[Relationship between vertebral CT values and bone mineral density in patients with chronic obstructive pulmonary...

Objective: To explore a simple method for early detection of osteoporosis in patients with chronic obstructive pulmonary disease (COPD), by analyzing the correlation between computed tomography (CT) values of the thoracolumbar vertebrae and dual energy X ray absorptiometry (DXA). Methods: 86 patients with acute exacerbation of COPD were included in this study. The average age of the patients, including 57 males and 29 females, was 74±10 years. They all received chest CT and DXA examination within 1 month after admission. The relation between each CT value from 6(th) thoracic vertebrae (T6) to 1(st) lumbar (L1) and T-score measured by DXA was analyzed by linear correlation analysis with SPSS 17.0 software. Results: The mean CT value of T6-L1 was significantly lower in patients with osteoporosis than that in patients with normal bone mineral density (P<0.05). The CT values of T6-L1 were positively correlated with T-score (P<0.001). The ROC curve analysis of T6-L1 CT value showed that the area under ROC curve of L1 CT value was the largest, and therefore the accuracy of diagnosis of osteoporosis by L1 CT value was better.A L1 CT value lower than 100 HU was proposed as the threshold for lower bone mass or osteoporosis in the patients. Conclusion: It is possible to detect osteoporosis in patients with COPD through evaluating the CT values of T6-L1. This method could potentially reduce X-ray irradiation and expense. Early detection and intervention in patients with COPD and osteoporosis could improve the prognosis of patients.