DETECTION OF OCCLUSIVE LESIONS IN INTRACRANIAL-ARTERIES BY 3-DIMENSIONAL TIME-OF-FLIGHT MAGNETIC-RESONANCE ANGIOGRAPHY

To evaluate the accuracy of 3-dimensional time-of-night magnetic reson ance angiography (3D TOF MRA) for detecting intracranial arterial occl usive disease, this technique was compared with conventional angiograp hy. The subjects were 54 patients with cerebrovascular ischemic diseas e. Using a semiquantified grading scheme, stenotic lesions were assess ed for each segment of the intracranial arteries to the level of the s econd segment. A high correlation in the degree of stenosis (Spearman rank correlation = 0.68, p = 0.0001, kappa statistic = 0.846) and an e xtremely high sensitivity (100%) for detecting occlusive lesions were found. Specificity for each segment of the intracranial arteries varie d from 94.8% (M1 portion of the middle cerebral artery) to 83.3% (A1 p ortion of the anterior cerebral artery). However, mild stenosis tended to be slightly overestimated, and false-positive readings in specific parts of the vessels (the carotid siphon, the anterior cerebral arter y orifice, and the middle cerebral artery bifurcation) were not insubs tantial. We conclude that despite a relatively high false-positive rat e in some regions, 3D TOF MRA is useful for evaluating intracranial ma jor vessels in stroke patients.