As part of our continuing series on vascular health and imaging, we’d like to talk about another way of seeing into your body and imaging blood vessels: MR angiography, or magnetic resonance angiography. MR angiography is different than CT angiography in that it uses MRI or magnetic resonance imaging with no radiation. This is a benefit of MR angiography.
MR angiography may or may not require use of an IV injection. When needed, MR angiography uses a different type of contrast material for injection - gadolinium-based instead of iodine-based. This is particularly helpful for people with iodine-contrast allergies or poor kidney function.
MR angiography can be used to image the blood vessels and blood flow. The procedure can produce some truly beautiful pictures of blood vessels (the physics behind creating those images is fascinating - and complex!). The vessel walls and adjacent tissues can be seen, as opposed to traditional angiography which shows only the vessel lumen or the inside of the vessel. CTA is the best tool for showing the walls of the vessels themselves.
So, what do we use MRA for?
We can use it to evaluate almost any artery or vein in the body. For example, MR angiography of the head (usually done without contrast) is helpful when looking for aneurysms (saclike outpouchings arising from blood vessels which can be deadly or disabling if they bleed) or areas of artery narrowing. To evaluate the abdominal aorta, we can look for aneurysms (abnormal dilatation) or dissection (when there is a tear in the vessel creating two channels). We may be asked to evaluate the renal arteries for narrowings- renal artery stenosis is one of the treatable causes of high blood pressure.
MR angiography can also be used to examine the leg arteries when needing to evaluate for causes of pain when walking. As we have discussed, there are lots of ways of imaging the blood vessels. Often, ultrasound with Doppler is used first to see if there is a need for further investigation. CT angiography or MR angiography can further define the vessels and identify problems that may need to be addressed either surgically or with interventional radiology procedures (angioplasty, stenting). Traditional catheter angiography is often reserved for those cases that will benefit from vascular intervention.
Originally published 6/13/14 on diagnosticimagingcenterskc.com.