Pursuit of reducing radiation dose by preoperative examination for dental implants: scan settings and image quality of cone-beam CT for dental use
| Project/Area Number |
15K20382
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Pathobiological dentistry/Dental radiology
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
NOMURA Yoshikazu 東京医科歯科大学, 歯学部附属病院, 医員 (60632081)
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2016: ¥130,000 (Direct Cost: ¥100,000、Indirect Cost: ¥30,000)
Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
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| Keywords | 歯科用CT / 画質 / インプラント / 雑音 / ノイズ / 金属アーチファクト / 撮影設定 / CBCT / CT / 画質評価 / コーンビームCT / 被ばく線量 / 画素値 / 撮像設定 / 管電圧 / 管電流 |
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| Outline of Final Research Achievements |
Although the target of this study plan was initially preoperative examinations using cone-beam CT for dental use (CBCT), postoperative examinations were also included due to the obtained findings. As a result, new findings were obtained regarding (1) ring artifacts and (2) metal artifacts caused by titanium implants in CBCT images.
In regard to (1), the ring artifacts of CBCT images had hardly been discussed so far; however, it is difficult to avoid those. We developed the technique to evaluate ring artifacts in CBCT images. In addition, we found that the closer to the gantry rotation axis, the stronger the noise.
In regard to (2), we found that the technique using the extreme value analysis reported for streak artifacts in medical CT images was applicable to metal artifacts in CBCT images. Moreover, we indicated that noise could be reduced by changing the scan settings without changing the dose.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究によりリングアーチファクトと金属アーチファクトについての新たな知見が得られた。
CBCT画像では撮影範囲内の中心付近が分解能が高いという報告があるが、我々はリングアーチファクトも同部付近で強いという知見を得た。歯根破折等を評価する場合は必ずしも歯根を中心に設置しない方が良い可能性がある。
また、CBCT画像上のチタンインプラント体の周囲には金属アーチファクトが発生するが、医科用CTで報告されていた手法を応用して、これを定量的に評価できることを確認した。また、線量(CTDIvol)を維持したまま、撮影設定の変更により金属アーチファクトを低減できることも確認した。
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Report
(5 results)
Research Products
(4 results)
