Fig. 7.

Floating thrombus in the supra-bulbar right internal carotid artery. A large eccentric non-calcified thrombus is clearly seen, on cross-sectional CTA images appearing as a central non-enhancing thrombus surrounded by a (semi-)circular enhancing lumen, the so-called “donut”-sign (arrow in a). A coronal CTA image further reveals the irregular outer border of this floating thrombus (arrow in b), indicative of a higher risk for distal emboli. This is further illustrated by an axial diffusion-weighted MR-image of the same patient revealing a recent ischemic infarct in the distribution region of the right media cerebral artery