Comparative Study of the Accuracies and Efficiencies of Dual-layer Spectral CT, QCT, and DXA for Osteoporosis Diagnosis

Objective: In this study, we aimed to compare the accuracies and efficiencies of dual-layer spectral computed tomography (CT), quantitative CT (QCT), and dual-energy X-ray absorptiometry (DXA) in diagnosing osteoporosis. Methods: From January to October, 2023, 30 outpatients, including 15 males (age (56.6±8.31) years old) and 15 females (age (65.13±7.16) years old), at the spine surgery department of Beijing Jishuitan Hospital were retrospectively analyzed. All patients underwent bilayer spectral CT, QCT, and DXA of the lumbar spine. Additionally, bone mineral density (BMD) values for the L1~L3 vertebral bodies and areal BMD values were measured using DXA. Based on the diagnostic criteria for osteoporosis using lumbar spine QCT and DXA, the study participants were divided into three groups: normal bone mass, abnormal/low bone mass, and osteoporosis groups. Accuracies of dual-energy spectral CT, QCT, and DXA for BMD measurements to diagnose osteoporosis were compared using Fisher’s exact test. Moreover, sensitivity and specificity of dual-energy spectral CT to measure volumetric BMD values for osteoporosis diagnosis were calculated using receiver operating characteristic curves. Results: A strong correlation was observed among the average BMD values for L1~L3 measured using all three methods (0.751~0.971). Accuracies of osteoporosis diagnosis using dual-energy spectral CT, QCT, and DXA were 66.7% (10/15), 53.3% (8/15), and 40% (6/15), respectively, in males and 93.3% (14/15), 86.7% (13/15), and 60% (9/15), respectively, in females, with statistically significant differences. Dual-energy spectral CT showed area under the curve values of 0.995 (sensitivity: 88.9%; specificity: 90.5%) and 0.784 (sensitivity: 60%; specificity: 93.3%) with QCT and DXA as reference standards, respectively, for osteoporosis diagnosis. Conclusion: Volumetric BMD values measured using dual-energy spectral CT were comparable to those measured using QCT for osteoporosis diagnosis, and both outperformed DXA in terms of diagnostic efficiency.