Recent advances in small-animal cardiovascular imaging

Because of the development of gene knockout and transgenic technologies, small animals, such as mice and rats, have be-come the most widely used animals for cardiovascular imaging studies. Imaging can provide a method to serially evaluate the effect of a particular genetic mutation or pharmacologic therapy (1). In addition, imaging can be used as a noninvasive screening tool for particular cardiovascular phenotypes. Out-come measures of therapeutic efficacy, such as ejection frac-tion, left ventricular mass, and ventricular volume, can be determined noninvasively as well. Furthermore, small-animal imaging can be used to develop and test new molecular imag-ing probes (2,3). However, the small size of the heart and rapid heart rate of murine models create special challenges for car-diovascular imaging