[Carotid stenoses. Non-invasive exploration]

Abstract

Doppler flowmeter and ultrasound imaging techniques, currently associated (duplex), have made important contributions to the simple and early non invasive diagnosis of carotid stenosis lesions in the cervical region for more than 20 years. These exploratory methods are reliable when a significant degree of stenosis (greater than about 60%) exists. Moderate degrees of stenoses or plaques are evaluated morphologically, calcifications and ulcerations being enhanced by staining techniques. But the evaluations have not really demonstrated exact correlations between anatomicopathologic and ultrasound images. The intracranial arteries and the circle of Willis are explored indirectly during the cervical examination by cautious compressive maneuvers or directly by trans-cranial Doppler. Whereas angiography competes with ultrasound imaging as a standard examination in the neck region, it nevertheless remains effective for the study of the intracranial arteries. Newer techniques, such as high-field MRI angiography, tridimensional ultrasonography or ultrasound recording of vascular flow rate without Doppler, will doubtlessly transform the diagnosis of symptomatic or asymptomatic carotid stenosis. From the strategic point of view, ultrasound imaging techniques will retain their role of a decisional pivot, since they are simple to use and are of very wide accessibility to competent vascular physicians in the context of an organized care network.