视觉刺激功能磁共振成像在枕叶病变患者中的初步应用

目的 观察枕叶病变患者患侧与健侧的功能磁共振成像（fMRI）特点，评价fMRI在视觉中枢功能性病变检查、枕叶肿瘤定位、手术入路选择以及切除范围方面的临床应用价值。设计 病例系列。研究对象 伴有同侧偏盲的视觉中枢功能性病变及单侧枕叶肿瘤患者各1例。方法 对上述2例患者应用自行设计的双眼棋盘格刺激（5Hz）行脑fMRI检查。所得数据应用SPM软件处理（P〈0．01），与Goldmann视野计检查结果相比较，验证视野损害与其大脑皮层投影改变的一致性。主要指标 统计参数图，脑激活图，激活脑区信号变化的时间曲线，与标准化T1像叠加的脑激活图。结果 在视觉刺激on时，枕叶视功能区激活；off时无信号；2例患者fMRI检查右侧视功能区激活明确，左侧视功能区无信号与视野检查双眼右半视野缺损相一致。结论 视觉刺激程序能够很好地引出视觉中枢fMRI；fMRI的检查结果与视野结果一致性较好；fMRI在视觉中枢功能性检查、枕叶肿瘤范围定位的确定方面有良好的临床应用前景。

Application of visual stimulated-fMRI in occipital lobe injury cases-a pilot study

Objective To observe the results of visual functional MRI(fMRI)of injury side with those of uninjured side,in patients with visual field defects and retrochiasmastic tumor.The potential clinical usefulness of visual fMRI data during functional examination on visual centre,defining the tumor field and surgery,was evaluated in patients with occipital lobe tumour.Design Case series.Participants Two patients with occipital lobe tumor and homonymous visual field defects,injury sides contrast with uninjured ones.Methods Patients were studied with fMRI using monocular checker stimulation(5Hz).The data obtained were analyzed with statistical parametric maps software(P<0.01)and were compared with results of Goldmann visual field perimetric evaluation.Main Outcome Measures Statistical parametric mapping,activation map of brain,plot of brain activation map-time,brain activation map stacked by normalized T1 images.Results fMRI were highly dependent on the choices of the visual stimulation;in both patients,the functional activations found in the visual cortex were consistent with the results of perimetric evaluation.Visual fMRI images showed that the function of uninjured side of occipital lobe was very well;while the function of injury side was vanished.Conclusions The visual process can induce the fMRI of occipital lobe correctly;there was a good correspondence between fMRI data and the results of perimetric evaluation.Visual fMRI would extent to examine the functional incapacitation of visual centre,evaluate the tumor field and be useful in surgical planning and tumor removal.