HELICOID SCANNER EXPLORATION OF THE CAROT ID BIFURCATION

Helical CT is a new technology leading to a rapid acquisition of a lar ge volume during the peak of intravascular enhancement. Indications ar e large in vascular pathology due to the possibilities of three dimens ional (3D) reconstructions providing angiogram-like images. To assess carotid bifurcations, this examination needs the choice of multiple pa rameters for acquisition (collimation, table speed, can time), injecti on (volume of contrast material, rate, scan delay) and reconstruction (increment, field of view). Post processing is performed on an indepen dent workstation. Helical CT provides a reliable analysis of carotid a rtery stenosis. Voluminous calcified plaques constitute the main limit ing factor preventing image analysis on the 3D reconstructions. Furthe rmore, image reconstructions require a long time, study of carotid sip hons remains inefficient and examination of the circle of Willis canno t be performed in the same time.