Abstract: ObjectiveTo explore the relationship between fractional anisotropy (FA) of corticospinal tract (CST) and motor function in stroke patients using diffusion tensor imaging (DTI). MethodsFrom January, 2013 to October, 2016, 36 stroke patients were evaluated with Fugl-Meyer Assessment (FMA), Japan Upper Limb Function Test and DTI before and eight weeks after rehabilitation. FA in posterior limb of internal capsule, cerebral peduncle and pons were obtained, including ipsilesional and contralesional CST. ResultsThe FA values within three sections of CST were significantly lower in the ipsilesional side than in the contralesional side both before and after rehabilitation (t>5.330, P<0.001). In posterior limb of internal capsule, the FA value increased after rehabilitation (t=-3.415, P<0.05), and no significant difference was found in the other two sections (t<1.653, P>0.05) in the ipsilesional side, as well as in all the sections in the contralesional side (t<1.021, P>0.05). The FA values were positively correlated with the scores of FMA and Japan Upper Limb Function Test in all the sections both before and after rehabilitation (r>0.43, P<0.05), especially the relationship between the FA value and the score of Japan Upper Limb Function Test in the posterior limb of internal capsule (r=0.67). ConclusionDTI can be used to evaluate CST injury and the relationship between CST injury and motor function.

Key words: stroke, corticospinal tract, diffusion tensor imaging, motor function