Non-invasive assessment of liver fibrosis and prognosis.

Over the past decade, several advances have been made in the non-invasive assessment of liver fibrosis. Both serum markers and imaging-based tissue elastography predict the presence of advanced fibrosis compared with liver biopsy. Serum markers may be indirect or direct markers of liver structure and function. Imaging-based techniques measure liver stiffness as a surrogate for fibrosis and include ultrasound and MRI-based methods. Most non-invasive techniques work well at identifying subjects at the extremes of fibrosis but may not accurately discern intermediate stages. In addition to being a diagnostic tool, elastography may have an evolving role in prognosis. Increasing stiffness is associated with higher rates of liver decompensation, need for transplantation, hepatocellular carcinoma, and death. There are special populations of patients where elastography may serve as a non-invasive method to impart useful clinical information, such as patients after liver transplantation, those with congenital heart disease and those being treated for chronic viral hepatitis. The role of non-invasive markers in accurately predicting the presence of fibrosis in obese patients needs to be further refined.