时间–空间相关成像技术评价胎儿右心室功能的临床研究

目的：探讨四维时间–空间相关成像(spatio-temporal image correlation，STIC)技术评价胎儿右心室功能的 优越性、可行性及临床意义。方法：应用三维容积探头采集180例24+0~37+6孕周正常胎儿的STIC心脏动态图像， 并结合虚拟器官计算机辅助分析(virtual organ computer-aided analysis，VOCAL)软件进行后期脱机分析，以获得右 心室舒张末期容积(right ventricular end-diastolic volume，RVEDV)和右心室收缩末期容积(right ventricular end-systolic volume，RVESV)，计算出右心每搏量(right stroke volume，RSV)、右心输出量(right cardiac output，RCO)和右心射血 分数(right ejection fraction，REF)；且根据产前常规超声检查时所测量头围(head circumference，HC)、腹围(abdominal circumference，AC)、股骨长度(femur length，FL)和胎儿估测体质量(estimated fetal weight，EFW)来标准化RCO，然 后将所有测量参数进行统计学分析。结果：本研究整体采集分析成功率为83.89%，且可重复性较好。正常胎儿的 RVEDV，RVESV，RSV，RCO和根据胎儿生物学参数(HC，AC，FL)分别标准化后的RCO均随孕周增长呈增加趋势， REF和RCO/EFW测值则在一定范围内波动。结论：应用STIC技术能够比较准确、客观地测量胎儿心室容积，有望成 为临床评价胎儿心脏功能的重要方法。

Assessment of the right ventricle function of fetus by spatio-temporal image correlation

Objective: To evaluate the superiority, feasibility and clinical signifi cance of the four-dimensional spatio-temporal image correlation (STIC) in detection of the right ventricle function of fetus. Methods: Th e STIC dynamic images of 180 normal fetal hearts at 24+0 to 37+6 weeks of gestation were obtained by the three-dimensional (3D) probe. Th e post-process evaluation was done off -line with the virtual organ computer-aided analysis (VOCAL) software. The computer recorded the right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and then calculated the right stroke volume (RSV), the right cardiac output (RCO) and the right ejection fraction (REF). RCO was standardized by biometric measurements obtained at prenatal screening, including head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW). Results: The overall successful rate in image acquisition was 83.89% and the repeatability was favorable. After the standardization of fetal biometric parameters (HC, AC, FL) and the right ventricle function indexes (RVEDV, RVESV, RSV), RCO was increased with the gestational age while the REF and RCO/EFW fluctuated within a certain range. Conclusion: STIC technique can accurately and objectively measure the fetal ventricular volume and it might be a potential strategy in the clinical assessment of the fetal cardiac function.