Method for Producing Anatomical Phantoms with Constituents Having Variable Densities

Abstract

A method of producing an anatomical phantom of an anatomical part having components of different density is described. The method includes providing a mold of an anatomical part, providing a constituent part having a size shape and density corresponding to a real constituent part of a real anatomical part, and placing the constituent part into the mold and supporting it in a location in the mold corresponding to an actual location of the real constituent part in the real anatomical part. The mold is filled with a hydrogel liquid precursor to encase the constituent part in the hydrogel liquid precursor. The hydrogel liquid precursor is then exposed to a cross linking agent to induce cross linking in the hydrogel liquid precursor to produce a hydrogel. When the hydrogel liquid precursor is cross linked, the resulting hydrogel exhibits a density corresponding to a density of tissue in the anatomical part.

1 - 24 . (canceled) 
     
     
         25 . A method of producing a hydrogel-based anatomical phantom of an anatomical part having components of different density, comprising:
 a) providing a mold of an anatomical part;   b) providing a constituent part having a size, shape and density corresponding to a real constituent part of a real anatomical part and placing the constituent part into the mold and supporting it in a location in the mold corresponding to an actual location of the real constituent part in the real anatomical part;   c) filling the mold with a hydrogel liquid precursor to encase the constituent part in the hydrogel liquid precursor; and   d) exposing the hydrogel liquid precursor to a cross linking agent to induce cross linking in the hydrogel liquid precursor to produce a hydrogel, the hydrogel liquid precursor being selected to have a composition such that once cross linked, the resulting hydrogel exhibits a density corresponding to a density of tissue in the anatomical part being represented by the hydrogel.   
     
     
         26 . The method according to  claim 25  wherein the hydrogel is poly(N-isopropyl acrylamide). 
     
     
         27 . The method according to  claim 26  wherein the cross linking agent is any one or combination of N,N′-Methylenebisacrylamide, N,N′-cystamine-bis-acrylamide and tetramethylenediamine. 
     
     
         28 . The method according to  claim 25  wherein the hydrogel is comprised of a blend of silicone rubber with a combination of hydrogel monomers, the combination of hydrogel monomers including N-Vinyl pyrrolidone, methacrylic acid, acrylic acid, poly-2-hydroxyethyl methacrylate. 
     
     
         29 . The method according to  claim 28  including providing any one or combination of substituted methacrylate and acrylates present in amounts to tune selected properties of the hydrogel. 
     
     
         30 - 31 . (canceled) 
     
     
         32 . The method according to  claim 25  wherein the constituent part provided in step b) is a nested constituent part comprising a pre-selected number of constituent parts arranged in a nested relationship, wherein each constituent part in the nested constituent part in ascending order has a size and shape such that each subsequent constituent part in the nested constituent part contains nested therein a smaller one of the constituent parts so that the constituent parts are arranged in the nested relationship with each other, and wherein step b) includes placing the nested constituent part into the mold. 
     
     
         33 . The method according to  claim 32  wherein each of the constituent parts in the nested constituent part is comprised of a polyvinyl alcohol cryogel (PVA-C) each formed by freezing a different polyvinyl alcohol solution having a different concentration such that the resulting hydrogels have different densities. 
     
     
         34 . The method according to  claim 32  wherein the nested constituent part comprises an encapsulating constituent part and an innermost constituent part contained within the encapsulating constituent part, and wherein the innermost constituent part is simulated blood vessel content and the encapsulating constituent part is simulated blood vessel. 
     
     
         35 . The method according to  claim 32  wherein the nested constituent part comprises an encapsulating constituent part and an innermost constituent part contained within the nested constituent part, and wherein the innermost constituent part is simulated lymphatic system content and the encapsulating constituent part is simulated vessels and nodes. 
     
     
         36 . The method according to  claim 25  wherein the hydrogel liquid precursor comprises polyvinyl alcohol such that the hydrogel is polyvinyl alcohol cryogel (PVA-C). 
     
     
         37 . The method according to  claim 36  wherein the polyvinyl alcohol is present in an amount in a range from 2 to 20 wt %. 
     
     
         38 . The method according to  claim 37  wherein the polyvinyl alcohol is cooled to a temperature in a range from −1° C. to −35° C. 
     
     
         39 . The method according to  claim 36  wherein the constituent part is formed by freezing a polyvinyl alcohol having a composition different from the polyvinyl alcohol of the liquid hydrogel precursor. 
     
     
         40 . The method according to  claim 25  wherein the constituent part is formed by freezing a liquid comprising any one or combination of polyvinyl alcohol) (PVA) in water, oil, wax, a solution of a contrast agent in water, a solution of a contrast agent in water and PVA, a salt or carbonate solution in water, a salt or carbonate solution in water and PVA, a suspension of nanoparticles in water, a suspension of nanoparticles in water and PVA, a suspension of fibrous materials in water, a suspension of fibrous materials in water and PVA. 
     
     
         41 . The method according to  claim 40  wherein the nanoparticles comprise any one or combination of anatase titania, rutile titania, silica, calcium carbonate, calcium chloride, talc, any one or combination of tinted, colored and pigmented nanoparticles. 
     
     
         42 . The method according to  claim 40  wherein the fibrous material comprises any one or combination of cellulose, cotton, silicone rubber, and chitin. 
     
     
         43 . The method according to  claim 25  wherein providing the mold of the anatomical part in step a) includes producing a mold of a generic anatomical part from an anatomical atlas. 
     
     
         44 . The method according to  claim 25  wherein providing the mold of the anatomical part in step a) includes acquiring preoperative imaging of the anatomical part and the real constituent part of a patient requiring a medical procedure, and based on the preoperative imaging producing the mold and positioning the constituent part in the mold in a location consistent with the location of the real constituent part in the preoperative imaging. 
     
     
         45 . The method according to  claim 44  wherein the real constituent part in the anatomical part is any one of a tumor, lesion, blood clot, or sub-anatomical structure in the patient.