Mild carotid artery atherosclerosis - Assessment by 3-dimensional time-of-flight magnetic resonance angiography, with reference to intravascular ultrasound imaging and contrast angiography

Background and Purpose-Our aim was to evaluate the usefulness of 3-dimensio nal time-of-flight magnetic resonance angiography (3-D TOF MRA) in detectio n and quantification of mild atherosclerotic changes of carotid arteries wi th reference to intravascular ultrasound (IVUS) and contrast angiography. Methods-TOF MRA at 1.5 T, IVUS, and selective digital subtraction angiograp hy were performed on 31 extracranial carotid arteries of 27 patients (mean age, 52 years; age range, 17 to 75 years) undergoing neuroendovascular inte rventions. The atherosclerotic lesions were registered, and quantitative me asurements of plaque thickness, luminal diameters, and diameter stenosis we re independently performed for the imaging modalities. Results-Among 170 arterial segments analyzed, IVUS revealed a total of 48 a therosclerotic lesions (mean diameter stenosis, 17%; range, 4% to 40%), onl y 25 of which were depicted on digital subtraction angiography. Analysis of the axial source images of TOF MRA resulted in sensitivity of 77% to 83% a nd specificity of 71% to 80% in lesion depiction for the 2 readers with ref erence to IVUS. The values of diameter stenosis measured from MRA and IVUS were closely interrelated (r = 0.53 to 0.61, P<0.001). Conclusions-Three-dimensional TOF MRA is feasible and moderately accurate f or evaluation of mild atherosclerotic changes of carotid arteries.