| Project/Area Number |
05557045
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| Research Category |
Grant-in-Aid for Developmental 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 | Kitami Institute of Technology |
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Principal Investigator |
SUZUKI Shigehito Kitami Institute of Technology, Engineering, Professor, 工学部, 教授 (50179214)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Kazuo Hokkaido University School of Medicine, Associate Professor, 医学部, 助教授 (40111166)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | SPECT / Attenuation and scatter correction / Nonunifrom medium |
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| Research Abstract |
1. Design of algorithm for nonunifrom attenuation correction in SPECT using x-ray CT image data
(1) Construction of the algorithm.Three kinds of the algorithm were constructed which are based on three methods reported by Chang, Tanaka, and Singh.The first two had originally been proposed for uniform attenuation correction, but in the algorithm they were modified for nonunifrom attenuation correction.From computer experiments, it was found that their first-order correction did not produce good correction results, but their second-order correction gave satisfactory resulsts only with a single iteration.
(2) Problems in clinical applications.Two major problems were found : the coincidence of anatomical positions between XCT image and the corresponding uncorrected image for SPECT,and the determination of average X-ray energy for the XCT image.This information is used when converting attenuation data for XCT to those attenuation for SPECT.A solution for the problems is the key to accurate attenuation correction in clinical applications.
2. Scatter correction
A theoretical evaluation of scattered radiation in detected photons was planned primarily, but its application to individual SPECT images was not practical in computation time.It was concluded that a practically promising method for accurate scatter correction is to evaluate scattered radiation from photon counts detected with plural energy windows.More detailed studies of this subject are being carried out.
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