Angiography, Digital SubtractionMagnetic Resonance AngiographyCerebral AngiographySubtraction TechniqueIntracranial AneurysmAngiographyIntracranial Arteriovenous MalformationsImaging, Three-DimensionalEmbolization, TherapeuticContrast MediaTomography, X-Ray ComputedCarotid Artery, InternalInjections, Intra-ArterialRadiographic Image EnhancementSensitivity and SpecificityAneurysm, RupturedCentral Nervous System Vascular MalformationsArterial Occlusive DiseasesSubarachnoid HemorrhageCarotid StenosisImage Processing, Computer-Assisted