POTHER: Patch-Voted Deep Learning-based Chest X-ray Bias Analysis for COVID-19 Detection

Tomasz Szczepański, Arkadiusz Sitek, Tomasz Trzcinski, Szymon Plotka

Abstract:

A critical step in the fight against COVID-19, which continues to have a catastrophic impact on peoples lives, is the effective screening of patients presented in the clinics with severe COVID-19 symptoms.
Chest radiography is one of the promising screening approaches. Many
studies reported detecting COVID-19 in chest X-rays accurately using
deep learning. A serious limitation of many published approaches is insufficient attention paid to explaining decisions made by deep learning
models. Using explainable artificial intelligence methods, we demonstrate
that model decisions may rely on confounding factors rather than medical pathology. After an analysis of potential confounding factors found
on chest X-ray images, we propose a novel method to minimise their negative impact. We show that our proposed method is more robust than
previous attempts to counter confounding factors such as ECG leads in
chest X-rays that often influence model classification decisions. In addition to being robust, our method achieves results comparable to the
state-of-the-art. The source code and pre-trained weights are publicly
available at (https://github.com/tomek1911/POTHER).