时间-空间相关成像技术“A平面旋转法”在中孕期胎儿心脏结构筛查中的应用

Application of 'a plane rotation method'of spatio-temporal image correlation in the screening of the fetal cardiac structure in second-trimester pregnancy

目的研究时间-空间相关成像技术(STIC)在中孕期胎儿心脏结构筛查中的应用,分析STIC技术应用于中孕期胎儿心脏检查中的最优条件及影响心脏容积数据采集成功的因素,探索后期图像快速处理的方法。方法 150例中孕期胎儿,经常规超声检查心脏结构无异常。采用STIC技术扫描获得整个胎儿心动周期的容积数据并采用"A平面旋转法"重建出左心室流出道切面(LVOT)、右心室流出道切面(RV-OT)、主动脉弓切面(LAV-AOA)、动脉导管弓切面(LAV-DA)、三血管切面(3VT)五个常用切面,根据胎心位置分为尖位四腔心组和侧位四腔心组,分析比较上述两组切面的重建率;分析影响数据采集的相关因素,如最大羊水深度、胎儿孕周、胎儿体重、胎儿心率、胎盘位置等。结果运用STIC技术采集150例中孕期胎儿心脏容积数据成功123例(82%),未成功27例(18%)。各因素对数据采集成功率的影响无统计学差异(P>0.05)。尖位四腔心组、侧位四腔心组两组间STIC重建率无统计学差异(χ2=0.624,P=0.891)。结论在胎儿静止状态下,其他因素对使用STIC技术采集容积数据影响较小,可获得满意容积数据。对不同体位胎儿后期图像处理,运用STIC正交平面技术可得到质量比较满意的图像。因此STIC技术可普遍用于中孕筛查期胎儿心脏检查,具有重要的临床应用价值。

Objective To research on the application of the spatio-temporal image correlation（STIC）in the fetal heart screening, analyze the optimal conditions of the fetal cardiac structure screening applying STIC and the impact factors to the successful collection, and quest for the methods to process the ultimate picture quickly. Methods 150 normal second-trimester fetuses screened by routine ultrasonic screening. To obtain the data of the volume in the fetal cardiac cycle by scanning the fetal heart from the four-chamber view with STIC, reconstruct five types of commonly-used plans of LVOT, RVOT, LAV-AOA, LAV-DA, 3VT with＇ a plane rotation method＇ of STIC, divide the plans into apical four-chamber group and lateral four-chamber group according to the acquisition position, and compare the plan reconstruction ratio of above two groups applied with X2 test, then the impact factors were analyzed with t test in data collection, such as the maximum depth of amniotic fluid, fetal gestational age, fetal weight, fetal heart rate,placenta position （X2 test）etc. Results Among the 150 cases in second-trimester fetuses screened with STIC, 123 （ 82% ） cases succeeded, 27 （ 18% ） cases failed. Each condition＇ s effect to success ratio of data collection had no significant difference（ P 〉 0. 05 ）. The STIC reconstruction rate of apical four-chamber group and the lateral four-chamber group had no significant difference （ X^2 = 0. 624, P = 0. 891 ）. Conclusions When the fetuses are still,applying STIC in the fetal heart screening can obtain satisfactory data of fetal heart volume with less other impact factors. At the same time,applying orthogonal planes methods of STIC in the ultimate picture processing can obtain image of satisfactory quality. So STIC possesses important clinical value and can be widely used in the second- trimester fetal heart examination.