The Multiscale Surface Vision Transformer.

Surface meshes are a favoured domain for representing structural and functional information on the human cortex, but their complex topology and geometry pose significant challenges for deep learning analysis. While Transformers have excelled as domain-agnostic architectures for sequence-to-sequence learning, notably for structures where the translation of the convolution operation is non-trivial, the quadratic cost of the self-attention operation remains an obstacle for many dense prediction tasks. Inspired by some of the latest advances in hierarchical modelling with vision transformers, we introduce the Multiscale Surface Vision Transformer (MS-SiT) as a backbone architecture for surface deep learning. The self-attention mechanism is applied within local-mesh-windows to allow for high-resolution sampling of the underlying data, while a shifted-window strategy improves the sharing of information between windows. Neighbouring patches are successively merged, allowing the MS-SiT to learn hierarchical representations suitable for any prediction task. Results demonstrate that the MS-SiT outperforms existing surface deep learning methods for neonatal phenotyping prediction tasks using the Developing Human Connectome Project (dHCP) dataset. Furthermore, building the MS-SiT backbone into a U-shaped architecture for surface segmentation demonstrates competitive results on cortical parcellation using the UK Biobank (UKB) and manually-annotated MindBoggle datasets. Code and trained models are publicly available at https://github.com/metrics-lab/surface-vision-transformers.

Fetal weight, maternal age and height are poor predictors of the need for caesarean section for arrest of labor.

Retrospective data on 228 patients was analyzed in order to develop a predictive model of operative delivery, caesarean section for arrest of labor. The ANOVA, discriminant analysis and the Fisher discriminant function of SPSS were used. Birth weight, maternal age and maternal height were statistically significant risk factors, but only 10.9% of caesarean sections could be predicted with these variables. Seven percent of patients who delivered vaginally were predicted as needing a caesarean section for arrest of labor.