健康人视觉刺激的fMRI研究

Study of functional MRI in healthy human beings with visual stimulation

目的:探讨健康人单眼及双眼刺激功能磁共振成像(fMRI)时双侧视觉皮层激活的特点及单、双眼刺激脑激活区的异同。方法:正常受试者25例,行单眼及双眼刺激fMRI检查。选择符合条件者16例。fMRI内容为全屏幕黑白翻转棋盘格刺激的Block设计。fMRI采用SPM2软件进行功能数据预处理、统计分析和结果显示,对单眼及双眼刺激行组间分析,并对三种刺激的激活两两配对进行SPM2基本模型配对t检验。结果:正常受试者左、右眼及双眼刺激纹状区、纹旁及纹周区(BA17,18,19)均见激活;单眼及双眼刺激组分析中引起视觉皮层反应的优势大脑半球均为右侧,同一个体的左眼、右眼及双眼刺激的优势半球一致;左、右眼刺激,双眼与左眼刺激枕区视觉皮层激活区未见显著性差异;双眼较右眼刺激仅有较小范围的视觉皮层激活明显增加。结论:健康人左、右眼刺激及双眼刺激引起的双侧视觉皮层激活不对称,存在右侧优势现象。

Objective：To study the characteristics of visual cortex activation in normal human beings with unilateral and bilateral visual stimulation with functional MRI （fMRI）,and the differences of cortex activation between monocular and binocular simulation.Methods：25 normal subjects received fMRI with monocular stimulation and binocular stimulation respectively.16 subjects which were in accord with the demands were selected.The fMRI stimulation content was block design of full screen black checker.Software SPM2 was used for preprocessing,statistical analysis and result display of functional data.Statistical analyses included：group effects analysis of cortex activation area performed with monocular stimulation and binocular stimulation;paired t tests of cortex activation area performed in the normal controls with left eye stimulation,right eye stimulation and binocular stimulation respectively.Results：The cortex activation areas were revealed in corpus striatum,para-and peri-corpus striatum （BA 17,18 and 19 area） by using monocular and binocular stimulation,the dominant cerebral hemisphere of visual cortex activation was the right side in all subjects with monocular and binocular stimulation.No significant differences of the visual cortex activation was found between left and right eye stimulation as well as between binocular eye and left eye stimulation.The activated extent and intensity was slightly increased in the left visual cortex with binocular stimulation compared with that of the right eye stimulation. Conclusion：There was asymmetric activation pattern in the visual cortex of normal human beings who undergone functional MRI with monocular and binocular stimulation.The right hemisphere is activated in a more dominant position and to a greater spatial extent than the left hemisphere.