TY - JOUR
T1 - Gemstone spectral imaging
T2 - Determination of CT to ED conversion curves for radiotherapy treatment planning
AU - Yagi, Masashi
AU - Ueguchi, Takashi
AU - Koizumi, Masahiko
AU - Ogata, Toshiyuki
AU - Yamada, Sachiko
AU - Takahashi, Yutaka
AU - Sumida, Iori
AU - Akino, Yuichi
AU - Konishi, Koji
AU - Isohashi, Fumiaki
AU - Tomiyama, Noriyuki
AU - Yoshioka, Yasuo
AU - Ogawa, Kazuhiko
PY - 2013
Y1 - 2013
N2 - The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the monochromatic image might be applied to radiotherapy treatment planning (RTP) to calculate dose distribution more accurately. Our goal here was to provide CT to electron density (ED) conversion curves with monochromatic images for RTP. Therefore, we assessed the reproducibility of CT numbers, an important factor on quality assurance, over short and long time periods for different substances at varying energy. CT number difference between measured and theoretical value was investigated. The scanner provided sufficient reproducibility of CT numbers for dose calculation over short and long time periods. The CT numbers of monochromatic images produced by this scanner had reasonable values for dose calculation. The CT to ED conversion curve becomes linear with respect to the relationship between CT numbers and EDs as the energy increases. We conclude that monochromatic imaging from a fast switching system can be applied for the dose calculation, keeping Hounsfield units (HU) stability.
AB - The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the monochromatic image might be applied to radiotherapy treatment planning (RTP) to calculate dose distribution more accurately. Our goal here was to provide CT to electron density (ED) conversion curves with monochromatic images for RTP. Therefore, we assessed the reproducibility of CT numbers, an important factor on quality assurance, over short and long time periods for different substances at varying energy. CT number difference between measured and theoretical value was investigated. The scanner provided sufficient reproducibility of CT numbers for dose calculation over short and long time periods. The CT numbers of monochromatic images produced by this scanner had reasonable values for dose calculation. The CT to ED conversion curve becomes linear with respect to the relationship between CT numbers and EDs as the energy increases. We conclude that monochromatic imaging from a fast switching system can be applied for the dose calculation, keeping Hounsfield units (HU) stability.
KW - CT to ED conversion curve
KW - Dual-energy CT
KW - Gemstone spectral imaging
KW - Monochromatic image
KW - Radiotherapy treatment planning
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U2 - 10.1120/jacmp.v14i5.4335
DO - 10.1120/jacmp.v14i5.4335
M3 - Article
C2 - 24036870
AN - SCOPUS:84884135591
SN - 1526-9914
VL - 14
SP - 173
EP - 186
JO - Journal of Applied Clinical Medical Physics
JF - Journal of Applied Clinical Medical Physics
IS - 5
ER -