Liver Ultrasound Elastography: Review of Techniques and Clinical Applications

Chronic liver disease remains a substantial worldwide problem. Accurate estimation of liver fibrosis is crucial for determining the stage of the disease, assessing the patient's prognosis and predicting treatment response. Staging hepatic fibrosis has traditionally been done with liver biopsy but clinical practice has been changing, partly because liver biopsy has several disadvantages: it is invasive; it is associated with rare but serious complications; and it is prone to sampling error representing a tiny portion of the total liver volume. An increasing number of non-invasive liver fibrosis assessment have been developed. These include elastographic methods involving ultrasound (US) and magnetic resonance (MR) imaging. In this review article we discuss the different ultrasound-based elastography techniques, their clinical applications and various confounding factors in the assessment of hepatic fibrosis that may affect the accuracy of the measurements.