mra is an abbreviation for magnetic resonance angiography, which is an angiography that can be performed to detect areas of vascular stenosis and occlusion. There are two ways to perform mra: one is to directly visualize the blood vessels without injecting contrast through a vein, using blood flow to contrast with the resting vessel wall and surrounding tissue. The other method is to inject the contrast agent with a high-pressure syringe. mra has become one of the routine techniques of MRI, and the clinical application of mra of blood vessels in the brain has become quite common. The contrast is accompanied by fast magnetic resonance imaging similar to CTA, called enhanced mra.