Noninvasive assessment of cerebral blood volume using diffusion and perfusion MRI

• 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
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2019: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 脳循環予備能 / IVIM / 脳血液量 / MRI / ASL

Outline of Research at the Start

本研究ではMRIを用いた高精度で無侵襲な脳循環予備能計測法として、1) 拡散強調画像に含まれる灌流情報(intravoxel incoherent motion, IVIM)を利用した手法と、2) arterial spin labeling (ASL)法灌流画像の経時的信号変化を利用した手法の異なる2つのアプローチからの脳血液量(cerebral blood volume, CBV)計測法の開発に取り組む。また、血行力学的脳虚血患者を対象に従来検査法のPETやSPECTと比較することで精度評価を行い、新たな検査法としての意義を明らかにする。

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.

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。

Research Products

• [Journal Article] Assessment of Impaired Cerebrovascular Reactivity in Chronic Cerebral Ischemia using Intravoxel Incoherent Motion Magnetic Resonance Imaging (2021)
  • Author(s): Ikuko Uwano, Masakazu Kobayashi, Kengo Setta, Kuniaki Ogasawara, Fumio Yamashita, Futoshi Mori, Tsuyoshi Matsuda, Makoto Sasaki
  • Journal Title: Journal of Stroke and Cerebrovascular Diseases Volume: 30 Issue: 12 Pages: 106107-106107
  • DOI: 10.1016/j.jstrokecerebrovasdis.2021.106107
  • Peer Reviewed
• [Journal Article] Spatial and temporal variations of flip-angle distributions in the human brain using an eight-channel parallel transmission system at 7T: comparison of three radiofrequency excitation methods (2021)
  • Author(s): Matsuda Tsuyoshi、Uwano Ikuko、Iwadate Yuji、Yoshioka Kunihiro、Sasaki Makoto
  • Journal Title: Radiological Physics and Technology Volume: 14 Issue: 2 Pages: 161-166
  • DOI: 10.1007/s12194-021-00612-8
  • Peer Reviewed
• [Journal Article] Detection of impaired cerebrovascular reactivity in patients with chronic cerebral ischemia using whole-brain 7T MRA (2020)
  • Author(s): Uwano Ikuko、Kameda Hiroyuki、Harada Taisuke、Kobayashi Masakazu、Yanagihara Wataru、Setta Kengo、Ogasawara Kuniaki、Yoshioka Kunihiro、Yamashita Fumio、Mori Futoshi、Matsuda Tsuyoshi、Sasaki Makoto
  • Journal Title: Journal of Stroke and Cerebrovascular Diseases Volume: 29 Issue: 9 Pages: 105081-105081
  • DOI: 10.1016/j.jstrokecerebrovasdis.2020.105081
  • Peer Reviewed
• [Journal Article] Predicting the consistency of intracranial meningiomas using apparent diffusion coefficient maps derived from preoperative diffusion-weighted imaging (2020)
  • Author(s): Miyoshi Kenya、Wada Tsukasa、Uwano Ikuko、Sasaki Makoto、Saura Hiroaki、Fujiwara Shunrou、Takahashi Fumiaki、Tsushima Eiki、Ogasawara Kuniaki
  • Journal Title: Journal of Neurosurgery Volume: in press Issue: 3 Pages: 1-8
  • DOI: 10.3171/2020.6.jns20740
  • Peer Reviewed / Open Access
• [Journal Article] Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET. (2020)
  • Author(s): Fujimoto K, Uwano I, Sasaki M, Oshida S, Tsutsui S, Yanagihara W, Fujiwara S, Kobayashi M, Kubo Y, Yoshida K, Terasaki K, Ogasawara K
  • Journal Title: AJNR Am J Neuroradiol Volume: in press Issue: 5 Pages: 785-791
  • DOI: 10.3174/ajnr.a6508
  • Peer Reviewed / Open Access