A study of functional MRI on whole brain measured by EPI sequence

EPI序列测量全脑功能MRI研究

• 批准号: 07557069
• 负责人: NISHITANI Hiromu
• 金额: $ 3.33万
• 依托单位: UNIVERSITY OF TOKUSHIMA
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07557069/
• 关键词: fMRI; frequency; brain; language; mapping; Fourier変換; BOLD効果; 記憶; 脳機能; MRI; EPI; 聴覚; 感覚; 言語; functional MRI; flip ahgle; gradient echo; BOLD

(1) functional MRI of 1.5T and 4TWe compared mapping results and time courses of intensity in same subjects using 4T and and 1.5T insturments. The statistical analysis was also conducted in the same manner and suitable thresh hold depending on differences of magnetic field strength was considerdd. The short memory task was applied to the same subjects on different days using two instruments. The BOLD effect at 4T was larger than that at 1.5T,but less than the theoretical expression. However the cerebral activated areas were presented in the almost same pattern two instruments and the multiphasic pattern of time signal intensity course was observed on 4T and 1.5T.We considered that even 1.5T would be as useful as 4T to detect function activity of the brain.(2) 1/f fluctuation of fMRI intensitiesThe frequency analysis was conducted to the time intensity courses of MRI and the relationship with the inverted frequency was studied. The frequency component of MRI single on both phantom and human had the inverted proportional part to the frequency and the power of frequency. The activation by task study caused perturbation from such a inverted frequency relationship. We considered that the deviation from the inverted frequency relationship showed functional activity and the extent of this deviation would reflect strength of activation.

(1)我们比较了4 T和1.5T两种仪器在同一受试者中的标测结果和强度时程。以相同的方式进行统计分析，并根据磁场强度的差异确定合适的阈值。短记忆任务在不同的日子使用两种仪器应用于相同的受试者。4 T下的BOLD效应大于1.5T下的BOLD效应，但小于理论值。但在4 T和1.5T两种仪器上显示的脑激活区几乎相同，且时间信号强度过程呈多相性。我们认为即使在1.5T上也能象4 T一样检测脑功能活动。(2)1. fMRI强度的1/f波动对MRI的时间强度过程进行了频率分析，并研究了与倒频的关系。体模和人体上MRI信号的频率分量均与频率和频率的功率成反比。任务研究的激活引起了这种倒置频率关系的扰动。我们认为，从倒频率关系的偏离表明功能活动，这种偏离的程度将反映激活的强度。

项目成果

M.Harada, et al.: "Physiological memory study using fMR imaging at 1.5 and 4T" Radiology. 205 (Sup). 195 (1997)

M.Harada 等人：“使用 1.5 和 4T 的 fMR 成像进行生理记忆研究”放射学。

M.Harada, et al.: "Spatial and temporal comparison between 4T and 1.5T on fMRI" Japanese Journal of Magnetic Resonance in Medicine. 17 (Sup). 147 (1997)

M.Harada 等人：“fMRI 上 4T 和 1.5T 的空间和时间比较”日本医学磁共振杂志。

M.Harada: "Physiological memory study using fMR imaging at 1.5T and 4T." Radiology. 205 (Sup). 195 (1997)

M.Harada：“使用 1.5T 和 4T 的 fMR 成像进行生理记忆研究。”

原田雅史: "Flip angleによるFunctional MRIの抽出能の変化について" 日本脳神経CI研究会 抄録集. 第15回. P155 (1995)

Masashi Harada：“由于翻转角度导致功能性 MRI 的提取能力发生变化”，日本脑 CI 研究组摘要，第 15 页（1995 年）。

M.Harada: "Spatial and temporal comparison between 4T and 1.5T on fMRI." Jpn J Magn Reson Med. 17 (Sup). 147 (1997)

M.Harada：“fMRI 上 4T 和 1.5T 的时空比较。”