Magnetic Resonance Imaging / Stroke / Prospective studies / Humans / Female / Male / Incidence / Length of Stay / Clinical Sciences / Aged / Public health systems and services research / Retrospective Studies / Circulation / Hospital Mortality / Aortic Valve / Cohort Studies / Severity of Illness Index / Male / Incidence / Length of Stay / Clinical Sciences / Aged / Public health systems and services research / Retrospective Studies / Circulation / Hospital Mortality / Aortic Valve / Cohort Studies / Severity of Illness Index