Project/Area Number |
14207039
|
Research Category |
Grant-in-Aid for Scientific Research (A)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Radiation science
|
Research Institution | University of Fukui (2004) 福井医科大学 (2002-2003) |
Principal Investigator |
YONEKURA Yoshiharu University of Fukui, Biomedical Imaging Research Center, Professor, 高エネルギー医学研究センター, 教授 (60135572)
|
Co-Investigator(Kenkyū-buntansha) |
FUJIBAYASHI Yasuhisa University of Fukui, Biomedical Imaging Research Center, Professor, 高エネルギー医学研究センター, 教授 (50165411)
OKAZAWA Hidehiko University of Fukui, Biomedical Imaging Research Center, Associate Professor, 高エネルギー医学研究センター, 助教授 (50360813)
KIMURA Hirohiko University of Fukui, Faculty of Medical Science, Associate Professor, 医学部, 助教授 (10242596)
TSUCHIDA Tatsurou University of Fukui Hospital, Assistant Professor, 医学部附属病院, 助手 (70303386)
小俣 直人 福井医科大学, 医学部附属病院, 助手 (30334832)
|
Project Period (FY) |
2002 – 2004
|
Project Status |
Completed (Fiscal Year 2004)
|
Budget Amount *help |
¥36,010,000 (Direct Cost: ¥27,700,000、Indirect Cost: ¥8,310,000)
Fiscal Year 2004: ¥10,010,000 (Direct Cost: ¥7,700,000、Indirect Cost: ¥2,310,000)
Fiscal Year 2003: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000)
Fiscal Year 2002: ¥15,470,000 (Direct Cost: ¥11,900,000、Indirect Cost: ¥3,570,000)
|
Keywords | Cerebrovascular disease / Cerebral ischemia / Cerebral blood flow and metabolism / Positron emission tomography / MRI / Single photon emission tomography / Hypoxic change and resistance properties |
Research Abstract |
To investigate relationship between pathological vascular change and hemodynamic alteration in the brain, regional cerebral blood flow (rCBF) and metabolic rate of oxygen (CMRO_2) were measured in patients with chronic cerebrovascular disease (CVD) using PET. ^<15>O-water PET studies were performed in 104 patients with major cerebral arterial stenoocclusive disease (mean age=61.0±14.0 y) at baseline and 10 min after the acetazolamide (ACZ) injection to evaluate regional changes in rCBF. All patients also underwent ^<15>O-gas PET studies using the steady-state method to measure total cerebral blood volume (CBV), oxygen extraction fraction (OEF) and CMRO_2. They were evaluated misery perfusion (stage II ischemia) defined by elevation of and residual vasodilatory capacity. The mean of % increase in rCBF induced by ACZ was significant in both hemispheres of all patients with CVD although there was a subgroup of patients who showed a significant reduction of the rCBF increase in the affecte
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d hemisphere. The absolute OEF in the affected cortical regions was not correlated with % change in rCBF, whereas asymmetry index of OEF in the same regions showed a weak correlation. Sixteen patients had cerebral regions with a significant increase in OEF, and 7 of them (43.8 %) showed a significant decrease in vascular reserve evaluated by the ACZ test. Of the 31 patients who had a reduction of rCBF increase in the affected hemisphere, only 7 patients (22.6 %) showed an OEF increase in the same region. The reduced rCBF response to the ACZ injection is not necessarily associated with misery perfusion in patients with CVD. The two hemodynamic parameters were not equivalent in the critical stage of chronic hemodynamic impairment. We also proposed a new parameter of arterial cerebral perfusion pressure (CPPa) defined by the ratio of rCBF to arterial-to-capillary blood volume (V_0) for assessment of impaired cerebral circulation. In 40 patients with severer vasoocclusiove disease, about half of them showed a reduction of vasodilatory capacity in the affected cerebral territories. In this severely impaired cerebral circulation group, strokes were significantly associated with reduction of CPPa in the ACZ test. Based on these findings from PET studies, MRI studies for evaluation of impaired cerebral circulation were designed and an excellent correlation was obtained between results from PET and MRI. We also applied the same methods to SPECT studies. Less
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