正常成人大脑白质纤维各向异性特征的弥散张量磁共振成像研究

目的：利用弥散张量磁共振成像研究正常成人大脑白质纤维的各向异性特征。材料和方法：应用弥散张量磁共振成像方法，观察10例正常志愿者的大脑白质纤维的FA图像，分别测量两侧大脑半球相对称的5个感兴趣区即外囊、内囊前肢、内囊后肢、胼胝体前部、胼胝体后部的FA值，并进行比较。结果：在FA图像上可清楚地观察到大脑白质纤维结构，呈高信号，各个部位信号是不同的，胼胝体信号较其他部位高，尤以压部信号最高。5个感兴趣区的FA值是外囊0．41、内囊前肢0．48、内囊后肢0．71、胼胝体前部0．72、胼胝体后部0．86。各个兴趣区之间进行秩和检验，结果为胼胝体后部与外囊比较有统计显著差异，胼胝体后部与内囊前肢比较有统计显著差异，胼胝体前部与外囊相比较亦有统计显著差异，其余各兴趣区之间相比较无统计显著差异。结论：弥散张量磁共振成像方法有效地显示大脑白质纤维的各向异性特，缸，为正确认识大脑白质纤维的正常解剖提供更多有价值的信息。

Study of Anisotropy of Normal Adult Cerebral White Matter Fibers by Using Diffusion-Tenser MR Imaging

Purpose: To study the anisotropy of normal adult cerebral white matter fibers by using diffusion-tensor MR imaging. Materials and Methods: 10 volunteers are examined using diffusion-tensor MR imaging, and the FA images are analyzed. The FA values of 5 regions of interest are measured; the ROIs are external capsule, anterior limb of the internal capsule, posterior limb of the internal capsule, anterior of corpus callosum, posterior of corpus callosum. Results: The cerebral white matter fibers, which are high intensity, can be clearly revealed in FA maps. The intensity of the corpus callosum is higher than other regions, and the splenium of the corpus callosum is highest. FA values of five region of interests are: external capsule: 0.41, anterior limb of the internal capsule: 0.48, posterior limb of the internal capsule: 0.71, anterior of corpus callosum: 0.72, posterior of corpus callosum: 0.86. The posterior of corpus callosum has statistical difference compared to the external capsule and anterior limb of the internal capsule (P<0.05). The anterior of corpus callosum has statistical difference compared to the external capsule (P<0.05). Conclusion: the anisotropy of normal adult cerebral white matter fibers can be effectively showed using diffusion-tensor MR imaging, and can assist useful information in recognizing the normal anatomy of the cerebral white matter fibers.