When you, unfortunately, get sick and go to a hospital, it is routine to be examined by the doctor. He or she may request some extra investigations – some of those may be painful as they involve pricking the skin. Other examinations may not be as painful and are more readily accepted by patients.
The “gold standard” of diagnosing chronic liver diseases has been through a core biopsy. This is an invasive procedure where the doctor pricks your liver through the skin and gets a little tissue which is then taken to the laboratory for assessment. After a few days, the results are availed.
There is a new non-invasive method that combines the power of ultrasound and mechanical vibration on the skin – this is what is termed transient elastography. TE is very useful in the assessment of patients with chronic liver disease, including chronic hepatitis C, chronic hepatitis B, chronic alcohol abuse and fatty liver. Because of the prominence of the Fibroscan brand, many clinicians simply refer to transient elastography (TE) as “Fibroscan” – it is now available in Kenya for the first time and can be done at the MP Shah Hospital by an experienced Radiologist.
How does it differ from conventional ultrasound? You may already know that many mothers in their antenatal visit are also done an ultrasound examination to check on the baby in their womb. This is the conventional ultrasound. It is also used to asses other organs as the thyroid, breasts, muscle and the spleen among others. Fibroscan uses both ultrasound as well as mechanical vibration on the skin.
When a patient has chronic liver disease, the liver tends to become hard or stiff. This is because the underlying disease affecting the liver causes small scars to form in the whole organ. As the disease progresses this stiffening of the liver tissue increases.
By estimating the stiffness of the liver, we can then classify the seriousness of the liver condition of the patient. This will then allow the doctor to then formulate a plan for the management of the disease. You may be referred to a gastroenterologist (a doctor specialized in diseases affecting the digestive system) for further specialized care.
How is transient elastography (TE) examination done? Usually the patient comes to the imaging department when they have starved for at least 4 hours. Then while lying on the couch, the special probe with a small stubby end is placed against the body on the right side where the liver is located – the cross-sectional area of this probe is equivalent to a fingertip and can therefore be comfortably placed between the patient’s ribs. The patient will feel a sensation akin to a gentle tap on the skin. This is repeated at least 10 times to ensure that the estimation of the liver stiffness is valid, with at least a 60% success rate needed.
Why is liver stiffness measurement important? The end stage of chronic liver disease is cirrhosis and is irreversible. This means that most of the liver has been replaced by scar tissue – it shrinks in size and cannot do its normal function. Stopping further deterioration becomes urgent or else liver failure ensues – only a liver transplant from a donor can help the patient.
The liver is an amazing organ – it is the second largest organ in the body and the only one that has the capability to grow back if a section of it is cut, through a process called liver regeneration. It normally takes the nutrients absorbed from the intestine and coverts them to other useful substances. It also helps to detoxify chemicals that we ingest or are produced by our bodies. In fact, estimates regarding the organ’s total number of functions may be as high as 500.
If the doctor becomes concerned about the health of your liver and you are diagnosed early, it is of great benefit to you.
The whole FibroScan examination takes approximately 10 to 15 minutes. Not only does the FibroScan examination obviate pain, it takes a short time while saving you money. It costs almost 1/3 to 1/2 of the actual cost of a liver biopsy.
The FibroScan examination can be repeated later and can reliably tell us whether the stiffness of the liver has reduced (improvement), has remained the same or the stiffness has increased (worsening).
Are there shortcomings of this TE technique? Transient elastography does not directly measure fibrosis and hence, over-estimation of liver fibrosis may be observed for several reasons: active liver inflammation or tumour within the liver or heart failure. Therefore, liver stiffness readings need to be interpreted carefully, and with consideration to these likely scenarios. That is why at the imaging department, the Radiologist (a doctor who is specialised in diagnostic imaging) also assesses the liver with conventional ultrasound to check for these factors with consideration of the laboratory results the patient may have done to avoid these pitfalls. The commonest cause of failure of Fibroscan examination is seen in obese patients. We however employ other techniques to ensure that we acquire valid results for the benefit of the patient.
This groundbreaking technology is new here in Kenya and we at MP Shah are the first to use it. It has been used in other countries for over 10 years now with a lot of research supporting its reliability.
By Dr. James Thuku, Consultant Radiologist at the MP Shah Hospital