Automated body composition quantification from non-contrast CT for urolithiasis classification and exploratory incident risk assessment.

A classification cohort (n = 481; 246 calcium, 104 non-calcium, 131 stone-free individuals) was divided into training, internal test and external validation sets.

A separate longitudinal cohort (n = 300) of stone-free individuals who underwent abdominal CT for non-urological indications was followed for a median of 5.2 years.

Using a prespecified threshold, high model-derived risk status was observed in 6 of 8 participants who later developed incident urolithiasis (sensitivity of 75%; 95% CI: 0.35-0.97), demonstrating a preliminary association with subsequent stone events, alongside a specificity of 89% (260 of 292 non-events).