Objective. Transient elastography (TE) is gaining popularity as a non-invasive method for predicting liver fibrosis, but intra- and interobserver agreement and factors influencing TE reproducibility have not been adequately assessed. This study addresses these aspects.
Setting. Tertiary referral Liver Unit.
Patients. Over a four month period, 200 patients with chronic liver disease (CLD) of different etiologies, consecutively underwent TE and liver biopsy.
Interventions. TE was performed twice by two different operators either concomitantly or within three days of the bioptic procedure (Metavir classification).
Main outcome measures. Intra- and interobserver agreement was analyzed using the intraclass correlation coefficient (ICC) and correlated with different patient and liver disease-related covariates.
Results. 800 TE examinations were performed with an indeterminate result rate of 2.4%. The overall inter-observer agreement ICC was 0.98(95% CI:0.977-0.987). Increased BMI(>28Kg/m2), steatosis, and low staging grades (<F2) were significantly associated to a reduced ICC. Intra-observer agreement ICC was 0.98 for both raters. By ROC curves, three diagnostic TE thresholds were identified: >7.9 for ≥F2, >10.3 for ≥F3 and >11.9 for F=4. TE values by the 2 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, since TE reproducibility is significantly reduced 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.
- liver fibrosis