title: The value of magnetic resonance cholangiopancreatography for the exclusion of choledocholithiasis.
abstract: OBJECTIVE
  To investigate the ability of Magnetic resonance cholangiopancreatography (MRCP) to exclude choledocholithiasis (CDL) in symptomatic patients.
  
  
  METHODS
  Patients suspected of choledocholithiasis who underwent MRCP from 2008 through 2013 in a population based study at the National University Hospital of Iceland were retrospectively analysed, using ERCP and/or intraoperative cholangiography as a gold standard diagnosis for CDL.
  
  
  RESULTS
  Overall 920 patients [66% women, mean age 55 years (SD 21)] underwent MRCP. A total of 392 patients had a normal MRCP of which 71 underwent an ERCP investigation demonstrating a CBD stone in 29 patients. A normal MRCP was found to have a 93% negative predictive value (NPV) and 89% probability of having no CBD stone demonstrated as well as no readmission due to gallstone disease within six months following MRCP. During a 6-month follow-up period of the 321 patients who did not undergo an ERCP nine (2.8%) patients were readmitted with right upper quadrant pain and elevated liver tests which later normalised with no CBD stone being demonstrated, three (0.9%) patients were readmitted with presumed gallstone pancreatitis, two (0.6%) patients were readmitted with cholecystitis and two (0.6%) patients were lost to follow-up. Seven patients of those 321 underwent an intraoperative cholangiography (IOC) and all were negative for CBD stones. For the sub-group requiring ERCP following a normal MRCP the NPV was 63%.
  
  
  CONCLUSIONS
  Our results support the use of MRCP as a tool for exclusion of choledocholithiasis with the potential to reduce the amount of unnecessary ERCP procedures.
authors.affiliation: a Department of Gastroenterology and Hepatology , The National University Hospital of Iceland , Reykjavík , Iceland ;
authors.forename: Jón H
authors.initials: JH
authors.lastname: Hjartarson
authors.affiliation: b Department of Radiology , The National University Hospital of Iceland , Reykjavík , Iceland ;
authors.forename: Pétur
authors.initials: P
authors.lastname: Hannesson
authors.affiliation: c Department of Surgery , The National University Hospital of Iceland , Reykjavík , Iceland.
authors.forename: Ingvar
authors.initials: I
authors.lastname: Sverrisson
authors.affiliation: c Department of Surgery , The National University Hospital of Iceland , Reykjavík , Iceland.
authors.forename: Sigurður
authors.initials: S
authors.lastname: Blöndal
authors.affiliation: b Department of Radiology , The National University Hospital of Iceland , Reykjavík , Iceland ;
authors.forename: Bjarki
authors.initials: B
authors.lastname: Ívarsson
authors.affiliation: a Department of Gastroenterology and Hepatology , The National University Hospital of Iceland , Reykjavík , Iceland ;
authors.forename: Einar S
authors.initials: ES
authors.lastname: Björnsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002760:Cholangiopancreatography, Endoscopic Retrograde; D049448:Cholangiopancreatography, Magnetic Resonance; D017081:Cholecystectomy, Laparoscopic; D002764:Cholecystitis / Q000453:epidemiology; D042883:Choledocholithiasis / Q000000981:diagnostic imaging*; D003135:Common Bile Duct / Q000000981:diagnostic imaging; D005260:Female; D042882:Gallstones / Q000453:epidemiology*; D006801:Humans; D007055:Iceland; D016015:Logistic Models; D059012:Lost to Follow-Up; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010195:Pancreatitis / Q000453:epidemiology; D011336:Probability; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Choledocholithiasis; ERCP; MRCP; common bile duct; intraoperative cholangiogram; logistic regression