Using routine CT scans for the detection of osteoporosis and exploring factors that affect DXA results

Abstract

Background Osteoporosis is prevalent among older adults but is an underdiagnosed condition. The purpose of this study was to explore the relationship between bone mineral density (BMD) and computed tomography (CT) attenuation based on dual-energy X-ray absorptiometry (DXA) as the reference standard and to predict the CT attenuation threshold for osteoporosis. Methods The cohort included 430 subjects (276 women and 154 men; mean age: 67.6 years) whose general information, CT attenuation, DXA, aortic calcification, and vertebral degeneration scores were collected. The relationship between DXA scores and aortic calcification and vertebral degeneration scores was analyzed by orderly logistic regression. The prediction of CT attenuation for osteoporosis was analyzed by receiver operating characteristic (ROC) curves. Results There was no significant difference in CT attenuation on the vertebral coronal, sagittal, or axial plane (p > 0.05). Obesity, paravertebral osteophytes, endplate sclerosis, and aortic calcification could impact the outcomes of DXA (p < 0.05). The sensitivity for distinguishing osteoporosis was at least 90% when the CT attenuation threshold was 120 HU; when the CT attenuation threshold was 81 HU, the specificity for distinguishing osteoporosis was at least 90%. When the threshold was 98 HU, the Youden index was the largest, with a specificity of 80.0% and a sensitivity of 82.3%. Conclusions CT attenuation of the lumbar spine can be used to identify patients with osteoporosis while reducing the influence of the bony structure around the vertebral body on the assessment of BMD.