Study on non-uniformity correction of the Gafchromic film and three-dimensional measurement of CT

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K10380
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Osaka Butsuryo University
• Principal Investigator: Katsuda Toshizo 大阪物療大学, 保健医療学部, 教授 (40379722)
• Co-Investigator(Kenkyū-buntansha): 野口 敦司 大阪物療大学, 保健医療学部, 教授 (10716202) ; 丹喜 信義 大阪物療大学, 保健医療学部, 助教 (60441573)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: エックス線 / CT / 線量計測 / ラジオクロミックフィルム

Outline of Final Research Achievements

The correction method of an uncertainty at low-dose range and non-uniformity error have been developed for three-dimensional X-ray CT dosimetry using a film-type dosimeter. The density equivalent to the beginning of the linear portion of the density-dose curve was used as the base density, and the uncertainty line portion of 2 to 10 mGy was corrected. In addition, double exposure method using ultraviolet rays for correcting non-uniformity error. In this film type dosimeter, the density increases in the white LED. Based on the principle of white LEDs, it was divided into yellow and blue, and it was clarified that the influence of blue light with a wavelength of 410 nm, which is almost the wavelength of ultraviolet light, is strong. In addition, for the creation of the three-dimensional dose distribution map, the two-dimensional plane dose distribution was rotated to create an image of the cross section of the virtual three-dimensional dose distribution.

Free Research Field

放射線科学

Academic Significance and Societal Importance of the Research Achievements

X線CTの線量分布の把握は困難である．3次元的かつ連続的に変化するX線量を高分解で把握することは新たな計測方法の開発として学術的な意義がある．特に最近多くの施設で行われている一度に広い範囲を検査できる検査方法についての線量計測法は現状の方法では大変困難が伴う．しかし，本方法では検査領域の広さにとらわれず，どのような場合においても線量計測が簡便にできるという学術的な意義がある．
また，現状では実際のX線量が把握でき，撮影方法の工夫や新たな方法の開発によって線量を低減させることも可能となることで社会的意義がある．