[Duplex ultrasonography in the study of carotid and vertebral artery stenosis (comparison with intra-arterial digitalized subtraction angiography)].

A prospective comparison was completed between duplex sonography and intraarterial digitalized subtraction angiography of the carotid and vertebral arteries. The sensitivity, specificity and overall accuracy of the duplex ultrasound were evaluated. In 85 patients 169 sides were investigated. The vessels were divided into normal, 1-24%, 25-49%, 50-74%, 75-99% stenosis and occlusion categories. For stenoses of less than 50% in the proximal internal carotid artery, sensitivity and specificity were excellent (95 and 92%), for lesions causing more than 50% stenosis were 87 and 95%, respectively. The overall accuracy for 0-99% stenosis was 93% and for total occlusions increased to 99%. Sensitivity was lesser (49-54%), but the specificity (92-96%) and overall accuracy (85-86%) were good for the evaluation of common and proximal external carotid artery. Our results indicate that duplex scanning is a valuable technique for measurement of patency and direction of blood flow in the vertebral arteries. The conventional duplex ultrasound can be regarded as an accurate, relatively cheap, and nonevasive screening method for stenoses and occlusions of cervical carotid and vertebral arteries of patients with ischaemic cerebrovascular disease.