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International Journal of Endocrinology
Volume 2013 (2013), Article ID 895474, 5 pages
http://dx.doi.org/10.1155/2013/895474
Clinical Study

Comparison of QCT and DXA: Osteoporosis Detection Rates in Postmenopausal Women

1Department of Radiology, Beijing Jishuitan Hospital, No. 31 Xinjiekou Street, Xicheng District, Beijing 100035, China
2Department of Spine Surgery, Beijing Jishuitan Hospital, No. 31 Xinjiekou Street, Xicheng District, Beijing 100035, China

Received 5 December 2012; Revised 1 March 2013; Accepted 4 March 2013

Academic Editor: Peng-Fei Shan

Copyright © 2013 Na Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. To compare the osteoporosis detection rates in postmenopausal women when measuring bone mineral density (BMD) with quantitative computed tomography (QCT) in the spine versus dual X-ray absorptiometry (DXA) in the spine and hip and to investigate the reasons for the discrepancy between the two techniques. Methods. Spinal volumetric BMD was measured with QCT, and areal spinal and hip BMDs were measured with DXA in 140 postmenopausal women. We calculated the osteoporosis detection rate for the two methods. Lumbar CT images of patients who had a discrepancy between QCT and DXA findings were reviewed to evaluate vertebral fractures, spinal degeneration, and abdominal aortic calcification. Results. For the entire 140 patients, the detection rate was 17.1% for DXA and 46.4% for QCT, a significant difference (P < 0.01). Of the 41 patients with conflicting diagnoses, 7 whose diagnosis by QCT was osteoporosis had vertebral fractures even though their DXA findings did not indicate osteoporosis. Varying degrees of spinal degeneration were seen in all of the 41 patients. Conclusion. QCT may avoid the overestimation of BMD by DXA associated with spinal degeneration, abdominal aortic calcification, and other sclerotic lesions. It may be more sensitive than DXA for detecting osteoporosis in postmenopausal women.