Posted on Nov 08, 2019
Cirrhosis - a type of advanced liver disease that develops as a result of continuous liver damage - is the leading cause for both liver cancer and liver failure. But research suggests that 69% of Americans with liver cirrhosis do not realize they have the disease.
Cirrhosis develops when scar tissue replaces healthy liver tissue. Mild scarring is called liver fibrosis. Severe scarring - or, advanced fibrosis - is called cirrhosis. While fibrosis can be treated and sometimes even reversed, cirrhosis cannot.
A FibroScan, alongside other medical imaging, is one of the most powerful tools being used to detect liver disease while it’s still treatable. From what causes fibrotic tissue and how it affects your liver to who should be getting a FibroScan and how to interpret your score - here’s your guide to understanding a FibroScan.
A FibroScan is a test used to help measure the amount of scarring (fibrotic tissue) in the liver. It’s essentially a specialized ultrasound specifically for the liver.
Liver fibrosis is the result of prolonged or repeated liver damage.
When the damage is limited, or a one-time thing, the liver can repair itself by making new cells. But if the liver is repeatedly damaged - say, by regular heavy alcohol consumption, a hep C infection, or constant liver inflammation caused by obesity - it’s forced to replace and repair damaged tissue over and over. This leads to the accumulation of scar tissue (fibrotic tissue).
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Much like other parts of the body, scarring is the liver’s response to repeated injury. But unlike healthy liver cells, scar tissue cells are unable to function properly. They do not have the ability to self-repair and, over time, become thick and stiff. When this happens, it can limit or block blood flow within the liver, causing healthy liver cells to die. This leads to the creation of more scar tissue. It’s a bit of a vicious cycle.
Nearly all forms of liver disease eventually lead to the development of fibrotic tissue. Fibrosis can lead to cirrhosis, and cirrhosis increases your risk for liver cancer and liver failure. In fact - about 80% of liver cancers occur in cirrhotic livers.
A Fibroscan is a great, non-invasive alternative to liver biopsy. The scan only takes about 5-10 minutes and does not involve any needles or other uncomfortable tools.
If you’ve had a liver ultrasound or other type of liver scan that shows fat deposits in your liver, a FibroScan can help confirm a fatty liver diagnosis. It can also be very helpful in gauging how advanced liver scarring is in a patient, which is essential for treatment planning.
It’s also important to keep in mind that distinguishing the difference between fat deposition and fatty liver in radiographic imaging can be challenging. The mischaracterization of fatty liver as 'fatty infiltration' is another possible diagnostic pitfall.
Benign liver lesions can also obscure liver scans - making a liver appear to be scarred when it is not. A second opinion from an expert subspecialty radiologist is the best way to ensure an accurate diagnosis.
FibroScan measures the stiffness of your liver to help determine the degree of scarring. Your healthcare provider will use your FibroScan fibrosis result and your medical history to determine your fibrosis score.
Depending on where you are, there are several different scoring systems used in a Fibroscan. Most imaging centers, however, use a 5-point scoring system to grade the degree of liver fibrosis.
A fibrosis result is measured in kiloPascal’s (kPa), ranging from 2 to 75 kPa. Between 2 and 6 kPa is considered a normal liver. The average normal result is 5.3 kPa. Anything outisde of the nomral range typically indicates liver disease.
Once a fibrosis result has been determined, the chart below is used to calculate the fibrosis grade. Patients can match their kPa result with their disease, find the range that includes their fibrosis result, and then look at the top of that column to see the fibrosis score.
Sometimes, patients may also receive a score ranging from A0 to A3. This is used to indictae the degree of inflammation - A0 meaning no inflammation and A3 meaning severe inflammation.
Fortunately, when caught early enough, some cases of fibrosis can be reversed by lifestyle changes.
But catching fibrotic tissue growth early on can be a challenge. Fibrosis itself does not cause symptoms. Depending on the disorder causing fibrosis, a patient may have symptoms related to that condition - but many forms of liver disease do not present noticeable health problems for years. So by the time fibrosis is detected, it’s often too far advanced to be reversed.
To prevent this from happening, it’s super important individuals know their risk of liver disease because nearly all forms will eventually lead to fibrosis. Fibrosis can then lead to cirrhosis (which is irreversible), and cirrhosis increases your risk for liver cancer and liver failure. Early detection of fibrosis is crucial to avoid cirrhosis. Once identified, the patient can make lifestyle changes to mitigate liver damage.
For instance, let’s look at the main contributors to non-alcoholic fatty liver disease (NASH) - obesity, pre-diabetes, and diabetes all put you at risk of NASH. If you’re at risk for any of these main contributors, it’s wise to start implementing lifestyle changes to reduce your risk.
Usually, cirrhosis develops 6 months to several years after liver disease appears. But once it develops, it can progress quickly. By 2020, cirrhosis is expected to be the leading cause or liver transplants.
While FibroScan results play an important role in liver disease diagnosis and staging - there are a few factors that can affect the results:
The following may cause your fibrosis result to be over-estimated (i.e. your liver may have less scarring than what your fibrosis result says):
In general, the liver is a complicated part of the body to image. For this reason, a FibroScan is best used in addition to other medical exams, such as liver ultrasound or MRI. A second opinion from a specialist is also extremely valuable in confirming a diagnosis and determining the best treatment approach.