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Gut 56:968-973 doi:10.1136/gut.2006.111302
  • Liver disease

Reproducibility of transient elastography in the evaluation of liver fibrosis in patients with chronic liver disease

  1. Mirella Fraquelli1,
  2. Cristina Rigamonti2,
  3. Giovanni Casazza3,
  4. Dario Conte1,
  5. Maria Francesca Donato2,
  6. Guido Ronchi2,
  7. Massimo Colombo2
  1. 1Second Division of Gastroenterology, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy
  2. 2First Division of Gastroenterology, A.M. & A. Migliavacca Center for Liver Disease, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy
  3. 3Istituto di Statistica Medica e Biometria, Università degli Studi di Milano, Milan, Italy
  1. Correspondence to:
    Dr Mirella Fraquelli
    Department of Internal Medicine, Pad Granelli III piano, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, Via F Sforza 35, 20122 Milano, Italy; mfraquelli{at}yahoo.it
  • Accepted 16 January 2007
  • Revised 22 December 2006
  • Published Online First 25 January 2007

Abstract

Objective: Transient elastography (TE) is gaining popularity as a non-invasive method for predicting liver fibrosis, but intraobserver and interobserver agreement and factors influencing TE reproducibility have not been adequately assessed. This study investigated these aspects.

Setting: Tertiary referral liver unit.

Patients: Over a 4-month period, 200 patients with chronic liver disease (CLD) with varying aetiology consecutively underwent TE and liver biopsy.

Interventions: TE was performed twice by two different operators either concomitantly or within 3 days of the bioptic procedure (METAVIR classification).

Main outcome measures: Intraobserver and interobserver agreement were analysed using the intraclass correlation coefficient (ICC) and correlated with different patient-related and liver disease-related covariates.

Results: 800 TE examinations were performed, with an indeterminate result rate of 2.4%. The overall interobserver agreement ICC was 0.98 (95% CI 0.977 to 0.987). Increased body mass index (>25 kg/m2), steatosis, and low staging grades (fibrosis (F) stage <2) were significantly associated with reduced ICC (p<0.05). Intraobserver agreement ICC was 0.98 for both raters. Using receiver operating characteristic curves, three diagnostic TE thresholds were identified: >7.9 kPa for F⩾2, >10.3 for F⩾3 and >11.9 for F = 4. TE values assessed by the two raters fell within the same cut-off of fibrosis in 88% of the cases for F⩾2, in 92% for F⩾3 and 91% for F = 4.

Conclusions: TE is a highly reproducible and user-friendly technique for assessing liver fibrosis in patients with CLD. However, because TE reproducibility is significantly reduced (p<0.05) in patients with steatosis, increased BMI and lower degrees of hepatic fibrosis, caution is warranted in the clinical use of TE as a surrogate for liver biopsy.

Footnotes

  • Published Online First 25 January 2007

  • Competing interests: None to declare