Cerebral AngiographyThrombosisAngiographyVenous ThrombosisMagnetic Resonance AngiographyAngiography, Digital SubtractionCoronary AngiographyCerebral ArteriesIntracranial AneurysmCerebral InfarctionSubarachnoid HemorrhageIntracranial Arteriovenous MalformationsTomography, X-Ray ComputedSinus Thrombosis, IntracranialCerebral VeinsCranial SinusesCerebrovascular CirculationIntracranial Embolism and ThrombosisCarotid Artery, InternalVertebral ArteryCerebral HemorrhageMoyamoya DiseaseCarotid Artery ThrombosisCoronary ThrombosisPosterior Cerebral ArteryCerebrovascular DisordersIschemic Attack, TransientCircle of WillisCentral Nervous System Vascular MalformationsAneurysm, RupturedMiddle Cerebral ArteryIntracranial ThrombosisBrain IschemiaArterial Occlusive DiseasesMagnetic Resonance ImagingFluorescein AngiographyBasilar ArteryEmbolization, TherapeuticCerebral RevascularizationVasospasm, IntracranialCerebral Arterial DiseasesAnterior Cerebral ArteryCerebral PalsyCarotid Artery DiseasesContrast MediaCarotid StenosisBrainVasculitis, Central Nervous SystemVertebrobasilar InsufficiencyTreatment OutcomeIntracranial ArteriosclerosisCarotid ArteriesEndarterectomyArteriovenous FistulaProspective StudiesCraniotomyBlood Flow VelocityCollateral CirculationBlindness, CorticalEpilepsy, Tonic-ClonicArteriovenous MalformationsConstriction, PathologicIntracranial EmbolismNeurosurgical ProceduresFollow-Up StudiesNeurologic ExaminationRetrospective StudiesTime FactorsSensitivity and SpecificityHematoma, SubduralInfarction, Middle Cerebral ArteryCavernous SinusCranial Fossa, AnteriorCarotid-Cavernous Sinus FistulaRisk FactorsPhlebographyVertebral Artery DissectionAnticoagulantsCatheterizationHeadacheMalaria, CerebralComaSurgical InstrumentsTemporal ArteriesHematoma, Subdural, IntracranialIntracranial HemorrhagesRupture, SpontaneousStentsHematomaRemission, SpontaneousRecurrenceLateral Medullary SyndromeUltrasonographyAneurysm, InfectedDura MaterCoronary Artery DiseaseRadionuclide AngiographyStrokeSagittal Sinus ThrombosisUltrasonography, Doppler, Transcranial