Magnetic Resonance Elastography Test and Procedure
Overview
Magnetic resonance elastography (MRE) is a noninvasive test that uses MRI combined with gentle vibrations to create a detailed image called an elastogram. This method is a type of elasticity imaging that measures how soft or stiff tissues are inside the body.
Doctors usually use MRE to find liver problems, like stiffness caused by fibrosis or long-term inflammation. Researchers are studying MRE as a way to look for disease in other organs. Thousands of diagnostic centers worldwide offer this method. Some key features include:
- Quantitative imaging for tissue stiffness.
- No surgery or needles required.
- Structure sensitive elastography imaging.
Purpose and Use
Doctors mainly use Magnetic Resonance Elastography (MRE) to assess how stiff the liver has become, which helps identify and monitor liver problems such as liver fibrosis and cirrhosis. Scarring inside the liver from chronic liver diseases, including hepatitis C and conditions leading to hepatic fibrosis, often increases liver stiffness.
Early-stage liver fibrosis usually does not cause symptoms. If not managed, it can progress to cirrhosis, which is advanced and severe scarring. MRE detects these changes before complications arise, like ascites—when fluid builds up in the abdomen. Here’s how MRE is useful:
| Advantages of MRE | Details |
|---|---|
| Noninvasive | No needles or surgical instruments needed |
| Evaluates the entire liver | Not restricted to a small tissue sample |
| Early detection of fibrosis | Sensitive to changes even at the beginning stage |
| Effective for people with obesity | Reliable results regardless of body size |
| Guides treatment and monitors progress | Helps physicians make decisions and track outcomes |
| Predicts risk of complications | Assesses chances of fluid build-up like ascites |
MRE supports the management of patients suffering from chronic liver disease by providing a clear view of how much the liver is affected. This tool guides care in conditions such as chronic liver diseases, cirrhosis, and liver complications that may not be obvious without testing. Compared with traditional biopsy, MRE offers comfort, safety, and more comprehensive results.
Possible Safety Concerns
MRE is usually safe, but some risks exist. Metal inside the body, like metallic joint prostheses, artificial heart valves, pacemakers, or cochlear implants, can cause problems during the scan. These items may affect image quality or lead to safety hazards.
Patients with metal clips, implantable defibrillators, or metal fragments (like bullets or shrapnel) should inform their doctor before getting an MRE. Anyone who may be pregnant should also talk to their healthcare provider first.
Metal Items to Report Before an MRE
| Item Type |
|---|
| Metallic joint prostheses |
| Artificial heart valves |
| Pacemaker or implantable heart defibrillator |
| Metal clips |
| Cochlear implants |
| Bullets, shrapnel, or metal fragments |
Unlike a liver biopsy, MRE does not involve breaking the skin. However, it is not recommended for everyone, so a careful review with a healthcare provider is needed before the test.
Steps to Get Ready
Preparing for this noninvasive test involves following simple guidelines. Patients are usually asked not to eat for four hours before the exam, but they can drink water. Regular medications should be taken unless told otherwise by the radiologist. Before the scan, patients must change into a hospital gown and remove these items:
- Jewelry
- Dentures
- Glasses
- Hairpins
- Hearing aids
- Watches
- Wigs
- Underwire bras
Follow all instructions for the best results. Standard practices help ensure each test is safe and reliable, such as using noninvasive palpation techniques instead of manual ones.
What Will Happen During the Test
During a magnetic resonance elastography (MRE) procedure, the patient changes into a gown and lies down for the exam. The technologist places a soft pad against the body, usually over the liver. This pad sends gentle, low-frequency mechanical waves into the area.
The magnetic resonance imaging (MRI) scanner collects images of these shear waves as they move through biological tissues. Advanced processing methods like motion-encoding gradients and spin echo create elastograms—a type of map that shows tissue stiffness. This step usually takes less than five minutes within a typical MRI appointment.
Key Points
- Exam takes about 15–45 minutes.
- MRE portion lasts under 5 minutes.
- Results show how waves travel through tissue and help spot stiffness or changes.
Outcomes
Magnetic resonance elastography produces detailed quantitative maps of tissue stiffness and mechanical properties. Results highlight values like shear modulus, storage modulus, and loss modulus to assess viscoelastic features.
The method helps doctors identify changes in biomechanics across organs, such as brain viscoelasticity or skeletal muscle properties. Results also capture variations in wavelength and viscoelasticity, supporting diagnostic performance and informing further care steps.
