Use of thoracic CT values in opportunistic screening for osteoporosis

Thoracic and abdominal computed tomography (CT) provide a valuable opportunity for osteoporosis (OP) screening regardless of the clinical indication for imaging. The diagnostic efficacy of thoracic CT values for OP is unclear. Our aim was to analyze the diagnostic efficacy of thoracic CT values based on conventional abdominal CT scans in screening for OP.

A retrospective analysis was conducted of the CT and bone mineral density (BMD) values of 318 patients who underwent routine abdominal CT and quantitative CT simultaneously, of whom 50 patients were selected to also undergo chest CT scans simultaneously. The Pearson correlation test was used to examine the relationship between vertebral CT values and BMD. The consistency of average CT values of T10-T12 vertebrae measured by chest CT and abdominal CT was analyzed using Bland-Altman plots. Receiver operating characteristic (ROC) curves were used to assess the diagnostic efficacy of average CT values of T10-T12 vertebrae in predicting OP.

A significant correlation was found between CT values of T10-L2 vertebrae and BMD (p < 0.01). Bland-Altman plots showed good consistency between the average CT values of T10-T12 vertebrae measured by chest CT and abdominal CT. In ROC analyses, the AUC values for predicting OP using average CT values of T10-T12 were 0.957. The sensitivity and specificity were 90.7%and 90.1%, respectively. The thresholds were 119.67 HU for OP. The average CT values of T10-T12 and L1-L2 showed no significant difference in AUC for predicting OP (p > 0.05).

There is a significant correlation between thoracic CT values and BMD. Thoracic CT values have high diagnostic efficacy for opportunistic OP screening.