Method of imaging lymphatic system using nanocapsule compositions

Abstract

A composition is provided accompanying nonoparticles having diameters in the range of about 100 to 800 nanometers with hollow cores and outer shells with mechanical properties such that they rupture on exposure to predetermined ultrasound energy. The composition is useful for identifying sentinel lymph nodes.

1 - 7 . (canceled)  
     
     
         8 . A method of identifying sentinel lymph nodes comprising the steps of: 
 a. administering subcutaneously by injection a composition comprising nanoparticles having diameters within the range of 100 to 1800 nanometers, said particles each having an outer shell and a gas-filled hollow core wherein the mechanical properties of said shell are selected to allow nanoparticle rupture and loss of gas within a biological region of interest upon exposure to ultrasound energy at an intensity and frequency suitable for imaging the nanoparticles rupture response,    b. allowing sufficient time for said nanoparticles to be taken up by the lymph system,    c. identifying said nodes with ultrasound by imaging the rupture response of said nanoparticle composition.    
     
     
         9 . A method according to  claim 8  wherein, said nanoparticle rupture response is detected using ultrasound B-mode harmonic imaging methods.  
     
     
         10 . A method according to  claim 8  wherein, said nanoparticle rupture response is detected using ultrasound power doppler methods.  
     
     
         11 . A method according to  claim 8  wherein, said nanoparticle rupture response is detected using ultrasound pulse inversion methods.  
     
     
         12 . A method according to  claim 8  wherein, said nanoparticle rupture response is detected using ultrasound imaging methods at a mechanical index of between 0.2 and 2.6.  
     
     
         13 . A method according to  claim 12  wherein, said nanoparticle rupture response is detected using ultrasound imaging methods at a mechanical index of between 0.5 and 1.6.  
     
     
         14 . A method according to  claim 8  comprising the additional step of repeating steps b and c.  
     
     
         15 . (canceled)