Vasospasm, IntracranialSubarachnoid HemorrhageCerebral AngiographyAngiographyMagnetic Resonance AngiographyAngiography, Digital SubtractionCoronary AngiographyCerebral ArteriesIntracranial AneurysmCerebral InfarctionIntracranial Arteriovenous MalformationsTomography, X-Ray ComputedCerebrovascular CirculationCerebral VeinsCranial SinusesVertebral ArteryMoyamoya DiseaseCarotid Artery, InternalCerebral HemorrhagePosterior Cerebral ArteryIschemic Attack, TransientCircle of WillisCentral Nervous System Vascular MalformationsCerebrovascular DisordersMiddle Cerebral ArteryAneurysm, RupturedBrain IschemiaFluorescein AngiographyIntracranial Embolism and ThrombosisCerebral RevascularizationMagnetic Resonance ImagingBasilar ArteryEmbolization, TherapeuticArterial Occlusive DiseasesCerebral Arterial DiseasesAnterior Cerebral ArteryCerebral PalsyVasculitis, Central Nervous SystemCarotid Artery DiseasesBrainContrast MediaCarotid StenosisVertebrobasilar InsufficiencySinus Thrombosis, IntracranialIntracranial ArteriosclerosisBlindness, CorticalCraniotomyArteriovenous FistulaEpilepsy, Tonic-ClonicEndarterectomyCollateral CirculationArteriovenous MalformationsBlood Flow VelocityCarotid ArteriesIntracranial EmbolismNeurologic ExaminationNeurosurgical ProceduresHematoma, SubduralCranial Fossa, AnteriorInfarction, Middle Cerebral ArteryConstriction, PathologicSensitivity and SpecificityCarotid-Cavernous Sinus FistulaProspective StudiesCavernous SinusVertebral Artery DissectionTreatment OutcomeMalaria, CerebralSurgical InstrumentsTemporal ArteriesHematoma, Subdural, IntracranialComaLateral Medullary SyndromeHeadacheFollow-Up StudiesRetrospective StudiesRadionuclide AngiographyIntracranial HemorrhagesAneurysm, InfectedHematomaTime FactorsRemission, SpontaneousCatheterizationRupture, SpontaneousUltrasonography, Doppler, TranscranialCarotid Artery ThrombosisDura MaterRadial ArteryImaging, Three-DimensionalUltrasonographyStrokeCoronary Artery DiseasePneumonia, AspirationEndarterectomy, CarotidAneurysm, DissectingCoronary StenosisTomography, Spiral ComputedRisk FactorsRecurrencePredictive Value of Tests