Cisterna MagnaFourth VentricleDandy-Walker SyndromeSubarachnoid SpaceVasospasm, IntracranialParaparesis, SpasticSubarachnoid HemorrhageBasilar ArteryPlatybasiaCranial Fossa, PosteriorArnold-Chiari MalformationCerebral VentriclesCerebrospinal FluidInjections, IntraventricularInjections, SpinalEchoencephalographySeptum of BrainIntracranial PressureSyringomyeliaInjectionsGolgi ApparatusUltrasonography, PrenatalFetal DiseasesHydrocephalusDogsFasciolidaeCatsPregnancy Trimester, SecondMagnetic Resonance ImagingCerebral ArteriesBrainRabbitsMicroscopy, ElectronCerebral AngiographyCerebrovascular Circulation