A Benchmark of Medical Out of Distribution Detection

Tianshi Cao, Chin-Wei Huang, David Yu-Tung Hui, Joseph Paul Cohen

TL;DR: Benchmark of OoD methods on medical tasks. A binary classifier trained on a neural network's features is best so far.

Abstract:

Motivation: Deep learning models deployed on medical tasks can be equipped with Out-of-Distribution Detection (OoDD) methods in order to avoid erroneous predictions. However it is unclear which OoDD methods are effective in practice.

Specific Problem: Systems trained for one particular domain of images cannot be expected to perform accurately on images of a different domain. These images should be flagged by an OoDD method prior to prediction.

Our approach: This paper defines 3 categories of OoD examples and benchmarks popular OoDD methods in three domains of medical imaging: chest X-ray, fundus imaging, and histology slides.

Results: Our experiments show that despite methods yielding good results on some categories of out-of-distribution samples, they fail to recognize images close to the training distribution.

Conclusion: We find a simple binary classifier on the feature representation has the best accuracy and AUPRC on average. Users of diagnostic tools which employ these OoDD methods should still remain vigilant that images very close to the training distribution yet not in it could yield unexpected results.

URL: https://github.com/caotians1/OD-test-master

Community Implementations: [ 5 code implementations](https://www.catalyzex.com/paper/arxiv:2007.04250/code)