Atlas-Based Interpretable Age Prediction In Whole-Body MR Images

TL;DR

This study uses whole-body 3D MRI images and interpretability techniques to identify key body regions associated with age, revealing insights into aging patterns and differences in accelerated or decelerated aging.

Contribution

It introduces a novel population-wide interpretability approach for age prediction in whole-body MRI, highlighting specific anatomical regions linked to aging.

Findings

The spine, back muscles, and cardiac region are most predictive of age.

Population-wide importance maps reveal key aging-related body parts.

Differences are observed between accelerated and decelerated aging subjects.

Abstract

Age prediction is an important part of medical assessments and research. It can aid in detecting diseases as well as abnormal ageing by highlighting potential discrepancies between chronological and biological age. To improve understanding of age-related changes in various body parts, we investigate the ageing of the human body on a large scale by using whole-body 3D images. We utilise the Grad-CAM method to determine the body areas most predictive of a person's age. In order to expand our analysis beyond individual subjects, we employ registration techniques to generate population-wide importance maps that show the most predictive areas in the body for a whole cohort of subjects. We show that the investigation of the full 3D volume of the whole body and the population-wide analysis can give important insights into which body parts play the most important roles in predicting a person's age. Our findings reveal three primary areas of interest: the spine, the autochthonous back muscles, and the cardiac region, which exhibits the highest importance. Finally, we investigate differences between subjects that show accelerated and decelerated ageing.