A type of contrast-enhanced magnetic resonance (MR) angiography has been shown to be highly effective in finding blockages in arteries that carry blood to the brain, according to a study in the February issue of Radiology.
"Contrast-enhanced MR angiography provided highly accurate information about the supra-aortic arteries," said Kambiz Nael, MD, research fellow and radiology resident at the David Geffen School of Medicine at UCLA. "MR angiography produced results comparable to the gold standard of digital subtraction angiography (DSA) and multidetector computed tomography (CT) angiography. In addition, this technology produced images with higher resolution over a larger field of view in a shorter amount of time than previous contrast-enhanced MR angiography techniques," he said.
Due to the risks that have been associated with DSA, such as the possibility of causing a mini-stroke, and slight risk of permanent neurological damage, CT and MR angiography are increasingly being used to diagnose arterial occlusive disease. MR angiography offers advantages over CT, particularly because it delivers no ionizing radiation to the patient, according to an RSNA release.
"MR angiography, using a small quantity of MRI dye injected into a vein in the arm, can produce detailed images of the arteries supplying the brain and can detect even minor degrees of narrowing or blockage. It does not involve exposure to x-rays and is widely regarded as a very safe, painless test," Nael said.
The researchers studied 80 patients (44 men and 36 women) with suspected arterial occlusive disease. The study was undertaken to compare contrast-enhanced MR angiography to DSA and CT angiography. One reader involved in the study found 208 blockages with MR angiography, whereas another found 218 segments of artery, which correlated significantly to the DSA and CT findings. MR angiography also proved highly accurate (94 to 100 percent) for detecting blockages of over 50 percent, and image quality was well rated for 97 percent of the arterial segments evaluated, according to the study results.
"This procedure should be highly cost effective for clinical use, because of the speed and modest dose of contrast required," Nael said. "In the absence of contraindications to MRI, I would recommend MR angiography over DSA and CTA for routine use-avoiding increased risk of mini-stroke and radiation exposure."
According to Nael, in many instances contrast-enhanced MR angiography could replace other diagnostic techniques for evaluation of all the arteries that supply blood to the brain.