慢性阻塞性肺疾病患者肋间肌质量和脂肪化程度与气流受阻程度关系的CT定量研究

The study of the correlations between the mass and fat infiltration of intercostal muscles and the severity of airflow obstruction in patients with chronic obstructive pulmonary disease by quantitative CT

目的采用CT定量分析探讨慢性阻塞性肺疾病（COPD）患者肋间肌质量和脂肪化程度与气流受阻程度的关系。 方法回顾性分析2015年8月至2017年3月行MSCT胸部平扫的163例COPD患者（COPD组）及102名正常对照组资料。COPD组与对照组均行肺功能检查（PFT），并根据＂慢性阻塞性肺疾病全球倡议（GOLD，2015更新版）＂将COPD组分为4个亚组：GOLD 1组（37例）、GOLD 2组（46例）、GOLD 3组（48例）、GOLD 4组（32例）。采用CT直方图软件＂X Section＂，手动勾画选定肋间肌的边缘，软件自动计算ROI的横截面积（CSA）与平均CT值，将其除以体重指数（BMI），得出CSA指数与平均CT值指数。应用独立样本t检验比较COPD组与对照组间差异，采用单因素方差分析分别比较不同GOLD分级COPD患者间肋间肌CSA指数以及CT值指数的差异，组间两两比较采用LSD法。利用Spearman相关分析患者肋间肌指数、CT值指数与GOLD分级之间的关系。 结果COPD组的CSA指数和平均CT值指数分别为（4.3±2.1）mm2·m2·kg－1、（-1.6±6.9）HU·m2·kg－1，均显著低于对照组[（6.9±1.7）mm2·m2·kg－1、（11.6±5.7）HU·m2·kg－1]，差异具有统计学意义（t值分别为12.82、10.87，P〈0.01）。COPD组各GOLD亚组与对照组间的CSA指数与平均CT值指数差异均有统计学意义（F值分别为92.79、8.80，P〈0.01）。CSA指数和平均CT值指数与GOLD分级均呈负相关，差异有统计学意义（r值分别为－0.615、－0.551, P值均〈0.05）。 结论COPD患者肋间肌质量和脂肪化程度与气流受阻程度具有相关性，气流受阻越严重，肋间肌质量下降越明显，脂肪化程度越重。

ObjectiveTo investigate the correlations between the mass and fat infiltration of intercostal muscles and their severity of airflow obstruction in patients with chronic obstructive pulmonary disease（COPD）. MethodsOne hundred and sixty-three COPD patients and 102 normal subjects between August 2015 to March 2017 underwent chest MSCT scans and all data were analyzed retrospectively. All subjects underwent pulmonary function tests （PFT）. According to the global initiative for chronic obstructive lung disease（GOLD, updated 2015）, the COPD patients were classified into GOLD 1（n=37）, GOLD 2（n=46）, GOLD 3 （n=48）, GOLD 4 （n=32） by pulmonary function results, respectively. The mass and fat infiltrations of intercostal muscles were quantified as the cross-sectional area （CSA） and attenuation of these muscles using CT histogram analysis. Intercostal indexes and attenuation indexes were defined as intercostal CSA and attenuation divided by body mass index（BMI）. Comparison of intercostal indexes and attenuation indexes between the COPD and control groups was perfomed using t test. The comparisons between the 4 COPD subgroups were carried out using ANOVA test, and comparison between the two groups by LSD. The correlation between intercostal indexes and attenuation indexes and PFT were evaluated by the Spearman rank correlation test. ResultsThe CSA and attenuation indexes of COPD patients groups were （4.3±2.1） mm2·m2·kg-1, （-1.6±6.9） HU·m2·kg-1, respectively,both were significantly lower than that of the control group [ （6.9±1.7） mm2·m2·kg-1, （11.6±5.7） HU·m2·kg-1]. The difference was statistically significant （t=12.82, 10.87, P〈0.01） . The CSA and attenuation indexes of COPD patients in any subgroups and the control group were of significant difference（F=92.79, 8.80, P〈0.01） .The CSA and attenuation indexes were negatively correlated with the GOLD grades, the difference was statistically significant （r=-0.615,-0.551, P〈0.05） . ConclusionsMass and fat infiltration of intercostal muscles of COPD patients measured by CT histogram analysis were correlated with their severity of airflow obstruction. In other words, a decrease in intercostal mass and an increase in intercostal fat are associated with worsening of COPD severity.