【作者】 许茜； 时高峰； 刘辉； 翟英敏； 彰俊杰；

【Author】 Xu Qian Shi Gao-Feng Liu Hui Zhai Ying-Min Zhang Jun-Jie Department of CT, The fourth hospital of Hebei medical university & Hebei provincial tumor hospital, Shijiazhuang, 050011, China

【机构】 河北医科大学第四医院暨河北省肿瘤医院CT室；

【摘要】 目的:探讨磁共振(MRI)弥散张量成像(DTI)对中枢神经系统肿瘤诊断的临床价值。方法:对照组为5名健康志愿者,男3人,女2人;年龄21～48岁,平均35．4岁。病例组24例,男15例,女9例,年龄16～77岁,平均48．6 岁。其中脑血管病9例,脱髓鞘疾病2例,肿瘤10例,脑萎缩3例。采用Siemens Avanto 1．5T核磁共振扫描仪,单次激发,加速因子(PAT Factor)2。TR／TE=6800／70ms, 层厚4mm,层间距0mm,矩阵128×128,层数60层,弥散方向:25个方向,全部采集时间(TA)5分46秒。常规MRI 检查,轴位FSE序列:T1WI、T2WI、FLAIR、DWI弥散加权(b=0,1000s／mm2)。冠状位FSE序列T2WI。重建FA图, 在半卵圆中心层面、基底节区层面分别测量FA值。结果:本组22例(91．67％)可见病变区脑白质纤维束消融,FA值减低;8例(30．33％)可见边界清楚的侵蚀状改变。10例肿瘤病例均可见病变区域旁的白质纤维束推压和移位。结论:DTI 可早期发现白质内的病变。与传统MRI相比,DTI能更好地显示脑白质纤维束的受损和移位。人体组织中的弥散均为各向异性弥散。普通的弥散加权序列无法体现弥散的各向异性, 而DTI序列在多个方向施加弥散梯度,并分别进行采集,继而得出多种数据,通过计算得出多种图像,从而对弥散的各向异性做出检测。其中常用的为FA(各向异性分数)。通过对24例异常DTI图像的回顾性分析,发现DTI有如下特点: (1)在FA图中,能显示白质纤维束因占位而导致的推压和移位。(2)DTI FA图能提供传统MRI所不能提供的解剖细节,能发现传统MRI不能发现的白质内纤维束微细结构和各向异性弥散早期的受损。(3)FA图的异常可有多种形式,纤维束可呈消融状,或呈边界清楚的侵蚀状损害。这些特点,为临床早期发现病灶,以及病程检测和疗效评估等提供了新的依据。更多还原

【Abstract】 Objective: Evaluate the clinic role of diffusion tensor imaging (DTI) in diagnosis of central nervous system diseases with matter fibro bands. Methods: Five healthy volunteers and twenty-four patients (9 cases of cerebral vascular disease, 2 cases of demyelinating disease, 10 cases of tumor, 3 cases of brain atrophy) underwent MRI examination, using Siemens Avan to 1.5T MRI, which included conventional T1WI, T2WI, FLAIR and diffusion tensor, Fractional anisotropy (FA) were measured in white matter tracts and gray matter. Results: Ablation of white matter fibro tracts and reduction of FA could be found in 22 patients (91.67%). Erosion like alteration was seen in 8 patients (30.33%). In all the patients with tumors showed push and displacement of the white matter fibro tracts. Conclusion: Diffusion tensor imaging can show lesions in white matter at early stage of some diseases. It is better in displaying damage or displacement of white matter tracts than conventional MRI.更多还原