Bimodal organ phantom and associated production method
A phantom for medical imaging instrumentation, the phantom including a first hydrogel matrix, said matrix containing additives for simulating the optical and acoustic properties of a living organ or tissue. In the phantom, the additives include Indian ink or haemoglobin, silica powder and titanium dioxide powder. The phantom may contain a tumor simulator in solid or liquid form. It may also comprise several hydrogel matrices, each matrix including additives in different concentrations depending on the organ or tissue simulated. A method of producing the phantom includes one or more freeze-thaw cycles for optimizing the characteristics of the phantom.
1. A phantom for medical imaging instrumentation, comprising a first hydrogel matrix, said matrix containing additives for simulating the optical and acoustic properties of a living organ or tissue, wherein the additives comprise at least one absorbent liquid, a silica powder and a titanium dioxide powder, the absorbent liquid including an absorber, said absorber being an ink or haemoglobin.
2. The phantom according to claim 1 , wherein the hydrogel consists of a mixture of water and PVA (polyvinyl alcohol) powder, the volume concentration of the PVA is between 5% and 20% of the volume of the water.
3. The phantom according to claim 1 , wherein the absorbent liquid is Indian ink.
4. The phantom according to claim 3 , wherein the volume concentration of the Indian ink is between 0% and 0.25% of the volume of the water.
5. The phantom according to claim 1 , wherein the weight concentration of the silica powder is between 0% and 4% of the weight of the water.
6. The phantom according to claim 1 , wherein the weight concentration of the titanium dioxide powder is between 0.0025% and 0.25% of the weight of the water.
7. The phantom according to claim 1 , further comprising a tumor simulator (T) in solid form.
8. The phantom according to claim 1 , further comprising a tumor simulator (T) in liquid form.
9. The phantom according to claim 8 , further comprising at least one envelope containing the liquid.
10. The phantom according to claim 8 , wherein the liquid is bovine haemoglobin or Indian ink, the concentration of which is greater than that of the bovine haemoglobin or of the Indian ink of the phantom.
11. The phantom according to claim 9 , wherein the envelope is a polystyrene bead or a glass or Teflon (PTFE) capillary tube.
12. The phantom according to claim 1 , further comprising several hydrogel matrices, each matrix containing additives for simulating the optical and acoustic properties of a different living organ or tissue so as to simulate an organ and its environment, the additives comprising one absorbent liquid, a silica powder and a titanium dioxide powder in different concentrations depending on the simulated organ or tissue.
13. The phantom according to claim 12 , wherein the simulated organ is a prostate gland.
14. A method of producing a phantom according to claim 2 , the phantom comprising at least a first hydrogel matrix produced according to at least the following steps:
distilled water is poured into a container;
Indian ink is added to this distilled water;
PVA powder is added;
the distilled water, Indian ink and PVA powder are mixed together in a container of a beaker type with magnetic stirring, the mixture being thermostatically controlled;
silica powder is added during mixing;
titanium dioxide is added during mixing;
the mixture is heated and stirred;
the mixture is subjected to a vacuum; and
one or more freeze-thaw cycles are carried out.
15. The method of producing a phantom according to claim 14 , wherein the number of freeze-thaw cycles is between 1 and 10.
16. The method of producing a phantom according to claim 15 , wherein the matrices are molded in nylon molds having the shape of the simulated organ.
17. The method of producing a phantom according to claim 14 , wherein the number of freeze-thaw cycles is between 2 and 6.