【摘要】 诊断骨质疏松症多采用双能X射线吸收方法测得的骨密度数据作为依据,但是该方法存在一定量的辐射,且准确性不高.该文设计并改进了一套核磁共振装置,通过在发射和接收线圈之间增加快速切换开关（Q-switch）,使得核磁共振自旋回波的回波时间缩短至80μs的超短回波时间范围,实现了对T₂弛豫时间很短的骨组织核磁共振自旋回波信号的采集;将T₂弛豫时间谱和双能X射线方法测量的骨密度数据进行了对比研究,发现核磁共振T₂弛豫时间谱上300⁵00μs之间的峰值与骨密度之间具有良好的线性关系,随着骨密度的增大,相应的T₂弛豫时间峰值缩短;利用核磁共振T₂弛豫时间谱技术,结合双能X射线吸收方法,提出了一种测量生物离体骨骼样本骨密度的方法.该测量方案具有测量速度快、对人体完全无害、跨时期比较性强等优点,很好的弥补了现有测量方法的不足,在骨质疏松症的诊断和疗效评估中有着良好的应用前景.更多还原

【Abstract】 Bone mineral density（BMD） measured by dual energy X-ray absorptiometry is often used as an index for diagnosis of osteoporosis. However, ionization radiation is present in X-ray BMD measurement, and the result can be inaccurate in some caese. In this work, we constructed an NMR equipment that used a Q-switch to achieve echo time as low as 80 μ s, and thus have the potential to be used for BMD measurement. In the T₂ relaxation time spectra of bone measured by this equipment, the peak area at 300⁵00 μ s was found to change linearly with the BMD measured by X-ray absorptiometry. Based on this observation, we put forward a method to measure in vitro BMD with NMR T₂ relaxation time spectra. This kind of method has advantages such as high measuring speed, no ionization radiation, and high cross-period comparability.更多还原