Improved Segmentation of Deep Sulci in Cortical Gray Matter Using a Deep Learning Framework Incorporating Laplace's Equation
This work addresses the problem of accurate cortical segmentation for neuroimaging researchers, offering an incremental improvement by integrating geometric constraints into existing deep learning frameworks.
The authors tackled the challenge of achieving topologically correct cortical segmentation in MRI by incorporating geometric prior knowledge via Laplace's equation into a deep learning loss function, resulting in improved performance over baseline methods on an ex vivo human medial temporal lobe dataset.
When developing tools for automated cortical segmentation, the ability to produce topologically correct segmentations is important in order to compute geometrically valid morphometry measures. In practice, accurate cortical segmentation is challenged by image artifacts and the highly convoluted anatomy of the cortex itself. To address this, we propose a novel deep learning-based cortical segmentation method in which prior knowledge about the geometry of the cortex is incorporated into the network during the training process. We design a loss function which uses the theory of Laplace's equation applied to the cortex to locally penalize unresolved boundaries between tightly folded sulci. Using an ex vivo MRI dataset of human medial temporal lobe specimens, we demonstrate that our approach outperforms baseline segmentation networks, both quantitatively and qualitatively.