If you or someone you love has had a blood clot, stroke, heart disease, or similar health problem, your doctor may recommend a magnetic resonance angiography (MRA) exam.
Similar to magnetic resonance imaging (MRI), an MRA is a test that allows your doctor to view inside the body. More specifically, an MRA helps your doctor review the condition of your blood vessels.
The test reveals details that will help your doctor to make an accurate diagnosis of your condition and to determine a customized treatment plan.
An MRI and an MRA are actually the same test. The only difference is the application of the technology. Unlike X-rays, which use ionizing radiation to create medical images, both the MRI and MRA use powerful magnets and radio waves to create images of the inside of the body.
In many cases, the MRA provides information that a doctor can’t detect using an ultrasound, regular X-ray, or CT scan. The exam is also noninvasive. The images may be stored on a computer or printed on film.
The difference between an MRI and an MRA is that an MRA is used specifically to examine blood vessels. An MRI is performed to examine other parts of the body, including the:
- internal organs
The "A" in MRA stands for "angiography." This term describes any medical test that looks at the inside of blood vessels, including veins and arteries. When blood vessels become blocked, narrowed, or otherwise damaged, they can lead to problems like chest pain, a heart attack, or a stroke. An MRA allows your doctor to find exactly which blood vessels are injured and to view the extent of the damage.
Your doctor may schedule an MRA if you have had any of the following:
- a stroke
- heart disease, including congenital heart disease
- vasculitis, which is an inflammation of blood vessels
- an aortic aneurysm, which is a swelling of the main artery of the body called the aorta
- a narrowing of the aorta
- atherosclerosis, which is a narrowing of arteries in the arms or legs
- renal artery stenosis, which is a narrowing of the blood vessels in the kidneys
- carotid artery disease, which is a narrowing of the blood vessels that supply blood to the brain
- mesenteric artery ischemia, which is a narrowing of one of the three arteries that supply blood to the small and large intestines
An MRA may also be used to guide a surgeon in making repairs to diseased blood vessels, to evaluate arteries feeding a tumor before surgery or radiation therapy, and to screen people for arterial disease.
Before the test, your doctor will likely instruct you not to eat or drink anything for four to six hours. If you’re pregnant, have a pacemaker or other metallic device in your body like an artificial heart valve, or weigh more than 300 pounds, you may not be eligible for the MRA.
Once you’re ready for the exam, you’ll be asked to change into a hospital gown and remove any metal objects or jewelry that may interfere with the magnetic field. If you’re nervous or claustrophobic, you may be given a sedative to help you relax. You’ll want to lie as still as you can during the test to create the best quality images.
Next, the technician may inject a contrast dye into your hand or forearm to help improve the quality of the images. Be sure to inform your doctor if you have any concerns about allergic reactions to the dye, if you have kidney disease, or if you’ve had prior kidney failure. Poor kidney function can affect your ability to flush the dye from your system.
Finally, you’ll lay flat on the table, which will slide through a doughnut-shaped chamber. Inside the chamber, the magnetic fields and radio waves surround your body and create the images. The procedure is painless. It may last anywhere from 30 to 90 minutes. You’ll be able to talk to the technician through a speaker, and you’ll also likely be provided with earplugs or earphones to help you relax.
MRAs are extremely safe. Since they don’t use radiation like X-rays do, they can be performed repeatedly without concern of risks. The only complications you’ll want to be aware of are those related to the dye and the sedatives.
The dye may cause:
- a warm sensation
- a headache
This is normal and should pass.
If you experience itching or shortness of breath, tell the doctor right away as that could indicate an allergic reaction. Also, if you’re sedated for the procedure, be sure to arrange a ride home because you should avoid driving.