Multiple imaging mode tissue marker

Abstract

An intracorporeal marker for marking a site within living tissue of a host having a body of porous hydroxyapatite whose physical properties permit the body to be distinguished from human soft tissue under visualization using ultrasonic and radiation imaging modalities.

1 - 15 . (canceled) 
     
     
         16 . A method of in vivo identification of a position in soft tissue, comprising:
 inserting a marker containing hydroxyapatite at a position in soft tissue of a living host;   passing ultrasonic energy through the living host to form an ultrasound image of the marker; and   using the image to locate a site for a medical treatment.   
     
     
         17 . The method of  claim 16 , wherein the hydroxyapatite is porous. 
     
     
         18 . The method of  claim 16 , wherein the marker consists substantially of hydroxyapatite. 
     
     
         19 . The method of  claim 16 , wherein the marker consists substantially of porous hydroxyapatite. 
     
     
         20 . A method of in vivo identification of a position in soft tissue, comprising:
 inserting a unitary hydroxyapatite marker containing a first hydroxyapatite portion and a second hydroxyapatite portion having differing porosities at a position in soft tissue of a living host;   passing energy through the living host to form one of an ultrasound image and an X-ray image of the unitary hydroxyapatite marker; and   using the image of the unitary hydroxyapatite marker to locate a site for a medical treatment.   
     
     
         21 - 23 . (canceled) 
     
     
         24 . A method of in vivo identification of a position in soft tissue, comprising:
 inserting a marker containing a porous ceramic at a position in soft tissue of a living host;   passing ultrasonic energy through the living host to form an ultrasound image of the marker;   passing radiant energy through the living host to form an X-ray image of the marker; and   using the image to locate a site for a medical treatment.   
     
     
         25 . The method of  claim 24 , wherein the porous ceramic includes hydroxyapatite. 
     
     
         26 . The method of  claim 24 , wherein the porous ceramic is substantially all hydroxyapatite. 
     
     
         27 - 29 . (canceled) 
     
     
         30 . The method of  claim 16 , wherein the marker containing hydroxyapatite includes:
 a core region made of porous hydroxyapatite; and   an outer region comprised of a second hydroxyapatite, the core region being completely contained with the outer region,   wherein the porous hydroxyapatite of the core region has a first porosity and the second hydroxyapatite of the outer region has a second porosity, wherein the first porosity of the porous hydroxyapatite of the core region is higher than the second porosity of the second hydroxyapatite of the outer region.   
     
     
         31 . The method of  claim 16 , wherein the marker containing hydroxyapatite includes a first hydroxyapatite portion having a first porosity and a second hydroxyapatite portion having a second porosity, wherein the first porosity of the first hydroxyapatite portion is different from the second porosity of the second hydroxyapatite portion. 
     
     
         32 . The method of  claim 16 , wherein the marker containing hydroxyapatite includes a porous body that has a central region and a surface that surrounds the central region, the porous body having pores filled with gas, the sizes of the pores and the gas being such that the porous body is configured to be visualized under ultrasound, wherein the porous body comprises a first dense hydroxyapatite at the central region, a second dense hydroxyapatite at the surface, and a porous hydroxyapatite between the central region and the surface, and wherein the porous hydroxyapatite has porosity levels in a range of 30 percent to 80 percent. 
     
     
         33 . The method of  claim 20 , wherein the first hydroxyapatite portion forms a core hydroxyapatite region having a first porosity and the second hydroxyapatite portion forms an outer hydroxyapatite region having a second porosity, wherein the first porosity of the core hydroxyapatite region is higher than the second porosity of the outer hydroxyapatite region. 
     
     
         34 . The method of  claim 24 , wherein the marker includes:
 a core region made of porous hydroxyapatite; and   an outer region comprised of a second hydroxyapatite, the core region being completely contained with the outer region,   wherein the porous hydroxyapatite of the core region has a first porosity and the second hydroxyapatite of the outer region has a second porosity, wherein the first porosity of the porous hydroxyapatite of the core region is higher than the second porosity of the second hydroxyapatite of the outer region.   
     
     
         35 . The method of  claim 24 , wherein the marker includes a first hydroxyapatite portion having a first porosity and a second hydroxyapatite portion having a second porosity, wherein the first porosity of the first hydroxyapatite portion is different from the second porosity of the second hydroxyapatite portion. 
     
     
         36 . The method of  claim 24 , wherein the marker includes a porous body that has a central region and a surface that surrounds the central region, the porous body having pores filled with gas, the sizes of the pores and the gas being such that the porous body is configured to be visualized under ultrasound, wherein the porous body comprises a first dense hydroxyapatite at the central region, a second dense hydroxyapatite at the surface, and a porous hydroxyapatite between the central region and the surface, and wherein the porous hydroxyapatite has porosity levels in a range of 30 percent to 80 percent.