Watanabe Hiroshi, Konno Masaya, Fujita Yuka, Kurihara Sho, Todokoro Kana, Hagiwara Miki, Yamamoto Kazuyuki, Sakamoto Hajime, Takenaka Mamoru, Hosono Makoto
School of Radiological Sciences, Faculty of Health Sciences, Gunma Paz University (Current address: Department of Radiological Sciences, Faculty of Medical Technology, Gunma Paz University).
Graduate School of Health Sciences, Gunma Paz University.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2022 Apr 20;78(4):364-371. doi: 10.6009/jjrt.2022-1149. Epub 2022 Mar 15.
In the revised Regulation on Prevention of Ionizing Radiation Hazards (April 2020), the equivalent dose limit for the lens of the eye was lowered to "100 mSv in 5 years and 50 mSv in 1 year." It is necessary to reduce occupational exposure in the healthcare sector. The purpose of this study was to facilitate comparison with the equivalent dose limit in an endoscopic retrograde cholangiopancreatography (ERCP) examination by measuring the scattered dose in an X-ray room as an individual dose equivalent.
The scattered dose was measured by dosimeters positioned in a grid pattern in the X-ray room. The dose rate was measured with and without the use of a protective cloth (0.25 mm Pb equivalent) suspended around the X-ray tube extending to the patient. The dose reduction rate of the material was evaluated during the simulated ERCP.
The maximum dose rate at the position of the surgeon performing an ERCP inspection in the standing position was 2.9 mSv/h (3 mm dose equivalent rate) at 150 cm from the ground. The number of ERCP examinations to comply with the equivalent dose limit of the equivalent dose of the lens of the eye without the protective cloth was 28 per year.
The results of this study suggest that individual dose equivalent measurements in the X-ray clinic may facilitate comparison with the equivalent dose limit.
在修订后的《电离辐射危害预防条例》（2020年4月）中，眼部晶状体的当量剂量限值降低至“5年内100 mSv，1年内50 mSv”。有必要减少医疗保健部门的职业照射。本研究的目的是通过测量X射线室内的散射剂量作为个人剂量当量，以便于与内镜逆行胰胆管造影（ERCP）检查中的当量剂量限值进行比较。
通过将剂量计以网格模式放置在X射线室内来测量散射剂量。在使用和不使用围绕X射线管延伸至患者的防护布（0.25 mm铅当量）的情况下测量剂量率。在模拟ERCP期间评估该材料的剂量降低率。
在距地面150 cm处，站立位进行ERCP检查的外科医生位置处的最大剂量率为2.9 mSv/h（3 mm剂量当量率）。在不使用防护布的情况下，符合眼部晶状体当量剂量当量剂量限值的ERCP检查次数为每年28次。
本研究结果表明，在X射线诊所进行个人剂量当量测量可能便于与当量剂量限值进行比较。
