@article{oai:repo.qst.go.jp:00043258,
 author = {Tsunoo, Takanori and Torikoshi, Masami and Sasaki, Makoto and Endo, Masahiro and Yagi, Naoto and Uesugi, Kentaro and 角尾 卓紀 and 取越 正己 and 佐々木 誠 and 遠藤 真広},
 issue = {5},
 journal = {IEEE Transactions on Nuclear Science},
 month = {Oct},
 note = {Knowledge of electron densities for materials is important for treatment planning for proton and heavier-ion radiotherapy. In order to obtain the electron densities with high precision, we have developed dual-energy x-ray computed tomography using synchrotron radiation. Two monochromatic x-rays with different energies generated from synchrotron radiation enables tomographic imaging which produces a cross sectional image based on electron density plus an additional image based on effective atomic number. Experiments for the dual-energy x-ray CT were made on the BL20B2 beamline at SPring-8. An image intensifier system and a CCD camera were used as the 2D detectors. The measured electron densities were agreement to within 2 % of the theoretical ones. Electron density and effective atomic number provide different contrast in images. Dual-energy x-ray CT can be used for quantitative measurement of the material.},
 pages = {1678--1682},
 title = {Distribution of Electron Density Using Dual-Energy X-Ray CT},
 volume = {50},
 year = {2003}
}