i
MVA = [3,14 x MV PISA R² x MV Alias V] : [MV Vmax x ( α : 180°)]

MV PISA R:  CD, Apical 4C view.
MV Alias V: CD, Apical 4C view.
MV Vmax: CW, Apical 4C view.

MVA - Mitral Valve Area
MV PISA R - Mitral Valve Proximal Isovelocity Surface Area Radius
MV Alias V - Mitral Valve Aliasing Velocity
MV Vmax - maximum Mitral Valve Velocity
 α - the opening angle of mitral leaflets relative to flow direction