Bulletin of Faculty of Health Sciences Okayama University Medical School
Published by Faculty of Health Sciences Okayama University Medical School

<Formerly known as>
岡山大学医療技術短期大学部紀要 (1巻-9巻)

ブートストラップセンシトメトリー用ステップウェッジの開発

Yoshida, Akira
Kobashi, Toshimi
Ohkawa, Yoshihiro
Mikami, Yasutaka
Hiraki, Yoshio
Yamada, Toshiharu
Sugita, Katsuhiko
Abstract
A new stepwedge has been developed for bootstrap sensitometry, which is used for determining the characteristic curve of radiographic screen/film systems. Since each step of the stepwedge is separated by the lead septum, flare generated under one step will not penetrate the region of another step. The metal of the stepwedge can be changed with various materials. Characteristic curves obtained with new stepwedge bootstrap (NSB) and conventional stepwedge bootstrap (CSB) techniques were compared with those obtained for screen/film systems with inverse sqare sensitometry. The inverse square method was used as the reference standard for accuracy. The NSB method provided characteristic curves that agreed well with those obtained using the inverse square method. The slope of the curve in the CSB method was lower than that in the inverse square or NBS method, because of scatter radiation. The shape of the characteristic curve from the NSB method did not vary with the materials of step metals (aluminum and copper). The cumulative error involved when using the bootstrap method is also discussed.
Keywords
Stepwedge
Bootstrap
Characteristic curves
Sensitometry
Radiographic screen/film systems
ISSN
0917-4494
NCID
AN10355371