Effects of Mid-Sagittal Plane Perturbation and Image Interpolation on Corpus Callosum Area Calculation

The corpus callosum (CC) is an anatomical structure that bridges the two brain hemispheres. It contains white matter tracts that participate in inter hemispheric communication. In multiple sclerosis (MS), the CC can have discrete lesions (MS plaques) or generalized tissue loss (atrophy), both of which affect the CC size. However, detection of changes in CC size depends on accurate identification of the mid-sagittal plane (MSP) in three dimensional space. We determine the error introduced in CC area when the plane of measurement is altered. Our contribution is the study of the effects of plane alteration and image interpolation. The interpolation techniques investigated are tricubic, trilinear and nearest neighbor. For measuring this error, we semi-automatically segment the CC in an MR volume. The voxels of the segmented volume are coded as binary values based on their position either inside or outside the CC. We then generate an MSP though reslicing and resampling of the volumetric data for varying values of MSP orientation and translation parameters. Finally we calculate the area of the CC whose cross section is embedded in the MSP