Utilization of diffusion tensor tractography in combination with spatial normalization to assess involvement of the corticospinal tract in capsular/pericapsular stroke: Feasibility and clinical implications.

Purpose: To investigate the feasibility of using spatial normalization in combination with diffusion tensor (DT) corticospinal tractography to assess corticospinal tract (CST) involvement in capsular or pericapsular stroke.

Materials And Methods: Corticospinal tractograms were created and segmented out using DT imaging (DTI) data from 10 normal volunteers. After spatial normalization was achieved with statistical parametric mapping (SPM), the whole ensemble of tractograms was used as a map of the CST. This was overlaid on the infarction site, which had also been spatially normalized from isotropic diffusion-weighted (DW) images of 14 patients with small symptomatic capsular or pericapsular infarction. We evaluated the extent of CST involvement within the infarction site. Differences were sought in relation to recovery of muscle strength.

Results: The CST was engulfed by the infarction in all patients. Muscle strength recovery occurred in 10 of the 14 patients. The extent of cross-sectional and longitudinal involvement in the infarction site was related to motor recovery (P = 0.041).

Conclusion: An evaluation of the involvement of the CST in cases of capsular or pericapsular infarction utilizing DT fiber tractography in combination with spatial normalization was found to be feasible as it clearly visualized the extent of CST involvement consistent with the symptom.