视觉皮层分区的功能MRI视网膜脑图  

The study of human visual cortex areas using functional MRI retinotopic mapping

作　　者：卢光明[1] 张志强[1] 黄伟[1] 郑罡[1] 鲍盛[1] 李兴峰 Robert F.Hess 何晖光[3] 吕彬[3] 黄振平[4] 马飞[4] 尹婕[4] 邵庆[4] 

机构地区：[1]南京军区南京总医院医学影像科,210002 [2]加拿大McGill大学影像研究中心 [3]中国科学院自动化所复杂系统与智能科学重点实验室 [4]南京军区南京总医院医学眼科,210002

出　　处：《中华放射学杂志》2007年第10期1045-1048,共4页Chinese Journal of Radiology

基　　金：国家自然科学基金(36670600)

摘　　要：目的探讨功能 MRI(fMRI)视网膜脑图描绘人视觉皮层各视区的技术方法和生理意义。方法采用1.5 T 超导 MR 设备,运用2种具有相位编码信息的投影刺激:离心外散和向心内聚的光环刺激,以及顺时针和逆时针方向旋转的极角刺激,对6名正常人(受试者)进行血氧水平依赖(BLOD)的 fMRI。将检测数据进行头动校正、配准等空间预处理,再根据刺激视野的时间相位编码,经傅立叶变换计算出视野特征,得到完整的视网膜脑图,并以二维和三维可视化方式显示。结果成功得到6名受试者初级视觉皮层的个体化分区图,描绘出视区 V1、V2(V2腹侧和背侧)、V3和 VP、V3A 和 V4V、V7和 V8等视区的精细分区,各视区以一定的拓扑结构分布于枕叶皮层。结论 fMRI视网膜脑图技术可以无创、精确地显示人脑视觉皮层功能分区。Objective To study the visual areas of human cortex by functional MRI （fMRI） retinotopic mapping. Methods Six normal volunteers were examined with 1.5 T MRI scanner, and stimulated with the pattern of phase-encoded polar angle with clockwise or counterclockwise rotating wedges, and the pattern of eccentricity with concentric expanding or contracting rings. After the data preprocessing with realignment, register, the functional data with phase-encoded of visual cortex were analyzed with fourier transform to obtain phase delay of each voxel. Visual field sign （VFS） was calculated based on the coding information of eccentricity gradient and polar angle gradient. Visual field representations were determined by VFS. The visualizations were performed with 2-dimension and 3-dimensions methods. Results In all subjects, the visual areas of V1, V2, V3/VP, V3A/V4v and the higher visual areas of V7 and V8 were delineated clearly. The visual areas were distributed on the occipital cortex as topological frame. Conclusion The technique of functional MRI retinotopic mapping can measure the retinotopic organization of human visual cortex non-invasively and precisely.

关 键 词：磁共振成像 视觉皮层 视区 

分 类 号：R445.2[医药卫生—影像医学与核医学]