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Decrease of post-stimulus undershoot in heavily diffusion-weighted functional magnetic resonance
https://repo.qst.go.jp/records/61730
https://repo.qst.go.jp/records/6173026f51658-f22d-4e58-8370-3d65e4fece04
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-08-24 | |||||
| タイトル | ||||||
| タイトル | Decrease of post-stimulus undershoot in heavily diffusion-weighted functional magnetic resonance | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Obata, Takayuki
× Obata, Takayuki× Tomiyasu, Moyoko× Kashikura, Kenichi× Hirano, Yoshiyuki× Nonaka, Hiroi× Ikehira, Hiroo× Kanno, Iwao× et.al× 小畠 隆行× 富安 もよこ× 柏倉 健一× 平野 好幸× 野中 博意× 池平 博夫× 菅野 巖 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | To reveal the relationship between post-stimulus undershoot in functional diffusion-weighted MRI (DWI) and the slow return to baseline in the ADC transient feature after stimulation, we analyzed post-stimulus undershoot in heavily DWI (b=1400 s/mm2), and compared it with that in weakly DWI (b=200 s/mm2). A visual stimulation study was conducted on six healthy volunteers (4 males and 2 females, ages 21 to 29 years). Across the 6 subjects, 224 pixels in the visual cortex passed the criteria for activation; the average curves for DWI (b=200 s/mm2 and 1400 s/mm2). The qualitative result was that the DWI (b=200 s/mm2) and BOLD curves were rather similar, but the DWI (b=1400 s/mm2) curve was distinctly different, as its signal exhibited a smaller post-stimulus undershoot than those observed in DWI (b=200 s/mm2) and BOLD images. The ratio of undershoot (baseline - undershoot) with activation (activation - baseline) in DWI (b=1400 s/mm2) was 22.9 +- 16.4%, significantly smaller than 64.4 +- 20.8% in DWI (b=200 s/mm2, n=6, paired-t test, p<0.01). The ADC curve showed a gradually decreasing slope during the stimulus and a slow return to baseline post-stimulus. These results were not in confkict with those of Darquie et al.. Simultaneous transient features were recognized in post-stimulus ADC changes and undershoot in BoLD, suggesting that the same physiological mechanism causes these changes. This may help to reveal the physiological condition in the brain after stimulation. Studies are now ongoing that will unravel the mechanism of the ADC changes in detail. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 第６回放射線生物学及び画像医学に関する日仏ワークショップ | |||||
| 発表年月日 | ||||||
| 日付 | 2006-06-22 | |||||
| 日付タイプ | Issued | |||||
