急性单侧大脑中动脉供血区局灶性梗死患者胼胝体各向异性的MRI初步研究

MR anisotropy of corpus callosum in patients with focal acute cerebral infarct in the area supplied by unilateral middle cerebral artery

目的:利用MR DWI技术探讨单侧大脑中动脉供血区急性脑梗死时胼胝体各部分各向异性可能存在的变化。方法:连续选取病灶位于单侧大脑中动脉供血区的急性脑梗死患者66例(分为4组)及同期行MRI检查且年龄、性别与病变组匹配的66例40岁以上健康成人作为对照组。应用SSEPI序列行正中矢状面DTI扫描,在FA图上分别测量胼胝体膝部、体部前1/3处、体部中部、体部后1/3处及压部的FA值并进行统计学分析。结果:胼胝体体部前1/3处、体部中部及体部后1/3处的FA值均为正常组大于梗死组,胼胝体体部前1/3处及体部后1/3处的FA值正常组(分别为0.698±0.054和0.769±0.049)与梗死组(分别为0.665±0.049和0.653±0.078)之间差异存在统计学意义(t值为2.697和7.381,P<0.05)。胼胝体膝部及压部FA值均为梗死组(分别为0.780±0.082和0.772±0.049)大于正常组(分别为0.723±0.061和0.748±0.049),且两组之间差异有统计学意义(t值为-3.28和-2.08,P<0.05)。结论:单侧大脑中动脉供血区发生急性梗死时,连接双侧脑半球相应部位的胼胝体体部各向异性值减低,非承担这些脑叶间相互连接功能的膝部及压部各向异性值增高。

Objective：Using MR diffusion tensor imaging （DTI） technique,to study the possible changes of anisotropy in different regions of corpus callosum in patients with focal acute cerebral infarct in the area supplied by unilateral middle cerebral artery. Methods：Sixty-six patients with focal acute cerebral infarct in the area supplied by unilateral middle cerebral artery were collected consecutively and divided into four groups. In the mean time, sixty-six age-,sex matched healthy adult volunteers were collected consecutively as control group. Saggittal DTI with single-shot turbo spin echo （SSEPI） sequence were performed in all cases of infarct group as well as control group. The fractional anisotropy （FA） values of the genu,anterior 1/3,middle part,posterior 1/3 of the body and splenium of corpus callosum were measured in FA map and analyzed. Results：The FA values of anterior 1/3 middle part and posterior 1/3 of the body of corpus callosum were higher in the control group than that in infarct group. FA values in the anterior 1/3 and posterior 1/3 of the corpus callosun body of the control group was 0. 698±0. 054 and 0. 769±0. 049 respectively;while which of the infarct group was 0. 665±0. 049 and 0. 653±0. 078 respectively,with significant differences （t=2. 697,P〈0. 05;t=7. 381,P〈0.05）. The FA values of genu and splenium of the corpus callosum were higher in the infarct group （0. 780±0. 082 and 0. 772;0. 049） than that in control group （0. 723±0. 061 and 0. 748±0. 049） ,with significant differences （t=-3.28 and -2.08,P〈0.05）. Conclusion：When acute cerebral infarct occurred in areas supplied by unilateral middle cerebral artery, the FA values decreased in corpus callosum which connecting bilateral cerebral hemisphere; while FA values of genu and splenium, which don＇t have connecting function between cerebral lobes, increased.