title: Diagnosis of biliary strictures after liver transplantation: which is the best tool?
abstract: OBJECTIVE
  To evaluate the diagnostic value of different indirect methods like biochemical parameters, ultrasound (US) analysis, CT-scan and MRI/MRCP in comparison with endoscopic retrograde cholangiography (ERC), for diagnosis of biliary complications after liver transplantation.
  
  
  METHODS
  In 75 patients after liver transplantation, who received ERC due to suspected biliary complications, the result of the cholangiography was compared to the results of indirect imaging methods performed prior to ERC. The cholangiography showed no biliary stenosis (NoST) in 25 patients, AST in 27 and ITBL in 23 patients.
  
  
  RESULTS
  Biliary congestion as a result of AST was detected with a sensitivity of 68.4% in US analysis (specificity 91%), of 71% in MRI (specificity 25%) and of 40% in CT (specificity 57.1%). In ITBL, biliary congestion was detected with a sensitivity of 58.8% in the US, 88.9% in MRI and of 83.3% in CT. However, as anastomotic or ischemic stenoses were the underlying cause of biliary congestion, the sensitivity of detection was very low. In MRI detected the dominant stenosis at a correct localization in 22% and CT in 10%, while US failed completely. The biochemical parameters, showed no significant difference in bilirubin (median 5.7; 4,1; 2.5 mg/dL), alkaline phosphatase (median 360; 339; 527 U/L) or gamma glutamyl transferase (median 277; 220; 239 U/L) levels between NoST, AST and ITBL.
  
  
  CONCLUSIONS
  Our data confirm that indirect imaging methods to date cannot replace direct cholangiography for diagnosis of post transplant biliary stenoses. However MRI may have the potential to complement or precede imaging by cholangiography. Optimized MRCP-processing might further improve the diagnostic impact of this method.
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital Essen, Hufelandstr. 55, D-45147 Essen, Germany. thomas.zoepf@uni-essen.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Zoepf
authors.forename: Evelyn-J
authors.initials: EJ
authors.lastname: Maldonado-Lopez
authors.forename: Philip
authors.initials: P
authors.lastname: Hilgard
authors.forename: Alexander
authors.initials: A
authors.lastname: Dechêne
authors.forename: Massimo
authors.initials: M
authors.lastname: Malago
authors.forename: Christoph E
authors.initials: CE
authors.lastname: Broelsch
authors.forename: Joerg
authors.initials: J
authors.lastname: Schlaak
authors.forename: Guido
authors.initials: G
authors.lastname: Gerken
mesh_terms: D000328:Adult; D000368:Aged; D001660:Biliary Tract Diseases / Q000175:diagnosis* / Q000453:epidemiology; D002758:Cholangiography; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D016031:Liver Transplantation / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography