Circulatory Arrest, Deep Hypothermia InducedHypothermia, InducedHypothermiaRewarmingHeart Arrest, InducedCardiopulmonary BypassPerfusionExtracorporeal CirculationPerioperative PeriodAorta, ThoracicAortic Aneurysm, ThoracicBlood Coagulation DisordersAortic AneurysmPerfusion ImagingAneurysm, DissectingBody TemperatureMyocardial Perfusion ImagingTime FactorsTreatment OutcomeHypoxia-Ischemia, BrainHeart ArrestRetrospective StudiesBody Temperature RegulationTomography, Emission-Computed, Single-PhotonCerebrovascular CirculationCoronary CirculationChemotherapy, Cancer, Regional PerfusionCardiopulmonary ResuscitationAsphyxia NeonatorumBrainShiveringDeep Brain StimulationCold TemperatureRegional Blood FlowBrain IschemiaComaRats, Sprague-DawleyLaser-Doppler FlowmetryBrain InjuriesTechnetium Tc 99m Sestamibi