Hepatic Elastography (FibroScan) for Cirrhosis
The prognosis and clinical management of patients with the chronic liver disease are primarily influenced by the accumulation of fibrosis and its progression over time, and the same therapeutic choices are conditioned by this parameter. This emphasizes the need for early diagnosis to prevent complications. Until a few years ago, liver biopsy was the only tool for assessing fibrosis. However, a biopsy is an invasive procedure that can sometimes be painful and induce complications, and this may discourage some to undergo this assessment.
As a consequence, many patients, especially in recent years, have been treated with antiviral drugs without knowing the actual severity of disease and others, however, have never been able to benefit from therapy, because afraid of undergoing this procedure. However, the accuracy of liver biopsy is influenced by sampling error and interpretation variability. These limitations can lead to underestimation of cirrhosis, especially if the biopsy sample is small or fragmented. This led to a new technique that obviated these problems: hepatic elastography.
What is hepatic or fibro scan elastography?
Hepatic elastography (also known under the trade name Fibro Scan Test or merely fibro scan) is a diagnostic method useful for quantifying liver fibrosis, namely the scarring phenomenon that results in diseases such as viral hepatitis and which can lead to cirrhosis liver.
How is the appliance made?
The device consists of an ultrasound probe mounted on a vibrating system, at first sight, similar to that of conventional echography. The probe contains a low-frequency vibrator that generates an elastic wave and a single element transducer that works at 5 MHz. The fibroscan probe is applied on the skin of the right rib: the impulse that generates determines the propagation of an elastic wave through the liver, whose speed, measured by ultrasound, is directly related to its rigidity (in turn dependent on the amount of fibrosis).
What is the use of liver elastography?
For its characteristics, therefore, the fibro scan test, is particularly useful for monitoring over time of liver diseases, their evolution and response to treatment.
Who is the ideal patient?
Anyone may be subjected to this investigation upon indication by the attending physician, or a specialist physician. Being a technique based on ultrasound (as opposed to radiography and CT scan) it can also be performed in women during pregnancy and lactation.
The benefits of fibro scan:
Liver elastography is a rapid, painless, non-dangerous, side-effect test, easily repeatable over time and representative of a liver tissue sample at least one hundred times greater than that obtained from a standard liver biopsy. Furthermore, elastography also has advantages for biomarkers as it provides a more direct measure of fibrosis, not influenced by the presence of concomitant diseases and is theoretically applicable to any chronic liver disease.
In fact, fibro scan has been used for the evaluation of fibrosis also in other diseases such as:
· Hepatitis B
· Co-infection
· Chronic cholestasis disorders
And more recently in alcoholic hepatitis and NASH. However, at least in a prospective study involving 183 patients with hepatitis C, the Fibroscan-Fibrotest combination provided the best diagnostic performance, especially for significant fibrosis.
The only drawback lies in the fact that - like all diagnostic techniques based on ultrasound - the elastography is an operator, so to give reliable results it must be performed by an expert doctor.
