title: Reproducibility of liver stiffness measurement by ultrasonographic elastometry.
abstract: OBJECTIVE
  Fibroscan is a noninvasive device that assesses liver fibrosis by liver stiffness evaluation (LSE) with ultrasonographic elastometry. We evaluated LSE reproducibility and its influencing factors.
  
  
  METHODS
  LSE was performed by 4 experienced physicians (>100 LSEs) in 46 patients with chronic liver disease at 4 different anatomic sites. Additional LSEs were performed for ancillary aims, so that 534 LSEs were available.
  
  
  RESULTS
  Overall interobserver agreement for LSE results was considered as excellent, with intraclass coefficient correlation (Ric) of 0.93. Low LSE level, nonrecommended sites, LSE interquartile range >25%, and body mass index > or =25 independently decreased agreement. Thus, agreement was fair (Ric = 0.53) for LSE <9 kilopascals and excellent (Ric = 0.90) beyond. The best measurement site for LSE reproducibility was the median axillary line on the first intercostal space under the liver dullness upper limit, with the patient lying in dorsal decubitus. When LSE results were categorized into fibrosis Metavir stages, interobserver discordance was noticed in about 25% of the cases and was the highest for F2 and F3 stages and the lowest for F4. Intraobserver (Ric = 0.94), intersite (Ric = 0.92-0.98), and interequipment (Ric = 0.92) agreements for LSE results were excellent. Preliminary standard ultrasonography or probe pressure changes did not improve interobserver agreement.
  
  
  CONCLUSIONS
  The best measurement site for LSE is the one generally used for liver biopsy. Reproducibility of LSE is globally excellent but is fair in patient with low liver stiffness. The fibrosis diagnosis by ultrasonographic elastometry in low stages or categorized into fibrosis Metavir stages must be interpreted with caution.
authors.affiliation: University of Angers, IFR 132, HIFIH Laboratory, UPRES 3859, Angers, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Boursier
authors.forename: Anselme
authors.initials: A
authors.lastname: Konaté
authors.forename: Gabriella
authors.initials: G
authors.lastname: Gorea
authors.forename: Stéphane
authors.initials: S
authors.lastname: Reaud
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Quemener
authors.forename: Frédéric
authors.initials: F
authors.lastname: Oberti
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hubert-Fouchard
authors.forename: Nina
authors.initials: N
authors.lastname: Dib
authors.forename: Paul
authors.initials: P
authors.lastname: Calès
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results