Magnetic Resonance Imaging (MRI) is used to image various parts of the body, bones, joints, soft tissues, muscles, internal organs and blood vessels. A specialized MR imaging technique known as angiography (MRA) is specifically intended to show the arteries and veins.
MRA enables radiologists to evaluate both healthy and diseased vessels in the brain and neck and to observe the blood flow within them.
When would I get a MR Angiography?
MRA can be used to evaluate most major arteries in the body. MRA can be used to examine the carotid arteries in the neck and the cerebral vessels in the brain. MRA can show their shape, size, location, and orientation. With this information, radiologists can diagnose diseases in these vessels and then determine the best way to treat them.
MRA is particularly valuable in screening for atherosclerosis, or hardening of the arteries. Over time, fat can be deposited along the walls of medium and large arteries in the body, causing them to become narrowed or even blocked. This blockage can eventually lead to a Transient Ischemic Attack (TIA) or even a stroke.
MRA is also performed to detect a brain aneurysm, which is an abnormal widening or ballooning of a cerebral vessel. Brain aneurysms occur when an injury or congenital defect weakens the wall of the vessel. Aneurysms are particularly dangerous because they can burst and cause potentially fatal bleeding.
In addition, MRA is helpful in assessing vascular malformations, which occur when blood or lymph vessels fail to develop normally before birth. The affected vessels become tangled and change the normal flow of the blood through the brain. Some patients have headaches and seizures, but others may be asymptomatic. Vascular malformations can cause hemorrhage and subsequent neurologic damage.
Lastly, MRA may aid in evaluating some types of headaches.
What Will I Experience?
MRI exams are painless. However, some patients find it challenging to remain still. Others may feel closed-in (claustrophobia) or anxious while in a conventional closed MRI scanner. The scanner can be noisy. Nervous or anxious patients may be offered a mild sedative.
A patient may also ask their medical provider to prescribe a mild sedative to take before the exam. If a mild sedative is taken, the patient will need to have someone drive them to our center and take them home once the exam is done.
It is normal for the area of your body being imaged to feel slightly warm. It is important that you remain perfectly still while the images are being recorded, which is typically only a few seconds to a few minutes at a time. You will know when images are being recorded because you will hear tapping or thumping sounds when the coils that generate the radiofrequency pulses are activated. You will be able to relax between imaging sequences, but will be asked to maintain your position as much as possible.
You will be asked to briefly hold your breath for short periods of time during the test.
You will usually be alone in the exam room during the MRI procedure. However, the technologist will be able to see, hear and speak with you at all times using a two-way intercom.
You will be offered earplugs or a headset to reduce the noise of the MRI, which produces loud thumping and humming noises during imaging.
In most MR angiography studies, you will receive an injection of intravenous contrast material. The intravenous needle may cause you some discomfort when it is inserted and once it is removed, you may experience some bruising. There is also a very small chance of irritation of your skin at the site of the IV tube insertion.
Typically, an MR angiography exam will take 45 to 60 minutes to complete.