摘要
目的 采用磁共振弥散张量成像（DTI）检测慢性闭角型青光眼（PACG）患者脑白质病变，用各向异性指数（FA）改变分析病变部位。方法 回顾性分析2008-2009年在天津医科大学总医院眼科就诊并行颅脑MRI检查患者的临床资料，其中确诊为慢性PACG并同时行DTI扫描的患者25例为慢性PACG组，根据视野损害程度分为轻度组和重度组；选取同一时间段行颅脑DTI扫描的健康人25例为正常对照组。采用FSL和DTIstudio软件处理原始数据得到FA图，输入SPM5软件做标准化处理，然后进行灰白质分割，对分割后的白质FA图进行平滑处理，最后对慢性PACG组和正常对照组FA图进行两样本t检验比较，采用FWE方法校正统计结果，取P＜0.05有统计学意义，将结果叠加于标准模板，显示阈值设定为10个体素。采用同样方法分析慢性PACG轻度组和重度组FA图差异。结果剔除头动明显受试者图像后，慢性PACG组和正常对照组各有22例入组，慢性PACG组分为轻度组13例、重度组9例。与正常对照组比较，慢性PACG患者双侧视束脚周段FA值明显降低（P＜0.05,FWE校正），左侧包含98个体素，右侧包含56个体素。慢性PACG轻度组与重度组FA值差异无统计学意义（P＞0.05）。结论 DTI可检测慢性PACG患者脑白质结构病变。FA值可反应双侧视束脚周段病变。
Objective To evaluate the brain white matter abnormality in the chronic primary angleclosure glaucoma （PACG） subjects with magnetic resonance diffusion tensor imaging （DTI）, and to identify the abnormal regions in white matter based on altered fractional anisotropy （FA）. Methods A retrespective study was conducted on the data of patients who underwent brain magnetic resonance imaging （MRI） at Department of Ophthalmology, Tianjin Medical University General Hospital between 2008 and 2009. Twenty-five patients who were proved to have chronic PACG and received brain DTI scan were recruited in the study （chronic PACG group）, and were further stratified into the mild chronic PACG group and the severe chronic PACG group according to severity of visual field loss. A contemporary cohort of 25 healthy subjects who also underwent brain DTI scan was recruited as normal controls. FSL and Dtlstudio software were applied to process the raw data and to calculate the FA map which was then entered into the SPM5 software for normalization and grey/white matter segmentation. Then the segmented FA map of white matter was smoothed.Two-sample t test was used to compare the FA map in the chronic PACG group and the normal control group.The comparison was further controlled by family-wise error （FEW）. Significantly different regions （as defined by P value less than 0.05） were overlaid on the normalized template, with the display threshold being 10 voxels. The same algorithm was used to compare the FA map between mild and severe chronic PACG groups.Results Each three subjects from the chronic PACG group and the normal control group were excluded due to obvious head motion, so that there were 22 subjects in each group. The chronic PACG group comprised 13 cases of mild and 9 of severe chronic PACG. Compared with the normal controls, the FA value at the root of bilateral optic tracts was significantly reduced among patients with chronic PACG （98 voxels on the left and 56 voxels on the right, P〈0.05, adjusted by FEW）. There was no difference in FA value between the mild and severe chronic PACG groups （P〉0.05）. Conclusions DTI can be used to investigate the brain white matter changes in chronic PACG. FA value may be a useful indicator for abnormality at the root of bilateral optic tracts.
出处
《中华生物医学工程杂志》
CAS
2011年第4期309-312,共4页
Chinese Journal of Biomedical Engineering
关键词
青光眼
磁共振成像
弥散
视通路
部分各向异性
弥散张量成像
Glaucoma
Diffusion magnetic resonance imaging
Visual pathways
Fractional anisotropy
Diffusion tensor imaging
