Magnetic Resonance Angiography
Magnetic Resonance Angiography is a minimally invasive medical test that uses a powerful magnetic field; thereby helping physicians diagnose medical conditions.
An angiogram uses imaging methods and, in some cases, a contrast material to produce pictures of major blood vessels throughout the body. MRA does not use x-rays or radiation and may be performed with or without contrast material.
MRA is commonly used to:
- Visualize blood flow in veins and arteries throughout the body
- Visualize blood flow specifically in the renal arteries in patients with high blood pressure and those suspected of having kidney disorders
- Identify aneurysms in the aorta or in other major blood vessels; also to identify dissection in the aorta or its major branches
- Identify a small aneurysm or arterio-venous malformation inside the brain that can be life-threatening
- Detect atherosclerotic disease that has narrowed the arteries to the legs
- Detect atherosclerotic disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke
MR Angiography (MRA) uses strong magnets, so it is important that you notify your doctor of any metal that may be implanted into your body. Jewelry should be left at home. If required, you’ll be asked to remove your watch, hearing aid, and other metal objects. Some makeup also contains traces of metal, so you might have to remove that, too. Braces and fillings normally aren’t a problem. You will be asked to change into a gown. Many clothing items contain metals that could potentially heat up and cause burns. Gowns are provided as well as secured lockers for valuables.
Notify your technologist if you have:
- Any prosthetic joints, such as hip and/or knee
- A heart pacemaker (or an artificial heart valve), a defibrillator or an artificial heart valve
- An intrauterine device (IUD)
- Any metal plates, pins, screws, or surgical staples in your body
- Any previous brain surgery
- Tattoos and permanent make-up
- Ever worked around grinding metal or had metal removed from your eye
- Any possibility that you may be pregnant or suspect you may be pregnant
- Claustrophobia and require a sedative. Please ask your referring physician to prescribe one for you
In many cases, patients with a pacemaker cannot have an MRA (your technologist can verify if you have a ‘safe’ pacemaker). Metal used in orthopedic surgery pose no risk during an MRA (in most cases). You will also be asked if you have ever worked with metal. If there is a possibility of metal shrapnel in the eyes, you will be asked to do an x-ray prior to the MRA.
Some scans require the patient to receive an injection of gadolinium: a contrast medium. If this is the case, it will be discussed with you before the procedure. This contrast medium has a lower risk of allergic reaction or kidney damage compared to other mediums commonly used for CT scans. The amount of the contrast injected is determined by the patient’s weight.
MRA is painless. Some patients may experience a “closed in” feeling, although, in most cases, our wide bore MRA scanners have alleviated this reaction. Plan on being with us for a minimum of 30 minutes, depending on the part of the body being scanned. You will be asked to remain still during the actual imaging process. You will hear loud tapping or thumping during the exam. Earplugs or earphones and your choice of music will be provided, if you choose.
Depending on the part of the body being scanned, a contrast material called gadolinium may be used to enhance the visibility of certain tissues or blood vessels. A small needle is placed in your arm or hand vein and a saline solution IV drip will run through the intravenous line to prevent clotting. About two-thirds of the way into your exam, the contrast material is injected.
You may return to normal activities as soon as the scan is complete. The radiologist will determine if there are any areas of concern in the internal organs or bone structures. The radiologist’s interpretation will then be available to your referring physician 48 hours after the exam. In most cases, your referring physician will discuss the results with you.
For more information on this topic, please visit Radiologyinfo.org/MR Angiography