title: [New method of estimating effective energy for X-ray CT scanners].
abstract: Because the exposure dose in X-ray computed tomography examinations is sometimes difficult to determine, it is important to be able to estimate the dose for these examinations. The effective energy of the X-ray CT scanner is required to estimate exposure dose. Although the half-value-layer (HVL) method has been used to calculate effective energy, it is not an easy method. This paper proposes a technique by which effective energy can be easily calculated. Certain details were found to cause change in effective energy, and the ratio (inner-metal center-air ratio: IMCAR) between air dose and dose in fixing the metallic pipe in the isocenter of an X-ray CT scanner was necessary. The IMCAR from a different X-ray CT scanner was required, and, when effective energy was calculated, it showed an error of less than 0.7% for the half-value-layer method. The effect of this error on dose estimation was slight (0.4%). This technique is useful, because effective energy can easily be calculated with a high degree of accuracy.
authors.affiliation: Department of Clinical Radiology, Gunma Prefectural College of Health Sciences.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nagashima
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sunaga
authors.forename: Toyohisa
authors.initials: T
authors.lastname: Mitome
authors.forename: Eiichi
authors.initials: E
authors.lastname: Koya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takei
authors.forename: Kunio
authors.initials: K
authors.lastname: Matsubara
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ogura
authors.forename: Akihisa
authors.initials: A
authors.lastname: Shiraishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimosegawa
authors.forename: Masao
authors.initials: M
authors.lastname: Hoshina
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Igarashi
mesh_terms: D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*