腰椎定量CT骨密度测量椎体内差异研究

The Intravertebral BMD Variation Measured by QCT

目的研究受检者椎体内不同感兴趣区(ROI)腰椎定量CT(QCT)骨密度测量结果的差异,以提高其测量的准确性和可重复性。资料与方法对206例受检者进行腰椎检查(99例经GE64排螺旋CT扫描,107例经东芝16排螺旋CT扫描),获取扫描数据,通过Mindways QCT PRO工作站进行分析处理,使用软件的3D测量模式进行测量,ROI分别放在每个椎体的上、中、下1/3部位,分别测量L1～L3椎体上、中、下3个部位松质骨骨密度(BMD)。结果 L1～L3椎体上、中、下平均BMD分别为(116.75±47.73)mg/cm3、(126.37±47.63)mg/cm3和(123.77±52.67)mg/cm3,椎体内BMD差异有统计学意义(P<0.01),椎体内各部分骨密度相差<8%。结论腰椎椎体内BMD存在区域性差异,QCT BMD测量时应选择相同的感兴趣区以减少误差,但在实际临床应用中影响较小。

Purpose To improve the reproducibility and accuracy of spinal QCT by measuring bone mineral density （BMD） within different regions of interest （ROI） in the same vertebral body. Materials and Methods Two CT scanners were used to scan the lumbar vertebrae in 206 subjects （99 examples using 16-row Toshiba CT scanner and 107 examples using 64-row GE CT scanner）. All CT scan data were transferred to the QCT pro workstation to measure the BMD of L1, L2 and L3 vertebral bodies. The region of interest （ROI） was placed in the upper, middle and lower parts of each vertebra to assess the variation of BMD. Results The average BMD values in the upper, middle and lower parts of L1-L3 was 116.75 （mg/cm^3） , 126.37 （mg/cm^3） and 123.77 （mg/cm^3）. This variation was statistically significant, but less than 8%. Conclusion There is intravertebral variation in BMD measured by QCT. The region of interest （ROI） should be placed in the middle of the vertebral body consistently to avoid measurement error.