Magnetic Resonance Elastography (MRE)

Magnetic Resonance Elastography (MRE) is a non-invasive medical imaging technique that combines magnetic resonance imaging (MRI) with mechanical vibrations to measure the elasticity and stiffness of tissues.

Principle

MRE works by applying low-frequency mechanical vibrations to the body, typically in the range of 20-100 Hz. These vibrations cause the tissue to deform, creating a shear wave that propagates through the tissue. The MRI scanner then detects the displacement of the tissue caused by the shear wave, allowing for the measurement of tissue stiffness and elasticity.

Procedure

The MRE procedure typically involves the following steps:

• The patient lies on an MRI table and is positioned within the MRI scanner.
• A device that generates mechanical vibrations, such as a pneumatic or electromagnetic driver, is placed against the body part being imaged.
• The MRI scanner applies a series of magnetic field gradients to encode the displacement of the tissue caused by the shear wave.
• The MRI scanner then reconstructs images of the tissue stiffness and elasticity based on the detected displacement.

Applications

MRE has several clinical applications, including:

• Liver disease diagnosis: MRE can measure liver stiffness, which is a marker for liver fibrosis and cirrhosis.
• Cancer diagnosis and treatment monitoring: MRE can help distinguish between malignant and benign tumors based on their stiffness and elasticity.
• Musculoskeletal disorders: MRE can evaluate the mechanical properties of muscles, tendons, and ligaments in conditions such as muscular dystrophy and tendonitis.
• Neurological disorders: MRE can assess the mechanical properties of brain tissue in conditions such as multiple sclerosis and Alzheimer's disease.

Advantages

MRE has several advantages, including:

• Non-invasive: MRE does not require any surgical incisions or injections.
• No ionizing radiation: MRE uses MRI technology, which does not involve ionizing radiation.
• High spatial resolution: MRE can provide high-resolution images of tissue stiffness and elasticity.

Limitations

MRE also has some limitations, including:

• Availability: MRE is not widely available and requires specialized equipment and expertise.
• Cost: MRE may be more expensive than other imaging modalities.
• Motion artifacts: Patient motion can cause artifacts in the MRE images, which can affect image quality.