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.

The second generation ultrasound contrast agents (UCA/USCA) are both sufficiently small and stable to pass into the systemic circulation, and these contrast media enhance the Doppler signal in various arteries after intravenous injection. Second generation agents have a short live, the contrast effect is over in a few minutes.

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.

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

Stress echocardiograms are used for detection of coronary artery disease, or to determine the cardiac performance. Stress echocardiograms are less performed to evaluate pulmonary artery pressures, pulmonary hypertension or the significance of valvular heart disease.
Stress increases the degree to which the heart contracts. After a myocardial infarction there will be a region of the heart muscle that contracts abnormal at rest. This area may worsen with stress. A coronary artery blockage most often do not impairs the function of the heart at rest. With stress, a region of the heart does not receive enough blood to work effectively and wall motion abnormalities occur. The echocardiographer compares rest and exercise and can determine the presence and severity of a coronary artery blockage.

Stress echocardiograms involve:
A bicycle stress echocardiogram involves transthoracic echocardiography performed at the rest baseline and after or during different stages of physical exercise.
A dobutamine stress echocardiography uses the drug dobutamine instead physical exercise.
Transthoracic echocardiograms are routinely performed during stress and rest.
Cardiovascular stress represents a minimal risk to the patient.

See also Transesophageal Echocardiography, Echocardiography, M-Mode, Curved Transducer, Doppler Ultrasound, History of Ultrasound and History of Ultrasound Contrast Agents.