Fig 3. A, Patient 5. Axial T1-weighted MR image shows hypoplasia of the left cerebral hemisphere with enlarged lateral ventricle and polymicrogyria of the anterior part of the hemisphere. B, Coronal view of MRA shows left carotid artery hyperplasia and intracavernous origin of the left anterior cerebral artery from which the right anterior cerebral artery (asterisk) also originates, and persistence of the trigeminal artery (arrow). The vertebrobasilar system is normal. C, Axial view of MRA shows the presence of the trigeminal artery in the left side (arrowhead).