Ultrasound imaging

Abstract

A combined preparation comprising: i) an ultrasound contrast agent capable of accumulation in tissue microvasculature; and ii) a pharmacologically effective amount of a vasodilator drug may be used in perfusion imaging, especially of the myocardium. The contrast agent accumulates in tissue in concentrations related to the regional rate of tissue perfusion, and the vasodilator drug enhances distinction between normally perfused and underperfused tissue.

What is claimed is:  
     
         1 - 10 . (Canceled)  
     
     
         11 . A combined preparation for use as a contrast agent in ultrasound perfusion imaging, said preparation comprising: 
 i) an ultrasound contrast agent which following injection into the vascular system of a human or non-human animal subject will accumulate in tissue microvasculature of said subject at concentrations dependent on regional rates of perfusion within said tissue; and    ii) a vasodilatation-inducing amount of a vasodilator drug.    
     
     
         12 . A preparation as claimed in  claim 11  wherein said vasodilator is a substance which is endogenous to said subject.  
     
     
         13 . A preparation as claimed in  claim 12  wherein said vasodilator drug is adenosine.  
     
     
         14 . A preparation as claimed in  claim 11  wherein said ultrasound contrast agent comprises a phase shift colloid.  
     
     
         15 . A preparation as claimed  claim 11  wherein said ultrasound contrast agent comprises a targetable ultrasound contrast agent having affinity for sites and/or structures within tissue microvasculature.  
     
     
         16 . A preparation as claimed in  claim 15  wherein said ultrasound contrast agent comprises at least one vector having affinity for normal or activated endothelial cells.  
     
     
         17 . A preparation as claimed in  claim 15  wherein said ultrasound contrast agent comprises at least one protein or peptide which binds to cell-surface proteoglycans.  
     
     
         18 . A method of generating enhanced perfusion images of a human or non-human animal subject which comprises the steps of: 
 i) injecting into the vascular system of said subject an ultrasound contrast agent which following injection will accumulate in tissue microvasculature of said subject at concentrations dependent on regional rates of perfusion within said tissue;    ii) coadministering a vasodilatation-inducing amount of a vasodilator drug; and    iii) generating an ultrasound image representing perfusion of a target organ or tissue.    
     
     
         19 . A method as claimed in  claim 18  wherein images representative of myocardial perfusion are generated.  
     
     
         20 . A preparation as claimed in  claim 12  wherein said ultrasound contrast agent comprises a phase shift colloid.  
     
     
         21 . A preparation as claimed in  claim 13  wherein said ultrasound contrast agent comprises a phase shift colloid.  
     
     
         22 . A preparation as claimed in  claim 12  wherein said ultrasound contrast agent comprises a targetable ultrasound contrast agent having affinity for sites and/or structures within tissue microvasculature.  
     
     
         23 . A preparation as claimed in  claim 13  wherein said ultrasound contrast agent comprises a targetable ultrasound contrast agent having affinity for sites and/or structures within tissue microvasculature.  
     
     
         24 . A preparation as claimed in  claim 11  wherein said ultrasound contrast agent comprises: 
 i) an injectable aqueous medium having gas dispersed therein, said dispersed gas having affinity for sites and/or structures within tissue microvasculature; and  
 ii) a composition comprising a diffusible component, said diffisible component being separate from said dispersed gas and being capable, following administration of said contrast agent to said subject, of diffusion in vivo into said dispersed gas so as to promote controllable growth and temporary retention of said dispersed gas within tissue microvasculature in said subject.