Congenital heart defects (CHDs) are one of the most common and devastating birth defects worldwide. The etiology of congenital heart defects remains largely unclear due to the complicated cause and the lack of tools to access early cardiac structures and functions.  Optical imaging tools have potentials to help because they have high resolution, high speed and they are non-invasive, allowing in vivo imaging and longitudinal imaging.
Optical coherence tomography (OCT), which provides high resolution, 3D imaging at high speed, a field of view(1–3 mm), is well suited to embryonic imaging, including structural imaging and blood flow imaging. OCT is noninvasive and can image embryos cultured under near-physiological conditions. Specifically, OCT is the main imaging modalities used in our CHD studies, including a cardiac neural crest cells (CNCCs) ablation CHD model and a fetal alcohol CHD model. Structural and functional defects at early and late stages were detected and quantified. The results support the hypothesis that early cardiac functions may be a potential cause to CHDs.
As one of the main functions of the heart, coordinated cardiac conduction plays an important role in cardiogenesis, not only for initiating rhythmic contractions of cardiac myocytes for efficient blood pumping, but also for maintaining normal cardiac development. Optical mapping (OM), which uses fluorescent voltage-sensitive dyes to measure membrane potential is currently the most effective method for electrophysiology studies in early embryonic hearts due to its noninvasiveness and large field-of-view. However, conventional embryonic cardiac OM is limited to 2D surface imaging. Therefore, we integrated OM with OCT, measured cardiac conduction function and 3D topology of the heart at the same time, and also developed a 3D conduction velocity correction algorithm. Furthermore, with a self-built light-sheet fluorescence microscopy system, 4D OM in the embryonic heart was achieved for the first time.

Pei Ma is currently an Assistant Professor at University of Shanghai for Science and Technology. She received her Ph.D. degree from Case Western Reserve University, Cleveland, Ohio, USA. Pei Ma’s research interests include the development of optical imaging technologies, such as optical coherence tomography, optical mapping, novel technologies in microscopy, and the applications of these technologies in biomedical diagnostics and developmental biology.