A method for supervoxel-wise association studies of age and other non-imaging variables from coronary computed tomography angiograms

TL;DR

This paper introduces a novel supervoxel-wise association method for analyzing localized age-related changes in coronary CT angiograms, revealing sex-specific differences and new regions linked to aging.

Contribution

The study develops a new image segmentation and registration-based approach for supervoxel-wise correlation analysis of age in coronary CT images.

Findings

High accuracy in image registration demonstrated by Dice coefficient and inverse consistency.

Localized associations with age identified outside traditional regions of interest.

Significant sex differences observed in age-volume association patterns.

Abstract

The study of associations between an individual's age and imaging and non-imaging data is an active research area that attempts to aid understanding of the effects and patterns of aging. In this work we have conducted a supervoxel-wise association study between both volumetric and tissue density features in coronary computed tomography angiograms and the chronological age of a subject, to understand the localized changes in morphology and tissue density with age. To enable a supervoxel-wise study of volume and tissue density, we developed a novel method based on image segmentation, inter-subject image registration, and robust supervoxel-based correlation analysis, to achieve a statistical association study between the images and age. We evaluate the registration methodology in terms of the Dice coefficient for the heart chambers and myocardium, and the inverse consistency of the transformations, showing that the method works well in most cases with high overlap and inverse consistency. In a sex-stratified study conducted on a subset of $n=1388$ images from the SCAPIS study, the supervoxel-wise analysis was able to find localized associations with age outside of the commonly segmented and analyzed sub-regions, and several substantial differences between the sexes in the association of age and volume.