1993 Fiscal Year Final Research Report Summary
The Development and Application of Diffusion-weighted Echo Planar Images
| Project/Area Number |
04670670
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
AZUMA Kazuyoshi Hiroshima Univ. Med. Hosp. Assist. Prof., 医学部・附属病院, 講師 (50127601)
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| Co-Investigator(Kenkyū-buntansha) |
AWAI Kazuo Hiroshima Univ. Med. Hosp. Resident, 医学部・附属病院, 医員
TSUJI Shuichi Hiroshima Univ. Med. Hosp. Research Associate, 医学部・附属病院, 助手 (30217301)
KAJIMA Toshio Hiroshima Univ. Sch. Med. Research Associate, 医学部, 助手 (00224410)
ITO Ktsuhide Hiroshima Univ. Sch. Med. Prof., 医学部, 教授 (20034035)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Cerebral ischemia / Diffusion-weighted image / Echo-planar image / Anisotropic diffusion |
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| Research Abstract |
Diffusion-weighted echo-planar images (DW-EPI) with motion-probing-gradient (MPG) method were acquired using MR imager (2.0 tesla). Apparent diffusion coefficient (ADC) were calculated from these images in ischemic lesions and in normal unoccluded regions. Focal cerebral ischemia was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in Wistar rats. Results were as follows.
1) Ischemic lesious could be detected on the DW-EPI at 1 hour after occlusion.
2) The ADC of water in the brain tissue was smaller than that of free water as a result of restricted diffusion.
3) Anisotropic diffusion that probably can be attributed to the myelin sheath was observed in the normal deep white matter.
4) In the ischemic lesions, the ADC decreased rapidly within 1-3 hours after occlusion and then decreased gradually after 24-48 hours. In the ischemic deep white matter, diffusion anisotropy disappeared at 24-48 hours after occlusion.
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