主动脉瓣环搏动变形特性的动态三维CT研究

Conformational pulsatile changes of the aortic annulus by 4-dimensional computed tomography

目的探讨主动脉瓣环三维形态的搏动变化。方法35例重度主动脉瓣狭窄患者[年龄（71±6）岁]及20例健康对照者[年龄（53±12）岁]行多排螺旋CT检查，每隔5％心动周期重建主动脉瓣环平面，测量其面积、周长、长轴径、短轴径并计算椭圆率指数。结果健康对照组瓣环面积、周长、长轴径及短轴径收缩期分别增加（26．9±8．1）％、（14．3±2．6）％、（8．0±2．1）％和（20．4±1．9）％，椭圆率指数则下降（18．4±8．3）％；主动脉瓣狭窄组瓣环面积、周长、长轴径及短轴径收缩期分别增加（19．3±8.3）％、（9．1±2．5）％、（5．4±1.9）％和（12．0±2．3）％，椭圆率指数则下降（12．5±4．6）％，上述参数变化差异均有统计学意义（P〈0．05）。结论主动脉瓣狭窄患者及健康对照者的主动脉瓣环面积、周长及径线在心动周期中均有显著变化，提示其存在变形搏动。上述特性可能对经皮导管主动脉瓣置换有重要意义。

Objective This study sought to investigate three-dimensional pulsatile changes of the aortic annulus. Methods Muhislice CT scans of 20 normal controls without aortic valves disease age （53±12）years and 35 patients with severe aortic stenosis age （71±6）years were analyzed. Images in plane with the aortic annulus were reconstructed for every 5% of the cardiac cycle. For each phase, cross-sectional area, perimeter, long-axis diameter, short-axis diameter and ellipticity index were measured. Results The area, perimeter, long-axis diameter and short-axis diameter increased in systole（26.9±8.1 ）%, （ 14.3±2.6）%, （8.0±2.1）% and （20.4±1.9）%, respectively in the normal coutrois and （19.3±8.3）%, （9.1±2.5）%, （5.4±1.9）% and （12.0±2.3）%, respectively in those with aortic stenosis, ellipticity index decreased （18.4±8.3）% in normal controls and （12.5±4.6）% in those with aortic stenosis. All the above parameters changed significantly over the cardiac cycle （P〈0.05）. Conclusion Significant area, perimeter and radius changes during the cardiac cycle were demonstrated in both the nondiseased annulus and the stenotic annulus, indicating deformation and stretch. This finding may be important for beating-heart transcatheter aortic valve implantation.