Imaging plate as a dosimeter for estimating ambient dose equivalent of scattered radiations and skin dose of patients in interventional radiology procedures

将成像板(IP)应用于被动剂量计，用于测量高水平X射线辐射，然后估算患者的皮肤剂量和介入放射学(IR)中散射辐射的环境剂量当量。主要研究成果如下：1.发展了彩色玻璃纸和退火法测量高剂量X射线辐射的两种新技术。这些技术可以将BAS-TR线性度的动态范围和上限分别扩展到102GY和10GY。2.在60~120KV的管电压下，用X射线照射BAS-TR线性度，研究了BAS-TR的特性。观察到灵敏度的变化在13%到33%之间，尽管它随X射线装置的类型而变化。为了准确估计X射线辐射剂量，需要在红外过程中获得平均电压。在除-90°或+90°外的任何管电压下，入射角度变化在±75°范围内均未观察到显著差异。3.在临床研究中，通过使用紧身衣在患者背部安装一大片IP来测量入射皮肤剂量(ESD)，这减小了IP与患者身体之间的剂量估计的几何差异。并与光致发光玻璃剂量计(PLD)芯片的ESD进行了比较。在所有剂量范围内，两种剂量显示出一致性，然而，使用PLD芯片获得的剂量始终低于使用IP获得的剂量。这是由于PLD芯片的角度相关性引起的灵敏度变化。4.通过BAS-MS在不同金属滤光片上测量的灵敏度数据，获得了平坦的剂量当量能量响应。环境剂量当量可以通过使用平坦响应来评估，而不需要知道散射光子辐射的有效能量。

Imaging plates (IPs) were applied to a passive dosimeter for measuring high level X-ray radiation and, then, estimating skin dose of patients and ambient dose equivalent of scattered radiations in interventional radiology (IR) procedures. Results were obtained as follows.1.Two new techniques of using color cellophane and annealing to measure high dose X-ray radiation have been developed. These techniques can extend the dynamic range and upper limit of a linearity of BAS-TR up to 10^2 Gy and 10 Gy, respectively.2.BAS-TR's characteristics were investigated by irradiating X-ray for tube voltages of 60 to 120 kV, which are used in IR procedures. Sensitivity variations of from 13 to 33% was observed, though it changed according to types of X-ray unit. To estimate doses of X-ray radiation accurately, an average tuve voltage should be obtained during IR procedures. The significant difference according to angular changes of incidences was not observed up to ±75° at any tube voltages except -90° or +90°.3.An entrance skin dose (ESD) was measured in clinical studies by fitting a large sheet of IPs around a patient's back using a corset, which lessens a geometric discrepancy in dose estimate between IP and the patient body. The ESD obtained by IPs was compared with that obtained by a photoluminescence glass dosemeter (PLD) chip. Both doses show agreement, overall in all dose range, however, the doses obtained with the PLD chips were consistently lower than those obtained with the IPs. It comes from a sensitivity variation caused by an angular dependence of the PLD chip.4.A flat energy response to the dose equivalent was obtained by the sensitivity data measured under different metal filters attached BAS-MS. The ambient dose equivalent can be evaluated by using a flat response, without requiring knowledge of the effective energies of scattered photon radiations.