Uncertainty quantification using Bayesian neural networks in classification: Application to ischemic stroke lesion segmentation

Yongchan Kwon, Joong-Ho Won, Beom Joon Kim, Myunghee Cho Paik

Abstract: Most recent research of neural networks in the field of computer vision has focused on improving accuracy of point predictions by developing various network architectures or learning algorithms. Uncertainty quantification accompanied by point estimation can lead to a more informed decision, and the quality of prediction can be improved. In medical imaging applications, assessment of uncertainty could potentially reduce untoward outcomes due to suboptimal decisions. In this paper, we invoke a Bayesian neural network and propose a natural way to quantify uncertainty in classification problems by decomposing predictive uncertainty into two parts, aleatoric and epistemic uncertainty. The proposed method takes into account discrete nature of the outcome, yielding correct interpretation of each uncertainty. We demonstrate that the proposed uncertainty quantification method provides additional insight to the point prediction using images from the Ischemic Stroke Lesion Segmentation Challenge.

Keywords: Uncertainty quantification, Bayesian neural network, Ischemic stroke lesion segmentation, Probabilistic interpretation

Author Affiliation: Seoul National University, Seoul National University Bundang Hospital