使用紫外线预先照射来提高使用 Gafchromic RTQA2 胶片进行低剂量 CT 测量的准确性。

USE OF ULTRAVIOLET RAY PRE-IRRADIATION TO IMPROVE THE ACCURACY OF LOW-DOSE MEASUREMENTS OF THE CT USING A GAFCHROMIC RTQA2 FILM.

机构信息

Medical Radiation Technology, Shizuoka College of Medicalcare Science, 2000, Hirakuchi, Hamakita-ku, Hamamatsu-city, Shizuoka 434-0041, Japan.

Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Okayama 702-0193, Japan.

出版信息

Radiat Prot Dosimetry. 2021 Aug 14;195(1):61-68. doi: 10.1093/rpd/ncab115.

DOI:10.1093/rpd/ncab115

PMID:34341820

Abstract

The purpose of this study is to develop a method for use at extremely low-dose ranges and to decrease the uncertainty outside the recommended range of Gafchromic RTQA2 (RTQA2). By this method, the CT dose including the scattered radiation region can be grasped. The base density was increased by ultraviolet (UV)-ray preirradiation. RTQA2 was irradiated with UV-A rays for 26 and 40 h. Subsequently, RTQA2 was exposed to 2, 4, 6, 8, 10, 25, 50, 75, 100, 150, 200 and 250 mGy X-rays using a segmentation method. Calibration curves with and without UV-A irradiation were compared. The calibration curve with 40-h UV-A ray irradiation was the most linear, and a steeper slope area was not observed. The uncertainty in the calibration curve was reduced (p < 0.05). UV-A ray irradiation is an effective method for treating RTQA2; the accuracy in the extremely low-dose range of RTQA2 was improved.

摘要

本研究旨在开发一种在极低剂量范围内使用的方法，并降低 Gafchromic RTQA2（RTQA2）推荐范围外的不确定性。通过这种方法，可以掌握包括散射辐射区域在内的 CT 剂量。通过紫外线（UV）预辐照增加基本密度。将 RTQA2 用 UV-A 射线辐照 26 和 40 小时。随后，使用分段法将 RTQA2 暴露于 2、4、6、8、10、25、50、75、100、150、200 和 250 mGy X 射线下。比较了有和没有 UV-A 辐照的校准曲线。经过 40 小时 UV-A 射线辐照的校准曲线最线性，并且没有观察到斜率更陡的区域。校准曲线的不确定性降低（p < 0.05）。UV-A 射线辐照是处理 RTQA2 的有效方法；提高了 RTQA2 在极低剂量范围内的准确性。