Fig. 2

Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain. a Contrasted MRI: partially thrombosed bilateral giant cavernous carotid aneurysms (CCAs, arrows). b Diffusion-weighted MRI: restricted diffusion of the right occipital lobe (arrow). c–e MRA: bilateral CCAs (white arrows) and dual vascular supply of right posterior cerebral artery (PCA, red arrows) from prominent posterior communicating artery (PCOM, yellow arrows) and P1 (green arrows). Left PCOM is absent