Magnetic resonance imaging (MRI) can be used to produce detailed images of almost any part of the body.
MRI scans are often used to examine the:
- brain and spinal cord
- bones and joints
- breasts
- heart and blood vessels
It is also possible for an MRI scan to be used to examine other internal organs, such as the lungs or liver.
Brain and spinal cord
An MRI scan can produce very detailed images of the brain and spinal cord (the bundle of nerves that runs from your brain down your spine).
This makes MRI ideal for helping to diagnose conditions that affect the brain and nervous system. For example:
Bones and joints
MRI scans are a very effective way of checking for damage or abnormalities to the soft tissue found in bones and joints, such as cartilage, tendons, muscles and ligaments.
This means that an MRI scan can be used to help diagnose conditions that affect the bones and joints, such as arthritis and osteomyelitis (infection of the bones).
An MRI scan can also be used to assess damage to the cartilage, tendons, muscles and ligaments in sports injuries, as well as other types of injury that can damage a joint.
Breasts
MRI scans are now often used to help diagnose breast cancer. They can provide a way of checking how much of the breast is affected by cancer, although they are not needed in all cases. MRI is also sometimes used to assess breast implants.
Heart and blood vessels
MRI scans can be used to produce detailed images of your heart. The images can often help detect specific problems with the heart, such as defects with the valves or chambers.
MRI scans can also help assess whether a person’s heart has been significantly damaged after having a heart attack.
A type of MRI that is known as magnetic resonance angiography (MRA) can be used to study your blood vessels. It can help to diagnose conditions that affect the blood vessels such as:
- aneurysms – a bulge in a blood vessel that is caused by a weakness in the vessel wall
- narrowing of the arteries that supply blood to organs, such as the kidneys, or the legs
Internal organs
MRI is widely used to study how far cancers that affect specific organs have spread – for example, in cases of prostate cancer and cancer of the womb (uterus).
An MRI scan is also useful for assessing whether cancer has spread beyond a specific organ into nearby tissues or to distant sites such as lymph nodes.
Lymph nodes are small glands that are found in several areas of the body, including in the armpits and groin. They act as filters, preventing foreign particles from entering the bloodstream.
Functional MRI
Functional MRI is a fairly new technique that is used to study the workings of the brain. A functional MRI takes repeated scans, usually one a second, rather than a single scan.
The scans are used to track the movement of blood through the brain. This allows the sections of the brain that are particularly active to be identified. It also shows how brain activity responds to outside events and activities.
For example, a volunteer may be asked to solve a problem or to remember a short phrase. Functional MRI can then be used to determine which parts of the brain are active during these tasks.
Functional MRI is sometimes used to help surgeons when planning complex brain surgery.
