| 研究課題/領域番号 |
20K08150
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分52040:放射線科学関連
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| 研究機関 | 国立研究開発法人量子科学技術研究開発機構 |
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研究代表者 |
Jeffrey Kershaw 国立研究開発法人量子科学技術研究開発機構, 量子医科学研究所 分子イメージング診断治療研究部, 主任研究員 (50508801)
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| 研究期間 (年度) |
2020-04-01 – 2024-03-31
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| 研究課題ステータス |
交付 (2022年度)
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| 配分額 *注記 |
4,290千円 (直接経費: 3,300千円、間接経費: 990千円)
2023年度: 1,040千円 (直接経費: 800千円、間接経費: 240千円)
2022年度: 1,040千円 (直接経費: 800千円、間接経費: 240千円)
2021年度: 520千円 (直接経費: 400千円、間接経費: 120千円)
2020年度: 1,690千円 (直接経費: 1,300千円、間接経費: 390千円)
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| キーワード | OGSE / diffusion-weighted MRI / frequency domain / asymptotic behaviour / structural universality / diffusion MRI |
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| 研究開始時の研究の概要 |
The main focus of this project is to develop a method to better understand blood signal attenuation in DWI. Rather than using a pair of diffusion coefficients to describe signal attenuation for separate tissue and blood components as the IVIM model does, a more general way to characterise incoherent molecular motion is to measure the velocity-correlation function (VCF) for the sample as a whole. The OGSE technique is ideally suited to this task as it directly measures the Fourier transform of the VCF, or velocity correlation spectrum (VCS), as a function of frequency.
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| 研究実績の概要 |
Our efforts over the past year include continued revision and other activity towards the publication of our second manuscript, which focusses on understanding the asymptotic high- and low-frequency limits of the signal when measured with OGSE-DWI. Based on the results in this manuscript a presentation was made at the ISMRM Japan Chapter meeting in Nagoya (Sept 10-11, 2022).
We have also extended our work on the ADC measured with OGSE-DWI. In particular, it has been demonstrated that the dynamic exponent characterising the global organisation of a medium may be systematically underestimated. This fact will be the core result in a presentation to be made at the ISMRM conference in Toronto in June 2023.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
Unfortunately, even though we have submitted our second manuscript to five different journals it has not yet been accepted for publication. As we understand it, the problem is not the quality or correctness of the work, but the highly technical nature of the contents and its suitability to the targeted journals. On the one hand, after submitting to a physics or specialist MR imaging journal we have been told that the work would be more suitable for an applied mathematics journal. However, after submitting to such a journal we have told the exact opposite; that is, the work should be submitted to a physics or specialist MR imaging journal. It has been quite frustrating, but we shall continue searching for a suitable journal.
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| 今後の研究の推進方策 |
Work continues on the preparation of a third manuscript where we generalise the results of our OGSE-DWI papers to any DWI sequence. This work will enable the results of asymptotic measurements from experiments using different DWI sequences to be compared. We hope to be able to submit it to the Journal of Magnetic Resonance sometime later this year.
Beyond the third manuscript, we plan to extend our work to better understand the relationship between gradient parameters and the spatial aspects (eg. field-of-view, voxel size) of the signal in the asymptotic limits. Such a generalisation may be important for anisotropic media like brain tissue.
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