title: Ultrasound-based transient elastography for the detection of hepatic fibrosis: systematic review and meta-analysis.
abstract: OBJECTIVE
  Ultrasound-based transient elastography is a promising noninvasive alternative to liver biopsy for detecting hepatic fibrosis. However, its overall test performance in various settings remains unknown. The aims of this study were to perform a systematic review and meta-analysis of diagnostic accuracy studies comparing ultrasound-based transient elastography with liver biopsy for hepatic fibrosis.
  
  
  METHODS
  Electronic and manual bibliographic searches to identify potential studies were performed. Selection of studies was based on reported accuracy of ultrasound-based transient elastography compared with liver biopsy. Data extraction was performed independently by 2 reviewers. Meta-analysis combined the sensitivities, specificities, and likelihood ratios of individual studies. Extent and reasons for heterogeneity were assessed.
  
  
  RESULTS
  Nine studies in full publication were identified. For patients with stage IV fibrosis (cirrhosis), the pooled estimates for sensitivity were 87% (95% confidence interval [CI], 84%-90%), specificity 91% (95% CI, 89%-92%), positive likelihood ratio 11.7 (95% CI, 7.9-17.1), and negative likelihood ratio 0.14 (95% CI, 0.10-0.20). Among 7 investigations reporting patients with stages II-IV fibrosis, the pooled estimates for sensitivity were 70% (95% CI, 67%-73%), specificity 84% (95% CI, 80%-88%), positive likelihood ratio 4.2 (95% CI, 2.4-7.2), and negative likelihood ratio 0.31 (95% CI, 0.23-0.43). Diagnostic threshold (or cut-off value) bias was identified as an important cause of heterogeneity for pooled results in both patient groups.
  
  
  CONCLUSIONS
  Ultrasound-based transient elastography appears to be a clinically useful test for detecting cirrhosis.
authors.affiliation: Advanced Liver Disease Study Group, Miles and Shirley Fiterman Center for Digestive Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Jayant A
authors.initials: JA
authors.lastname: Talwalkar
authors.forename: David M
authors.initials: DM
authors.lastname: Kurtz
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Schoenleber
authors.forename: Colin P
authors.initials: CP
authors.lastname: West
authors.forename: Victor M
authors.initials: VM
authors.lastname: Montori
mesh_terms: D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results