三维近端等速表面积法测量二尖瓣狭窄患者二尖瓣口面积的初步研究

Assessment of mitral valve area in patients with mitral stenosis with 3-dimensional proximal isovelocity surface area

目的探讨三维近端等速表面积（3d—PISA）法测量二尖瓣狭窄患者二尖瓣口面积（MVA）的准确性，并探讨应用3d-PISA法测量MVA的最佳Nyquist速度极限。方法对20例二尖瓣狭窄患者分别采用胸骨旁切面直接勾勒法、二维近端等速表面积（2d-PISA）法及3d—PISA法测量MVA，以胸骨旁切面直接勾勒法测量的MVA为参照标准，分析不同的Nyquist速度极限下上述3种方法测量MVA的异同。结果在不同的Nyquist速度极限（32cm／s、26cm／s、19cm／s）时，3d_PISA法测量的MVA均不同。在Nyquist速度极限为19cm／s时：①胸骨旁切面直接勾勒法与3d_PISA法、2d—PISA法测量的MVA差值均最小；②与2d-PISA法测量的MVA相比，3d_PISA法测量的MVA与胸骨旁切面直接勾勒法测量的MVA更接近；③2d—PISA法、3d．PISA法测量的MVA与胸骨旁切面直接勾勒法测量的MVA均有相关性，相关系数分别为（r=0．98，r=0．89）。结论在Nyquist速度极限为19cm／s时，3d—PISA法测量的二尖瓣狭窄患者MVA与胸骨旁短轴切面直接勾勒法测量的MVA差值最小。

Objective To determine the most suitable Nyquist velocity for applying the three- dimensional proximal isovelocity surface area （PISA） （3d-PISA） to calculate mitral valve area （MVA） in patients with mitral stenosis （MS）. Methods 20 patients with MS were studied by single-beat three-dimensional color Doppler echocardiography. The MVA was measured by the methods of planimetry （MVApl）, two-dimensional PISA （MVA2d-PISA） and 3d-PISA （MVA3d-PISA）. MVApl was used as reference methods. At the Nyquist velocities of 32,26 and 19 cm/s, the differences between MVA2d-PISA, MVA3d-PISA and MVApl were analyzed, and then the correlation between MVA2e-PtSA, MVA3d-PISA and MVADI were analyzed respectively. Results The 3d-PISA method provided the most accurate estimation of MVA at the Nyquist velocity of 19 cm/s when compared with planimetry. MVA3d-PISA was more accurate than MVA2d-PISA. The acceptable correlations were observed between MVA3d-PISA, MVA2d-PISA and MVApl respectively （r = 0.98, r = 0.89）. Conclusions The 3d-PISA method provided the most accurate estimation of MVA at the Nyquist velocity of 19 cm/s, which provided a new method to calculate mitral valve area with mitral stenosis.