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.

(Perfluorocarbon exposed sonicated dextrose albumin) PESDA are sonicated dextrose albumin microbubbles containing decafluorobutane gas. PESDA is a sonicated self made contrast agent and not a commercial product.
PESDA microbubbles can be used as a blood pool contrast agent in echocardiography to improve the detection of myocardial perfusion abnormalities.

Echocardiography is the ultrasound examination of the heart. Depending on the used ultrasound system, echocardiograms can be two-dimensional slices or 3D real-time images of the heart. Based on the ultrasound principles the direction and speed of blood flow can be utilized e.g., to diagnose a leaking or stenosed valve or to identify intracardiac shunts.

Different types of echocardiography:
The transthoracic echocardiogram (images are taken through the chest wall) is a non-invasive, highly accurate and quick assessment of the overall health of the heart.
A more invasive method is to insert a specialized scope containing an echocardiography transducer (TEE probe) into the esophagus, and record images from there. The advantages are clearer images, since the transducer is closer to the heart.
Contrast echocardiogram (CE) is already a valuable tool to delineate endocardial borders, direct invasive procedures, detect intracardiac shunts, assess myocardial perfusion and viability, and quantify coronary flow reserve and blood volumes (see also hemoglobin). The mechanism of microbubble CE is based on the physical principles of rarefaction and compression, leading to volume pulsations of microbubbles, and it is this change that results in CE signal.
Stress echocardiograms are echocardiography exams used for detection of coronary artery disease.

See also Diastole, Bicycle Stress Echocardiography, Resistive Index, and M-Mode Echocardiography.

EchoGen® is a fluorocarbon-based (dodecafluoropentane) third generation USCA. EchoGen® consists of microbubbles stabilized with surfactants in a phase shift colloid emulsion (perflenapent). EchoGen® requires no preparation, reconstitution, or refrigeration.
Perflenapent emulsion would represent a significant advance in contrast echocardiography caused by effective and long lasting opacification of the left ventricle and enhanced endocardial border delineation.
The persistence of the contrast effect permits interrogation in multiple echocardiographic views, as well as the visualization and localization of myocardial perfusion deficits at rest by producing a negative contrast effect.
October 12, 2000
Sonus Pharmaceuticals, Inc. announced a strategic decision to refocus the Company on the development of its drug delivery and blood substitute products. At the same time, Sonus has withdrawn the NDA (New Drug Application) and discontinued clinical activity for its ultrasound contrast product, EchoGen®.
August 06, 2001
Sonus Pharmaceuticals, Inc. announced that it has entered into an agreement to sell its ultrasound contrast assets for $6.5 million to Amersham plc. As part of the agreement, Sonus has also assigned to Nycomed its interest in the ultrasound contrast patent license agreement entered into with Chugai Pharmaceutical Co. Ltd. and Molecular Biosystems Inc in January 2001.

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.