Martini Giuseppe, Valenti Roberto, Gennari Luigi, Salvadori Stefania, Galli Beatrice, Nuti Ranuccio
Department of Internal Medicine and Metabolic Diseases, University of Siena, Siena, Italy.
J Clin Densitom. 2004 Fall;7(3):349-54. doi: 10.1385/jcd:7:3:349.
The aim of our study was to evaluate the reproducibility and the diagnostic accuracy of a new device for the assessment of bone mineral density (BMD) of the heel, called dual X-ray and laser (DXL Calscan). This technique associates X-ray absorptiometry to the measure of heel thickness with a laser beam. The calcaneus BMD, calcaneus quantitative sonography (QUS), and lumbar spine and total-body BMD, were evaluated in 40 postmenopausal women. On the basis of the BMD T-score measured by dual-energy X-ray absorptiometry (DXA) of L2-L4, 20 women were classified as osteoporotic and 20 women were considered nonosteoporotic according to the WHO classification. The short-term coefficient of variation of the DXL was 2.4% and 1.7% in osteoporotic and nonosteoporotic women, respectively. The calcaneus BMD was lower in osteoporotic than in nonosteoporotic women. Among osteoporotic patients, 14 patients had a T-score lower than -2.5 at Calscan, whereas only 4 patients classified as nonosteoporotic based on the lumbar spine BMD were misclassified by Calscan. In these patients, the sensitivity and specificity of heel ultrasound measurements were 70% and 85%, respectively. The DXL BMD was highly correlated with the total-body BMD, Stiffness at the calcaneus, and the L2-L4 BMD. In conclusion, the new measuring device the Calscan DXL appeared easy to use, the time of examination was relatively short, and the reproducibility was sufficiently good; the diagnostic accuracy and relationships with other devices were good.
我们研究的目的是评估一种名为双能X射线与激光（DXL Calscan）的新型足跟骨矿物质密度（BMD）评估设备的可重复性和诊断准确性。该技术将X射线吸收测定法与用激光束测量足跟厚度相结合。对40名绝经后女性的跟骨BMD、跟骨定量超声（QUS）以及腰椎和全身BMD进行了评估。根据L2-L4双能X射线吸收测定法（DXA）测得的BMD T值，按照世界卫生组织的分类标准，20名女性被归类为骨质疏松症患者，20名女性被认为是非骨质疏松症患者。DXL在骨质疏松症女性和非骨质疏松症女性中的短期变异系数分别为2.4%和1.7%。骨质疏松症女性的跟骨BMD低于非骨质疏松症女性。在骨质疏松症患者中，14名患者在Calscan测量时T值低于-2.5，而在基于腰椎BMD被归类为非骨质疏松症的患者中，只有4名被Calscan误分类。在这些患者中，足跟超声测量的敏感性和特异性分别为70%和85%。DXL BMD与全身BMD、跟骨硬度以及L2-L4 BMD高度相关。总之，新型测量设备Calscan DXL使用方便，检查时间相对较短且可重复性良好；诊断准确性以及与其他设备的相关性良好。
