title: Can MRCP replace the diagnostic role of ERCP for patients with choledochal cysts?
abstract: BACKGROUND
  MRCP is rapidly replacing diagnostic ERCP in various pancreaticobiliary diseases. This study was designed to evaluate the accuracy of MRCP in detecting and determining the extent of choledochal cysts, as well as associated ductal anomalies or lesions.
  
  
  METHODS
  The study design was an 8-year retrospective survey conducted at a tertiary referral center, Asan Medical Center (University of Ulsan College of Medicine, Seoul, Korea). There were 72 patients with choledochal cysts. All patients underwent both MRCP and ERCP. MRCP findings were compared with those of ERCP as the criterion standard.
  
  
  RESULTS
  The overall detection rate of MRCP for choledochal cysts was 96% (69/72). The sensitivity, the specificity, the positive predictive value, and the negative predictive value of MRCP for classifying choledochal cysts according to Todani's classification were 81%, 90%, 86%, and 86% in type I, respectively; 73%, 100%, 100, and 95% in type III, respectively; 83%, 90%, 80%, and 91% in type IVa, respectively; 100%, 100%, 100%, and 100% in type IVb, respectively; and 100%, 100%, 100%, and 100% in type V, respectively. The sensitivity, the specificity, and the accuracy of MRCP for detecting ductal anomalies were 83%, 90%, and 86%, respectively. The detection rate of MRCP for concurrent cholangiocarcinoma and choledocholithiasis was 87% (13/15) and 100% (8/8), respectively.
  
  
  CONCLUSIONS
  MRCP showed overall good accuracy in the detection and the classification of choledochal cysts and revealed associated cholangiocarcinoma and choledocholithiasis with excellent accuracy. MRCP, therefore, may supersede the diagnostic role of ERCP for the patients with choledochal cysts. However, MRCP showed limited capacity to detect minor ductal anomalies or small choledochocele.
authors.affiliation: Department of Internal Medicine, Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Park
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Lee
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Jung Sik
authors.initials: JS
authors.lastname: Choi
authors.forename: Yoon Seon
authors.initials: YS
authors.lastname: Lee
authors.forename: Dong Wan
authors.initials: DW
authors.lastname: Seo
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Won
authors.forename: Min-Young
authors.initials: MY
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D015529:Choledochal Cyst / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology*; D042883:Choledocholithiasis / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution