Noninvasive assessment of cerebral blood volume using diffusion and perfusion MRI

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K09462
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56010:Neurosurgery-related
• Research Institution: Iwate Medical University
• Principal Investigator: Uwano Ikuko 岩手医科大学, 医歯薬総合研究所, 講師 (20468317)
• Co-Investigator(Kenkyū-buntansha): 小笠原 邦昭 岩手医科大学, 医学部, 教授 (00305989) ; 佐々木 真理 岩手医科大学, 医歯薬総合研究所, 教授 (80205864)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 脳循環予備能 / IVIM / 脳血液量 / MRI

Outline of Final Research Achievements

The severity of chronic cerebral ischemia can be assessed using cerebrovascular reactivity (CVR) to acetazolamide challenge, which is measured by SPECT; however, this is an invasive method. We investigated whether intravoxel incoherent motion (IVIM) MRI can assess impaired CVR in preoperative patients with chronic cerebral ischemia and compared it to SPECT-CVR. As result, the IVIM-f value on the affected side was significantly higher than those on the unaffected side and the IVIM-f ratio of the ipsilateral side against the contralateral side showed a significantly negative correlation with the SPECT-CVR value. In addition, IVIM-f ratio detected impaired CVR (< 18.4%) with a sensitivity/specificity of 0.71/0.90. These results suggest that IVIM-f can be a non-invasive alternative to ACZ-SPECT for assessing the severity of chronic cerebral ischemia.

Free Research Field

MRIによる脳循環代謝解析

Academic Significance and Societal Importance of the Research Achievements

本研究にて利用したIVIM解析のような非造影MRIによる無侵襲CBV計測は、PETやSPECTに代わる汎用的な脳循環予備能検査となることが期待される。また、独自に開発済の定量的磁化率画像による脳酸素摂取率(oxygen extraction fraction, OEF)やarterial spin labeling (ASL)法による脳血流量(CBF)と組み合わせることで、包括的な無侵襲脳循環代謝検査に発展させることが可能であり、脳血管障害をはじめとする種々の脳神経疾患の病態解明に役立つことが期待される。