Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792-3252, USA.
J Bone Miner Res. 2012 Jul;27(7):1494-500. doi: 10.1002/jbmr.1595.
This study compared microscopic magnetic resonance imaging (µMRI) parameters of trabecular microarchitecture between postmenopausal women with and without fracture who have normal or osteopenic bone mineral density (BMD) on dual-energy X-ray absorptiometry (DXA). It included 36 postmenopausal white women 50 years of age and older with normal or osteopenic BMD (T-scores better than -2.5 at the lumbar spine, proximal femur, and one-third radius on DXA). Eighteen women had a history of low-energy fracture, whereas 18 women had no history of fracture and served as an age, race, and ultradistal radius BMD-matched control group. A three-dimensional fast large-angle spin-echo (FLASE) sequence with 137 µm × 137 µm × 400 µm resolution was performed through the nondominant wrist of all 36 women using the same 1.5T scanner. The high-resolution images were used to measure trabecular bone volume fraction, trabecular thickness, surface-to-curve ratio, and erosion index. Wilcoxon signed-rank tests were used to compare differences in BMD and µMRI parameters between postmenopausal women with and without fracture. Post-menopausal women with fracture had significantly lower (p < 0.05) trabecular bone volume fraction and surface-to-curve ratio and significantly higher (p < 0.05) erosion index than postmenopausal women without fracture. There was no significant difference between postmenopausal women with and without fracture in trabecular thickness (p = 0.80) and BMD of the spine (p = 0.21), proximal femur (p = 0.19), one-third radius (p = 0.47), and ultradistal radius (p = 0.90). Postmenopausal women with normal or osteopenic BMD who had a history of low-energy fracture had significantly different (p < 0.05) µMRI parameters than an age, race, and ultradistal radius BMD-matched control group of postmenopausal women with no history of fracture. Our study suggests that µMRI can be used to identify individuals without a DXA-based diagnosis of osteoporosis who have impaired trabecular microarchitecture and thus a heretofore-unappreciated elevated fracture risk.
本研究比较了双能 X 射线吸收仪（DXA）检测骨密度正常或骨量减少的绝经后女性中，骨折组与无骨折组之间的小梁微观结构的微观磁共振成像（µMRI）参数。该研究纳入了 36 名年龄在 50 岁及以上的绝经后白人女性，其 DXA 检测的腰椎、股骨近端和三分之一桡骨的骨密度 T 评分均大于-2.5。其中 18 名女性有低能量骨折史，18 名女性无骨折史，作为年龄、种族和三分之一桡骨骨密度匹配的对照组。使用同一台 1.5T 扫描仪对所有 36 名女性的非优势腕关节进行了分辨率为 137µm×137µm×400µm 的三维快速大角度自旋回波（FLASE）序列。使用高分辨率图像测量了小梁骨体积分数、小梁厚度、表面到曲线比和侵蚀指数。Wilcoxon 符号秩检验用于比较有骨折和无骨折的绝经后女性之间的骨密度和 µMRI 参数的差异。有骨折的绝经后女性的小梁骨体积分数和表面到曲线比显著降低（p < 0.05），侵蚀指数显著升高（p < 0.05），而无骨折的绝经后女性则无显著差异（p > 0.05）。有骨折和无骨折的绝经后女性之间的小梁厚度（p = 0.80）、脊柱骨密度（p = 0.21）、股骨近端骨密度（p = 0.19）、三分之一桡骨骨密度（p = 0.47）和三分之一桡骨骨密度（p = 0.90）均无显著差异。有低能量骨折史且骨密度正常或骨量减少的绝经后女性的µMRI 参数与无骨折史且年龄、种族和三分之一桡骨骨密度匹配的对照组有显著差异（p < 0.05）。我们的研究表明，µMRI 可用于识别无 DXA 骨质疏松症诊断但具有受损小梁微观结构的个体，从而提高了以前未被认识到的骨折风险。
