Influence of Diffusion Time and Temperature on Restricted Diffusion Signal: A Phantom Study
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- Oshiro Hinako
- Graduate School of Human Health Sciences, Tokyo Metropolitan University Center for Brain Science, RIKEN
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- Hata Junichi
- Graduate School of Human Health Sciences, Tokyo Metropolitan University Center for Brain Science, RIKEN School of Medicine, Keio University Division of Regenerative Medicine, The Jikei University School of Medicine
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- Nakashima Daisuke
- School of Medicine, Keio University
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- Hayashi Naoya
- Graduate School of Human Health Sciences, Tokyo Metropolitan University Center for Brain Science, RIKEN
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- Haga Yawara
- Graduate School of Human Health Sciences, Tokyo Metropolitan University Center for Brain Science, RIKEN
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- Hagiya Kei
- Center for Brain Science, RIKEN
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- Yoshimaru Daisuke
- Center for Brain Science, RIKEN School of Medicine, Keio University Division of Regenerative Medicine, The Jikei University School of Medicine
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- Okano Hideyuki
- Center for Brain Science, RIKEN School of Medicine, Keio University
抄録
<p>Purpose: Diffusion MRI is a physical measurement method that quantitatively indicates the displacement of water molecules diffusing in voxels. However, there are insufficient data to characterize the diffusion process physically in a uniform structure such as a phantom. This study investigated the transitional relationship between structure scale, temperature, and diffusion time for simple restricted diffusion using a capillary phantom.</p><p>Methods: We performed diffusion-weighted pulsed-gradient stimulated-echo acquisition mode (STEAM) MRI with a 9.4 Tesla MRI system (Bruker BioSpin, Ettlingen, Germany) and a quadrature coil with an inner diameter of 86 mm (Bruker BioSpin). We measured the diffusion coefficients (radial diffusivity [RD]) of capillary plates (pore sizes 6, 12, 25, 50, and 100 μm) with uniformly restricted structures at various temperatures (10ºC, 20ºC, 30ºC, and 40ºC) and multiple diffusion times (12–800 ms). We evaluated the characteristics of scale, temperature, and diffusion time for restricted diffusion.</p><p>Results: The RD decayed and became constant depending on the structural scale. Diffusion coefficient fluctuations with temperature occurred mostly under conditions of a large structural scale and short diffusion time. We obtained data suggesting that temperature-dependent changes in the diffusion coefficients follow physical laws.</p><p>Conclusion: No water molecules were observed outside the glass tubes in the capillary plates, and the capillary plates only reflected a restricted diffusion process within the structure.</p><p>We experimentally evaluated the characteristics of simple restricted diffusion to reveal the transitional relationship of the diffusion coefficient with diffusion time, structure scale, and temperature through composite measurement.</p>
収録刊行物
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- Magnetic Resonance in Medical Sciences
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Magnetic Resonance in Medical Sciences 23 (2), 136-145, 2024
日本磁気共鳴医学会