Vibration-controlled Transient Elastography

A Practical Approach to the Noninvasive Assessment of Liver Fibrosis

Elliot B. Tapper; Nezam H. Afdhal


Curr Opin Gastroenterol. 2015;31(3):192-198. 

In This Article

Vibration-controlled Transient Elastography for the Patient With Nonalcoholic Fatty Liver Disease

Several lines of evidence suggest that NAFLD is likely to be the major cause of liver-related morbidity and mortality. The respective prevalence of NAFLD and NASH among Americans is 46 and 12% and rising.[32,33] Outpatient visits for Medicare beneficiaries for the primary reason of NAFLD care have doubled from 2005 to 2010.[34] The rate of hospitalizations for patients with NAFLD has increased by 97% between 2000 and 2012.[3] Patients with suspected NAFLD must be evaluated for the risk of complications in a cost-effective manner. Yet, it is often hard to assess that risk with the history, physical exam and conventional laboratory tests.[35] Guidelines recommend liver biopsy for those with possible advanced liver disease.[32]

VCTE is a well tolerated and reliable alternative to the liver biopsy for patients with NAFLD.[10,13,14,17,33,36] VCTE also readily determines the risk of advanced liver disease as well as the burden of hepatic steatosis. A cutoff of 10.3 kPa possesses an AUROC of 0.95 with an NPV of 99% for the presence of cirrhosis.[13] When used in the context of a comparison of the M and XL probes, this cutoff identified patients with cirrhosis with an AUROC of 0.94 and 0.93, respectively.[17] An XL probe cutoff of 16.0 kPa for cirrhosis, however, was employed in a smaller Canadian cohort with excellent results: 100% NPV and 40% PPV.[14] When performing VCTE, one may also assess for steatosis using a novel adaptation of VCTE termed controlled attenuation parameter that yields a result expressed in dB/m.[37,38] In a prospective study of 5323 examinations, a French group found diagnosed steatosis greater than 10% with an AUROC of 0.79 and 33% or greater with an AUROC of 0.84.[10] Precise cutoffs are yet to be determined. In their excellent meta-analysis, Shi et al.[38] found that grades of steatosis were discerned with the following median values: 232.5 dB/m (S1), 255 dB/m (S2) and 290 dB/m (S2). The hierarchical summary AU ROC for each grade of steatosis was 0.82, 0.87 and 0.86.