Ultrasonography, Doppler, DuplexUltrasonography, Doppler, ColorUltrasonography, DopplerUltrasonographyVenous InsufficiencyBlood Flow VelocityVaricose VeinsUltrasonography, Doppler, TranscranialUltrasonography, Doppler, PulsedVaricose UlcerDoppler EffectLegCarotid StenosisPopliteal VeinFemoral VeinSensitivity and SpecificityAngiography, Digital SubtractionCarotid Artery, ExternalArterial Occlusive DiseasesProspective StudiesUltrasonography, PrenatalVeinsSaphenous VeinAngiographyEchocardiography, Doppler, PulsedCarotid Artery, InternalMagnetic Resonance AngiographyEchocardiography, Doppler, ColorIntermittent Pneumatic Compression DevicesCarotid Artery DiseasesVascular PatencyVenous ThrombosisRenal Artery ObstructionCircle of WillisPeripheral Vascular DiseasesVertebral ArteryMesenteric Vascular OcclusionRegional Blood FlowPhlebographyReproducibility of ResultsConstriction, PathologicPreoperative CareCarotid ArteriesThrombophlebitisGraft Occlusion, VascularLower ExtremityPredictive Value of TestsPlethysmographyFollow-Up StudiesTreatment OutcomeEndarterectomy, CarotidPopliteal ArteryIliac ArteryRetrospective StudiesTomography, X-Ray ComputedFemoral ArteryAngioplasty, BalloonTime FactorsVascular Surgical ProceduresEndosonographyROC CurveSeverity of Illness IndexIntermittent ClaudicationUltrasonography, InterventionalLaser-Doppler FlowmetryPulsatile FlowRecurrenceNucleic Acid ConformationPregnancyUltrasonography, MammaryIschemiaUmbilical ArteriesArteriosclerosisNucleic Acid DenaturationRisk FactorsBlood Vessel Prosthesis ImplantationDNAContrast MediaChronic DiseasePostoperative ComplicationsStentsNucleic Acid HeteroduplexesSulfur HexafluorideBase PairingFetal DiseasesEchoencephalographyImaging, Three-DimensionalObserver VariationDiastoleGestational AgeOligodeoxyribonucleotidesOligonucleotidesPlacental CirculationBase SequenceCerebrovascular CirculationUltrasonicsVascular ResistanceMiddle Cerebral ArteryUterusFetal Growth Retardation