From Sonus Pharmaceuticals
QW7437 (SonoGen) is a perfluorocarbon-based ultrasound contrast agent under development. This anionically charge-stabilized emulsion, similar to EchoGen, has been designed for echocardiographic examinations with greater safety and efficacy.

SonoGen (QW7437) is an anionically charged 2% perfluorocarbon emulsion under development as a transpulmonary myocardial ultrasound contrast agent (UCA). The SonoGen microbubbles have a reduced adherence to the negatively charged vascular endothelium and reduced coalescence. SonoGen, a second generation USCA has the theoretical potential to provide high safety and efficacy and improved tissue grayscale persistence compared to first generation fluorocarbon contrast agents.