To date, histological assessment of the liver using liver biopsy has served as the reference standard for evaluation of the presence and severity of NAFLD as well as for the assessment of disease progression or regression.
Non-invasive tests to evaluate fibrosis rely on either changes in the physical properties of the liver or on changes in levels of specific chemical moieties reflective of fibrogenesis.
Simple non-invasive laboratory aids can be used to rule out clinically significant fibrosis in those with chronic liver disease. Tests with higher specificity are being developed to increase the positive predictive value of testing and enhance the ability to rule in advanced fibrosis. Vibration-controlled transient elastography and magnetic resonance elastography are often used for this purpose.