Microbubble Contrast Imaging of the Cardiovascular System of the Chick Embyro

Ultrasound imaging of the chick embryo cardiovascular system is limited to B-scan and Doppler technologies. This study demonstrates microbubble contrast imaging of the embryonic cardiovascular anatomy and physiology. Day 8-19 (Hamburger & Hamilton Stage 34-43) chick embryos are examined in ovo using high-frequency ultrasound imaging through an opening in the blunt end (air cell) of the egg. A chorioallantoic vein is cannulated, and small boluses of octofluoropropane lipid microspheres (Definity®) are injected to visualize the chick embryo cardiovascular system. The entire chick embryo cardiovascular system including the two embryologic arteriovenous (AV) shunts can be visualized. More accurate physiologic measurements of ejection fractions and cardiac output measurements can be obtained using this technology. Microbubble contrast ultrasound imaging in the chick embryo greatly expands the ability to study cardiovascular development. Also, the two natural embryonic A-V shunts provide an excellent model to study the bioeffects of microbubbles in the arterial system.