194   Volumetric Analysis of Cerebral Peduncles and Cerebellar Hemispheres for Predicting XXXX Following Hemispherectomy.

@entity1 @entity86 @entity302 @entity1269
INTRODUCTION: Better ways to predict motor outcome following hemispherectomy are necessary to implement the informed consent process in @entity1 with @entity302 . The volumetric analysis of cerebral peduncles and cerebellar hemispheres in @entity1 who had undergone hemispherectomy may determine prognostic implications for @entity86 . METHODS: Twenty-two @entity1 who underwent hemispherectomy at our institution, who had follow-up of at least 6 months and had accessible preoperative volumetric MRIs were retrospectively included. With the use of iPlan/BrainLAB imaging software, the volumes of bilateral cerebral peduncles and cerebellar hemispheres were calculated. After defining the borders of region of interest the volume of the resulting enclosed figure was calculated using software iPlan cranial via a semiautomatic voxel-based segmentation method. RESULTS: Eleven @entity1 were found to have improved or unchanged @entity1269 (group 1); these were compared with 11 who had worsening @entity1269 following hemispherectomy (group 2). The ratio of ipsilateral/contralateral peduncle volume in group 1 was 0.535 with a standard deviation of 0.23 (laterality refers to side of hemispherectomy), significantly lower than the ratio in group 2 (0.79 with a standard deviation of 0.21; P value <.0139). No @entity1 with a peduncle ratio of less than 0.5 experienced worsening of @entity1269 . CONCLUSION: While @entity1 who undergo hemispherectomy are heterogeneous, we report a method of predicting @entity86 only using a standard volumetric MRI. This information could be used in the preoperative discussions with @entity1 and families to help better understand that chance of retaining baseline motor function.
