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


METHODS
Tertiary referral liver unit.


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


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


METHODS
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/m(2)), 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.
Fraquelli
Mirella
M
Second Division of Gastroenterology, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy. mfraquelli@yahoo.it
Rigamonti
Cristina
C
Casazza
Giovanni
G
Conte
Dario
D
Donato
Maria Francesca
MF
Ronchi
Guido
G
Colombo
Massimo
M
D000328:Adult; D000368:Aged; D001706:Biopsy; D002908:Chronic Disease; D004548:Elasticity; D005234:Fatty Liver / Q000150:complications; D005260:Female; D019694:Hepatitis B, Chronic / Q000150:complications; D019698:Hepatitis C, Chronic / Q000150:complications; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000209:etiology; D008104:Liver Cirrhosis, Alcoholic / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D016037:Single-Blind Method