Your liver fibrosis (FIB-4) test is an accurate and non-invasive scoring system which helps to estimate the amount of scarring in your liver. Fibrosis is the first stage of liver-scarring, which can later develop into liver cirrhosis if left untreated. Since liver fibrosis often shows no symptoms in its early stages, the FIB-4 test is an accurate way to assess whether you have scarring in your liver.