正常人听觉皮层BOLD-fMRI的研究

Functional MRI study of auditory cortex in healthy subjects

目的利用血氧水平依赖(blood oxygenation level dependent,BOLD)功能磁共振成像(functional magnetic res-onance imaging,fMRI)(BOLD-fMRI)技术观察纯音刺激时正常人大脑两半球听觉皮层激活情况,对激活体积和信号强度进行定量分析,比较其差异。方法15例健康志愿者行听觉刺激BOLD-fMRI检查。刺激声音为声强90dB、频率l000Hz的正弦波纯音脉冲。采用梯度回波平面成像(gradient echo planar imaging,GRE-EPI),快速采集全脑影像。所有数据均经统计参数图(statistical parametric mapping2,SPM2)软件离线后处理,获得听觉功能的解剖功能图、激活体积和信号强度。结果15例健康志愿者纯音刺激时颞叶区均出现激活,颞上回激活率最高,其次为颞中回、颞横回。刺激单耳时对侧听觉皮层激活体积和信号强度明显大于同侧(P<0.01)。结论正常人纯音刺激单耳时一般都有双侧听觉皮层激活,对侧听觉皮层激活体积和信号强度明显大于同侧,表现为对侧半球传导优势。

Objective Bold oxygenation level dependent functional magnetic resonance imaging （BOLD-fMRI） was used to observe the volume and intensity of the activated auditory cortex evoked by pure tone stimuli in healthy subjects, and to analyze the volume and intensity of the two hemispheres of the activated auditory cortex quantitatively, and to compare the difference of the auditory cortex between left and right hemispheres. Methods Fifteen healthy subjects were taken BOLD-fMRI examina- tion. The sound of 90 dB pure tone and 1000 Hz was used as stimulating signal. The gradient echo planar imaging （GRE-EPI） was used to rapidly acquire whole brain imaging. SPM2 software was used to deal with the original pictures in the off-line work station, and to get maps, volume and intensity of the activated auditory cortex in left and right hemispheres. Results Significant activation was found in temporal lobe in all the healthy subjects. When unilateral ear got signal, there was significant difference between contralateral and ipsilateral activated auditory cortex of all the 15 healthy subjects （P〈0.01）. Conclusion When one ear got stimulated by pure tone, bilateralis auditory cortexes show actived, the volume and intensity of the contralateral activated auditory cortex is greater than that of the ipsilateral auditory cortex, contralateral predominance is quite clearly.