Automated volumetric MRI quantification of body fat and skeletal muscle in the UK Biobank: technical validation against expert manual segmentations and comparison with single-slice techniques

Automated volumetric MRI delivers gold-standard fat and muscle quantification at scale, validated against expert manual segmentations. Lumbar single-slice measurements are strongly correlated with volumes, enabling fast routine assessments. Interchangeable, vendor-neutral methods standardize body composition endpoints for clinics and trials—enabling confident monitoring and scalable, trial-ready biomarkers.