title: Effect of X-ray beam quality on determination of exposure index.
abstract: We investigated the effect of X-ray beam qualities RQA3, 5, 7, and 9 on the exposure index (EI) as defined by International Electrotechnical Commission guideline 62494-1. Half-value layers (HVLs) of RQA5 X-rays passing through anti-scatter grids (grid ratios 6:1, 8:1, 10:1, and 12:1) were also evaluated because grids are frequently used in clinical situations. The maximum percent differences in the EIs for RQA3, 7, and 9 with respect to RQA5 were 35.0, 11.6, and 38.7 %, respectively. The range of HVLs for RQA5-7 beams was 7.10-9.10 mm of aluminum (mm Al). This was wider than the range of HVLs when grids were used (6.94-7.29 mm Al). The effect of variations in X-ray beam qualities in the RQA series on the EI was significantly greater than the effect of grids. This study indicated that, in clinical settings, the EI should be used carefully in X-ray examinations with different X-ray beam qualities.
authors.affiliation: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. shogo.yasumatsu@gmail.com.
authors.forename: Shogo
authors.initials: S
authors.lastname: Yasumatsu
authors.affiliation: Department of Radiological Science, Faculty of Health Sciences, Junshin Gakuen University, 1-1-1 Chikushigaoka, Minami-ku, Fukuoka, 815-8510, Japan.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Tanaka
authors.affiliation: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Iwase
authors.affiliation: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Morishita
mesh_terms: D004781:Environmental Exposure / Q000032:analysis*; D011786:Quality Control; D011856:Radiographic Image Enhancement; D012542:Scattering, Radiation; D014965:X-Rays
keywords: Anti-scatter grid; Computed radiography; Digital radiography; Exposure index; X-ray beam quality