A magnetic resonance angiogram (MRA) uses a magnetic field and pulses of radio wave energy to make pictures of blood vessels inside the body. It is a type of magnetic resonance image (MRI) scan. In many cases MRA can give information that cannot be seen from an X-ray, ultrasound, or computed tomography (CT) scan.

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. The test is often used to check the blood vessels leading to the brain, kidneys, and legs. Information from an MRA can be saved and stored on a computer for more study. Photographs of selected views can also be made.

During MRA, the area of the body being studied is put inside an MRI machine. A dye (contrast material) is often used during MRA to make blood vessels show up more clearly.