Portal VeinHypertensionHypertension, PortalBlood PressurePressureHypertension, PulmonaryPortal SystemPortal PressureHypertension, RenalAntihypertensive AgentsUltrasonographyBlood Pressure DeterminationHydrostatic PressureUltrasonicsHypertension, RenovascularUltrasonic TherapyHypertension, MalignantHigh-Intensity Focused Ultrasound AblationBlood Pressure Monitoring, AmbulatoryUltrasonography, InterventionalVenous PressureHemodynamicsMicrobubblesLiver CirculationProspective StudiesHeart RateIntraocular PressureTransducers, PressureTime FactorsVascular ResistanceIntracranial PressureUltrasonography, PrenatalArterial PressurePulmonary ArteryHypertension, Pregnancy-InducedPregnancyRisk FactorsKidneyRats, Inbred SHRReninTreatment OutcomeOcular HypertensionUltrasonography, DopplerEsophageal and Gastric VaricesTransducersFollow-Up StudiesSystoleBlood Flow VelocityIntracranial HypertensionPortasystemic Shunt, SurgicalAtmospheric PressureRegional Blood FlowAir PressureUltrasonography, Doppler, ColorRetrospective StudiesSensitivity and SpecificitySplenic VeinRats, Inbred WKYLiver CirrhosisPulmonary Wedge PressureReproducibility of ResultsVentricular PressureRats, Sprague-DawleyDisease Models, AnimalPrevalencePredictive Value of TestsAngiotensin IISodium Chloride, DietaryDogsHepatic VeinsMesenteric VeinsDiastolePortographyDesoxycorticosteroneVasodilator AgentsRenin-Angiotensin SystemLiverContrast MediaCentral Venous PressurePregnancy Complications, CardiovascularArteriesHepatic ArterySympathetic Nervous SystemCardiovascular DiseasesReference ValuesEchocardiographyCross-Sectional StudiesPulseCardiac OutputHypertrophy, Right VentricularSplanchnic CirculationHypertrophy, Left VentricularTomography, X-Ray ComputedCohort StudiesImaging, Three-DimensionalAge FactorsVasodilationAldosteroneAnalysis of VarianceMicroscopy, Acoustic