Development of fMRI quantification and high-resolution cerebral oxygen metabolism measurements for elucidating cerebral circulatory metabolic coupling

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03537
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 51010:Basic brain sciences-related
• Research Institution: National Institute of Information and Communications Technology
• Principal Investigator: Kida Ikuhiro 国立研究開発法人情報通信研究機構, 未来ICT研究所脳情報通信融合研究センター, 副室長 (60374716)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 機能的MRI / 定量化 / 酸素代謝 / 脳血流量 / 脳血液量 / 超高磁場 / 高分解能 / 脳機能計測

Outline of Final Research Achievements

We conducted the establishment of high-resolution multi-modal measurement techniques using 7 Tesla MRI. We optimized the imaging parameters, considering various issues such as image distortion, shortening of RF pulse wavelength, and relaxation time changes caused by the increase in magnetic field strength. As a result, in cerebral blood volume measurements, we were able to measure activity in the motor cortex at submillimeter resolution and revealed that the signal dependence within the gray matter varies depending on the motor task conditions. In cerebral blood flow measurements, stable measurements were achieved using ASL in ultra-high-field MRI. In addition, we showed that the signal related to cerebral blood flow could be used to be more accurate indicator than the BOLD signal at high spatial resolution.

Free Research Field

脳機能計測

Academic Significance and Societal Importance of the Research Achievements

BOLD信号に基づく機能的MRI（fMRI）法は定量性がないため、活動量の同定が難しく、様々な条件の比較は原理的にはできない。しかし、脳血流量や脳血液量といった定量性を持つ脳活動計測により、刺激や被験者間での比較が可能となる。また、皮質層レベルの解像度でのこれらの計測法は、皮質層ごとの脳循環代謝の関係が明らかになり、BOLD信号の定量性が期待できる。