In response to the article by R. Leischik et al.: Reproducibility of stress echocardiography using intravenous injection of ultrasound contrast agent (BY963) (see volume 13/5: 387-394).

Many contrast agents will soon be available to the clinicians, but as is evident, contrast echocardiography and the development of agents is still in its infancy. For successful clinical use of contrast echocardiography requires integration of: the development of contrast agents; modifications to ultrasound machines; development and validation of the specific clinical application software.