title: [New method of measuring effective energy using copper-pipe absorbers in X-ray CT].
abstract: The general method of measuring the half-value layer (HVL) for X-ray computed tomography (CT) using square aluminum-sheet filters is inconvenient in that the X-ray tube has to be set to stationary mode. To avoid this inconvenience, we investigated a new method using copper-pipe filters that cover the ionization chamber (copper-pipe method). Using this method, the HVL can be measured at the isocenter in the rotation modes of CT. We examined the accuracy and reproducibility of the copper-pipe method compared with those of the general method. The effective energy measured using the copper-pipe method correlated well with the general method (y=1.064x, r=0.987), and its error was 1.81±1.38%. The results indicate that the copper-pipe method enables accurate measurement of the effective energy of X-ray CT and is a convenient method suited to all general X-ray equipment as well as all X-ray CT.
authors.affiliation: Department of Radiology, Kanazawa University Hospital.
authors.forename: Hiroji
authors.initials: H
authors.lastname: Iida
authors.forename: Kimiya
authors.initials: K
authors.lastname: Noto
authors.forename: Wataru
authors.initials: W
authors.lastname: Mitsui
authors.forename: Tadanori
authors.initials: T
authors.lastname: Takata
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Kousuke
authors.initials: K
authors.lastname: Matsubara
mesh_terms: D003300:Copper; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
chemical_list: D003300:Copper