多层螺旋CT对慢性阻塞性肺疾病肺容积的应用研究

1、多层螺旋CT对慢性阻塞性肺疾病肺容积的应用研究        【中文摘要】目的:采用多层螺旋CT对COPD病人和正常查体志愿者肺容积改变进行功能-影像对照研究,应用低剂量MSCT对51例受试者进行容积扫描,探讨MSCT评估全肺及单肺容积的可行性;探讨中、重度COPD组和正常组肺叶容积的变化及与CT肺密度参数的相关性,及双肺各叶在不同呼吸时相肺容积的改变及其临床意义。方法:20例正常查体者和31例COPD病人行MSCT低剂量深吸气和深呼气双相全肺容积扫描及临床肺功能检查。扫描参数:120 kV,50mA,螺距1.37

2、51,层厚10mm,间隔10mm。标准算法重建,重建层厚1.25mm,间隔0.6mm。使用ADW4.2工作站软件进行三维后处理及肺容积自动丈量,采用域值限定技术遮蔽表面显示三维肺模型(SSD 3D-lung)建模,阈值上限设为-300HU,下限设为-1024HU。对MSCT肺容积指标与临床肺功能容积指标间进行相关分析。分别采用SSD 3D-lung法和阈值限定技术下手工半自动法测定深吸气末和深呼气末左、右肺容积。采用两配对样本资料t检验对两种方法测定的左、右肺容积指标进行检验。应用阈值限定技术下手工半自动法测定全部受试者深吸气相和深呼气相左、右肺及各肺叶容积,计算左、右肺及各肺叶在不同呼吸时相

3、所占比例。对中、重度COPD组和正常组肺叶容积的变化进行单因素方差分析,方差齐且组间差别有统计学意义者采用SNK-q检验进行方差分析及两两比较。对COPD组呼吸两相容积差分别与均匀肺密度变化和像素指数进行相关性检验,对中、重度COPD组和正常组各肺叶-910HU呼气相像素指数进行符号秩和检验。结果:1、采用阈值限定技术遮蔽表面显示三维肺模型自动丈量的深吸气末和深呼气末左、右肺容积和阈值限定技术下手工半自动法测得的左、右肺容积之间无统计学差异。2、正常组左肺、右肺及右肺中叶深吸气相和深呼气相所占全肺的比例无统计学差异,中度组具有和正常组相似的规律,而重度组呼吸两相各叶比例的变化较大。3、中、重度

4、COPD组全肺容积的变化较正常组减小,尤以重度为著。除右肺中叶外,中、重度COPD组和正常组左、右肺,左肺上、下叶,右肺上、下叶深吸气相和深呼气相肺容积的变化均存在统计学差异。4、均匀肺密度的变化与肺容积的变化明显相关。5、各肺叶容积变化与各肺叶PI具有相关性,中、重度COPD组和正常组PI除右肺中叶外,其余各叶均存在统计学差异。结论:1、阈值限定技术下手工半自动法测定肺容积具有可行性。2、中度组左、右肺及各肺叶在不同呼吸时相的比例变化具有正常组相似的规律,而重度组各叶比例的变化较大。3、均匀密度的变化能够反映肺容积的改变,为通气功能提供定量指标。4、COPD组和正常组肺叶容积的变化存在差异,

5、肺气肿程度不同引起各肺叶容积变化不同。');【Abstract】 Objective:To study the volume changes of groups of COPD and volunteers, pulmonary function-imaging control study was done using MSCT.To study the possibility of using MSCT to evaluate volumes of whole lung and single lobes,51 subjects were done low dose volume sc

6、anning.To study the changes of different lobes in different stages and its possible clinical value,the volume changes of lobes in different stages and the corelationships between volume changes and CT attenuation parameters were compared.Mathod:20 volunteers and 31 COPD patients were done the dual p

7、hase volume MSCT and pulmonary function test.The scanning parameters were:120kV,50mA, pitch 1.375:1,layer thickness 10mm,septa 10mm.The reconstitution was standard algorithm,reconstituted thickness 1.25mm,septa 0.6mm.The post processing was used threshold limitation combine three dimensional lung mo

8、del and threshold limitation combine semi-automatic method to measure lung volumes.The lower threshold was -1024HU,the upper limit was -300HU.The volumes of left or right lung in full inspiration and full expiration using the two methods separately were compared using two paried sample document t te

9、st.The threshold limitation combine semi-automatic method was used to mearsure the left and right lung and all lobes in different stages,then computed the percentage of left and right lung and different lobes,Analysis of variance was used to compare volume changes of different lobes of moderate and

10、heavy groups of COPD patients and voluteers.Analysis of variance was used to compare the PIs(volumes below -910HU in expiration)of different lobes between groups of COPD and volunteers.Pearson correlation analysis was used to compare the changes of MLD and PIs with volume changes.Result:1.There were

11、 no differences between the volumes of left or right lung in full inspiration and full expiration using the two methods separately.2.There were no differences between the percentage of left or right lung and right middle lobe in different stages,the moderate group had the similar tendency with volun

12、teers,but the heavy group had no regularities.3.The volume changes of moderate and heavy groups of COPD were smaller than volunteers,especially heavy group.Besides right middle lobe,there were differences between other lobes by comparing the volume changes of different lobes among different groups o

13、f COPD and volunteers.4.The changes of MLD could reflect volume changes.5.Besides right middle lobe,there had differences among other lobes by comparing PIs of different lobes between groups of COPD and volunteers,and there also had correlations between volume changes and PIs.Conclusion:1.There was

14、no difference in volume measurements between using threshold limitation combine 3D-lung model and semi-automatic methold demonstrated the possibility of lung volume mearsurement using semi-automatic method.2.The percentages of left or right lung and different lobes in different stages were recommended,and there were no differences between the percentage of left or right lung and right middle lobe in different stages,the moderate group had the similar tendency with normal group,but the heavy group had no regularities.3.The changes of MLD correlated with volume