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Measurement of electron density in dual-energy x-ray CT with monochromatic x rays and evaluation of its accuracy
https://repo.qst.go.jp/records/45458
https://repo.qst.go.jp/records/45458df3946ab-d5bd-4914-b6e4-3e10c8e9ae67
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2009-03-26 | |||||
| タイトル | ||||||
| タイトル | Measurement of electron density in dual-energy x-ray CT with monochromatic x rays and evaluation of its accuracy | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Tsunoo, Takanori
× Tsunoo, Takanori× Torikoshi, Masami× Ohno, Yumiko× Uesugi, Kentaro× Yagi, Naoto× 角尾 卓紀× 取越 正己× 大野 由美子 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Information on electron density is important for radiotherapy treatment planning in order to optimize the dose distribution in the target volume of a patient. At present, the electron density is derived from a computed tomography (CT) number measured in x-ray CT scanning; however, there are uncertainties due to the beam hardening effect and the method by which the electron density is converted from the CT number. In order to measure the electron density with an accuracy of +-1%, the authors have developed dual-energy x ray CT using monochromatic x rays. They experimentally proved that the measured linear attenuation coefficients were only a few percent lower than the theoretical ones, which led to an accuracy within 2% for the electron density. There were three factors causing inaccuracy in the linear attenuation coefficient and the electron density: the influence of scattered radiation, the nonlinearity in the detector response function, and a theoretical process to derive the electron density from the linear attenuation coefficients. The linear attenuation coefficients of water were experimentally proved to differ by 1 - 2 % from the theoretical one even when the scattering effect was negligible. The nonlinearity of the response function played an important role in correcting the difference in the linear attenuation coefficient. Furthermore, the theoretical process used for deriving the electron density from the linear attenuation coefficients introduces about 0.6% deviation from the theoretical value into the resultant electron density. This deviation occurs systematically so that it can be corrected. The authors measured the electron densities for seven samples equivalent to soft tissue in dual-energy x-ray CT, and finally obtained them with an accuracy of around +-1%. |
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| 書誌情報 |
Medical Physics 巻 35, 号 11, p. 4924-4932, 発行日 2008-11 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0094-2405 | |||||
