不同自适应统计迭代重组水平对肺功能定量CT参数影响

The Effect of Adaptive Statistical Iterative Reconstruction Levels on Quantitative Analysis of Lung Function using MDCT

目的探讨自适应统计迭代重组(ASIR)不同水平设定对于肺功能定量CT参数测定影响。方法搜集2016年2月至2016年3月28例吸烟患者,男20例,女8例;年龄(58.43±17.26)岁。高分辨率CT检查数据,间隔10%设定ASIR进行图像重组,利用机器自带肺功能软件进行定量分析,观察10%~90%ASIR水平肺内低密度区(<-950 HU)比例以及全肺体积变化。不同ASIR水平肺功能定量参数[肺内低密度区占比(LAA%)、全肺体积(TLV)]间采用Friedman检验或单因素重复测量方差分析方法。P<0.05为差异具有统计学意义。结果ASIR水平对于LAA%结果具有明显影响,随着ASIR数值提高,LAA%呈下降趋势(χ^2=29.426,P<0.001)。不同ASIR水平之间TLV不存在明显统计学差异(F=1.046,P=0.325)。结论不同ASIR水平对于肺功能定量CT参数LAA%具有明显影响,在利用CT对小气道病变进行定量分析,或者不同研究中心数据进行对比时,需考虑到ASIR水平可能带来的影响。

Objective The aim of the study was to investigate the influence of different ASiR levels on quantitative analysis of lung function using MDCT.Methods Twenty-eight smokers(20 male,8 female;age 58.43±17.26 y)who underwent chest high resolution CT were enrolled in the study.The raw data was reconstructed using different ASiR levels(interval 10%,range 10%~90%),then postprocessed on GE Advantage workstation and analyzed using in-house thoracic VCAR-parenchyma analysis software.The values of low attenuation area ratio(LAA%)and total lung volume(TLV)were recorded and compared among different ASiR levels constructed images using Friedman test or one-way repeated measures ANOVA analysis.Statistical significance was set at 5%.Results ASiR levels demonstrated significant influence on final LAA%results,which showed a downward trend with higher ASiR level(χ^2=29.426,P<0.001).However,the values of TLV showed no statistical differences among different ASiR levels constructed data(F=1.046,P=0.325).Conclusion The quantitative measurement of LAA%has been effectively influenced by ASiR level.Hence,care should be taken in ASiR level on assessment of small airways with CT data or comparison results from different research centers.