3D VCA analysis
Three-dimensional color Doppler dataset was acquired to perform off-line analysis of 3D vena contracta area (VCA). Care was taken to include the entire proximal convergence region in the data set with the highest volume rate. The Nyquist limit was controlled within 50–60 cm/s for optimal visualization of the MR jet. Using the commercial software 3DQ (Cardiac 3D Quantification; Philips Medical Systems), the two-orthogonal long-axis planes were aligned parallel with the direction of the proximal MR jet. The transverse plane was then scanned proximally to distally in order to identify the narrowest portion of the jet immediately distal to the regurgitant orifice. The resultant short-axis image of the VC was traced to obtain the 3D VCA.[14]