title: Comparison of acoustic radiation force impulse imaging (ARFI) to liver biopsy histologic scores in the evaluation of chronic liver disease: A pilot study.
abstract: OBJECTIVE
  Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the localized mechanical properties of tissue by utilising short, high intensity acoustic pulses (shear wave pulses) to assess the mechanical response (tissue displacement), providing a measure of tissue elasticity. The aim of this study is to investigate the feasibility of ARFI imaging as a non-invasive method for the assessment of liver fibrosis compared to liver biopsy scores.
  
  
  METHODS
  A prospective blind comparison study of ARFI elastography (Virtual Touch Imaging., ACUSON S2000 Ultrasound Unit, Siemens, Mountain View CA) in a consecutive series of patients who underwent liver biopsy for assessment of fibrosis in chronic liver disease. ARFI shear-wave propagation velocity was measured in meters per second. Mean ARFI velocities were compared with both Batts-Ludwig (F0 to F4) and Modified Ishak scores (F0 to F4) for fibrosis in liver biopsy findings. Twenty-one patients with chronic liver disease (Hepatitis C (HCV) =16, Hepatitis B (HBV) = 1, both HCV and HBV = 1 Alcoholic liver disease (ALD) = 1, others = 2) underwent ARFI and liver biopsy on the same day.
  
  
  RESULTS
  The Spearman correlation coefficients between the median values of the ARFI measurements and the histological fibrosis stage of the Modified Ishak score and Batts-Lud- (3) wig score were both highly significant (p < 0.01) with rho = 0.69 and rho = 0.72 respectively. The median ARFI (total 180 replications; minimum 5, maximum 10 measurements per patients) velocities for our study population range from 0.92 to 4.17 m/sec. Areas under the receiver operating characteristic curve for the accuracy of ARFI imaging was 1.00 and 0.35, for the diagnosis of moderate fibrosis (histologic fibrosis stage, F (3) 2) and 0.85 and 0.85 respectively for Ishak and Batts-Ludwig score, for the diagnosis of cirrhosis.
  
  
  CONCLUSIONS
  ARFI imaging has a strong correlation with the fibrosis stage of both Batts-Ludwig and shak score in chronic liver disease. It.s accuracy in prediction of severe fibrosis and cirrhosis is maximal in comparison with earlier stages.
authors: Division of Gastroenterology, University of British Columbia, Canada.
authors: Mazhar
authors: M
authors: Haque
authors: Charlotte
authors: C
authors: Robinson
authors: David
authors: D
authors: Owen
authors: Eric M
authors: EM
authors: Yoshida
authors: Alison
authors: A
authors: Harris
mesh_terms: D001706:Biopsy / Q000379:methods / Q000592:standards*; D002908:Chronic Disease; D054459:Elasticity Imaging Techniques / Q000379:methods / Q000592:standards*; D019694:Hepatitis B, Chronic / Q000000981:diagnostic imaging / Q000473:pathology; D019698:Hepatitis C, Chronic / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000473:pathology; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D008108:Liver Diseases, Alcoholic / Q000000981:diagnostic imaging / Q000473:pathology; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012015:Reference Standards; D015203:Reproducibility of Results