title: Evaluation of acoustic radiation force impulse elastography for fibrosis staging of chronic liver disease: a pilot study.
abstract: BACKGROUND
  Acoustic radiation force impulse (ARFI) is a new technology integrated into conventional B-mode ultrasonography. ARFI is used to evaluate tissue stiffness in several organs, but this method has not been applied for liver fibrosis.
  
  
  OBJECTIVE
  The aim of this study was to determine whether ARFI elastography is useful for the evaluation of liver fibrosis.
  
  
  METHODS
  This study enrolled 55 consecutive patients with chronic liver disease who underwent a liver biopsy for histological assessment of liver fibrosis by the Metavir scoring system. Liver stiffness of the 55 patients and 25 healthy volunteers was evaluated by ARFI elastography and was expressed as the shear wave velocity. Cut-off values were determined using receiver-operating characteristic (ROC) curves.
  
  
  RESULTS
  Histological liver fibrosis was evaluated by Metavir scoring; F0: six cases, F1: 14 cases, F2: nine cases, F3: nine cases and F4: 17 cases. Liver stiffness determined by ARFI elastography was correlated with histological liver fibrosis (P<0.0001). The areas under the ROC curves were 0.94 (95% confidence intervals, 0.87-0.99) for F2-F4, 0.94 (0.88-0.99) for F3-F4 and 0.96 (0.91-1.01) for F4. The cut-off values of the shear wave velocity were as follows: >1.34 m/s for F2-F4 (sensitivity 91.4%, specificity 80%); >1.44 m/s for F3-F4 (sensitivity 96.2%, specificity 79.3%); and >1.80 m/s for F4 (sensitivity 94.1%, specificity 86.8%).
  
  
  CONCLUSIONS
  Ultrasonic ARFI elastography is a novel, non-invasive and reliable method for the assessment of liver fibrosis in patients with chronic liver disease.
authors.affiliation: Department of Internal Medicine, Saga Medical School, Nabeshima, Saga, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Naofumi
authors.initials: N
authors.lastname: Ono
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Takahisa
authors.initials: T
authors.lastname: Eguchi
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Kitajima
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Shunya
authors.initials: S
authors.lastname: Nakashita
authors.forename: Iwata
authors.initials: I
authors.lastname: Ozaki
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Mizuta
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
authors.forename: Sho
authors.initials: S
authors.lastname: Kudo
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyoshi
authors.forename: Kohji
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Kazuma
authors.initials: K
authors.lastname: Fujimoto
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D016022:Case-Control Studies; D002908:Chronic Disease; D016001:Confidence Intervals; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008107:Liver Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index