Alternative names: Nuclear Magnetic Resonance Imaging (NMRI), Magnetic Resonance Tomography (MRT)
The main disadvantages are that it takes quite a long time (30-90 minutes) and is not available at all hospitals. However, MRI provides excellent contrast between different tissues in the body, making it more suitable than X-rays or CT scans for imaging the brain, muscles, heart, and cancers.
MRI provides clear images of soft tissue and is usually tool of choice for viewing joints, the spine, and muscles. It is currently the best method for examining the brain for signs of stroke, tumors, and multiple sclerosis.
MRI is useful for detecting herniated discs, arthritis, deteriorating joint surfaces, ligament and tendon tears and injury, spinal cord trauma, infections, plaques in blood vessels, narrowing of the blood vessels, breast malignancies (these typically cause increased blood flow), and much more.
The patient lies as still as possible on a table that slides into the MRI scanner as the scan progresses. The MRI device creates a magnetic field and then pulses radio waves into the target part of the body, causing internal tissues to resonate. By recording the resulting vibrations, a computer is able to piece together a highly detailed two-dimensional picture of the body's internal structure.
Unlike CT scans, MRI works without ionizing radiation. Instead, magnetic fields and a sophisticated computer system are used to produce high-resolution pictures of bones and soft tissues.
Tell your doctor if you have implants, metal plates, screws, or other metal objects in your body before undergoing an MRI scan.
Although no negative effects of MRI on the fetus have been recorded, MRIs are only recommended for pregnant women if deemed absolutely necessary.