| Project/Area Number |
03454285
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | Keio University, School of Medicine |
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Principal Investigator |
KUBO Atsushi Keio Univ., School of Med., Dept. of Radiology, Assoc. Prof., 医学部, 助教授 (90051771)
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| Co-Investigator(Kenkyū-buntansha) |
OGAWA Koichi Hosei Univ., College of Eng., Dept. of EE., Assoc. Prof., 工学部, 助教授 (00158817)
TSUKATANI Yasushi Keio Univ., School of Med., Dept. of Radiology, Instructor, 医学部, 助手 (60197647)
NAKAMURA Kayoko Keio Univ., School of Med., Dept. of Radiology, Assist. Prof., 医学部, 専任講師 (20124480)
NAKAJIMA Masato Keio Univ., Faculty of Sci. and Eng., Dept. of EE., Professor, 理工学部, 教授 (20051766)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1991: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | Compton scatter / Scatter Correction / Single Photon Emission CT / Image Processing / Monte Carlo method / Energy window / エネルギ-ウィンドウ |
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| Research Abstract |
The study was carried out to reconstruct a quantitative SPECT image by eliminating the counts of scattered photons from a planar image. We have developed a new scatter correction method considering the local scatter fraction of the planar image. In this method, the count data are acquired at each pixel by using three windows: a main window centered at photopeak energy and two subwindows on both sides of the main window. The scattered photons included in the main window are estimated as a trapezoidal region shaped by the counts of the subwindows and the width of the main window. By subtracting the count of those photons from that acquired with the main window, the count of the primary photons can be estimated for each pixel. The method was evaluated by a Monte Carlo simulation using numerical phantoms. The simulation tests showed good agreement between the activity distributions reconstructed from unscattered photons and those reconstructed from corrected data by the proposed method. Then we made phantom studies and preliminary clinical studies using a commercially available gammacamera system (Toshiba GCA-9300A) equipped with special hardware. In the clinical studies we used a new Tc-99m myocardial perfusion imaging agent (P-53). These results showed that quantitative measurement of activity in clinical study is possible without adding data acquisition/processing time.The method is also applicable to conventional scintigrams and to multi-photopeak radionuclide studies.
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