CT examination does not diagnose all liver diseases, CT mainly determines the disease by the morphological changes in the liver, or the presence of abnormal echogenic structures in the liver. Some diseases only show abnormal liver function and no morphological changes, such as hepatitis B, hepatitis A, hepatitis E, EBV hepatitis, and drug hepatitis. When the degree of hepatitis is mild, CT may not even detect the presence of hepatitis. If the hepatitis is very severe, CT will suggest a change in density, but it will not be able to determine the cause of the change in density. However, in the case of hepatocellular carcinoma or biliary obstruction or cirrhosis, the problem can be detected on CT. For autoimmune hepatitis and inborn genetic metabolic diseases, such as hepatomegaly, CT cannot be relied upon for diagnosis either.