further statistic values of MRCP findings for evaluation of the biliary and pancreatic tract.

Patients and methods: Seventy-eight patients referred for ERCP were studied prospectively with MRCP and ERCP during a 12-month period. All images were interpreted on a blinded basis by two radiologists. Any dilations, strictures, and intraductal abnormalities were recorded and correlated with the clinical diagnoses.

Results: MRCP images of diagnostic quality were obtained in 76 of the 78 patients (97%). Magnetic resonance cholangiography (MRC) showed sensitivities (and positive predictive values) of 71% (62%) for recognition of normal bile ducts, 83% (91%) for recognition of dilation, 85% (100%) for recognition of strictures, 77% (91%) for correct stricture location, and 80% (100%) for diagnosing bile duct calculi. In addition, the sensitivity of MRC in classifying benign and malignant strictures was 50% and 80%, respectively. The statistical values (sensitivity and positive predictive value) for magnetic resonance pancreatography findings were determined for the recognition of normal pancreatic ducts (33% and 50%), recognition of dilation (62% and 100%), recognition of strictures (76% and 87%) and correct location (66% and 100%), diagnosis of benign strictures (87% and 87%) and malignant strictures (60% and 75%), and for diagnosing pancreatic duct stones (60% and 100%).

Conclusions: MRCP is capable of providing diagnostic information equivalent to ERCP in many patients, and should be applied whenever established techniques provide no results, or inadequate results.