| Project/Area Number |
20K08150
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 52040:Radiological sciences-related
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| Research Institution | National Institutes for Quantum Science and Technology |
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Principal Investigator |
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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| Project Period (FY) |
2020-04-01 – 2025-03-31
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| Project Status |
Granted (Fiscal Year 2023)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2023: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2022: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2021: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2020: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | OGSE-DWI / OGSE / diffusion-weighted MRI / frequency domain / asymptotic behaviour / structural universality / diffusion MRI |
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| Outline of Research at the Start |
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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| Outline of Annual Research Achievements |
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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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
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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| Strategy for Future Research Activity |
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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