Contrast echocardiography: mechanism of action, safety and clinical applications.

Since its initial description by Gramiak and Shah in 1968, contrast echocardiography has become an established practice world-wide. Microbubbles have the unique property of being pure intravascular tracers. The basic rationale behind bubble imaging is the characteristic responses to ultrasound power that results in enhanced ultrasound images from the blood pool. Therefore, whenever there is blood pool there is a potential application for contrast ultrasound. Clinical applications of contrast echocardiography have been vastly grown from diagnostic applications such as detection of a persistent foramen ovale to drug delivery. This article reviews the mechanism of action, safety and clinical applications of contrast echocardiography.