Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, UK.
Phys Med Biol. 2010 Feb 21;55(4):1177-88. doi: 10.1088/0031-9155/55/4/018. Epub 2010 Jan 28.
We have developed a novel phantom material: a solution of polyvinyl alcohol (PVAL) in ethanol and water, freeze-thawed to produce a solid yet elastically compressible gel. The x-ray attenuation and mechanical properties of these gels are compared with published measurements of breast tissue. Gels with PVAL concentrations from 5 to 20% w/v were produced. The linear x-ray attenuation coefficients of these gels range from 0.76 to 0.86 cm(-1) at 17.5 keV, increasing with PVAL concentration. These values are very similar to the published values of breast tissue at this energy, 0.8-0.9 cm(-1). Under compression cancerous breast tissue is approximately ten times stiffer than healthy breast tissue. The Young's moduli of the gels increase with PVAL concentration. Varying the PVAL concentration from 7.5 to 20% w/v produces gels with Young's moduli from 20 to 220 kPa at 15% strain. These values are characteristic of normal and cancerous breast tissue, respectively.
聚乙烯醇（PVAL）在乙醇和水中的溶液，经过冷冻-解冻处理后产生一种固体但弹性可压缩的凝胶。这些凝胶的 X 射线衰减和机械性能与已发表的乳房组织测量值进行了比较。制备了浓度为 5 至 20%（w/v）的 PVAL 凝胶。这些凝胶的线性 X 射线衰减系数在 17.5keV 时范围从 0.76 到 0.86cm(-1)，随着 PVAL 浓度的增加而增加。这些值与该能量下发表的乳房组织值非常相似，为 0.8-0.9cm(-1)。在压缩下，癌性乳房组织的硬度大约是健康乳房组织的十倍。凝胶的杨氏模量随 PVAL 浓度的增加而增加。将 PVAL 浓度从 7.5 至 20%（w/v）变化会产生杨氏模量为 20 至 220kPa 的凝胶，在 15%应变时。这些值分别是正常和癌性乳房组织的特征。
