运动想象训练（MIT）是脑卒中偏瘫康复治疗的新方法。MIT究竟是通过何种机制来发挥作用，目前尚不清楚。以往fMRI研究多通过任务态fMRI观察任务引起的脑区激活情况，忽略了脑区间存在的相互作用，从脑网络连接性的角度研究卒中后的恢复机制仅有少量报道, 用fMRI方法研究MIT干预后皮层下脑卒中患者脑网络连接性的变化目前国内外未见报道。课题组前期对脑卒中患者静息态fMRI研究发现, 手功能恢复较差的患者与恢复较好患者相比，损伤侧初级运动区和损伤对侧中央后回、顶上小叶及损伤同侧顶下小叶之间的功能性连接减弱，且这种连接性减弱和患者上肢运动功能评分具有相关性。本研究是对前期研究的深入,结合静息态fMRI和任务态fMRI两种实验模态分别从脑区间功能性连接(无向连接)和有效性连接(有向连接)两方面去了解皮层下脑卒中患者MIT干预后脑网络连接性的变化，为探讨脑重塑作用机制提供理论依据，进一步指导临床。

Motor imagery training (MIT) is a new therapy for stroke patients with hemiplegia. The mechanism of MIT in stroke patients is still unclear. Most former fMRI researchers focused on the change of activation in different cerebral cortices induced by the specific tasks through task-based fMRI. The interaction between these cortices should also be considered. At present there is a few studies about the cerebral network connectivity after stroke, however, no research has been reported corresponding the change of cerebral network connectivity in subcortical stroke patients after MIT. Our previous study has noted changes in resting-state functional connectivity between two subgroups: completely paralyzed hands (CPH) and partially paralyzed hands (PPH).The functional connectivity of the ipsilesional M1 with contralesional postcentral gyrus, superior parietal lobule and ipsilesional inferior parietal lobule was reduced in the CPH group compared with the PPH group. Moreover, the connectivity of these regions was positively correlated with the Fugl-Meyer Assessment scores (hand + wrist) across all stroke patients. This research is the further study to observe the change of the functional (undirected) and effective (directed) connectivity separately through resting-state fMRI and task-based fMRI in stroke patients after MIT intervention. It will provide a theoretical basis for mechanism of cerebral plasticity and guide our clinical work.