Niharika Gajawelli1, Sinchai Tsao1, Darryl Hwang1, Bryce Wilkins1, Stephen Kriger2, Manbir Singh1
1Radiology and Biomedical Engineering, University of Southern California, Los Angeles, CA, United States; 2Center for Imaging of Neurodegenerative Diseases, VA Medical Center, San Francisco, CA, United States
FreeSurfer parcellation of the T1 weight human brain often fails in the presence of cerebral infarcts. This study presents a method of using voxels from the contralateral hemisphere to fill-in the cerebral infarct. The technique relied on SPM normalization including the normal and the hemispherically flipped versions of the brain, without any manual intervention other than an initial masking. A novel validation methodology was developed based on comparing ratios of FreeSurfer parcellated regions in a simulation study where the ground truth was known. Results show successful processing of 16 stroke subjects after filling, whereas processing in half failed before filling.