Non-invasive diagnosis of liver fibrosis.

Although histopathological determination by 'invasive' liver biopsy remains the gold standard for evaluating the progression of chronic liver disease, the procedure has several limitations including invasiveness, sampling error, and interobserver variability. These drawbacks have stimulated the development of 'non-invasive' tools for diagnosing the stage of hepatic fibrosis. The non-invasive methods currently available rely on two distinct approaches, a 'biological' approach based on the determination of serum levels of biomarkers of fibrosis, and a 'physical'' approach that measures liver stiffness. 'Biological' approaches are classified as 'direct', 'indirect', and combined biomarkers. "Physical" approaches include transient elastography, real-time tissue elastography, and other methods using more advanced modalities. This article provides an overview of the available non-invasive diagnostic methodologies and their possible integration for the evaluation of liver fibrosis in clinical practice.