Predicting Osteoporosis Using Thoracic Spine HU Values from Chest CT: Validation Across Multiple CT Scanner Vendors

Osteoporosis is a common metabolic bone disease, and early bone mineral density (BMD) assessment is essential for timely intervention. Although dual-energy X-ray absorptiometry (DXA) is the diagnostic gold standard, its accuracy may be affected by spinal degenerative changes. Hounsfield unit (HU) measurements from thoracic CT scans offer a potential alternative for opportunistic screening, yet the consistency across different CT manufacturers remains unclear.This retrospective study included 207 patients who underwent thoracic CT and DXA within 60 days. Patients were grouped by CT manufacturer: Toshiba (n = 120), United Imaging (n = 57), and Siemens Healthineers (n = 30). HU values at T10 were measured, excluding cases with metabolic bone disease or image artifacts. One-way ANOVA compared HU values among groups, and Pearson correlation evaluated associations with the lowest DXA T-score.Mean HU values were: Toshiba 191.8 ± 60.55, United Imaging 172.8 ± 58.62, Siemens 172.2 ± 63.77 (P = 0.081). HU values correlated significantly with T-scores (r = 0.6213–0.6588), with no significant intergroup differences (P = 0.940).Thoracic HU values are consistent across CT devices and correlate well with BMD, supporting their use as a reliable, cost-effective tool for opportunistic osteoporosis screening.