2026-03-06T18:52:55Z https://kanazawa-u.repo.nii.ac.jp/oai

oai:kanazawa-u.repo.nii.ac.jp:00013769 2024-06-27T01:20:28Z 4281:4291:4312

アジア圏で開催される国際学会での研究発表のススメ Tanaka, Rie 40361985 田中, 利恵 Purpose: This study was performed to develop a computerized method to optimize imaging conditions and image quality based on simulation images. We tried to develop a prototype system and ensure consistency between the resulting images and actual images obtained using a digital X-ray imaging system. Methods and Materials: An RQA5 X-ray spectrum was used for determination of input-output characteristic and noise power spectrum (NPS) in an indirect-type flat-panel detector (FPD) system. The relationship between tube current-time product (mAs), exposure dose at the detector surface, and pixel values of images was addressed and a conversion function was then created. The incident quantum numbers determined from the conversion function were input into random values generator and image noise was simulated. Simulation images provided at different noise levels were compared with the actual images provided by use of the FPD system, objectively and subjectively. Results: Average NPS of actual image in each dose level were 5.39×10－6，6.77×10－6, and 3.46×10－5 and those of simulation image were 1.10×10－6, 4.53×10－6, and 4.41×10－5, respectively. In observers study, both images showed almost the same signal detectability which decreased with decreasing exposure dose. It was confirmed that image noise was simulate almost properly. Conclusions: The present system could allow us to estimate necessary dose from image quality and also to estimate image quality from exposure dose. These results suggested that appropriate exposure dose could be determined based on necessary image quality using the simulation images. Japanese Society of Radiological Technology = 日本放射線技術学会 2012-01-01 2017-10-03 jpn journal article VoR https://doi.org/10.24517/00013756 http://hdl.handle.net/2297/31987 https://kanazawa-u.repo.nii.ac.jp/records/13769 10.24517/00013756 10.6009/jjrt.2012_JSRT_68.2.179 http://www.jsrt.or.jp/ https://www.jstage.jst.go.jp/article/jjrt/68/2/68_2_179/_article/-char/ja/ 1881-4883 日本放射線技術学会雑誌 Nihon Hoshasen Gijutsu Gakkai zasshi 68 2 179 180 https://kanazawa-u.repo.nii.ac.jp/record/13769/files/ME-PR-TANAKA-R-68_179.pdf application/pdf 579.1 kB 2017-10-03