Deep Learning for Distinguishing Normal versus Abnormal Chest Radiographs and Generalization to Unseen Diseases

TL;DR

This study developed an AI system to classify chest X-rays as normal or abnormal, demonstrating its ability to generalize across diverse populations and unseen diseases, and reducing diagnostic turnaround times.

Contribution

The paper presents a robust AI model trained on a large multi-national dataset that effectively generalizes to unseen diseases and populations, advancing clinical applicability.

Findings

AI system generalizes to new populations and unseen diseases

Reduced turnaround time for abnormal case detection by 7-28%

Demonstrates potential for AI to assist in clinical triage workflows

Abstract

Chest radiography (CXR) is the most widely-used thoracic clinical imaging modality and is crucial for guiding the management of cardiothoracic conditions. The detection of specific CXR findings has been the main focus of several artificial intelligence (AI) systems. However, the wide range of possible CXR abnormalities makes it impractical to build specific systems to detect every possible condition. In this work, we developed and evaluated an AI system to classify CXRs as normal or abnormal. For development, we used a de-identified dataset of 248,445 patients from a multi-city hospital network in India. To assess generalizability, we evaluated our system using 6 international datasets from India, China, and the United States. Of these datasets, 4 focused on diseases that the AI was not trained to detect: 2 datasets with tuberculosis and 2 datasets with coronavirus disease 2019. Our results suggest that the AI system generalizes to new patient populations and abnormalities. In a simulated workflow where the AI system prioritized abnormal cases, the turnaround time for abnormal cases reduced by 7-28%. These results represent an important step towards evaluating whether AI can be safely used to flag cases in a general setting where previously unseen abnormalities exist.