Magnetic Resonance Angiography
Magnetic Resonance Angiography (MRA)
What is it?
Cardiac magnetic resonance angiography (MRA) uses a magnetic resonance imaging (MRI) machine to study the blood vessels leading to the brain, heart, kidneys and legs. MRA uses the same technology as MRI, but technicians use special settings on the machine to detect and diagnose blood vessel diseases.
How does it work?
MRI machine looks like a long, narrow tube. When placed inside the tube, the body is surrounded by a magnetic field. The machine uses large magnets and radio-frequency waves to produce high-quality still and moving pictures. The scan monitors energy changes in tissues reactiving to magnetic forces and a computer analyzes these changes and creates images which can be seen on a computer monitor.
MRA can usually give doctors very clear images of the blood vessels without exposing the patient to radiation. In some cases, a harmless dye may be used to make the images even clearer. The MRA dye highlights the blood vessels, making them stand out from the tissues around them.
Reasons for MRA
The angiography procedure is specifically designed to examine the heart and the blood vessels entering the brain, kidney and lungs. MRA can find problems with the blood vessels that may be causing reduced blood flow. With MRA, both the blood flow and the condition of the blood vessel walls can be seen. An MRA can also look for:
- Aneurysm, clot or calcium deposits caused by plaque in the blood vessels leading to the brain
- Aneurysm or tear in the aorta
- Narrowing (stenosis) of the blood vessels leading to the lungs, kidneys or legs
What to Expect
If you are having an MRA procedure that does not require a contrast dye, the procedure will be just like an MRI procedure. This risk-free test is non-invasive, painless, and uses no radiation. The scan takes approximately one hour. The MRI machine will surround a patient during the test, and some people may feel closed in or claustrophobic. The patient will be asked to lie still, and possibly hold their breath briefly while the technician takes pictures of the heart.
If a contrast dye is needed, it will be injected (usually in the arm) over 1 to 2 minutes, and then more scans will be done. The dye used for the test is harmless.