PROJECT SUMMARY/ABSTRACT This proposal requests support for the purchase of a VisualSonics Vevo 3100 Imaging Platform, which will be used for structural and functional analysis of the cardiovascular system in experimental animal models of common human cardiovascular diseases. It will be housed and operated in the Mouse Cardiovascular Phenotyping Core facility of the Center for Cardiovascular Research at Washington University School of Medicine. This dedicated in vivo micro-imager will markedly advance the capabilities of the Cardiovascular Phenotyping Core, which has been for over 20 years, a highly successful, large volume Core facility, performing thousands of echocardiographic studies and surgical procedures annually. The Core has served numerous researchers from a wide variety of disciplines across multiple departments and schools at Washington University, as well as nationwide. Indeed, the users’ work depends on the availability of high- quality echocardiographic analysis. As a result of the quality and success of the research projects of the Core investigators, there has been a steady rise in the volume and complexity of the echocardiographic studies over the years. This has brought us to the point that the existing system can no longer adequately satisfy the demands of the User Group on the scale and scope that is required for the scientific needs of each participant. There is now a compelling scientific need and a pressing logistical demand to replace the old and outdated system. The VisualSonics Vevo 3100 is a highly versatile ultrasound platform capable of providing researchers with the ability to visualize and quantify small animal anatomical targets, hemodynamics, and therapeutic interventions with resolution down to 30 microns. Its state-of-the-art technical features are uniquely suited for cardiovascular phenotyping in genetically manipulated mice. An upgrade to the new ultrasound system will provide immediate benefit to the Core users in accomplishing the scientific goals of their NIH funded projects.