Clinical value of dual detector spectral CT in fracture risk prediction in patients with type 2 diabetes mellitus: A retrospective cross-sectional study

This retrospective cross-sectional study aimed to evaluate the clinical utility of dual-layer detector spectral CT (DLCT) in identifying bone mass abnormalities and predicting fracture risk among patients with type 2 diabetes mellitus (T2DM). Fifty patients with T2DM (28 males, 22 females; mean age, 65.21 ± 8.32 years) who underwent dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), and DLCT imaging of the lumbar spine and hips between January 2023 and December 2024 were retrospectively analyzed. Areal bone mineral density and T-scores at L1-L2 and bilateral hips were obtained using DXA, while volumetric bone mineral density (vBMD) was assessed by QCT. DLCT virtual monoenergetic images at 40 and 70 keV were reconstructed to calculate the energy spectral attenuation slope (γ value, HU/keV). Bone mass status was classified as normal, low bone mass, or osteoporosis according to WHO and Chinese QCT criteria. Statistical analysis included Fisher exact test and Pearson correlation. The detection rates of abnormal bone mass by DXA, QCT, and DLCT were 35.7%, 60.7%, and 64.3% in males, and 45.5%, 68.2%, and 72.7% in females, respectively. QCT and DLCT had significantly higher detection rates than DXA (P < .05), with no significant difference between QCT and DLCT (P > .29). DLCT-derived γ values showed strong correlations with QCT-measured vBMD at L1, L2, and both hips (r = 0.921-0.984, all P < .05), with consistent findings in sex-stratified analyses (r ≥ 0.933, P < .05). DLCT-derived γ values are strongly correlated with QCT-derived vBMD and outperform DXA in detecting bone abnormalities in T2DM patients. DLCT offers a reliable, opportunistic tool for fracture risk assessment during routine CT imaging.