An in-phantom dosimetry system using pin silicon photodiode radiation sensors for measuring organ doses in x-ray CT and other diagnostic radiology.
An in-phantom dosimetry system using pin silicon photodiode radiation sensors for measuring organ doses in x-ray CT and other diagnostic radiology.
复制标题
一种使用针硅光电二极管辐射传感器的体模剂量测定系统，用于测量 X 射线 CT 和其他诊断放射学中的器官剂量。
DOI：
10.1118/1.1489042
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发表时间：
2002
期刊：
影响因子：
3.8
通讯作者：
C. Kawaura
中科院分区：
文献类型：
--
作者：
T. Aoyama;S. Koyama;C. Kawaura
使用商用 pin 硅光电二极管作为传感器的剂量测定系统，用于 X 射线 CT 和其他诊断放射学中的体模剂量测量。在 23.5 至 72 keV 的有效能量范围内，作为 X 射线有效能量的函数测量的系统灵敏度在 0.37 至 0.49 V/mGy 之间。不确定度为 25% 的最小可检测器官剂量估计为 0.02 mGy。在 0.03 至超过 10 mGy 的剂量范围内具有出色的输出线性度，系统灵敏度的平坦剂量率响应高达 35 mGy s(-1)，但灵敏度表明在整个诊断能量范围内存在一定的能量依赖性，最大值约为 10%/10 keV。由于光电二极管传感器灵敏度的角度依赖性足够小，因此引起的剂量误差可以忽略不计。沿接受 CT 胸部检查的胸部体模轴的剂量分布测量表明，剂量值在小于 0.2 至 12 mGy 的两个数量级范围内的可靠性。本剂量测定系统具有灵敏度高、可立即读出剂量值、成本低且易于构造等优点，将广泛用作 TLD 剂量计的替代品，用于 CT 和其他诊断放射学中的器官和皮肤剂量测量。
A dosimetry system using commercially available pin silicon photodiodes as the sensor is evaluated for in-phantom dose measurements in x-ray CT and other diagnostic radiology. System sensitivity measured as a function of the effective energy of x rays was between 0.37 and 0.49 V/mGy at an effective energy range between 23.5 and 72 keV. The minimum detectable organ dose with 25% uncertainty was estimated to be 0.02 mGy. The excellent output linearity was found over a dose range from 0.03 to more than 10 mGy with flat dose rate response of system sensitivity up to 35 mGy s(-1), though the sensitivity indicated some energy dependence across the diagnostic energy range with a maximum of about 10%/10 keV. Since angular dependence of the sensitivity of the photodiode sensor was found to be small enough it would induce negligible dose error. Dose profile measurement along the axis of a thoracic phantom undergoing CT chest examination indicated the reliability of dose values over a range of two orders of magnitude from less than 0.2 to 12 mGy. The present dosimetry system having advantages of high sensitivity with immediate readout of dose values, low cost, and easy construction would widely be used as an alternative to TLD dosimeters for organ and skin dose measurements in CT and other diagnostic radiology.