多层螺旋CT肺功能成像在评价石棉沉着病病人肺功能的应用研究

摘要

目的 应用多层螺旋CT(MSCT)肺功能成像技术评价石棉沉着病病人在疾病不同分期中肺功能指标的变化及特点.方法 选取2013年1月1日—2015年12月31日间明确诊断的石棉沉着病病人21例及正常对照组21例,同时收集受检者年龄、性别、接触史、工种等基本信息.对每位受检者分别在深吸气末和深呼气末屏气行全肺扫描,采用Siemens Pulmo肺定量分析软件对CT肺容积、密度指标进行测定.采用独立样本t检验对石棉沉着病组与对照组的肺容积指标和平均肺密度指标进行比较,采用LSD-t检验对石棉沉着病不同分期组与对照组间各项肺功能指标进行多重比较,并分别采用秩和检验和Fisher确切概率检验对石棉沉着病不同分期组间的粉尘接触史和工种类型进行比较.结果 ①石棉沉着病Ⅰ期组与Ⅱ期组在职业接触史时间上差异有统计学意义(Z=5.023,P<0.05),并且随着职业接触史时间的延长,Ⅱ期病人的出现概率增高;而两组病人在不同工种之间差异无统计学意义(P>0.05).②石棉沉着病组吸气相肺容积(Vin)、左肺Vin(LVin)、右肺Vin(RVin)、吸气相和呼气相的肺容积差(Vin-Vex)均较对照组减小;右肺呼气相肺容积(RVex)、呼气相和吸气相的肺容积比(Vex/Vin)较对照组增大(均P<0.05);而两组间Vex和LVex差异无统计学意义(均P>0.05).③两组间吸气相平均肺密度(MLDin)、吸气相左肺平均肺密度(LMLDin)和吸气相右肺平均肺密度(RMLDin)差异无统计学意义(均P>0.05).石棉沉着病组呼气相平均肺密度(MLDex)、呼气相左肺平均肺密度(LMLDex)、呼气相右肺平均肺密度(RMLDex)、呼气相和吸气相的平均肺密度比(MLDex/MLDin)均较对照组增大,而呼气相和吸气相的平均肺密度差(MLDex-MLDin)较对照组减小,其差异均有统计学意义(均P<0.05).④石棉沉着病Ⅱ期组较Ⅰ期组和对照组的RVex均增大;石棉沉着病Ⅰ期组和Ⅱ期组的Vin-Vex均较对照组减小,且Ⅱ期组的Vin-Vex低于Ⅰ期组(均P<0.05);3组间其余肺容积指标和CT平均肺密度各项指标差异均无统计学意义(均P>0.05).结论 石棉沉着病病人肺功能改变的特点为肺总量、左肺和右肺总量减低,双肺残气量、左肺和右肺残气量升高,用力肺活量降低,肺气肿形成,而且石棉沉着病病人的粉尘接触时间越长其病情越严重.多层螺旋CT肺功能成像技术在评价石棉沉着病病人肺功能方面具有重要作用.%Objective To explore the characteristics of pulmonary function in patients with asbestosis at different stages and normal volunteers by using multislice spiral CT. Methods Twenty one asbestosis patients and 21 normal volunteers were selected from January 1, 2013 to December 31, 2015. The demographics including age, gender, contact, jobs and other basic information were collected. Paired inspiratory and expiratory multislice spiral CT scans were obtained from all subjects. Pulmonary volume indices and mean lung density indices were measured with Siemens Pulmo quantitative analysis software. Two independent samples t test was used to compare the differences of lung volume and lung mean density between patient and control groups. ANOVA with LSD post-hoc test was used to compare differences of the pulmonary function-indices between the control group and the different stages of asbestosis. Wilcoxon rank sum test and the Fisher's exact test were also used to compare the exposure history, the types of work at different stages of asbestosis. Results 1) The length of exposure time significantly differed beween Ⅰand Ⅱ stages, (Z=5.023, P<0.05), the longer occupational exposure, the higherprobability of developing disease stage Ⅱ. However, there was no significant difference in type of work between the two groups (P>0.05). 2) The inspiratory lung volume (Vin), left lung inspiratory volume (LVin), right lung inspiratory volume (RVin), and volume difference between Vin and expiratory lung volume (Vex) (Vin-Vex) in asbestosis patient group were significantly lower than that of control group, and the right lung Vex (RVex), and volume ratio (Vex/Vin) were significantly higher than that of control group (P<0.05). However, there was no significant difference in Vex and left lung Vex (LVex) between two groups (P>0.05). 3) The inspiratory mean lung density (MLDin), left lung MLDin (LMLDin), and right lung MLDin (RMLDin) were not significantly differences between the asbestosis patients and the controls (P>0.05). The expiratory mean lung density (MLDex), left lung MLDex (LMLDex), right lung MLDex (RMLDex), and density ratio (MLDex/MLDin) in asbestosis patients were significantly higher, but the density differences (MLDex-MLDin) was significantly lower than that of control group (P<0.05). 4) The RVex was significantly higher at asbestosis stageⅡthan stageⅠ or control group (P<0.05). The Vin-Vex at both diseaseⅠandⅡstage were significantly lower than that of the control group (P<0.05), and was significantly lower at stageⅡthan stageⅠ(P<0.05). There was no significant difference in the pulmonary volume indices and mean lung density indices among the three groups (P>0.05). Conclusions The characteristics of pulmonary function in asbestosis patients include the decreased total lung volume, left lung and right lung volume, and forced vital capacity , increased residual volume, left lung, and right lung residual volume, and emphysema formation. The longer the dust contact time, the more serious the disease. Multislice spiral CT pulmonary function imaging plays an important role in the evaluation of lung function in asbestosis patients.