title: Liver fibrosis in viral hepatitis: noninvasive assessment with acoustic radiation force impulse imaging versus transient elastography.
abstract: OBJECTIVE
  To compare, in a pilot study, acoustic radiation force impulse (ARFI) imaging technology integrated into a conventional ultrasonography (US) system with both transient elastography (TE) and serologic fibrosis marker testing for the noninvasive assessment of liver fibrosis.
  
  
  METHODS
  Informed consent was obtained from all subjects, and the local ethics committee approved the study. ARFI imaging involved the mechanical excitation of tissue with use of short-duration acoustic pulses to generate localized displacements in tissue. The displacements resulted in shear-wave propagation, which was tracked by using US correlation-based methods and recorded in meters per second. Eighty-six patients with chronic viral hepatitis underwent TE, ARFI imaging, and serum fibrosis marker testing. Results were compared with liver biopsy findings, which served as the reference standard.
  
  
  RESULTS
  ARFI imaging (rho = 0.71), TE (rho = 0.73), and serum fibrosis marker test (rho = 0.66) results correlated significantly with histologic fibrosis stage (P < .001). Median ARFI velocities ranged from 0.84 to 3.83 m/sec. Areas under the receiver operating characteristic curve for the accuracy of ARFI imaging, TE, and serum fibrosis marker testing were 0.82, 0.84, and 0.82, respectively, for the diagnosis of moderate fibrosis (histologic fibrosis stage, > or = 2) and 0.91, 0.91, and 0.82, respectively, for the diagnosis of cirrhosis.
  
  
  CONCLUSIONS
  ARFI imaging is a promising US-based method for assessing liver fibrosis in chronic viral hepatitis, with diagnostic accuracy comparable to that of TE in this preliminary study.
  
  
  BACKGROUND
  http://radiology.rsnajnls.org/cgi/content/full/252/2/595/DC1.
authors.affiliation: Department of Internal Medicine 1, J. W. Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany. Mireen.Friedrich-Rust@kgu.de
authors.forename: Mireen
authors.initials: M
authors.lastname: Friedrich-Rust
authors.forename: Katrin
authors.initials: K
authors.lastname: Wunder
authors.forename: Susanne
authors.initials: S
authors.lastname: Kriener
authors.forename: Fariba
authors.initials: F
authors.lastname: Sotoudeh
authors.forename: Swantje
authors.initials: S
authors.lastname: Richter
authors.forename: Joerg
authors.initials: J
authors.lastname: Bojunga
authors.forename: Eva
authors.initials: E
authors.lastname: Herrmann
authors.forename: Thierry
authors.initials: T
authors.lastname: Poynard
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Dietrich
authors.forename: Johannes
authors.initials: J
authors.lastname: Vermehren
authors.forename: Stefan
authors.initials: S
authors.lastname: Zeuzem
authors.forename: Christoph
authors.initials: C
authors.lastname: Sarrazin
mesh_terms: D000162:Acoustics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006525:Hepatitis, Viral, Human / Q000000981:diagnostic imaging*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D055815:Young Adult