From POINT Biomedical Corp
M1134 is a nitrogen-filled submicron ultrasound contrast agent under development with a bilayered shell composed of a biodegradable polymer and a human serum albumin outer coating. The microbubbles have initial diameters from 500 nm to 1.3 μm, with more than 50% having a diameter smaller than a micron.
M1134 can be used in targeted contrast imaging by entering the lymphatic system after injection into the interstitium and accumulation at lymph nodes.
M1134 and M1091 are two agents made of the same polymer with the same relative wall thickness, differing only in the microbubble diameter.

Non-linear imaging is used to detect primary non-linear components of the received echo. Non-linear methods like harmonic imaging and pulse inversion imaging are designed to detect ultrasound contrast agents.

See also Contrast Pulse Sequencing, and Power Modulation.

(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.

Ultrasound is the ideal tool to examine children of all ages. It is fast, painless, uses no ionizing radiation, and does not require a baby to remain still for long periods. Real-time modes show movement of internal tissues and organs. Advanced ultrasound imaging techniques such as color Doppler, 4D ultrasound, harmonic imaging, and higher resolution, as well as the application of ultrasound contrast agents broaden the potential of ultrasound.
Pediatric [paediatric, Brit.] ultrasound can be used in all body regions and reduce the number of more invasive or radiating examinations that often additionally need sedation or intravenous iodinated contrast agents.

See also Fetal Ultrasound, Reflux Sonography, Ultrasound Safety, Abdominal Ultrasound and Pregnancy Ultrasound.

The persistence of microbubbles is depended of the shell stability and the density of the gas.
This is defined by the equation:
(R x d)/(DIFS x const_sat)
where R is the bubble radius, d the gas density, DIFS the gas diffusivity and const_sat the saturation constant.
Microbubbles are stabilized with thin coatings of substances such as palmitic acid or by encapsulation in microspheres made with albumin, lipids, or polymers. Low-solubility low-diffusibility gases dramatically improve the persistence. Most recently developed ultrasound contrast agents combine these two approaches to prolong contrast enhancement.
Persistence is also a type of temporal smoothing used in both gray scale and color Doppler imaging. Successive frames are averaged as they are displayed to reduce the variations in the image between frames, hence lowering the temporal resolution of the image.