Visualization of scattered X-rays sources using a pinhole camera in general radiography, computed tomography examinations, and interventional radiology

• Published in: 日本放射線看護学会誌 Vol. 12; no. 2; pp. 44 - 53
• Main Authors: Osanai Minoru, Tamura Rina, Tanaka Chihiro, Mikami Hazuki, Noro Tomuhiro, Kudo Kohsei, Hosokawa Shota, Tsushima Megumi, Yamaguchi Ichiro, Hosoda Masahiro, Saito Yoko
• Format: Journal Article
• Language: Japanese
• Published: 日本放射線看護学会 31.12.2024; The Radiological Nursing Society of japan
• Subjects: occupational radiation exposure; pinhole camera; radiation education; radiation protection; scattered X-ray; ピンホールカメラ; 放射線教育; 放射線防護; 散乱X線; 職業被ばく
• ISSN: 2187-6460; 2433-5649
• DOI: 10.24680/rnsj.24-002

With the reduction of the equivalent dose limit to the lens of the eye, effective management of occupational radiation exposure is imperative. This study, as one of the approaches to radiation visualization based on actual measurements, conducted a phantom study using a self-made lead pinhole camera to identify the source of scattered X-rays in general radiography, computed tomography (CT) examinations, and interventional radiology procedures. The aim is to obtain materials to optimize protection against scattered X-rays. In addition to patient phantoms, considerable X-rays were found to emanate from equipment components such as the diaphragm cover of the X-ray tube, bed, and mylar ring (the window of the gantry aperture) of the CT equipment. Recommendations include implementing more appropriate protective measures, such as improving the standing position of medical staff and adjusting how protective shield is used. Future research will quantify the pinhole image and develop the real-time visualization of pinhole images. 眼の水晶体の等価線量限度が引き下げられた現在、職業被ばく管理の適正化が求められている。本研究では、実測に基づく放射線可視化のアプローチのひとつとして、単純X線撮影、コンピュータ断層撮影（computed tomography: CT）検査、画像下治療（interventional radiology: IVR）を対象とし、自作の鉛製ピンホールカメラによるファントム実験にて散乱X線の発生源を特定し、散乱X線に対する防護の最適化に資する知見を収集することを目的とした。患者ファントムに加え、X線管の可動絞りカバーや寝台、CT装置のマイラリング（ガントリ開口部の窓）といった装置の構成パーツからも無視できない散乱X線が発生していることが明らかとなった。医療スタッフの立ち位置や防護板の使用方法の改善といった、より適切な防護策の検討が望まれる。今後はピンホール画像の定量化やリアルタイム化に向けて取り組みたい。