基于定量CT和CT灌注成像的腰椎骨密度与骨肌血流灌注、肌量相关性的初步研究

Correlation between lumbar bone mineral density,musculoskeletal perfusion and muscle mass:a preliminary study based on quantitative CT and CT perfusion

目的探讨腰椎骨密度(BMD)与骨肌血流灌注、肌量的相关性。方法回顾性收集2019年5月至2020年8月同济大学附属第十人民医院临床申请需要接受腹部CT灌注(CTP)检查的91例患者,扫描范围包括L1~L3椎体。在行CT平扫的同时行定量CT(QCT)检查,测量L1~L3椎体BMD并计算平均值,根据BMD分为骨量正常组(n=33)、骨量减少组(n=41)及骨质疏松组(n=17)。基于QCT计算L3水平椎体周围肌指数及脂肪分数。基于CTP图像测量L3椎体及椎体周围肌群灌注参数。3组间各参数比较采用Kruskal-Wallis H检验或单因素方差分析,相关性采用Pearson或Spearman相关分析。结果3组间椎体周围肌指数与脂肪分数差异有统计学意义(P<0.05)。3组间椎体骨灌注参数血流量(BF)、血容量(BV)、流量提取参数(FE)差异有统计学意义(P<0.05),且与BMD呈正相关(r值分别为0.444、0.312、0.266,P值均<0.05;校正年龄、性别因素后r值分别为0.437、0.340、0.337,P值均<0.05)。3组间椎体周围肌灌注参数差异无统计学意义(P>0.05)。椎体周围肌指数与脂肪分数呈负相关(r=-0.599,P<0.001;校正年龄、性别因素后r=-0.404,P<0.001),二者与椎体周围肌灌注参数间均无相关性。结论随BMD改变,L3水平骨肌含量变化同步,椎体骨量下降伴随周围肌量下降、肌内脂肪含量增多以及骨血流灌注下降。L3水平椎体和周围肌肉血流灌注变化不同步,骨质疏松患者血流灌注下降可能仅限于骨内。

Objective To investigate the correlation between lumbar bone mineral density(BMD),musculoskeletal perfusion andmuscle mass.Methods From May 2019 to August 2020,totally 91 patients who applied for CT perfusion(CTP)examination of abdomen(the scan range included the vertebral body of L1-L3)in Shanghai Tenth People′s Hospital of Tongji University were retrospectively analyzed.The mean BMD of L1-L3 vertebral body was measured by quantitative CT(QCT)at the same time of CT plain scan.According to BMD,the subjects were divided into normal BMD group(n=33),osteopenia group(n=41)and osteoporosis(OP)group(n=17).The L3 level perivertebral muscle mass index and fat fraction were calculated based on QCT examination.The lumbar vertebral and perivertebral muscle perfusion parameters were measured based on CTP images.The parameters of QCT and CTP among three groups were analyzed by Kruskal-Wallis H test or one-way ANOVA.The correlation analysis was conducted between these parameters using Pearson or Spearman analysis.Results The differences of the perivertebral muscle mass index and fat fraction among three groups were statistically significant(P<0.05).The differences of the lumbar vertebral perfusion parameters including blood flow(BF),blood volume(BV)and flow extraction product(FE)among three groups were statistically significant(P<0.05),and BF,BV and FE were positively correlated with BMD(r=0.444,0.312 and 0.266 respectively,all P<0.05;adjusted for age and gender r=0.437,0.340 and 0.337 respectively,all P<0.05).There was no statistically significant difference in perivertebral muscle perfusion parameters among three groups(P>0.05).Perivertebral muscle mass index was negatively correlated with fat fraction(r=-0.599,P<0.001;adjusted for age and gender r=-0.404,P<0.001),and there was no correlation between perivertebral muscle mass index and muscle perfusion parameters,as well as perivertebral muscle fat fraction and muscle perfusion parameters.Conclusions With the changes of BMD,bone mass and perivertebral muscle mass at L3 level are synchronous.Decreased vertebral bone mass is accompanied with reduced perivertebral muscle mass,increased muscle fat and decreased bone perfusion.The changes of vertebral perfusion and perivertebral muscle perfusion at L3 level are asynchronous,which implies that reduced perfusion in OP patients may be confined to the bone.