[New non-invasive tool for assessment of liver fibrosis: transient elastography]

Formation of connective tissue causing liver fibrosis is the common trait of chronic liver diseases. The "gold-standard" of the evaluation of liver fibrosis is liver biopsy, but it is an invasive, painful procedure, and carries a significant, although small risk of life-threatening complications. It may have contraindications, and it is certainly not the ideal procedure for serially repeated assessment of disease progression. A new, non-invasive method for the assessment of liver fibrosis by measuring liver stiffness is the transient elastography. The velocity of the propagation of a shear wave is measured by ultrasound. The procedure is painless, rapid, and does not need any preparation. So far, transient elastography has been mostly validated in chronic hepatitis C, but it is applicable in liver diseases with other etiologies. The diagnostic accuracy of transient elastography increases with stage of fibrosis, and is more accurate in advanced fibrosis (F≥2, Metavir score) and in cirrhosis. Indication of antiviral therapy for chronic viral hepatitis B and C are the main field of the application of the transient elastography, and it is also a useful tool for follow-up the disease progression. It is applicable for early, non-invasive detection of graft damage after liver transplantation. Evaluation of liver damage, the stage of liver fibrosis by transient elastography may have an important role in the decision before surgery, or application of potentially hepatotoxic drugs. Histological examination of the liver tissue is not substituted in every case by transient elastography, but liver biopsy is supplanted by measuring liver stiffness for evaluation of liver fibrosis in many cases.