A nomogram for predicting low bone mineral density in the elderly using chest CT

Area of Science:

• Radiology
• Geriatrics
• Bone Metabolism

Background:

• Osteoporosis causes fragility fractures, posing a significant health burden on aging populations.
• Early detection of bone loss is crucial for timely clinical intervention and management.
• Current screening methods may not be universally accessible or cost-effective for all individuals.

Purpose of the Study:

• To develop a predictive nomogram for low bone mineral density (BMD) using opportunistic chest CT scans.
• To identify key clinical and imaging predictors of diminished BMD.
• To evaluate the performance and clinical utility of the developed nomogram.

Main Methods:

• Retrospective analysis of 217 patients who underwent both chest CT and DXA within 30 days.
• Stratification into Normal and Low BMD groups based on DXA T-scores.
• Multivariate logistic regression to identify predictors, with model performance assessed by ROC curves, calibration, and Decision Curve Analysis (DCA).

Main Results:

• T11 CT attenuation, age, and BMI were significant independent predictors of low BMD (P < 0.05).
• The CT-based nomogram achieved an AUC of 0.864, indicating good discriminatory performance.
• Model fit and clinical net benefit were confirmed by Hosmer-Lemeshow test, DCA, and calibration plots.

Conclusions:

• An opportunistic CT-based nomogram can effectively identify individuals at risk for bone mass deterioration.
• This tool offers a potential cost-effective screening approach for bone loss in middle-aged and older adults.
• Leveraging existing chest CT scans can facilitate opportunistic prediction of osteoporosis risk.