Uncertainty-Based Biological Age Estimation of Brain MRI Scans

TL;DR

This paper introduces a novel organ-specific biological age estimation method using 3D brain MRI scans, predicting age and uncertainty to identify atypical aging, with applications in Alzheimer's disease assessment.

Contribution

It presents a new framework for brain-specific biological age estimation that incorporates uncertainty and iterative training to improve accuracy and detect atypical aging.

Findings

Predicted biological age correlates with cognitive decline in Alzheimer's patients.

Uncertainty scores effectively identify atypical aging individuals.

Method demonstrates potential for organ-specific aging assessment.

Abstract

Age is an essential factor in modern diagnostic procedures. However, assessment of the true biological age (BA) remains a daunting task due to the lack of reference ground-truth labels. Current BA estimation approaches are either restricted to skeletal images or rely on non-imaging modalities that yield a whole-body BA assessment. However, various organ systems may exhibit different aging characteristics due to lifestyle and genetic factors. In this initial study, we propose a new framework for organ-specific BA estimation utilizing 3D magnetic resonance image (MRI) scans. As a first step, this framework predicts the chronological age (CA) together with the corresponding patient-dependent aleatoric uncertainty. An iterative training algorithm is then utilized to segregate atypical aging patients from the given population based on the predicted uncertainty scores. In this manner, we hypothesize that training a new model on the remaining population should approximate the true BA behavior. We apply the proposed methodology on a brain MRI dataset containing healthy individuals as well as Alzheimer's patients. We demonstrate the correlation between the predicted BAs and the expected cognitive deterioration in Alzheimer's patients.