Over the last years Toshiba has actively participated in the development of Contrast Harmonic Imaging. Around 1996 one of the first agents that became available on the European market was Levovist TM (Schering AG, Berlin, Germany). This was a galactose-based contrast agent. Levovist could be used as a Doppler signal enhancer throughout the entire vascular system. With the development of these contrast agents significant advances in diagnostic ultrasound technology took place as well. Compared to tissue, contrast shows a typical and strong non-linear behaviour. Microbubbles resonate and rupture when exposed to acoustic power at the level used in clinical ultrasound studies. Contrast-specific modes like Harmonic Imaging für grey-scale and Power Angio allowed a significant reduction of echo components from surrounding tissue and thus enhancing contrast between tissue and contrast agent.