中文摘要：

本文提出了一种测量胚胎心脏流出道径向应变的方法.使用光学相干层析成像系统对早期鸡胚流出道进行4D（x,y,z,t）扫描,重建流出道图像后计算多普勒角度;在任意走向的流出道的断层图像中采用半自动边缘检测算法,提取管壁内外边缘,测量管壁面积和短轴长度信息;结合多普勒角度、管壁面积和短轴长度得到管壁壁厚信息,从而实现心脏流出道管壁径向应变的计算.对HH18阶段鸡胚心脏流出道的径向应变进行测量,结果表明该方法能够在任意流出道倾角下测量其径向应变,有效扩大了心脏应变测量的范围,为胚胎心脏生物力学特性的研究提供了一种工具.

英文摘要：

During cardiac development, the growth, remodeling and morphogenesis of embryonic hearts are closely linked to hemodynamic forces. An understanding of the interaction mechanism between hemodynamic forces and heart development is important for the early diagnosis and treatment of various congenital defects. The myocardial wall strain（MWS） in embryonic heart is a critical parameter for quantifying the mechanical properties of cardiac tissues. Here, we focus on the radial strain which is defined as the change of the myocardial wall thickness. An effective measurement of MWS is conductive to studies of embryonic heart development. Chick embryo is a popular animal model used for studing the cardiac development due to the similarity of cardiac development between the human heart and the chick heart at early developmental stages and its easy access. Although various imaging methods have been proposed, there still remain significant challenges to imaging of early stage chick embryo heart because it is small in size and beats fast. Optical coherence tomography（OCT） is a non-contact three-dimensional imaging modality with high spatial and temporal resolution which has been widely used for imaging the biological tissue. In this paper, we describe a method to measure in vivo MWS of chicken embryonic hearts with a high speed spectral domain OCT（SDOCT） system worked at1310 nm. We perform four-dimensional（4D）（x, y, z, t） scanning on the outflow tract（OFT） of chick embryonic hearts in a non-gated way. The transient states of the OFT are extracted from the 4D data by using the beating synchronization algorithm. The OFT center line can be achieved by image processing. Assuming that the blood flow is parallel to the center line in the blood vessel, we calculate the Doppler angle of blood flow from the OFT center line. In a certain OFT cross-section, the OFT myocardial wall（inner and external borders） is segmented from the OCT images with a semiautomatic boundary-detection algorithm. Then, the myocardial