| abstract |
The invention relates to ultrasound contrast agents comprising porous particles of an inorganic material containing an entrapped gas or liquid and having an average particle diameter of about 0.05 to 500 microns, said inorganic material being selected from one or more of the group consisting of: monomeric or polymeric borates; monomeric or polymeric aluminas; monomeric or polymeric carbonates; monomeric or polymeric silicas; and monomeric or polymeric phosphates; and pharmaceutically acceptable organic or inorganic cationic salts thereof. |