What is it?
As the name suggests, Magnetic Resonance Elastography (MRE) is a scan used to assess the elasticity of any soft tissue or organ. Combining MRI techniques with vibrations directed at specific sites, an image called an elastogram is generated.
It is commonly used in patients with various liver diseases ranging from liver cirrhosis to hepatitis, or fatty liver disease, to determine the extent of liver fibrosis (stiffening).
How do I prepare for an MR Elastography?
- Your Gastroenterologist may ask you to fast 4-6 hours before your test. This is because the stiffness of the liver may increase after a meal for patients with chronic liver disease.
- Avoid applying deodorants, perfumes or body lotions before the exam. These may contain metals that could interfere with the scans.
What to expect from MR Elastography Scan?
An MRE scan can be done during an MRI liver, with an additional elastography component. The process of the MRI is similar to what was described above. For the elastography, a small pad called an MR driver is placed on your stomach, over your liver, and it delivers painless, low-frequency vibrations to the target organ. The MRI machine is able to quantify the speed of vibrations and generate a visual map of the stiffness or lack of elasticity of the liver.
What is Elastography of the liver for?
The main purpose of a liver elastography is for detecting and staging fibrosis in patients with liver disease.
How long does an MR Elastography take?
Generally, the test takes about 45 minutes.
Does an MR Elastography have radiation?
No, an MRE offers no radiation exposure. Unlike X-rays and computed tomography (CT) scans, which use ionizing radiation, MRI uses a strong magnetic field and radio waves to produce detailed images of the inside of the body. As a result, MRE is a safe and effective alternative for individuals who may be concerned about exposure to ionizing radiation.
What’s the difference between Ultrasound elastography and MR Elastography?
Both tests are helpful in evaluating elasticity of tissues in the body. However, there are some key differences between the two:
- Technology: Ultrasound elastography uses high-frequency sound waves to produce images of the inside of the body. MRE uses magnetic resonance imaging (MRI) technology to create images of the body.
- Image quality: MRE typically produces higher-quality images than ultrasound elastography. This is because MRE uses MRI technology, which provides more detailed images of the inside of the body.
- Evaluation of tissue stiffness: Both ultrasound elastography and MRE can evaluate the stiffness of tissues in the body, but MRE is often considered to be a more sensitive and specific test for detecting changes in tissue elasticity.
Limitations
The risks and contraindications to going for an MRE are the same as that of a regular MRI, as both utilise the same machine and imaging techniques. These include:
- For patients with gadolinium/dye allergies or pre-existing kidney disease, an MRI scan without contrast or alternative imaging modalities may be recommended instead.
- If you have severe claustrophobia, prolonged time spent in the small MRI tunnel may cause distress. Be sure to highlight this to your doctor or the radiographer prior to the scan.
References
- “Magnetic resonance elastography.” Mayo Clinic, 5 March 2022, https://www.mayoclinic.org/tests-procedures/magnetic-resonance-elastography/about/pac-20385177. Accessed 9 January 2023.
- “MR elastography | Radiology Reference Article.” Radiopaedia, 15 November 2021, https://radiopaedia.org/articles/mr-elastography. Accessed 9 January 2023.
