QCT对腰椎BMD值的测量及BMD值与相关实验室指标分析

摘要

目的 探讨不同范围及部位的ROI选取对QCT测量腰椎松质骨BMD值的影响;BMD与血钙、血磷、ALP、PTH、BAP等相关实验室指标的相关性.方法 收集2016年2月~2017年2月在我院行无体模QCT检查,且临床资料及相关实验室检查资料完整者46例,平均年龄(66.73 ± 5.71)岁.无体模QCT检查扫描L2~L4椎体中间层面,并通过后处理工作站分别选取不同直径的类圆形脂肪组织感兴趣区ROI(d=1.5cm及d=0.5cm)及不同部位(皮下脂肪组织及腹腔内脂肪组织)的ROI,测得相应腰椎松质骨BMD值;分析ROI不同的选取测得的BMD值对诊断骨质减少组及骨质疏松组是否有统计学差异.对血钙、血磷、ALP、PTH、BAP实验室指标与BMD值进行线性相关性分析.结果 BMD值随着年龄增大而减少;不同部位脂肪组织与骨质减少组和骨质疏松组的相关性如下:皮下脂肪组织ROI(d=1.5cm)骨质减少组BMD均值为(92.80 ± 10.31)mg/cc,骨质疏松组BMD均值为(56.32 ± 16.66)mg/cc;皮下脂肪组织ROI(d=0.5cm)骨质减少组BMD均值为(92.68 ± 12.42)mg/cc;骨质疏松组BMD均值为(57.80 ± 13.96)mg/cc;腹腔内脂肪组织ROI(d=0.5cm)骨质减少组BMD均值为(91.07 ± 13.39)mg/cc;骨质疏松组BMD均值为(57.32 ± 13.26)mg/cc;脂肪组织ROI的不同选取对骨质减少组间及骨质疏松组间BMD值均无统计学差异( P值均>0.05).三种测量方法的BMD值与PTH值呈负相关,r值分别为 =-0.530;-0.548;-0.604,P <0.01.BMD值与 ALP、BAP、血钙、血磷指标无明显相关性( P >0.05).结论 QCT后处理中不同范围和不同部位的脂肪组织ROI选取对BMD测量结果无明显影响,对于体型偏瘦者皮下脂肪ROI选取受限时,可缩小脂肪组织ROI选取范围或选取腹腔内脂肪替代;骨质疏松发生率与PTH指标升高具有相关性.%Objective To explore the effect of ROI selected under the different ranges and sites on the measurement of BMD in lumbar bone with QCT and to investigate the correlations between BMD and related laboratory indexes in terms of serum calci-um,serum phosphorus,ALP,PTH,and BAP.Methods A total of 46 cases,which underwent phantom-less QCT examination in Ningbo NO.2 Hospital from February 2016 to February 2017,with complete clinical and related laboratory data,were collect-ed. The average age was(66.73 ± 5.71) years old. Phantom-less QCT examination scanned the intermediate level of L2~L4 vertebra,the different ranges(d=1.5 cm and d=0.5 cm) and sites(subcutaneous adipose tissue and intra-abdominal adipose tissue) of ROI were selected by workstation,and the BMD of the corresponding lumbar cancellous bones was measured. The BMD values obtained from different ROI were analyzed to judge whether there was a statistically significant difference in the diagnosis of osteopenia and osteoporosis. The linear correlation analysis of the related laboratory indexes of serum calcium,phosphorus,ALP, PTH,or BAP with BMD was performed.Results BMD values decreased with age. The correlation of adipose tissue indifferent parts with osteoporosis or osteopenia was as follows:the mean BMD of osteopenia with subcutaneous adipose tissue ROI(d=1.5 cm) was (92.80 ± 10.31) mg/cc;The mean BMD of osteoporosis was (56.32 ± 16.66) mg/cc; the mean BMD of osteopenia with subcutaneous adipose tissue ROI(d=0.5 cm) was(92.68 ± 12.42) mg/cc;The mean BMD of osteoporosis was(57.80 ± 13.96) mg/cc;the mean BMD of osteopenia with intra-abdominal adipose tissue ROI (d=0.5 cm) was (91.07 ± 13.39) mg/cc,and the mean BMD of osteoporosis was (57.32 ± 13.26) mg/cc. There was no statistical difference in BMD with different measurement methods of ROI between osteopenia and osteoporosis ( P >0.05). There was a negative correlation between BMD and PTH. r =-0.530;-0.548; -0.604,P <0.01. There was no significant correlation between BMD and ALP, BAP, serum calcium,or serum phosphorus ( P >0.05).Conclusion The selection of ROI in adipose tissue of different range and sites had no significant effect on BMD measurement. We can narrow the ROI selection range or select the intra-abdominal fat replacement for the thinner,in whom the subcutaneous fat ROI selection is limited. The osteoporosis is associated with an increase in PTH.