MRA is also very accurate when evaluating thoracic or abdominal aortic aneurysms and is especially useful in patients who have a contraindication to iodinated contrast (i.e. patients with renal insufficiency or who have an allergy to the contrast). Like CTA, 3-dimensional imaging with MRA can be useful in assessing for branch involvement as well as following aneurysm size before and after repair.
One area where MRA is extremely useful and is used commonly is when evaluating for renal artery stenosis in patients with suspected renovascular hypertension or in patients with worsening renal insufficiency. MRA of the renal arteries is often used as the next imaging modality in a patient who has a negative renal artery ultrasound when clinical suspicion is high. At some institutions, MRA is being used as the initial noninvasive imaging modality to evaluate the renal arteries when assessing for renal artery stenosis.
MRA of the lower extremity arteries is being used with more frequency prior to catheter angiography in the workup of patients with lower extremity ischemia, particularly in people who may have a contraindication to iodinated contrast. Although not currently as sensitive when evaluating the small arteries of the foot, MRA provides great anatomical detail of the aorta and arteries of the pelvis as well as the arteries in the thigh and calf. MRA can be especially helpful when planning for potential surgical bypass graft or possible percutaneous treatment (balloon treatment or stenting) in order to provide improved arterial flow to the lower extremities.
One disadvantage of MRA is that patients with pacemakers or certain metallic implants are contraindicated to getting into the magnet. In addition, some patients may experience claustrophobia inside the bore of the magnet. Despite this, with newer techniques as well as stronger magnets becoming available, MRA will play a very important role in the future regarding noninvasive vascular imaging.

Future of Noninvasive Imaging
As technology continues to improve with regard to ultrasound, CT and MRI, imaging of the vascular structures will become faster with higher resolution. In addition to identifying lesions and how significant they may be, advancements are being seen in vulnerable plaque imaging. In the future we may be able to determine what is causing the blockage and whether the plaque is stable or may potentially break off and possibly cause a heart attack or stroke. It is likely that all three modalities will continue to play a role and have their indications when it comes to noninvasive evaluation of the vessels.

Next Page   1 | 2 | 3 | 4 | 5