In Vivo Evaluation of the Cardiovascular System of Mouse Embryo and Fetus Using High Frequency Ultrasound

Genetically engineered mice have been widely used for studying cardiovascular development, physiology and diseases. In the past decade, high frequency ultrasound imaging technology has been significantly advanced and applied to observe the cardiovascular structure, function, and blood flow dynamics with high spatial and temporal resolution in mice. This noninvasive imaging approach has made possible longitudinal studies of the mouse embryo/fetus in utero. In this chapter, we describe detailed methods for: (1) the assessment of the structure, function, and flow dynamics of the developing heart of the mouse embryo during middle gestation (E10.5-E13.5); and (2) the measurement of flow distribution throughout the circulatory system of the mouse fetus at late gestation (E17.5). With the described protocols, we are able to illustrate the main cardiovascular structures and the corresponding functional and flow dynamic events at each stage of development, and generate baseline physiological information about the normal mouse embryo/fetus. These data will serve as the reference material for the identification of cardiovascular abnormalities in numerous mouse models with targeted genetic manipulations.