PerfusionPerfusion ImagingMagnetic Resonance ImagingMyocardial Perfusion ImagingTomography, Emission-Computed, Single-PhotonBrainTomography, X-Ray ComputedAicardi SyndromeSensitivity and SpecificityOrganotechnetium CompoundsNeurologic ExaminationBrain DiseasesCerebrovascular CirculationRetrospective StudiesDiffusion Magnetic Resonance ImagingProspective StudiesMagnetic Resonance AngiographyElectrocardiographyChromosome AberrationsPredictive Value of TestsRadiopharmaceuticalsLeukoencephalopathiesContrast MediaRadiography, ThoracicFollow-Up StudiesReproducibility of ResultsImage Processing, Computer-AssistedEpilepsies, PartialPrognosisChemotherapy, Cancer, Regional PerfusionInfant, NewbornHeartBrain Damage, ChronicElectroencephalographyCoronary CirculationTime FactorsImage EnhancementTechnetium Tc 99m MedronateCerebral InfarctionAtrophyTomography, Emission-ComputedImage Interpretation, Computer-AssistedExercise TestEchocardiographyTreatment OutcomeNeuropsychological TestsRegional Blood FlowAbnormalities, MultipleEarly DiagnosisUltrasonographyBiopsyRisk FactorsAcute DiseaseTechnetium Tc 99m SestamibiCerebral AngiographyCoronary AngiographyReference ValuesLungEpilepsyCohort StudiesPregnancyLung DiseasesCognition DisordersSeverity of Illness IndexVaginal SmearsIschemic Attack, TransientInfant, PrematurePrevalenceMyocardial InfarctionRespiratory Function TestsCase-Control StudiesDisease ProgressionVentilation-Perfusion RatioMicrocirculationStrokeBlood Flow VelocityLaser-Doppler FlowmetryThallium RadioisotopesDipyridamoleBiological Markers