🤖 AI Summary
This work addresses key limitations in existing multi-scale feature fusion approaches in computational pathology, which often rely on predefined magnification levels, lack cross-scale associations, and incur high computational costs. To overcome these challenges, the authors propose a plug-and-play Multi-Scale Pyramid Network (MSPN) that enables cross-scale feature generation through grid remapping. MSPN incorporates a Coarse-to-fine Guidance Network (CGN) to reconstruct low-magnification representations from high-magnification features and integrates an attention-based multiple instance learning (MIL) framework for progressive whole-slide analysis. Notably, MSPN operates without fixed magnification levels and is compatible with diverse backbone models and MIL architectures. Extensive experiments across four clinical tasks, three backbone networks, and multiple MIL frameworks consistently demonstrate performance improvements, highlighting MSPN’s lightweight design, flexibility, and plug-and-play utility.
📝 Abstract
Multiple-instance Learning (MIL) is commonly used to undertake computational pathology (CPath) tasks, and the use of multi-scale patches allows diverse features across scales to be learned. Previous studies using multi-scale features in clinical applications rely on multiple inputs across magnifications with late feature fusion, which does not retain the link between features across scales while the inputs are dependent on arbitrary, manufacturer-defined magnifications, being inflexible and computationally expensive. In this paper, we propose the Multi-scale Pyramidal Network (MSPN), which is plug-and-play over attention-based MIL that introduces progressive multi-scale analysis on WSI. Our MSPN consists of (1) grid-based remapping that uses high magnification features to derive coarse features and (2) the coarse guidance network (CGN) that learns coarse contexts. We benchmark MSPN as an add-on module to 4 attention-based frameworks using 4 clinically relevant tasks across 3 types of foundation model, as well as the pre-trained MIL framework. We show that MSPN consistently improves MIL across the compared configurations and tasks, while being lightweight and easy-to-use.