Measuring effective orifice area of bileaflet mechanical valves in patients after aortic valve replacement using phase-contrast cine MR imaging

Introduction Mismatch of patients and prostheses is a critical issue for patients undergoing aortic valve replacement (AVR), because it increases postoperative mortality. Mismatch can be determined by measuring the effective orifice area (EOA) of a prosthetic valve. Although EOA is usually measured by transthoracic ultrasonography, its accuracy remains unclear because the prosthetic valve and/or turbulent flow may produce artifacts and results depend on the examiner’s skill.