@misc{oai:repo.qst.go.jp:00067455,
 author = {Tsunoo, Takanori and Torikoshi, Masami and Endo, Masahiro and Natsuhori, Masahiro and Kakizaki, Takehiko and Yamada, Naoaki and Ito, Nobuhiko and Uesugi, Kentaro and Yagi, Naoto and Hyoudou, Kazuyuki and 角尾 卓紀 and 取越 正己 and 遠藤 真広 and 夏堀 雅宏 and 柿崎 竹彦 and 山田 直明 and 伊藤 伸彦 and 兵藤 一行},
 month = {Aug},
 note = {The electron density is one of the most important element for the
treatment planning in the radiotherapy, because this information is
used for the range estimation of the heavy-ion beam. Although the
electron density has been converted from CT number obtained by
conventional x-ray computed tomography(CT) at present, it is not
enough for the more detailed planning due to uncertainties that arise
from the beam hardening effect and the conversion process. In order to
take more accurate electron density, we have developed the dual-energy
x-ray CT system using the synchrotron radiation. The dual-energy x-ray
CT has no influence of the beam hardening because of scanning using
monochromatic x-rays. The experiments were carried out using two
monochromatic x-rays at the monochromatic beam-lines in KEK-AR and
SPring-8. As the result, it was succeeded that the electron densities
by the dual-energy x-ray CT were agreement with the theoretical values
with the accuracy less than 1% for some materials. In addition, as the
application for more practical use in diagnostics, the CT using the
mixture of main and harmonics x-rays produced by the monochromator has
been investigated. From the preliminary experiments, it was found that
the accuracy was as same as that by dual-energy x-ray CT. We will
describe the dual-energy x-ray CT system and discuss the
quantitativity and the image characteristic for this system., Eighth International Conference on Synchrotron Radiation Instrumentation},
 title = {Study on Dual-Energy X-ray Computed Tomography using Synchrotron Radiation},
 year = {2003}
}