Comparison of magnetic resonance angiography and digital angiography of the epiaortic vessels

Atheromasic lesions and other pathologic conditions of the arterial vessels of the neck are the most frequent causes of cerebrovascular disease. Diagnostic imaging currently employs digital subtraction angiography (DSA), Doppler, and color-Doppler US to study these conditions. Digital subtraction intraarterial angiography (DSAA) can provide both an early diagnosis and an accurate preoperative depiction of neck vessels; however, in spite of its effective value, it still remains an invasive technique. Magnetic Resonance angiography (angio-MR) is the latest technique allowing the depiction of neck vessels morphology. It shares with digital angiography the capability of supplying spatial depiction of all the examined vascular structures, and with US its noninvasiveness. The authors investigated angio-MR capabilities in providing accurate and detailed images of neck arteries; the images were then compared with DSA ones. Thirty patients with cerebrovascular diseases were studied. MR imaging was performed with a 1.5 T unit with a dedicated coil, and gradient-echo sequences were employed. Refocused sequences for flow were acquired on both the coronal and the sagittal planes, with the following parameters: TR 40, TE 10, flip angle 25 degrees, acquisition volumes 80-35 mm, 64-15 frames. Digital angiography demonstrated 101 vascular lesions: 27 slight stenoses (less than 30%), 19 mild stenoses (31-70%), 12 severe stenoses (71-99%), 7 occlusions, 14 coilings, 7 kinkings, and 15 hypoplasias of vertebral artery. In slight stenoses, angio-MR underestimated the condition in 11/27 patients. In mild and severe stenoses, as well as in occlusive diseases, angio-MR tended to overestimate the condition. In coiling, kinking, and hypoplasia, angio-MR yielded the same results as DSA.