Peripheral veins are easily tested using a 5 to 10 MHz transducer. The venous walls are smooth, thin, and compressible. Venous ultrasound imaging requires the compression of the veins in the transverse view. If compression is performed in the longitudinal view, the vein may roll away from the transducer possibly creating a false-negative examination.
The lumen of the normal vein is echo free. Increasing the gain will display low level echoes representing venous blood moving towards the heart. When performing Doppler spectral analysis or color Doppler the gate should be placed in the center of the vessel. In case of a non-obstructing or recanalized thrombosis, the Doppler gate should be placed within the remaining vessel lumen for flow detection.

See also Maximum Venous Outflow and Zero Offset.

California-based research and development company. Alliance Pharmaceutical Corporation. The principal activities of the Company is identifying, designing, and developing novel medical products. The Company is engaged in development of scientific discoveries into medical products and licensing these products to multinational pharmaceutical companies in exchange for fixed payments and royalty or profit sharing payments. The Company has developed three innovative products through initial clinical (human) trials. The products are Oxygent™, Liquivent and Imavist™. The Company's strategy is to identify potential new medical products though its own efforts and scientific collaborations with researchers and clinicians in universities and medical centers. In Dec 2000 the company acquired Molecular Biosystems Inc a developer of intravenous ultrasound contrast agent for the heart.

'September 20, 2001 Alliance Pharmaceutical Corp. announced that it has won a favorable Final Judgment from the United States Patent and Trademark Office's Board of Patent Appeals and Interferences regarding claims in U.S. Patent No. 5,558,854, which is owned by Nycomed Imaging, AS. The Final Judgment determined that claims made in the Nycomed patent with respect to 'microbubbles' that contain perfluorohexane filling gas are invalid and are therefore unpatentable.'
June 04, 2010, the company announced in their quartzerly report: 'We no longer have working capital to fund our operations. Because adequate funds have not been available to us in the past, we have already delayed our Oxygent development efforts and have eliminated our other product development programs.'

Ultrasound Contrast Agents:

Blood volume per time measured in: cm³/s.
The sonographic detection of blood flow in vascular ultrasound is limited by factors such as tissue motion (clutter), attenuation properties of the intervening tissue, and slow or low-volume flow.

Different flow types in human body:

See also Antegrade, Bi-directional Flow, Velocity, Poiseulles Law, and Venous Ultrasound.

From GE Healthcare;;
Optison is the first 'second generation USCA' marketed in the US.
Ultrasound contrast agents used during an ultrasound imaging procedure, enable more accurate diagnosis of the patient's heart condition. The application of Optison allows to image the endocardial borders of the heart, to see cardiac wall motion abnormalities and to guide the selection and monitoring of treatment.
Optison represents a class of microbubbles with a shell formed by sonicating a solution of capsules filled with a perfluoropropane gas. The high molecular weight slows microbubble dissolution and prolongs the enhancement for several minutes. The human albumin-stabilized cavitation bubbles have a surface tension of 0.9 N/m and a surface dilatational viscosity 0.08 msP.

'August 06, 2001 Molecular Biosystems Inc., a subsidiary of Alliance Pharmaceutical Corp, announced the amendment of the Optison Product Rights Agreement (OPRA) dated May 9, 2000 with Mallinckrodt Inc, a unit of Tyco Healthcare. Optison, an intravenous ultrasound contrast agent, was developed by MBI and is being marketed by Mallinckrodt in the U.S. and Europe. Under the amended agreement, MBI will receive an immediate cash payment plus additional unspecified royalties for a two-year period. The amendment of OPRA coincides with an announcement by Nycomed Amersham Imaging that Nycomed and Mallinckrodt will terminate their joint commercialization and development agreement for ultrasound contrast agents, including Optison, effective Dec. 31, 2001. Effective Jan. 1, 2002, all selling and marketing activities will be resumed solely by Nycomed Amersham.'

Vascular ultrasound obtains images and measures blood flow velocity in the carotids, abdominal aorta, and vessels of kidneys, arms, or legs. Blockages in arteries, blood clots in veins, or abdominal aortic aneurysm can be detected.
These abnormalities in blood flow are usually examined with different Doppler techniques. In addition, the speed and direction of blood flow can be color coded in a color map. Duplex techniques show both, the vessels and the surrounding tissue. The use of ultrasound contrast agents improves the left ventricular opacification in cardiac ultrasound examination. Usually, for a vascular ultrasound no special preparation is needed.

See also Echocardiography, Venous Ultrasound, Adventitia, Intima, Temporal Mean Velocity, and Intravascular Ultrasound.