title: Interobserver agreement in duplex scanning for vein grafts.
abstract: BACKGROUND
  although the precision of duplex scanning is of utmost importance in vein-graft surveillance, it has not been properly assessed. This study aims to analyse interobserver agreement on duplex scanning.
  
  
  METHODS
  a blinded comparative trial of 69 infrainguinal vein bypass reconstructions. Two consecutive duplex scans were performed by different examiners and duplex ultrasound machines on the same patient. The duplex examinations were also compared with angiography, when available, and clinical follow-up.
  
  
  RESULTS
  interobserver agreement in Kappa statistics was 0.69, signifying "good" agreement between the examinations in detecting haemodynamically significant changes in the grafts. The sensitivity, specificity and accuracy figures compared with a combination of angiography and follow-up data for the two scans were 80%, 91%, 88% and 85%, 93%, 91%, respectively. The limits of agreement were, however, wide for Doppler-derived velocity characteristics.
  
  
  CONCLUSIONS
  duplex scanning is an accurate and reproducible method for detecting haemodynamically significant changes in infrainguinal vein grafts.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Helsinki, Finland.
authors.forename: L
authors.initials: L
authors.lastname: Ihlberg
authors.forename: A
authors.initials: A
authors.lastname: Albäck
authors.forename: W D
authors.initials: WD
authors.lastname: Roth
authors.forename: J
authors.initials: J
authors.lastname: Edgren
authors.forename: M
authors.initials: M
authors.lastname: Lepäntalo
mesh_terms: D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001783:Blood Flow Velocity; D019917:Blood Vessel Prosthesis Implantation; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D015588:Observer Variation; D010690:Phlebography; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex / Q000706:statistics & numerical data; D014680:Veins / Q000000981:diagnostic imaging* / Q000637:transplantation