Correlation between lumbar bone mineral density, musculoskeletal perfusion and muscle mass: a preliminary study based on quantitative CT and CT perfusion / 中华放射学杂志

ABSTRACT

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.