Infratentorial NeoplasmsEpendymomaSupratentorial NeoplasmsEmpyema, SubduralSturge-Weber SyndromeIntracranial Hemorrhage, HypertensiveCranial Fossa, PosteriorGlioma, SubependymalMastoiditisCerebellar NeoplasmsMagnetic Resonance ImagingCerebellar DiseasesCerebral Ventricle NeoplasmsFourth VentricleIntracranial Arteriovenous MalformationsHydrocephalusBrain NeoplasmsCerebellumIntracranial HemorrhagesTomography, X-Ray ComputedNeurosurgical ProceduresBrain StemCerebral HemorrhageCerebral Ventricles