Ultrasonography, DopplerUltrasonography, Doppler, ColorUltrasonographyUltrasonography, Doppler, PulsedUltrasonography, Doppler, TranscranialBlood Flow VelocityUltrasonography, PrenatalDoppler EffectPulsatile FlowCerebrovascular CirculationSensitivity and SpecificityUmbilical ArteriesUltrasonography, Doppler, DuplexRegional Blood FlowProspective StudiesEchocardiography, Doppler, PulsedPregnancyScrotumEchoencephalographyPlacental CirculationPortal VeinVascular ResistanceEchocardiography, Doppler, ColorTesticular DiseasesCerebral ArteriesMiddle Cerebral ArteryFetal DiseasesArteriesReproducibility of ResultsHepatic VeinsPortographySpermatic CordOphthalmic ArteryContrast MediaPredictive Value of TestsTomography, X-Ray ComputedIntracranial Embolism and ThrombosisUterusHepatic ArteryArterial Occlusive DiseasesUltrasonography, InterventionalOvarian CystsSubclavian Steal SyndromeRenal ArteryMetacarpophalangeal JointFetal Growth RetardationValsalva ManeuverLiver CirculationCerebrovascular DisordersCarotid Artery DiseasesGestational AgeIntracranial PressureObserver VariationEndosonographyBrain Hemorrhage, TraumaticHemodynamicsMesenteric Artery, SuperiorHemangioma, CapillaryAngiographyUltrasonicsSynovitisThoracic CavityCarotid Artery, InternalLaser-Doppler FlowmetryVertebral ArteryConstriction, PathologicPregnancy Trimester, SecondRetrospective StudiesHypertension, PortalReference ValuesImaging, Three-DimensionalFetal HeartArteriovenous MalformationsVenous ThrombosisAbdomenCarotid ArteriesTrophoblastic NeoplasmsVaginaTreatment OutcomePregnancy Trimester, FirstUltrasonography, MammaryInfant, NewbornBlood PressureFollow-Up StudiesCarotid StenosisVena Cava, InferiorVeinsROC CurveAnemia, Sickle CellMagnetic Resonance ImagingCerebral AngiographySplenic ArteryAngiography, Digital SubtractionFetusIschemic Attack, TransientBasilar ArteryIntracranial EmbolismSeverity of Illness IndexOvaryCollateral Circulation