Fig. 3

Blunt cerebrovascular occlusion (grade IV lesions according to the Biffl classification). a, b A 51-year-old man who had suffered a motorcycle accident. The axial MPR image (a) (3-mm thickness) shows the absence of contrast material within the right vertebral artery (arrow) and the coexistence of a C4 lateral mass fracture (arrowhead) involving the right vertebral channel; the same findings (arrows and arrowhead) are clearly detectable on the sagittal MPR image on which the presence of contrast material is detectable within the right vertebral artery upstream and downstream the occlusion. The patient underwent anti-aggregation and no neurological deficit occurred. c, d A 28-year-old man who had suffered a bicycle accident. The axial MPR image (c) (3-mm thickness) shows multiple skull basis fractures (arrows) involving the clivus too and no contrast material within the basilar artery (arrowhead). Mid-face fractures were also present. The sagittal MIP reconstruction (d) (4-mm thickness) confirms a focal absence of contrast material within the lumen of the basilar artery. The patient did not undergo anti-aggregation because of high haemorrhagic risk and developed a brainstem infarction responsible of a locked in syndrome