Context-Aware Convolutional Neural Network for Grading of Colorectal Cancer Histology Images

Muhammad Shaban, Ruqayya Awan, Muhammad Moazam Fraz, Ayesha Azam, David Snead, Nasir Rajpoot

IEEE Transactions on Medical Imaging · 2020 · 12 citations · 32 references

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TL;DR

Digital histology images contain vast pixel data that makes them suitable for convolutional neural networks, yet conventional patch‑based CNNs ignore high‑resolution contextual information. The study proposes a context‑aware CNN that processes 1792 × 1792‑pixel images to capture larger contextual information. The framework encodes local histology patches into high‑dimensional features, aggregates them by spatial organization, and applies the resulting representation to colorectal cancer grading across two datasets, with a detailed analysis of model variants. The proposed method outperformed traditional patch‑based, problem‑specific, and other context‑based approaches in colorectal cancer grading.

Abstract

Digital histology images are amenable to the application of convolutional neural networks (CNNs) for analysis due to the sheer size of pixel data present in them. CNNs are generally used for representation learning from small image patches (e.g. 224×224 ) extracted from digital histology images due to computational and memory constraints. However, this approach does not incorporate high-resolution contextual information in histology images. We propose a novel way to incorporate a larger context by a context-aware neural network based on images with a dimension of 1792×1792 pixels. The proposed framework first encodes the local representation of a histology image into high dimensional features then aggregates the features by considering their spatial organization to make a final prediction. We evaluated the proposed method on two colorectal cancer datasets for the task of cancer grading. Our method outperformed the traditional patch-based approaches, problem-specific methods, and existing context-based methods. We also presented a comprehensive analysis of different variants of the proposed method.

References

32