中老年人群L1椎体兴趣区域选取范围及位置对CT值的影响

Influence of the selected range and location of L1 vertebral interest region on CT values in middle-aged and elderly people

中文关键词:  骨密度  CT值  三维重建  骨质疏松症

英文关键词:Bone mineral density  CT value  Three-dimensional reconstruction  Osteoporosis

中文摘要:

  【摘要】 目的：分析中老年群体L1椎体兴趣区域选取范围及位置对CT值之间的差异。方法：收集2019年7月~2021年7月在我院行腰椎CT扫描及双能X线吸收法（dual-energy X-ray absorptiometry，DXA）检查的55例患者，其中男19例，女36例，年龄45~85岁（66.5±9.7岁）。收集患者CT图像资料和DXA测量的L1椎体骨密度。重建L1椎体，分别在冠状面、矢状面、横断面三等分截面中部选取面积为50mm2、200mm2、400mm2的兴趣区域测量CT值。重建L1椎体内松质骨并测量CT值。以组内相关系数评估CT值测量的一致性。根据兴趣区域选取面积和位置进行分组，采用双因素方差分析对CT值进行比较分析。根据比较结果再进行兴趣区域同面积不同部位、同部位不同面积CT值多重比较。观察多重比较的结果，将同条件下统计学差异结果的兴趣区域组的平均CT值与松质骨CT值比较分析、与DXA 测量L1骨密度进行相关性分析。结果：CT值测量具有可靠的测量者内一致性和测量者间一致性[组内相关系数（intraclass correlation coefficient，ICC）>0.8，P＜0.001]。兴趣区域选取面积和位置对CT值影响交互效应显著（F=3.28，P＜0.05）。兴趣区域选取同位置不同面积多重比较：横断面3部、冠状面3部和矢状面左右1/3部，兴趣区域50mm2与200/400mm2CT值存在显著性差异（P＜0.05）；兴趣区域200mm2与400mm2CT值存在显著性差异（P＜0.05）。矢状面中1/3部，兴趣区域50mm2、200mm2、400mm2相互之间CT值存在显著性差异（P＜0.05）。兴趣区域选取同面积不同部位多重比较：兴趣区域50mm2，横断面/矢状面3部、冠状面前1/3部CT值之间无显著性差异（P＞0.05），横断面/矢状面3部、冠状面前1/3部与冠状中后1/3部有显著性差异（P＜0.05）；兴趣区域200mm2，横断面3部、冠状面前1/3部、矢状面左右1/3部相互无显著差异（P＞0.05），横断面3部、冠状面前1/3部、矢状面左右1/3部与冠状面中后、矢状面中1/3部有显著性差异（P＜0.05）；兴趣区域400mm2，横断面上下1/3部、矢状面中右1/3部、冠状面前1/3部相互无显著差异（P＞0.05），横断面3部、矢状面中右1/3部相互无显著差异（P＞0.05），冠状位中后1/3部、矢状面中1/3部相互之间无显著性差异（P＞0.05），冠状位中后1/3部、矢状面中1/3 部与冠状位前1/3部、矢状面中、右1/3部、横断面3部CT值相互之间有显著性差异（P＜0.05），横断面中1/3部与冠状位前1/3部CT值之间有显著性差异（P＜0.05）。根据比较差异情况，将50mm2椎体前部CT值与L1椎体松质骨CT值无明显差异（P＞0.05），50mm2椎体前部CT值与DXA测量L1椎体BMD无显著相关性。结论：中老年人群中，L1椎体兴趣区域选取位置和面积能影响CT值测量结果，兴趣区域选取横断面、矢状面、冠状面前1/3部50mm2时CT值更能准确反映松质骨骨密度情况。

英文摘要:

