 There is no evidence of mass or acute infarct. There are no areas of abnormal parenchymal signal. The ventricles and basal cisterns are unchanged in size and configuration. There is no midline shift or herniation. The major intracranial arterial flow voids are intact and appear to be within normal caliber. However, the details of arterial branches especially posterior fossa branches such as superior cerebellar artery, AICA and PICA are not clearly visualized.The skull, paranasal sinuses, and scalp soft tissues are unremarkable. There is unchanged severe hypoplasia of the vermis with only minimal residual superior vermian tissue as well as severe cerebellar hemispheric hypoplasia, right greater than left. The brain stem is also hypoplastic, notably the pontine belly. The posterior fossa is not significantly expanded.All above described findings are compatible with cerebellar incomplete agenesis or hypogenesis. And these findings do not show any significant interval change since prior exam.There is an unchanged 11 mm T1 isointense pineal cyst.
1.Unchanged cerebellar incomplete agenesis and brainstem hypoplasia. An MRA is recommended to further characterize the intracranial vasculature. 2.Unchanged 11 mm pineal cyst.