Background and Aims: Vibration-controlled transient elastography
(VCTE), point shear wave elastography (pSWE), 2-
dimensional shear wave elastography (2DSWE), magnetic resonance
elastography (MRE), and magnetic resonance imaging
(MRI) have been proposed as non-invasive tests for patients with
non-alcoholic fatty liver disease (NAFLD). This study evaluated
their diagnostic accuracy for liver fibrosis and non-alcoholic
steatohepatitis (NASH).
Methods: PubMED/MEDLINE, EMBASE and the Cochrane Library
were searched for studies examining the diagnostic accuracy of
these index tests, against histology as the reference standard, in
adult patients with NAFLD. Two authors independently screened
and assessed methodological quality of studies and extracted
data. Summary estimates of sensitivity, specificity and area under
the curve (sAUC) were calculated for fibrosis stages and
NASH, using a random effects bivariate logit-normal model.
Results: We included 82 studies (14,609 patients). Meta-analysis
for diagnosing fibrosis stages was possible in 53 VCTE, 11 MRE, 12
pSWE and 4 2DSWE studies, and for diagnosing NASH in 4 MRE
studies. sAUC for diagnosis of significant fibrosis were: 0.83 for VCTE, 0.91 for MRE, 0.86 for pSWE and 0.75 for 2DSWE. sAUC for
diagnosis of advanced fibrosis were: 0.85 for VCTE, 0.92 for MRE,
0.89 for pSWE and 0.72 for 2DSWE. sAUC for diagnosis of
cirrhosis were: 0.89 for VCTE, 0.90 for MRE, 0.90 for pSWE and
0.88 for 2DSWE. MRE had sAUC of 0.83 for diagnosis of NASH.
Three (4%) studies reported intention-to-diagnose analyses and
15 (18%) studies reported diagnostic accuracy against prespecified
cut-offs.
Conclusions: When elastography index tests are acquired successfully,
they have acceptable diagnostic accuracy for advanced
fibrosis and cirrhosis. The potential clinical impact of these index
tests cannot be assessed fully as intention-to-diagnose analyses
and validation of pre-specified thresholds are lacking.
Lay summary: Non-invasive tests that measure liver stiffness or
use magnetic resonance imaging (MRI) have been suggested as
alternatives to liver biopsy for assessing the severity of liver
scarring (fibrosis) and fatty inflammation (steatohepatitis) in
patients with non-alcoholic fatty liver disease (NAFLD). In this
study, we summarise the results of previously published studies
on how accurately these non-invasive tests can diagnose liver
fibrosis and inflammation, using liver biopsy as the reference.We
found that some techniques that measure liver stiffness had a
good performance for the diagnosis of severe liver scarring