| Project/Area Number |
12557170
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
補綴理工系歯学
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
MAEKAWA Kenji Dental Hospital, Assistant Professor, 歯学部附属病院, 講師 (20304313)
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| Co-Investigator(Kenkyū-buntansha) |
KISHI Kanji Graduate School of Med and Dent, Professor, 大学院・医歯学総合研究科, 教授 (30033202)
SUZUKI Kouji Graduate School of Med and Dent, Research Associate, 大学院・医歯学総合研究科, 助手 (30304322)
KUBOKI Takuo Graduate School of Med and Dent, Associate Professor, 大学院・医歯学総合研究科, 助教授 (00225195)
WAKASA Touru Dental Hospital, Assistant Professor, 歯学部附属病院, 講師 (50191713)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2000: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | magnetic resonance imaging / T2-weighted MRI / signal intensity / muscle / blood volume / near infra-red spectroscopy / 慢性筋痛 / 僧帽筋 / 咬筋 / 筋組織内血液動態 / 咀嚼 |
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| Research Abstract |
The original purpose of this study was not achieved, because mastication provoked motion artifact to image brain hemodynamics using MRI. For this reason, we were forced to change the research protocol and investigated the cerebral cortical activation during volitional swallowing using functional MRI. The results showed that the swallowing task activated the inferior parts of the pre- and postcentral gyri. Additionally, we also investigated the correlation between T2 weighted MRI signal intensity (S1) and intramuscular blood volume in human muscle. First, we compared blood volume changes transcutaneously measured using near-infrared (NIR) spectroscopy against SI changes taken from a transverse T_2-weighted MR image of the masseter muscle in healthy human subjects before, during and after contraction. The data showed that both NIR-based total blood volume and T_2-weighted MRI-based SI levels clearly decreased during muscle contraction and a clear post-contraction rebound response was evi
… More
dent after the contraction. The NIR data were found to be highly correlated to MRI-based SI data (Pearson's r=0.945, p<0.0001). Next, we evaluated the ability of SI in T2-weighted trapezius muscle MRI to detect intramuscular hemodynamic changes upon cold pressor stimulation (sympathetic nerve activator). Cold pressor stimulation (4℃) was applied to each subject's right foot and ankle for 2 min. The SI changes were recorded continuously for 7 min before, 2 min during, and 6 min after withdrawal of cold pressor stimulation. The mean SI level in T2-weighted trapezius muscle MRI significantly increased during cold pressor stimulation (p<0001, one way repeated measure ANOVA and post hoc contrast analysis) and returned to the baseline level after cold pressor withdrawal. These findings are identical to the cold pressor-induced hemodynamic changes documented in the trapezius muscle by NIR spectroscopy evaluation (Acero et al., 1999). Both studies provided the evidence that SI measurement in T2-weighted muscle MRI is sufficiently sensitive to detect intramuscular hemodynamics in humans. Less
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