| Project/Area Number |
02670904
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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 |
外科・放射線系歯学
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| Research Institution | Nagasaki University |
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Principal Investigator |
OHKI Masafumi Nagasaki University School of Dentistry Dept. of Oral Radiology, Lecturer, 歯学部, 講師 (10160441)
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| Co-Investigator(Kenkyū-buntansha) |
IZUMI Masahiro Nagasaki University School of Dentistry Dept. of Oral Radiology, Research Assist, 歯学部, 助手 (40212956)
YAMADA Miho Nagasaki University School of Dentistry Dept. of Oral Radiology, Research Assist, 歯学部, 助手 (80200749)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Dual energy imaging / Digital radiography / Intraoral radiography / Bone mineral content / 骨塩量 / デュアルエネルギ- |
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| Research Abstract |
The dual energy imaging technique has demonstrated its diagnostic potential in many areas of x-ray imaging, such as chest radiography, mammography, and computed tomography. In this research, single exposure dual energy imaging was applied to intraoral radiography and selective bone images were produced using digital image processing to allow accurate measurement of alveolar bone density without hindrance from soft tissue. A pair of intraoral films separated with an inter-film filter was used in a conventional radiographic system, and an aluminum equivalent image was decomposed from these images by computerized image processing. The optimum material and thickness of the inter-film filter was investigated by computer simulation and'experimental studies. An image decomposition algorithm was proposed for single exposure dual energy imaging. In addition, the accuracy of bone mineral content measurement by this method was also investigated. The results was shown as follows. Bone equivalent images could be separated by single exposure dual energy imaging in intraoral radiography. A copper foil of 0. I mm in thickness was found to be optimal as an inter-film filter in the present imaging system. Measurement error of bone mineral content in this method was 0.57 mm in aluminum thickness for an aluminum object of less than 16 mm thickness even though it overlaid with 40 mm thick Mix-DP as soft tissue. Single exposure dual energy imaging has a potential to add further diagnostic information to a conventional intraoral radiogram with no additional dosage and no additional examinations to the patient. With this technique, the front film can be used for conventional radiographic diagnosis and the bone equivalent image can be used to quantify the absolute mineral content of alveolar bone.
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