Institut für Radiologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München, Germany.
Curr Med Chem. 2013;20(38):4844-52. doi: 10.2174/09298673113206660279.
Osteoporosis is classified as a public health problem due to its increased risk for fragility fractures. Osteoporotic fractures, in particular spine and hip fractures, are associated with a high morbidity and mortality, and generate immense financial cost. The World Health Organisation (WHO) based the diagnosis of osteoporosis on the measurement of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). However, BMD values of subjects with versus without osteoporotic fractures overlap. Furthermore, it was reported that the anti-fracture effects of drugs could be only partially explained by their effects on BMD. Bone strength reflects the integration of BMD and bone quality. The later can be partly determined by measurements of bone microstructure. Therefore, substantial research efforts have been undertaken to assess bone microstructure by using high-resolution imaging techniques, including high-resolution peripheral quantitative computed tomography (hr-pQCT), high-resolution multi-detector computed tomography (MDCT), and high-resolution magnetic resonance imaging (MRI). Clinical MDCT and MRI systems are broadly available and allow an adequate depiction of the bone microstructure at the clinically most important fracture sites, i.e. radius, spine and hip. Bone microstructure parameters and finite element models can be computed in high-resolution MDCT and MR images. These measurements improved the prediction of bone strength beyond the DXA-derived BMD and revealed pharmacotherapy effects, which are partly not captured by BMD. Therefore, high-resolution bone imaging using clinical MDCT and MRI may be beneficial for osteoporosis diagnostics and allow a highly sensitive monitoring of drug treatment, which plays an important role in the prevention of fragility fractures.
骨质疏松症因其脆性骨折风险增加而被归类为公共卫生问题。骨质疏松性骨折，特别是脊柱和髋部骨折，与高发病率和死亡率相关，并产生巨大的经济成本。世界卫生组织（WHO）基于双能 X 射线吸收法（DXA）测量骨密度（BMD）来诊断骨质疏松症。然而，患有和不患有骨质疏松性骨折的受试者的 BMD 值存在重叠。此外，据报道，药物的抗骨折作用只能部分通过其对 BMD 的影响来解释。骨强度反映了 BMD 和骨质量的综合。后者可以部分通过骨微结构的测量来确定。因此，已经进行了大量研究来使用高分辨率成像技术评估骨微结构，包括高分辨率外周定量计算机断层扫描（hr-pQCT）、高分辨率多探测器计算机断层扫描（MDCT）和高分辨率磁共振成像（MRI）。临床 MDCT 和 MRI 系统广泛可用，允许在临床上最重要的骨折部位（即桡骨、脊柱和髋部）充分描述骨微结构。可以在高分辨率 MDCT 和 MR 图像中计算骨微结构参数和有限元模型。这些测量方法提高了对骨强度的预测能力，超出了 DXA 衍生的 BMD，并揭示了部分不能被 BMD 捕捉到的药物治疗效果。因此，使用临床 MDCT 和 MRI 的高分辨率骨成像可能对骨质疏松症的诊断有益，并允许对药物治疗进行高度敏感的监测，这在预防脆性骨折方面起着重要作用。
