Renal Plasma Flowp-Aminohippuric AcidKidneyPerfusionPerfusion ImagingMyocardial Perfusion ImagingKidney DiseasesKidney TransplantationKidney TubulesKidney CortexAcute Kidney InjuryTomography, Emission-Computed, Single-PhotonKidney Failure, ChronicChemotherapy, Cancer, Regional PerfusionKidney GlomerulusCoronary CirculationKidney NeoplasmsKidney MedullaPolycystic Kidney DiseasesKidney Tubules, ProximalKidney Function TestsCerebrovascular CirculationRegional Blood FlowTechnetium Tc 99m SestamibiOrganotechnetium CompoundsContrast MediaKidney CalculiTime FactorsDogsKidney Tubules, CollectingPolycystic Kidney, Autosomal DominantGlomerular Filtration RateHeartMicrocirculationRadiopharmaceuticalsRats, Sprague-DawleyMagnetic Resonance AngiographyVentilation-Perfusion RatioBlood Flow VelocityLiverLaser-Doppler FlowmetryBlood PressureRenal CirculationOrgan PreservationKidney Tubules, DistalIschemiaKidney Concentrating AbilityThallium Radioisotopes