 There is redemonstration of a extensive absence of the majority of the upper right cerebral hemisphere, including much of the right frontal lobe and majority of the right parietal lobe. There is associated mild ex vacuo dilatation of the distorted right lateral ventricle. However, there is suggestion of post extra-axial CSF signal intensity collection which has progressively increased size and density of the right hemicranium compared to multiple prior exams. There is also evidence of mass effect upon the residual right cerebral parenchyma as well as the right lateral ventricle areas the right lateral ventricle maintains at differentiating margin from this collection. In 2008, this collection measured 2.8 cm transverse x 4.1 cm the x 6.0 cm AP, and now measures 5.7 cm transverse x 6.8 cm CC x 14.3 cm AP.The left lateral ventricle is within normal limits, as are the third and fourth ventricles. A thin strip of brain parenchyma remains along the right aspect of the falx inferiorly. There is suggestion of very mild FLAIR hyperintensity along the margins of the residual right cerebral parenchymal tissue which may relate to gliosis. There is slight expansion of the right hemicranium as compared to the contralateral side. The right cerebral peduncle is small, as well as the right aspect of the brainstem, likely relating to Wallerian degeneration. There is slight rightward bowing of the medial aspect of the left thalamus.No mass effect or midline shift. There is increased prominence of the left cerebral convexity subarachnoid space with widening of the associated sulci to asymmetric volume loss. The left cerebellum remains diminutive in size which is favored to relate to crossed cerebellar diaschisis, given normal appearance at birth.The cisterns remain patent. There is no diffusion abnormality. No extra-axial fluid collection is identified. Normal flow-voids are demonstrated in the major intracranial vascular structures. Corpus callosum is severely thinned, with sparing of the anterior and posterior portions. The midline structures and craniocervical junction are within normal limits.Mastoid air cells are underpneumatized with fluid on the left side.ORBITS
1.Redemonstration of absence of the majority of the right cerebral hemispheric parenchyma, with associated right-sided Wallerian degeneration and left crossed cerebellar diaschisis.2.Right hemispheric cavity/collection, with previous peripheral hemosiderin deposition in the collection, consistent with previous large hematoma which may been parenchymal in location, resulting in extensive cystic encephalomalacia of the right cerebral hemisphere. The collection is progressively increasing in size given the associated expansion of the right hemicranium and mass effect upon the residual right cerebral structures. No MR sequelae of its hypoxic ischemic injury present as previously questioned.3.Unremarkable contrast enhanced MR appearance of the orbits. No definite elevation of optic nerve heads.