  【Abstract】 Objectives: To analyze the differences in CT values between different sizes and locations of region of interest(ROI) in L1 vertebral body of middle-aged and elderly populations. Methods: A total of 55 patients undergone lumbar spine CT scan and dual-energy X-ray absorptiometry(DXA) examination in our hospital from July 2019 to July 2021 were collected, including 19 males and 36 females, aged 45-85 years(66.5±9.7 years) old. The CT image data and bone mineral density(BMD) of L1 vertebral body measured by DXA were collected. The L1 vertebral body was reconstructed, and the ROI with an area of 50mm2, 200mm2, and 400mm2 in the middle of the coronal, sagittal, and cross-sectional trisections were selected to measure the CT values. The cancellous bone in L1 vertebral body was reconstructed and measured in CT values. The intraclass correlation coefficient was used to evaluate the consistency of CT value measurement. The patients were divided according to the area and location of ROI, and the CT values were compared by two-way analysis of variance, and multiple comparisons were further carried out on the CT values of ROI of different parts of the same area and different areas of the same site. The results of multiple comparisons were observed, and the average CT value of the ROI group with statistically different results under the same conditions was compared with the CT value of cancellous bone, and its correlation with L1 BMD measured with DXA was analyzed. Results: The CT value measurements showed reliable intraobserver and interobserver consistency[intraclass correlation coefficient(ICC)＞0.8, P＜0.001]. The interaction effect of the selected area and location of ROI on CT values was significant(F=3.28, P＜0.05). In terms of ROI of one same site with different areas, there were significant differences in CT values in the ROI between 50mm2, 200mm2 and 400mm2 of 3 cross-sectional sections, 3 coronal sections and the left and right 1/3 of the sagittal plane(P＜0.05); There was a significant difference in CT values in the ROI between 200mm2 and 400mm2(P＜0.05); In the middle 1/3 of the sagittal plane, the CT values of 50/200/400mm2 were significantly different from each other(P＜0.05). In terms of ROI with same area in different sites, for 50mm2 ROI, there was no significant difference between the CT values of the 3 sections in the transverse/sagittal plane and the anterior 1/3 of the coronal plane(P＞0.05), and there were significant differences between the 3 sections of the transverse/sagittal plane, the anterior 1/3 of the coronal plane and the middle and posterior 1/3 of the coronal plane(P＜0.05); For 200mm2 ROI, there was no significant difference between the 3 parts of the transverse plane, the anterior 1/3 of the coronal plane, and the left and right 1/3 of the sagittal plane(P＞0.05), and there were significant differences between the 3 sections of the transverse plane, the anterior 1/3 of the coronal plane, the left and right 1/3 of the sagittal plane and the middle and posterior 1/3 of the coronal plane and the midle 1/3 of the sagittal plane(P＜0.05); For 400mm2 ROI, there was no significant difference between the upper and lower 1/3 of the transverse plane, the middle and right 1/3 of the sagittal plane, and the front 1/3 of the coronal plane(P＞0.05), there was no significant difference between the 3 parts of the transverse plane and the middle and right 1/3 of the sagittal plane(P＞0.05), there was no significant difference between the middle and posterior 1/3 of the coronal plane and the middle 1/3 of the sagittal plane(P＞0.05). The CT values of the middle and posterior 1/3 of the coronal plane, the middle 1/3 of the sagittal plane and the anterior 1/3 of the coronal plane, the middle and right 1/3 of the sagittal plane, and the 3 parts of transverse plane were significantly different from each other(P＜0.05), and there was a significant difference in CT values between the middle 1/3 of the transverse plane and the anterior 1/3 of the coronal plane(P＜0.05). According to the differences, there was no significant difference between the CT values of the anterior part of the 50mm2 vertebral body and the cancellous bone of L1 vertebral body(P＞0.05). There was no significant correlation between the CT values of the anterior 50mm2 vertebral body and the BMD of L1 vertebral body measured by DXA. Conclusions: The location and area of ROI in L1 vertebral body can affect the CT value measurement results in middle-aged and elderly people. The CT values can reflect the BMD of cancellous bone more accurately when the ROI is 50mm2 in the transverse plane, sagittal plane and the anterior 1/3 of the coronal plane.