Topologically constrained cortical surfaces from MRI
David W. Shattuck, Richard M. Leahy · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
We present a semi-automated method for constraining the topology of inner cerebral cortex volumes generated from T1- weighted magnetic resonance images (MRI). An initial tissue classification is generated based on a measurement model that accounts for partial volume effects and the presence of image inhomogeneities due to field non-uniformities. This classification is used to generate an interior cerebral white matter brain volume. This volume is processed by our algorithm to ensure that the topology of the cortical surface, that of a two-dimensional sheet, is represented in tessellations of the volume. We extend our previous work on topological constraints, which introduced an automated correction procedure that creates graph representations of volumetric objects in order to identify topological defects in their segmentation. We improve this method by performing an iterative correction process that limits the severity of changes made to the initial segmentation. The previous method also requires the duplication of slices of data wherever a change is required, which significantly increases the size of the volume. In the new method we identify a set of corrections that can be made without slice duplication. The key benefits to the improvements in our method are improved localization and correction of topological defects resulting in increased accuracy of the resulting cortical surface representation and a decrease in the size of the resulting volume.