From the Guidelines
Transient elastography is a non-invasive medical imaging technique used to assess liver stiffness, which serves as an indicator of liver fibrosis or scarring, and is the preferred method for evaluating liver disease severity and prognosis, as it has been widely validated and has a high range of values (2-75 kPa) 1.
Key Points
- The most common commercial device is FibroScan, which works by sending a mechanical pulse wave through the liver and measuring the speed at which this wave travels—faster speeds indicate a stiffer liver and potentially more advanced fibrosis.
- During the procedure, patients lie on their back with their right arm raised, while a probe is placed on the skin over the liver area.
- The test takes about 5-10 minutes, requires no sedation, and provides immediate results.
- The measurements are reported in kilopascals (kPa), with higher values suggesting more severe fibrosis.
- Transient elastography has largely replaced liver biopsies for many patients because it's painless, quick, has no complications, and can be repeated easily to monitor disease progression.
- It's particularly useful for conditions like chronic hepatitis B and C, alcoholic liver disease, and non-alcoholic fatty liver disease.
- However, results may be less reliable in obese patients, those with ascites (fluid in the abdomen), or acute inflammation of the liver, and the technique has some limitations, such as the need for a dedicated device and the potential for false positives in certain cases 1.
Advantages and Limitations
- Advantages:
- Non-invasive and painless
- Quick and easy to perform
- No sedation required
- Immediate results
- High range of values (2-75 kPa)
- Widely validated
- Limitations:
- Less reliable in obese patients or those with ascites
- Potential for false positives in certain cases (e.g. acute hepatitis, extra-hepatic cholestasis)
- Requires a dedicated device
- May not be suitable for patients with certain medical conditions (e.g. iron overload) 1
From the Research
Definition and Purpose of Transient Elastography
- Transient elastography, also known as FibroScan, is a non-invasive method used to evaluate liver fibrosis by measuring liver stiffness 2, 3, 4, 5.
- The technique is based on the principle that the stiffness of the liver increases with the degree of fibrosis, allowing for the assessment of liver disease severity 2, 3.
Clinical Applications and Effectiveness
- Transient elastography has been validated as a reliable tool for assessing liver fibrosis in patients with various liver diseases, including hepatitis C and B, non-alcoholic steatohepatitis, and cirrhosis 2, 3, 4, 6.
- The method has been shown to be effective in detecting significant fibrosis, severe fibrosis, and cirrhosis, with high positive and negative predictive values 2, 3.
- Transient elastography can also be used to monitor disease progression and response to treatment, as well as to identify patients at risk of complications such as oesophageal varices and hepatocellular carcinoma 2, 4, 6.
Advantages and Limitations
- The main advantages of transient elastography are its non-invasive nature, ease of use, and reproducibility, making it an attractive alternative to liver biopsy 3, 4, 5.
- However, the method may have limitations, such as falsely high liver stiffness measurements in certain conditions, including acute hepatitis and congestive heart failure, and failed acquisition in obese patients 4.
- Further research is needed to fully explore the potential applications and limitations of transient elastography in clinical practice 5, 6.