Ultrasonography, DopplerUltrasonography, Doppler, ColorUltrasonography, Doppler, TranscranialUltrasonographyUltrasonography, Doppler, PulsedTranscranial Magnetic StimulationBlood Flow VelocityDoppler EffectUltrasonography, PrenatalPulsatile FlowCerebrovascular CirculationEchoencephalographyEchocardiography, Doppler, PulsedUltrasonography, Doppler, DuplexSensitivity and SpecificityEchocardiography, Doppler, ColorMiddle Cerebral ArteryEvoked Potentials, MotorCerebral ArteriesRegional Blood FlowProspective StudiesUmbilical ArteriesPregnancyReproducibility of ResultsPlacental CirculationContrast MediaScrotumVascular ResistancePredictive Value of TestsIntracranial Embolism and ThrombosisPortal VeinFetal DiseasesUltrasonography, InterventionalMotor CortexTomography, X-Ray ComputedEndosonographyTesticular DiseasesOphthalmic ArteryLaser-Doppler FlowmetryArteriesArterial Occlusive DiseasesIntracranial EmbolismValsalva ManeuverHepatic VeinsUltrasonicsUterusCerebrovascular DisordersCarotid Artery DiseasesTrans Fatty AcidsObserver VariationPortographyMagnetic Resonance ImagingUltrasonography, MammaryGestational AgeHemodynamicsOvarian CystsFetal Growth RetardationCarotid StenosisSpermatic CordImaging, Three-DimensionalCarotid Artery, InternalMetacarpophalangeal JointIntracranial PressureReference ValuesVertebral ArterySubclavian Steal SyndromeHepatic ArteryAngiographyRetrospective StudiesTreatment OutcomeCerebral AngiographyRenal ArteryCarotid ArteriesTime FactorsConstriction, PathologicPregnancy Trimester, SecondFetal HeartBasilar ArteryFollow-Up StudiesBlood PressureLiver CirculationSulfur HexafluorideAngiography, Digital SubtractionSynovitisInfant, NewbornMesenteric Artery, SuperiorBrain Hemorrhage, TraumaticIschemic Attack, TransientVaginaAbdomenDiastolePregnancy Trimester, FirstROC CurveCollateral CirculationSeverity of Illness IndexStrokeAnemia, Sickle CellMonitoring, IntraoperativeHemangioma, CapillaryVenous Thrombosis