Farquharson M J, Spyrou N M, al-Bahri J, Highgate D J
Department of Physics, University of Surrey, Guildford, U.K.
Appl Radiat Isot. 1995 Aug;46(8):783-90. doi: 10.1016/0969-8043(95)00025-9.
The object of the study was to measure the linear attenuation coefficients of hydrophilic materials with the aim of investigating their suitability as tissue equivalent materials. Hydrophilic materials are used in the ophthalmic industry for the manufacture of soft contact lenses. Hydrophilic materials have the trade name "Biogel" and are commonly known as hydrogels. Two types of hydrophilic material were tested, ED4C (72% water uptake by weight) and EDIS (60% water uptake by weight). The measurements were obtained using gamma-ray photons of energy 59.5 keV, and x-ray photons of energies 44.23 and 17.44 keV. Measurements were made for material types ED4C and EDIS in both the dry and fully hydrated state. Measurements were also made on powdered samples of ED4C at different hydration levels using a photon energy of 17.44 keV and powdered samples of EDIS at different hydration levels using a photon energy of 59.5 keV. The precision of the measurements was approx. 1%. It was found that material ED4C has linear attenuation coefficients that closely match those of the calculated values for soft tissue across the range of energies used.
本研究的目的是测量亲水性材料的线性衰减系数，以调查其作为组织等效材料的适用性。亲水性材料在眼科行业用于制造软性隐形眼镜。亲水性材料的商品名为“Biogel”，通常被称为水凝胶。测试了两种亲水性材料，ED4C（重量吸水率为72%）和EDIS（重量吸水率为60%）。测量是使用能量为59.5 keV的伽马射线光子以及能量为44.23 keV和17.44 keV的X射线光子进行的。对处于干燥和完全水合状态的ED4C和EDIS材料类型进行了测量。还使用17.44 keV的光子能量对不同水合水平的ED4C粉末样品以及使用59.5 keV的光子能量对不同水合水平的EDIS粉末样品进行了测量。测量的精度约为1%。结果发现，在所用能量范围内，材料ED4C的线性衰减系数与软组织的计算值密切匹配。
