Posterior Cerebral ArteryInfarction, Posterior Cerebral ArteryCerebral ArteriesCircle of WillisCerebral AngiographyMiddle Cerebral ArteryCerebral InfarctionCerebral Arterial DiseasesHemianopsiaCerebrovascular CirculationInfarction, Middle Cerebral ArteryIntracranial AneurysmAnterior Cerebral ArteryBasilar ArteryUltrasonography, Doppler, TranscranialVertebral ArteryMagnetic Resonance AngiographyAneurysm, RupturedOccipital LobeTomography, X-Ray ComputedBrain IschemiaMagnetic Resonance ImagingDyslexia, AcquiredArteriesBlood Flow VelocityCarotid Artery, InternalEmbolization, TherapeuticOphthalmoplegic MigraineVertebrobasilar InsufficiencyMoyamoya DiseaseTonic PupilBrainAmobarbitalAnisocoriaEchoencephalographySubarachnoid HemorrhageIntracranial Arteriovenous MalformationsOculomotor Nerve DiseasesArterial Occlusive DiseasesEclampsiaAngiography, Digital SubtractionCerebrovascular DisordersHemiplegiaCollateral CirculationCerebral RevascularizationDominance, CerebralVasoconstrictionIschemic Attack, TransientIntracranial Embolism and ThrombosisCarotid ArteriesPulmonary ArteryTreatment OutcomeStrokeCarotid StenosisRegional Blood FlowMuscle, Smooth, VascularVasodilationThalamusBlood PressureTemporal LobeRetrospective StudiesCerebral PalsyIntracranial ArteriosclerosisFollow-Up StudiesImage Processing, Computer-AssistedMesenteric ArteriesFemoral ArteryRenal ArteryArtifactsReference ValuesInfarction, Anterior Cerebral ArteryBrain EdemaCerebral HemorrhageTemporal ArteriesCerebral Veins