An MRA is an advanced type of MRI scan that specifically maps out the body’s complex vascular system—the "plumbing" that carries blood to and from your heart, brain, and other vital organs.
Doctors request this scan when investigating risk factors for a stroke, suspected blood clots, or narrowed arteries.
Unlike traditional angiograms that require placing a catheter directly into an artery, an MRA is completely non-invasive and uses powerful magnetic fields and radio waves to generate detailed, 3D images of your blood vessels without X-ray radiation.
Why would my doctor ask for an MRA?
Your doctor may recommend an MRA to look closely at your blood vessels, especially if you have:
- Symptoms of a stroke or a "mini-stroke" (Transient Ischemic Attack, or TIA).
- Chronic, severe headaches that could point to a blood vessel abnormality in the brain.
- Pain or cramping in your legs when walking, which may indicate poor circulation.
- High blood pressure that is difficult to control (to check the arteries supplying your kidneys).
- A family history of aneurysms or heart disease.
What can an MRA detect?
An MRA helps doctors visualize:
- The major arteries supplying blood to the brain, heart, neck, kidneys, and legs.
- The speed and direction of blood flow through these pathways.
It is particularly useful for identifying:
- Aneurysms (weak, bulging spots in the blood vessel wall that could rupture).
- Atherosclerosis (plaque buildup causing narrowed or blocked arteries).
- Blood clots, such as a deep vein thrombosis (DVT).
- Vascular malformations (abnormal tangles of blood vessels).
Do I need any special preparation for an MRA?
There is usually no special preparation. However:
- Remove all jewelry, body piercings, hairpins, and clothing with metal zippers or snaps.
- Inform your doctor or radiographer if you have any implanted medical devices (especially pacemakers, aneurysm clips, or cochlear implants) as the strong magnets can be dangerous with certain metals.
- You can generally eat, drink, and take your regular medications prior to the scan unless explicitly told otherwise.
Will I be injected with dye for this scan?
Often, yes. While some MRA techniques can visualize blood flow without dye, many require an intravenous (IV) injection of a contrast agent called gadolinium. This dye travels through your bloodstream, making the blood vessels shine brightly against the dark background of surrounding tissues. Tell your doctor if you have severe kidney problems or a known contrast allergy.
What does an MRA feel like?
The scan is completely painless. You will lie flat on a padded table that slides slowly into the tunnel-shaped MRI scanner.
The machine will make loud, repetitive knocking, thumping, or humming sounds while capturing the images. You will be provided with earplugs or headphones for comfort.
Depending on the location of the blood vessels that are being scanned, you may be asked to hold your breath for short 10-to-20-second bursts to keep your chest or abdomen perfectly still.
Is it safe for pregnant women or children?
Yes. An MRA does not use ionizing radiation, making it generally safe. However, pregnant women should consult their doctor. If contrast dye is required, it is typically avoided during pregnancy unless absolutely medically necessary.
How long does the MRA take?
The scan usually takes between 30 and 60 minutes, depending on how large an area of the body is being examined.
When will I get my results?
After the scan, a Radiologist will carefully review the vascular images and prepare a report for your doctor. Results are typically ready within a few days. Your doctor will discuss the findings and outline any necessary treatments, such as medication or surgery to clear a blockage.
What is the difference between an MRI and an MRA?
While both procedures use the exact same scanner machine, they are programmed to look at different things. An MRI is broad and designed to produce highly detailed images of soft tissues and internal organs (like the brain tissue, liver, or muscles). An MRA is specifically "tuned" to ignore the surrounding tissues and only highlight the blood flowing through the vessels.
What if I’m nervous about being inside the scanner?
It’s common to feel claustrophobic or anxious inside the machine. You will be in contact with the Radiographer the entire time through an intercom system and will hold a squeeze ball to alert them if you need a break. You can also ask your doctor to prescribe a mild, calming sedative to take shortly before your appointment.
When should I seek urgent help?
Seek emergency care for stroke symptoms, a sudden severe or “thunderclap” headache, collapse, new limb pain with coldness or colour change, or severe chest or back pain. MRA is diagnostic and should not delay urgent treatment.
Sources and further reading
Conclusion
MRA can map blood vessels without ionising radiation and may identify narrowing, blockage, aneurysm, or other vascular abnormalities. It has limitations and is interpreted alongside symptoms and other tests; emergency stroke or aneurysm symptoms require urgent care rather than waiting for an outpatient scan.