Non-invasive Assessment of Liver Fibrosis

Abstract

In the USA, there is a growing prevalence of liver disease, particularly from alcohol and fatty liver, as well as improvements in hepatitis C therapy that should be adjusted for level of fibrosis. There is accordingly a great need for rapid non-invasive fibrosis testing (NIT) to determine who should be referred for specialty care, started on specific therapies, screened for varices and malignancy, and selected for clinical trials. It is not only the accuracy of NIT that matters, but the order in which they are applied and the population selected for screening. All NIT to date have high negative predictive value for ruling out advanced fibrosis, and despite high specificity, have limited positive predictive value due to the relative infrequency of advanced fibrosis in screened populations. A testing algorithm based on primary care screening (e.g., with FIB-4) followed by referral for specialty confirmatory testing (e.g., vibration-controlled transient elastography) would best fit most practice models. This focused review will characterize the most validated non-invasive blood tests and imaging and discuss their practical applications for real-world use.