40-MHz echocardiography scanner for cardiovascular assessment of mouse embryos

Congenital heart disease results from genetic defects that are manifested a t early stages of embryogenesis. The mouse is the preferred animal model fo r studies of mammalian embryonic development and for an increasing number o f human disease models. A number of genes identified in the mouse are criti cal for normal cardiovascular development, but an understanding of the unde rlying mechanisms regulating heart development is still incomplete, in part because of the lack of methods to measure hemodynamics in live mouse embry os. We describe the development of a 40-MHz ultrasound scanner, which allow s image-guided continuous-wave and pulsed Doppler blood flow measurements i n mouse embryos, in utero, at the critical early developmental stages. Dopp ler waveforms acquired from mouse embryonic umbilical vessels, descending a orta, and cardiac ventricles are presented to demonstrate the utility of th e method. By combining image-guided ultrasound Doppler with the many availa ble mouse mutants, this approach should lead to new insights into embryonic cardiovascular structure-function relationships. (C) 1998 World Federation for Ultrasound in Medicine & Biology.