Deep Regression for Biological Age Estimation in Multiple Organs: Investigations on 40,000 Subjects of the UK Biobank

Age plays an important role in shaping medical decisions, but the biological changes associated with aging do not solely depend on the chronological age. Genetics, lifestyle, and environment cause variations in age-related characteristics, even within the same chronological age group. Biological age (BA) was introduced to better capture an individual’s actual aging process, although its imprecise definition remains a challenge. Organ systems can age at different rates, necessitating organ-specific BA evaluation. To our knowledge, there have been no studies assessing age regionally across multiple organ systems. These age estimations, reflecting various body parts, enable a comprehensive patient-based analysis. We conducted brain, heart, kidney, liver, spleen, pancreas, and retinal fundus age estimations using MRI and OCT scans in 40,000 subjects of the UK Biobank with an uncertainty-aware ResNet-based network. Our results demonstrate the feasibility of organ-specific age estimation with cross-organ correlations of age-related changes. We achieve a mean age difference between predicted and chronological age of 2.72 years across all organs and an averaged Pearson correlation coefficient of 0.87.