Late subacute, enhancing PCA distribution infarcts, secondary to dissection of the right vertebral artery

Edema is seen in the thalamus, high signal intensity in the hippocampus on DWI (principally T2 shine through), and abnormal enhancement post-contrast in these regions together with the medial occipital lobe (all on the right). CE-MRA reveals the right vertebral artery to be narrowed in its midportion, with a small pseudoaneurysm at the level of transition in vessel caliber, and a crescent of methemoglobin (image not shown) on axial imaging, all consistent with a vertebral artery dissection.

Late subacute, enhancing PCA distribution infarcts, secondary to dissection of the right vertebral artery
Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015)