MRX 115 is a liposome based microbubble formulation and has been demonstrated as effective for cardiac blood pool imaging, Doppler enhancement and potentially myocardial perfusion imaging.
MRX 115 is based upon the demand for a stable, robust blood pool ultrasound contrast agents, also called DMP 115 or Aerosomes™ (ImaRx LLC) and now Definity®.

(AALs) Acoustically active lipospheres and ultrasound are under development to deliver bioactive molecules to the vascular endothelium. The AALs are similar to both ultrasound contrast agents and drug-delivering liposomes. They can carry bioactive substances using biologically inert shells and deliver those substances when disrupted by ultrasound.
The lipospheres consist of a small gas microbubble surrounded by a thick oil shell and are enclosed by an outermost lipid layer. The gas bubble contained in these vehicles makes them acoustically active, similar to ultrasound contrast agents. Acoustically active lipospheres can be nondestructively deflected using ultrasound radiation force, and fragmented with high intensity ultrasound pulses. Their lipid-oil complex can carry bioactive substances at high concentrations. An optimized sequence of ultrasound pulses can deflect the AALs toward a vessel wall then disrupt them, painting their contents across the vascular endothelium.

See also Filling Gas, and MRX 115.

From Lantheus Medical Imaging.
Activated DEFINITY® Injectable Suspension is indicated for use in patients with suboptimal echocardiograms to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border. The perflutren lipid microspheres exhibit lower acoustic impedance than blood and enhance the intrinsic backscatter of blood.
Echocardiography with Definity produced more detailed images of the heart in difficult-to-image patients versus echocardiography alone, and images obtained with the contrast agent provided a more accurate assessment of segmental wall motion compared with unenhanced images.

See also Coherent Contrast Imaging.

In August 2001 DuPont Pharmaceuticals Company received FDA approval.