Magnetic resonance cholangiopancreatography

Abstract

Magnetic resonance cholangiopancreatography (MRCP) refers to selective or partially selective MR imaging of the pancreatic and biliary ducts. Complete or partial selectivity for ductal imaging is an important component of this definition, because this selectivity distinguishes MRCP from other cross-sectional modalities such as CT and ultrasound, which can also be used to assess pancreatic and biliary ductal disease. MRCP was first described in the 1980s. Since then MRCP has undergone considerable technical evolution and maturation and has reached the stage at which MRCP is a viable alternative to diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in most settings (Fig. 1). This article discusses some of the relative advantages and disadvantages of MRCP, important aspects of technique, and major clinical applications. Emphasis is placed on the scientific data supporting the contention that MRCP is competitive with ERCP. It should be noted that many clinical studies of MRCP use ERCP as the standard of reference. This carries the implicit and unstated assumption that ERCP results are absolute and objective. It is true that in practice ERCP is often considered the definitive test for structural disease of the pancreatic and biliary ducts. However, as with any other imaging test, ERCP is subject to error and variability, as illustrated by studies in which clinical or surgical results are used as the standard of reference. For example, in a study of 124 patients with suspected pancreatic cancer in which the standard of reference was biopsy or one year of clinical follow-up, the sensitivity and specificity of MRCP for the diagnosis of pancreatic cancer were 84% and 97%, respectively, compared with a sensitivity and specificity of 70% and 94% for ERCP. 1 Adamek HE Albert J Breer H Weitz M Schilling D Riemann JF. Pancreatic cancer detection with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography: a prospective controlled study. Lancet. 2000; 356: 190-193 Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar Similarly, in a study of 72 patients undergoing cholecystectomy, preoperative ERCP had a sensitivity and specificity of 91% and 100%, respectively, for the diagnosis of common duct stones, using intraoperative cholangiography and bile duct exploration as a standard of reference. 2 Frey CF Burbige EJ Meinke WB Pullos TG Wong HN Hickman DM et al. Endoscopic retrograde cholangiopancreatography. Am J Surg. 1982; 144: 109-113 Abstract Full Text PDF PubMed Scopus (60) Google Scholar