When comparing computed tomography angiography (CTA) and magnetic resonance angiography (MRA) for occlusive peripheral artery disease (PAD), Seth Toomay highlighted that interventions planned with CTA or MRA are both successful.
Speaking at the 34th Annual scientific meeting of the Society of Interventional Radiology, held in San Diego between 7-12 March in 2009, Dr Seth Toomay, Assistant Professor, University of Texas Southwestern found that CTA and MRA have similar sensitivities and specificities.
In a presentation titled, “CTA or MRA for occlusive peripheral artery disease: which test is better?” Toomay began by clarifying that lower limb peripheral arterial disease (PAD) is characterised by atheromatous narrowing or occlusion of one or more of the arteries of the leg. Symptoms include intermittent claudication, ischaemic rest pain, ulceration and gangrene and patients showed an ankle-brachial index < 0.90, he said.
The doctor from Texas, disclosing that his department used CTA, said that the advantages of the system were easy availability, rapid acquisition and lower cost. He also drew attention to the fact that the disadvantages in using CTA for PAD included radiation, the need for a nephrotoxic contrast agent and decreased sensitivity for patients showing extensive vascular calcifications, 3D reconstruction time.
On the other hand, he said, MRA had the advantages of not requiring a nephrotoxic contrast agent, it did not have the same sensitivity to calcium and significantly, there was no radiation from the procedure. But the disadvantages included patients developing nephrogenic systemic fibrosis associated with exposure to gadolinium, frequently used as a contrast substance for MR, and increased cost. Contraindications included patients who had pacemakers and claustrophobia and being aware that metal could cause MRI artifacts.
Referencing Ouwendijk et al and their 2005 publication in Radiology on the issue, Toomey said that when it came to CTA vs MRA, both provide equivalent diagnostic confidence.
In summary, CTA and MRA have similar sensitivities and specificities. “Interventions planned with CTA or MRA are both successful,” said Toomey. He pointed out that with both procedures six-month outcomes are equivalent, and recommended to colleagues to “use the test that works best for you.”
