How is Liver Fibrosis Diagnosed?
Early fibrosis can be difficult to diagnosis because it is often asymptomatic. If a blood test indicates fibrosis of the liver, typically, a liver biopsy will be performed. A liver biopsy requires a needle to remove a small sample of liver tissue so that doctors can assess the extent of liver damage and stage the degree of fibrosis.
Several scales are used to stage fibrosis. One common classification is a scale from 0 to 4 where
- stage 0 indicates no fibrosis;
- stage 1 indicates enlargement of the portal areas by fibrosis;
- stage 2 indicates fibrosis extending out from the portal areas with rare bridges between portal areas;
- stage 3 indicates many bridges of fibrosis that link up portal and central areas of the liver; and
- stage 4 indicates cirrhosis.
The degree of fibrosis can be assessed as none, minimal, mild, moderate or severe.
Considered the “gold standard” for determining the extent of liver disease, several points of interest regarding liver biopsy should be considered. Liver biopsy is not always accurate and has several shortcomings. The procedure is invasive and not without potential complications such as bleeding and infection. At least 20 percent of patients have pain that requires medications after liver biopsy. Rare complications include puncture of another organ, infection, and bleeding. Significant bleeding after liver biopsy occurs in one out of 100 to one out of 1,000 cases, and deaths are reported in one out of 5,000 to one out of 10,000 cases.
Researchers have been seeking less invasive ways to diagnose liver disease, developing and testing clinical tools such as a highly sensitive imaging procedure called Magnetic Resonance Elastography (MRE) in which a special kind of mechanical energy called “shear waves” to probe the mechanical properties of tissue is used. MRE can measure elasticity – detecting abnormal hardening of liver tissue – sparing some patients the need for a biopsy and allowing physicians to begin intervention aimed at treating their disease before it progresses to cause irreversible damage.