Release burst imaging is a method based on the combination of multiple high frequency, broadband-detection pulses with a separate release burst. Release burst imaging is optimally suited to the characteristic of ultrasound contrast agents.
This method allows to improve both contrast sensitivity and imaging resolution. Imaging and transient enhanced scattering can be optimized separately. The release burst mode can be combined with a Doppler method to remove residual clutter signals from moving tissue.

See also Repetition Rate.

SONUS Pharmaceuticals, Inc., is engaged in the research and development of ultrasound contrast agents (USCA) and drug delivery systems for use in the diagnosis and treatment of heart disease, cancer and other conditions.
Sonus Pharmaceuticals and OncoGenex Technologies Inc., a privately held biopharmaceutical development company, announced 2008 the signing of a definitive agreement to merge the two companies. The combined company will operate as OncoGenex Pharmaceuticals, Inc.

Ultrasound Contrast Agents:

Sonazoid™ is an ultrasound contrast agent (UCA) consisting of stabilized gas microbubbles in an aqueous suspension. Sonazoid™ has overcome the stability problems of first generation USCA and can produce myocardial perfusion images. Myocardial imaging using ultrasound contrast agents provides diagnosis of chronic heart disease and assessment of the coronary arteries and of the coronary blood flow reserve.
Sonazoid™ is taken up by healthy Kupffer cells in the liver and spleen, but break down in high amplitude ultrasound imaging modes such as color Doppler imaging. The bubble rupture produces a transient pressure wave, which results in a characteristic mosaic color pattern from tissues containing the microbubbles (induced acoustic emission). Liver tumors without Kupffer cells will not display the mosaic pattern and can therefore be identified easily.

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.

From Bracco Diagnostics Inc
SonoRx® is a gas-shadowing reduction agent, used in abdominal ultrasound to enhance the delineation of upper abdominal anatomy. This ultrasound contrast agents is designed to adsorb and displace stomach and bowel gas and should be taken after fasting for at least four hours. Ingestion orally of the simethicone-coated cellulose suspension over 15 minutes in dosages of 200 to 400 ml results in a homogeneous transmission of sound through the contrast-filled stomach.
Bristol-Myers Squibb, under license from ImaRx LLC;; marketed by Bracco Diagnostics Inc, Source: FDA approvals - 11/03/98