Evaluation of eccentric mitral regurgitation using a modified PISA algorithm

The PISA (Proximal Isovelocity Surface Area) method based on the foundation of the Doppler color proximal flow convergence, has been accepted by clinic to assess the severity of the central MR (mitral regurgitation). However, the result tend to be greatly underestimated when the PISA is applied to eccentric MR. In order to estimate eccentric MR, two parameters named turbulent intensity and regurgitate angle were proposed to modify the effective regurgitate orifice area (EROA) based on traditional PISA algorithm. 23 patients with various severity of eccentric MR were studied to compare modified PISA algorithm with the traditional one. The results showed the grading results of eccentric MR evaluated by the modified PISA algorithm were more rational and accurate, compared with the results obtained from live-3D color Doppler flow imaging method.