摘要
目的采用fMRI方法评价垂体大腺瘤患者视觉中枢的激活形式,观察视野改变与初级视觉皮层功能变化之间的关系。方法对23例伴视交叉受压的垂体大腺瘤患者及18名正常志愿者的左右眼分别进行组块设计的fMRI实验,刺激内容为全视野黑白翻转棋盘格,对照内容为黑色屏幕中心的白色"+",6个对照组块与5个刺激组块交替进行,每个组块20s。采用1.5TMR扫描仪。数据后处理采用SPM2软件。采用两样本t检验的组间分析方法分别获得左眼及右眼刺激下患者组与对照组间的激活差异图。分析患者视野缺损类型与初级视觉皮层激活形式之间的对应关系。结果在严格控制头动和机械噪声等影响因素后,最终左、右眼刺激各入组12例。患者组与对照组比较,初级视觉皮层激活范围及强度均明显缩小,左眼刺激时患者组以右侧初级视觉皮层激活下降为主,右眼刺激时患者组以左侧初级视觉皮层激活下降为主。6例患者表现为典型左颞侧视野缺损,左眼刺激时表现为左侧初级视觉皮层激活,而右侧激活明显下降或无激活。7例患者为典型右颞侧视野缺损,右眼刺激时表现为右侧初级视觉皮层激活,而左侧激活明显下降或无激活。结论垂体大腺瘤患者初级视觉皮层的激活形式与视野缺损类型存在对应关系,颞侧视野缺损主要以对侧初级视觉皮层激活下降为主。fM-RI是研究前视路病变对视觉中枢皮层影响的有效方法。
Objective To evaluate the activation of visual cortex in patients with large pituitary adenoma, and to observe the relationship between visual field deficits and activation in visual cortex. Methods Twenty three patients with large pitui tary adenoma and eighteen matched subjects were recruited in this study. Block-designed fMRI was performed with 1.5T MR scanner. Black and white check board and ＂＋＂ were used as stimulus and control respectively with 6 control and 5 stim ulus blocks running alternately; every block lasted for 20 s. Bilateral eyes in two groups received stimulus individually. The fMRI data were processed with SPM2. Different mappings between two groups during bilateral eyes experiments were ob tained respectively with inter-group analysis. The relationship between visual field deficits and activation in visual cortex was analyzed. Results The number of patients for group analysis in left and right eye experiments were both twelve after head motion effect was ruled out. In contrast to the control subjects, activated extent and intensity of visual cortex decreased in patients group, especially in contralateral visual cortex. Six patients with typical visual field deficits on the left temporal side presented with decreased or diminished activation in the right visual cortex during the left eye experiment. Seven patients with typical visual field deficits on the right temporal side appeared as decreased or diminished activation in the left visual cortex during the right eye experiment. Conclusion There is a corresponding relationship between visual field deficits and activation of visual cortex in patients with large pituitary adenoma. Visual field deficit on temporal side of each eye mainly cause activation decrease in the contralateral visual cortex. Functional MRI is an effective method for studying effect of diseases in anterior visual pathway on visual cortex.
出处
《中国医学影像技术》
CSCD
北大核心
2009年第3期383-386,共4页
Chinese Journal of Medical Imaging Technology
关键词
垂体肿瘤
视觉皮层
视野
磁共振成像
Pituitary neoplasms
Visual cortex
Visual field
Magnetic resonance imaging
