Wang Yu, Zhou Wei, Hao Yan-Jie, Li Guang-Tao, Deng Xue-Rong, Zhao Juan, Zhang Zhuo-Li
Department of Rheumatology and Immunology, Peking University First Hospital, Beijing 100034, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2013 Oct 18;45(5):766-9.
To evaluate the ability of calcaneus quantitative ultrasound (QUS) to diagnose osteoporosis in connective tissue disease (CTD) patients.
In the study, 126 female patients with established CTD underwent dual-energy X-ray absorptiometry (DXA) of the lumber and right hip and QUS of the right heel at the same time. Sensitivity, specificity, as well as positive and negative predictive values were calculated to determine the correlation between cases of osteoporosis detected by the QUS heel scan and by DXA.
The mean age of the 126 patients was (43.4 ± 19.8) years (ranging from 30.0 to 80.0 years). Based on their DXA data, 36 (28.6%) patients had normal bone mineral density (BMD, T score ≥ -1.0), 90 (71.4%) patients had abnormal BMD. In abnormal BMD patients, 45 (35.7%) had osteopenia (-2.5 < T score<-1.0), and 42 (33.3%) were osteoporotic (T score ≤ -2.5), while 3 (2.4%) patients had fragile fracture. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were all significantly different between osteopenia and the normal group when scanning with QUS. QUS T score was positively correlated with DXA T score, both at lumber and right hip respectively (r=0.491, 0.648, P<0.01). After correction by age and BMI, QUS T score remained positively correlated with DXA T score by partial correlation analysis (Pearson partial vertebral r=0.430, P=0.006; right hip r=0.593, P<0.001). The area under the ROC curve for diagnosis of lumber and hip osteoporosis were 0.836 (95%CI: 0.695, 0.977) and 0.647 (95%CI: 0.579, 0.957) separately. The sensitivity and specificity for identifying osteoporosis in lumber were 70% and 83.3% respectively when the T score threshold of QUS was defined as -1.5; however, the sensitivity and the specificity for identifying osteoporosis at right hip were 72.7% and 88.9% when T score threshold of QUS was defined as -1.85. The best SI threshold was defined as 76 for identifying osteoporosis, with sensitivity being 0.800 and specificity 0.741.
Our study confirmed that QUS measurements performed at calcaneus with quantitative ultrasound bone analysis were capable of screening osteoporosis defined by axial BMD using DXA in female CTD patients.
评估跟骨定量超声（QUS）诊断结缔组织病（CTD）患者骨质疏松症的能力。
本研究中，126例确诊为CTD的女性患者同时接受了腰椎和右髋部的双能X线吸收法（DXA）检查以及右足跟的QUS检查。计算敏感性、特异性以及阳性和阴性预测值，以确定通过QUS足跟扫描和DXA检测出的骨质疏松症病例之间的相关性。
126例患者的平均年龄为（43.4±19.8）岁（范围为30.0至80.0岁）。根据DXA数据，36例（28.6%）患者骨密度正常（BMD，T值≥ -1.0），90例（71.4%）患者BMD异常。在BMD异常的患者中，45例（35.7%）患有骨量减少（-2.5 < T值 < -1.0），42例（33.3%）为骨质疏松症（T值≤ -2.5），而3例（2.4%）患者发生了脆性骨折。使用QUS扫描时，骨量减少组与正常组之间的宽带超声衰减（BUA）、声速（SOS）和硬度指数（SI）均存在显著差异。QUS T值与DXA T值呈正相关，分别在腰椎和右髋部（r = 0.491，0.648，P < 0.01）。经年龄和BMI校正后，通过偏相关分析，QUS T值与DXA T值仍呈正相关（Pearson偏相关系数：腰椎r = 0.430，P = 0.006；右髋部r = 0.593，P < 0.001）。诊断腰椎和髋部骨质疏松症的ROC曲线下面积分别为0.836（95%CI：0.695，0.977）和0.647（95%CI：0.579，0.957）。当QUS的T值阈值定义为-1.5时，识别腰椎骨质疏松症的敏感性和特异性分别为70%和83.3%；然而，当QUS的T值阈值定义为-1.85时，识别右髋部骨质疏松症的敏感性和特异性分别为72.7%和88.9%。确定骨质疏松症的最佳SI阈值定义为76，敏感性为0.800，特异性为0.741。
我们的研究证实，使用定量超声骨分析在跟骨处进行的QUS测量能够筛查出女性CTD患者中由DXA定义的轴向BMD骨质疏松症。
