Sex- and age-specific distributions of intervertebral disc morphology on T2-weighted MR imaging: a population-based study

Abstract Objectives To perform a large-scale, automated morphometric analysis of intervertebral discs and characterize age- and sex-specific distributions of intervertebral disc (IVD) height, diameter, volume, and signal intensity in adults aged 19–74 years using T2-weighted MR imaging. Materials and methods Sagittal T2-weighted MR images from 30,927 participants of the German National Cohort (NAKO) were analyzed. Participants with back pain or osteoporosis were excluded. Intervertebral discs were segmented using a validated machine learning–based algorithm (SPINEPS). Morphometric parameters (IVD height, diameter, volume, and signal intensity) were extracted and analyzed separately for the cervical, thoracic, and lumbar spine. Analyses were stratified by sex and predefined age groups ( < 30, 30–39, 40–49, 50–59, ≥ 60 years). Multivariable fractional polynomial regression models were used to assess associations with age, body height, and body weight. Results After exclusion, 22,979 adults remained (13,307 men, 9672 women; mean age 47.0 ± 12.5 years). Across all spinal regions, IVD height, diameter, and volume were higher in men than in women. Increasing age was associated with progressive reduction in IVD height, volume, and signal intensity, accompanied by an increase in IVD diameter. Higher body weight was associated with increased IVD signal intensity in the lower cervical spine, whereas an inverse association was observed in the lower lumbar spine. Conclusion Using automated, large-scale MRI, this study characterizes age- and sex-specific distributions of intervertebral disc morphology in a large population-based cohort. These findings provide a comprehensive, normative reference of age- and sex-specific distributions of intervertebral disc morphology across the cervical, thoracic, and lumbar spine, offering a framework to support clinical interpretation, spine research, and surgical planning. Key Points Question What are the age- and sex-specific distributions of intervertebral disc morphology across the cervical, thoracic, and lumbar spine in a large population-based adult cohort? Findings Men exhibited higher disc height, diameter, and volume than women. Increasing age reduced disc height, volume, and signal intensity, while disc diameter increased. Clinical relevance These population-based data provide descriptive distributions of intervertebral disc morphology, supporting spine imaging interpretation and future clinical, epidemiological, and research applications .