| Project/Area Number |
06670913
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | Shinshu University |
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Principal Investigator |
AOKI Jun Shinshu University, School of Medicine, Associate Professor, 医学部・放射線医学, 講師 (80212364)
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| Co-Investigator(Kenkyū-buntansha) |
KORAKIDA Osamu Shinshu University Hospital, Assistant Professor, 医学部附属病院・中央放射線部, 助手 (50233995)
TAKIZAWA Masaomi Shinshu University, School of Medicine, Assistant Professor, 医学部・放射線医学, 助手 (40101159)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Imaging diagnosis / Image processing / Bone tumors / Biomechanics |
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| Research Abstract |
Bone has a potency to alter its shape and internal architecture in response to mechanical stress externally loaded on it (Wolffs law) . We have developed a semi-quantitative method to assess this adaptation ability of bone on plain radiographs using a personal computer, in an attempt to utilize this phenomenon to differentiate benign bone lesions from malignant bone tumors.
Seventeen normal controls, six nonossifying fibromas, four bone systs and five bone metastases in the femur were analyzed by the following method. Plain radiographs were digitized with 200 microns sampling quantization and 10 bit depth, and the digitized data were stored in an optical disc system. Within a ROI (10x10-20 cm) on the digitized images displayd on a CRT monitor screen, detection of cortical surfaces, subtraction of soft tissue density, and decision of middle points of bone density (gravity points) on all transaxial lines of the femur were automatically done through multiple calculations by a personal computer. Direction and distance of the maximum deviation of the gravity points from the line drawn from the top gravity point to the bottom one were assessed.
The deviation of the gravity points was greater in the malignant tumors than in the benign bone tumors. The direction of the deviation was toward the lesions, side in the benign lesions, while it was toward the opposite side of the lesions in the malignant lesions.
Our method using a concept of gravity line in the femur indicates that bone can change its construction (or mineral distribution) to support bone defects caused by benign bone lesions, and that organized bone remodeling can not occur to mechanically compensate bone defects made by malignant bone tumors. Accordingly, our semi-quantitative analysis of plain radiographs would be helpful in differentiation between benign and malignant bone tumors.
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