Usefulness of three-dimensional time-of-flight mr angiography for evaluation of carotid artery bifurcation stenosis

We evaluated the usefulness of three-dimensional time-of-flight magnetic resonance angiography (3-D TOF MRA) in the estimation of carotid artery bifurcation stenosis by comparing it with conventional angiography in 81 vessels of 44 patients with cerebrovascular ischemic diseases. Agreement of interpretation on 3-D TOF MRA between two observers was equivalent to that on conventional angiography, indicating that both modalities were similarly reliable. A high correlation between MRA and conventional angiography assessments was apparent (Spearman rank correlation coefficients = 0.96, p = 0.0001). Calculating sensitivity and specificity of MRA for each cutoff point of severity, sensitivity ranged from 93.8 to 100%, and specificity from 96.1 to 98.5%. The only limitation of 3-D TOF MRA was that severe stenosis often mimicked occlusion. We concluded that 3-D TOF MRA is useful for evaluation of narrowing of carotid artery bifurcation.