Cyst decompression and Ommaya reservoir placement. There has been interval insertion of a left transoccipital catheter that terminates in the right cerebral hemisphere cavity. There is scattered pneumocephalus. There are postoperative findings related to right hemispherectomy with an unchanged heterogeneous fluid collection in the right extradural space deep to the craniectomy flap that measures up to approximately 15 mm in thickness and midline shift to the right. The deformed third and lateral ventricles are not significantly changed in appearance. There is no significant interval change in size of the cystic compartments in the left occipital lobe that appear to communicate with ventricular system, although precise comparison is limited due to differences in head positioning. There is unchanged diffuse confluent cerebral white matter T2 hyperintensity in a large portion of the left hemisphere, particularly in the periventricular region. There is a left transparietal tract, but no shunt catheter is present. There is unchanged posterior deviation and areas of encephalomalacia in the upper cervical spinal cord. There is no evidence of acute intracranial hemorrhage, mass, or acute infarct. The major cerebral flow voids are intact.
1. Interval insertion of a right transoccipital Ommaya catheter without evidence of acute intracranial hemorrhage or infarction.2. Chronic postoperative findings related to right hemispherectomy with no significant change in the deformed ventricular system, gliotic portions of the left cerebral hemisphere, and cystic compartments in the left cerebral hemisphere.3. Unchanged posterior deviation and areas of encephalomalacia in the upper cervical spinal cord, which may be attributable to adhesions and chronic infarction, respectively. 