Ultrasound contrast agents are "microbubble" or "microsphere" drugs that are usually injected
into the vascular system in order to improve the diagnostic information obtained from
ultrasound-based images. The gas contained within these products enhances the acoustic signal
and provides contrast between the vascular system and surrounding structures.

"Microbubble" drugs consist of a gas core encased within a molecular shell, such that the
bubbles oscillate in response to ultrasound waves. AI-700 is a "microsphere" drug, in that it
consists of a mechanically "rigid" particle which contains pores that encase a gas. The relative
inflexibility of the microsphere is proposed to allow longer ultrasound visualization, in
comparison to microbubble products. Because the AI-700 microspheres are generally smaller
than a red blood cell, injection of AI-700 into a vein results in the passage of the product through
the pulmonary vasculature and into the arterial system, including the left ventricle and coronary
arterial system. Dispensation of AI-700 within the arterial system allows ultrasound
visualization of the left ventricular cavity and perfused myocardial tissue.

AI-700 (Imagify™) is the subject of a New Drug Application (NDA) with the following
proposed indication:

"Imagify is an ultrasound imaging agent indicated for patients with stable chest pain being
evaluated for inducible ischemia for the detection of coronary artery disease (CAD) based on
assessment of myocardial perfusion and wall motion. Imagify echocardiography is
accomplished with rest and stress techniques."

Full paper available for download as a PDF here