Non-Invasive Assessment of the Liver – Serum Markers and Imaging Techniques

Management and prognosis of the liver diseases highly depends on the advancement of the liver lesions. It is particularly important to distinguish patients at greatest risk of developing liver cirrhosis, liver failure and hepatocellular carcinoma. Liver biopsy remains the gold standard for evaluating the liver tissue. It allows not only for establishing the grade of inflammatory activity and the stage of fibrosis, but also for more accurate differential diagnosis and detection of coexisting liver diseases. Needle biopsy removes, however, only about 1/50,000 of the liver tissue and carries the risk of sampling error. Furthermore, the specimen should be sufficient in length (20-25 mm), width, fragmentation and number of complete portal tracts (at least 11) [Cholongitas et al., 2006]. Moreover, liver assessment is affected by significant interpretative error and interobserver variability of histological interpretation. Besides, many patients are reluctant to experience repeated biopsies, which limits the ability to monitor disease progression and the effects of treatments. Search for new non-invasive approaches have been initiated as a result of the limitations of the liver biopsy. Non-invasive tests for the assessment of the severity of chronic liver diseases seem to be an attractive option designed to replace liver biopsy in the near future. Ideal non-invasive marker of particular liver lesion should be reliable, liver specific, inexpensive and easy to perform. In addition, it should allow not only to diagnose particular liver problem but also to monitor its progression. Recently extensive research is performed to evaluate non-invasive techniques for the detection of liver fibrosis, necroinflammatory activity and steatosis in various liver diseases. This chapter revises currently used noninvasive techniques of liver assessment.