| 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 – 2025-03-31
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| 研究課題ステータス |
交付 (2023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-DWI / 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 |
Work over the past year has centred on the preparation of a third manuscript where we generalise the results of our OGSE-DWI papers to any DWI gradient waveform. 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. A primary result of this work is that the surface-to-volume ratio, an important quantity characterising complex media, may be overestimated if the data analysis does not consider the specific gradient waveform used to acquire the data. This work will be presented at the ISMRM conference in Singapore in May this year.
We have also continued to search for a suitable journal to publish our second manuscript. Unfortunately, we have not yet been successful so to avoid extended delay in publication we have posted it to the well-known arXiv website.
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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
Progress on our third manuscript has been relatively smooth but not rapid. The reason for this is the effort required to solve various technical problems. For example, to solve various integrals and derive asymptotic approximations to the exact results has required us to search for and learn many new analytical techniques, all of which required time. We continue to advance towards our goal though.
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| 今後の研究の推進方策 |
For the moment work continues on the preparation of our third manuscript. It is anticipated that the work will be submitted to the Journal of Magnetic Resonance sometime later this year.
After completing the third manuscript, we plan to extend our work to better understand the relationship between gradient parameters and the dependence of the signal on spatial parameters like the field-of-view, voxel size etc in the asymptotic limits. Such a generalisation may be important for the description of complex anisotropic media like brain tissue.
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