Ultrasonography, DopplerUltrasonography, Doppler, ColorUltrasonographyDoppler EffectUltrasonography, Doppler, PulsedBlood Flow VelocityUltrasonography, Doppler, TranscranialUltrasonography, PrenatalEchocardiography, Doppler, PulsedEchocardiography, Doppler, ColorUltrasonicsUmbilical ArteriesPulsatile FlowRegional Blood FlowUltrasonography, InterventionalSensitivity and SpecificityPregnancyUltrasonography, Doppler, DuplexLaser-Doppler FlowmetryProspective StudiesPlacental CirculationReproducibility of ResultsImaging, Three-DimensionalGestational AgeUltrasonic TherapyPredictive Value of TestsEchoencephalographyContrast MediaFetal DiseasesObserver VariationCerebrovascular CirculationMiddle Cerebral ArteryEndosonographyMicrobubblesPregnancy Trimester, SecondVascular ResistanceUltrasonography, MammaryFetal Growth RetardationUterusOphthalmic ArteryHigh-Intensity Focused Ultrasound AblationArteriesCerebral ArteriesFetal HeartFetal MonitoringTransducersHeart Rate, FetalUterine ArteryEchocardiographyAngiographyCarotid Artery DiseasesPortal VeinHemodynamicsMitral ValveIntracranial Embolism and ThrombosisAdnexal DiseasesBlood PressureCarotid StenosisTomography, X-Ray ComputedPregnancy Trimester, ThirdDiastoleSulfur HexafluorideFemoral ArteryCarotid ArteriesLegInfant, NewbornArterial Occlusive DiseasesImage EnhancementAdnexa UteriPregnancy Trimester, FirstBrachial ArteryRheologyRetrospective StudiesIntracranial EmbolismReference ValuesTime FactorsEmbolism, AirConstriction, PathologicFetusCardiac OutputPregnancy OutcomeImage Interpretation, Computer-AssistedTreatment OutcomeHyperemiaCoronary CirculationFollow-Up StudiesCardiac CatheterizationSystoleUterine HemorrhageForearmFeasibility StudiesValsalva ManeuverVentricular Function, LeftRenal ArteryPlacenta DiseasesMagnetic Resonance ImagingMetacarpophalangeal JointROC CurveVenous ThrombosisHepatic Veins