What diagnostic methods are available?
The diagnosis and monitoring of chronic hepatic pathologies depend on clinical examinations, biological explorations, histology based on biopsy puncture, and non-invasive imaging examinations such as ultrasound and pulse elastography.
As we have seen, the progress of fibrosis and hepatic steatosis is initially completely asymptomatic, and can quietly develop into cirrhosis. This change takes place over the course of several years. Cirrhosis can then be discovered by chance during a clinical examination, or from irregularities in the results of scheduled liver tests, or when a complication arises.
The clinical exam, in the absence of cirrhosis, often reveals very little, except possibly a 'drinker's liver' (hepatomegaly) on palpation. When cirrhosis is present, a clinical exam can reveal: an icterus, signs of liver deficiency (blood-naevus, palmar erythrosis, hepatic encephalopathy), signs of portal hypertension (collateral venous circulation, enlarged spleen), and ascites, which can be a sign of cirrhosis.
Biological tests can reveal irregularities, but they only appear when hepatic cirrhosis is present. There is the possibility of anaemia or thrombopenia. The levels of bilirubin, alkaline phosphatase, and GGT can be elevated. The prothrombin ratio (PR) and V factor can be low, indicating liver deficiency. A lowering of the albumen level will promote the appearance of ascites. For cases of Hepatitis C without comorbidity, the AASLD and IDSA societies recommends the use of non-invasive biological blood tests combined with a FibroScan examination (see below) for non-invasive assessment of liver disease. These non-invasive biological tests must be prescribed and interpreted by specialists, because their results may be affected by other factors, such as inflammation, etc.
Abdominal Ultrasound is used to evaluate the uniformity of the hepatic parenchyma, which can appear hyperechogenous in the case of steatosis. The liver can have an augmented volume and may have more or less deformed contours. Signs consistent with portal hypertension may be visible (venous dilation, splenomegaly, collateral circulation).
Liver Biopsy remains the touchstone test for the diagnosis and quantification liver disease. This is an invasive examination and is not without disadvantages, or even risks: 20% of subjects find it painful, there are hemorrhaging complications in 0.1% of cases, and it causes the death of 0.01% of patients. It is therefore not easy for most patients to repeat. Moreover, it is subject to variability from one operator to another and from one procedure to another, as well as sampling errors.
Vibration-Controlled Transient Elastography or FibroScan® (VCTE™), is an FDA approved technology. FibroScan® offers a quick and painless approach to assessing liver health. FibroScan® emits a pulse of energy, which you may feel as a slight vibration on your skin. FibroScan then measures the speed of this energy and immediately provides this information to your physician, who then uses it as part of a broader evaluation of your liver health.
FibroScan® (VCTE™) is used for the non-invasive measurement of liver health.