FIG. 2.

Axial FLAIR (A), axial T₁-weighted (B and D), and axial susceptibility-weighted (C) images demonstrate a rounded area of abnormal signal and susceptibility within the right cerebellum (green arrows) of a concussed football player. At the C1–C2 level, there is loss of the normal right vertebral artery flow void (red arrow), suggestive of slow flow or occlusion. There is a normal left vertebral artery flow void (yellow arrow). The subject sustained a traumatic right vertebral artery dissection and resultant right cerebellar infarct with internal petechial hemorrhage. FLAIR, fluid-attenuated inversion recovery. Color image is available online.