Abstract：
OBJECTIVE: This study reports a sensitivity enhancement of gold-coated contact lens-type ocular in vivo dosimeters (CLODs) for low-dose measurements in computed tomography (CT).
METHODS: Monte Carlo (MC) simulations were conducted to evaluate the dose enhancement from the gold (Au) layers on the CLODs. The human eye and CLODs were modeled, and the X-ray tube voltages were defined as 80, 120, and 140 kVp. The thickness of the Au layer attached to a CLOD ranged from 100 nm to 10 μm. The thickness of the active layer ranged from 20 to 140 μm. The dose ratio between the active layer of the Au-coated CLOD and a CLOD without a layer, i.e., the dose enhancement factor (DEF), was calculated.
RESULTS: The DEFs of the first 20-μm thick active layer of the 5-μm thick Au-coated CLOD were 18.4, 19.7, 20.2 at 80, 120, and 140 kVp, respectively. The DEFs decreased as the thickness of the active layer increased. The DEFs of 100-nm to 5-μm thick Au layers increased from 1.7 to 5.4 for 120-kVp X-ray tube voltage when the thickness of the active layer was 140 μm.
CONCLUSIONS: The MC results presented a higher sensitivity of Au-coated CLODs (∼20-times higher than that of CLODs without a gold layer). Au-coated CLODs can be applied to an evaluation of very low doses (a few cGy) delivered to patients during CT imaging.
METHODS: Monte Carlo (MC) simulations were conducted to evaluate the dose enhancement from the gold (Au) layers on the CLODs. The human eye and CLODs were modeled, and the X-ray tube voltages were defined as 80, 120, and 140 kVp. The thickness of the Au layer attached to a CLOD ranged from 100 nm to 10 μm. The thickness of the active layer ranged from 20 to 140 μm. The dose ratio between the active layer of the Au-coated CLOD and a CLOD without a layer, i.e., the dose enhancement factor (DEF), was calculated.
RESULTS: The DEFs of the first 20-μm thick active layer of the 5-μm thick Au-coated CLOD were 18.4, 19.7, 20.2 at 80, 120, and 140 kVp, respectively. The DEFs decreased as the thickness of the active layer increased. The DEFs of 100-nm to 5-μm thick Au layers increased from 1.7 to 5.4 for 120-kVp X-ray tube voltage when the thickness of the active layer was 140 μm.
CONCLUSIONS: The MC results presented a higher sensitivity of Au-coated CLODs (∼20-times higher than that of CLODs without a gold layer). Au-coated CLODs can be applied to an evaluation of very low doses (a few cGy) delivered to patients during CT imaging.
摘要：
目的：本研究报告了金涂层隐形眼镜型眼体内剂量计（CLOD）在计算机断层扫描（CT）中低剂量测量的敏感性增强。
方法：进行蒙特卡罗（MC）模拟以评估CLOD上的金（Au）层的剂量增强。对人眼和CLODs进行了建模，并且X射线管电压被定义为80、120和140kVp。附着于CLOD的Au层的厚度为100nm至10μm。活性层的厚度为20至140μm。Au涂覆的CLOD的活性层与没有层的CLOD之间的剂量比，即，剂量增强因子（DEF），已计算。
结果：在80、120和140kVp下，5μm厚的Au涂层CLOD的第一个20μm厚的活性层的DEF分别为18.4、19.7、20.2，分别。DEF随着活性层厚度的增加而降低。当活性层的厚度为140μm时，对于120kVpX射线管电压，100nm至5μm厚的Au层的DEF从1.7增加到5.4。
结论：MC结果显示，Au涂层的CLODs具有更高的灵敏度（比没有金层的CLODs高出约20倍）。Au涂层的CLODs可用于评估在CT成像期间递送至患者的极低剂量(几个cGy)。
方法：进行蒙特卡罗（MC）模拟以评估CLOD上的金（Au）层的剂量增强。对人眼和CLODs进行了建模，并且X射线管电压被定义为80、120和140kVp。附着于CLOD的Au层的厚度为100nm至10μm。活性层的厚度为20至140μm。Au涂覆的CLOD的活性层与没有层的CLOD之间的剂量比，即，剂量增强因子（DEF），已计算。
结果：在80、120和140kVp下，5μm厚的Au涂层CLOD的第一个20μm厚的活性层的DEF分别为18.4、19.7、20.2，分别。DEF随着活性层厚度的增加而降低。当活性层的厚度为140μm时，对于120kVpX射线管电压，100nm至5μm厚的Au层的DEF从1.7增加到5.4。
结论：MC结果显示，Au涂层的CLODs具有更高的灵敏度（比没有金层的CLODs高出约20倍）。Au涂层的CLODs可用于评估在CT成像期间递送至患者的极低剂量(几个cGy)。
