Uncertainty-Based Biological Age Estimation of Brain MRI Scans
This work addresses organ-specific biological age estimation for brain health, potentially aiding in early detection of conditions like Alzheimer's, but it is an initial study with incremental methodology.
The authors tackled the problem of estimating biological age from brain MRI scans by proposing a framework that uses aleatoric uncertainty to filter out atypical aging patients, then trains a model on the remaining population to approximate true biological age, demonstrating correlation with cognitive deterioration in Alzheimer's patients.
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.