Automatic Bilateral Symmetry (Midsagittal) Plane Extraction from Pathological 3D Neuroradiological Images

Most pathologies (tumor, bleed, stroke) of the human brain can be determined by a symmetry-based analysis of neural scans showing the brain's 3D internal structure. Detecting departures of this internal structure from its normal bilateral symmetry can guide the classi cation of abnormalities. This process is facilitated by rst locating the ideal symmetry plane (midsagittal) with respect to which the brain is invariant under re ection. An algorithm to automatically identify this bilateral symmetry plane from a given 3D clinical image has been developed. The method has been tested on both normal and pathological brain scans, multimodal data (CT and MR), and on coarsely sliced samples with elongated voxel sizes.