title: Imaging patients with "post-cholecystectomy syndrome": an algorithmic approach.
abstract: OBJECTIVE
  To assess the role of ultrasound (US), magnetic resonance cholangiopancreatography (MRCP) and liver function tests (LFTs) in the evaluation of selected patients presenting with late post-cholecystectomy syndrome (PCS) who were referred for endoscopic retrograde cholangiopancreatography (ERCP).
  
  
  METHODS
  In a retrospective study a final group of 42 patients with PCS referred for diagnostic ERCP underwent MRCP and abdominal US. ERCP and MRCP images were assessed for bile duct diameters and the presence of strictures and stones. A common bile duct (CBD) diameter of < 10mm was considered normal, whereas > or = 10mm was considered abnormal on US. Findings were correlated to LFTs with contingency table results performed for single techniques and combination of methods.
  
  
  RESULTS
  In total 14 stones and one stricture were seen. US had a high negative predictive value (86.4%). MRCP had a sensitivity of 100% and specificity of 88.0%. ERCP is the most accurate test but failed in 11 patients, five of whom had a stone. The accuracy of US and LFTs increases to 93.8% if test results agree in either negative or positive outcome.
  
  
  CONCLUSIONS
  US and LFTs are first-line tests in PCS. If the CBD on US is > or = 10mm, but no cause is identified, MRCP should be performed. If US and LFTs are normal then MRCP is not necessary. The availability of LFTs raises the diagnostic value of imaging.
authors.affiliation: Department of Academic Radiology, Beaumont Hospital and Royal College of Surgeons Medical School, Beaumont Road, Dublin, Ireland.
authors.forename: O A
authors.initials: OA
authors.lastname: Terhaar
authors.forename: S
authors.initials: S
authors.lastname: Abbas
authors.forename: F J
authors.initials: FJ
authors.lastname: Thornton
authors.forename: D
authors.initials: D
authors.lastname: Duke
authors.forename: P
authors.initials: P
authors.lastname: O'Kelly
authors.forename: K
authors.initials: K
authors.lastname: Abdullah
authors.forename: J C
authors.initials: JC
authors.lastname: Varghese
authors.forename: M J
authors.initials: MJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods; D042883:Choledocholithiasis / Q000175:diagnosis / Q000000981:diagnostic imaging; D002779:Cholestasis / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008111:Liver Function Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D017562:Postcholecystectomy Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography