Comparative Analysis Of The CT Manifestations Of Mixed Ground-glass Nodule And The Pathological Basis Of Lung Adenocarcinomas

Objective To investigate the relationship between CT manifestations of mixed ground-glass nodule(m GGN)and the pathological basis of lung adenocarcinomas.Analyzing the correlation between the solid component features in m GGN and pathological classification of adenocarcinoma in situ(AIS),microinvasive adenocarcinoma(MIA),and invasive adenocarcinoma(IAC).Methods CT data of 145 cases(with 152 nodules)confirmed to be lung adenocarcinoma,from the First Affiliated Hospital of Anhui Medical University between December 2015 to June 2018,were analyzed retrospectively.Based on the pathological findings,there were 20 AIS cases,32 MIA cases and 100 IAC cases.Many CT features,especially the solid components,are analyzed.The following radiological image features were included: 1)overall nodule attributes: location of the nodule,average size,shape,peripheral margin(lobulation,spiculation,interface between tumor and lung,and pleural tag),inner feature(vacuole sign and bronchus sign)and blood vessel attributes(blood vessel cross and vessel twist/enlarge/aggregation),2)features of the solid component: count,shape,location,peripheral margin(lobulation and spiculation),interface with GGN,average size,ratio,and average CT value.The qualitative analysis used Chi-squared test and Fisher's exact test.One factor analysis of variance and Kruskal-wallis H test were used for quantitative analysis.A receiver operating characteristic(ROC)curve was drawn with one factor analysis of variance as the independent variable and invasive findings as the dependent variable.AIS,MIA and IAC were classified as level 1,2 and 3,respectively.The correlation between pathological classification level and m GGN average size,average size/ratio/CT value of the solid components were analyzed with nonparametric Spearman rank correlation analysis.Results 1.Among the 145 cases(152 nodules),there was a significant statistical difference between those three pathological levels,in terms of m GGN size,shape,lobulation,spiculation,pleural tag,bronchus sign,blood vessel change,and tumor/lung interface.2.There was a significant statistical difference between those three pathological levels,in terms of count,shape,lobulation,spiculation of the solid component.3.The average size /ratio/CT value of the solid components were significantly different between AIS and MIA,MIA and IAC(p < 0.001),while insignificantly between AIS and MIA(p > 0.05).4.The ROC results between non-invasive(AIS and MIA)and invasive(IAC)groups,in terms of average size of m GGN,average size of the solid component,ratio of the solid component,and average CT value of the solid component,were as following: 1)AUC: 0.801,0.826,0.713,and 0.838;2)threshold: 16.54 mm,4.83 mm,46.67% and-39.66 HU;3)sensitivity: 68.0%,78.0%,50.0%,and 82.0%;4)specificity: 84.6%,73.1%,88.5% and 78.8%;5)95% confidence interval:(72.8%,87.4%),(76.1%,89.0%),(62.9%,79.6%)and(76.9%,90.7%).5.The Spearman rank correlation analysis showed positive correlation(p < 0.001)between pathological levels and average m GGN size,average size of the solid component,ratio of the solid component,and average CT value,with coefficient being0.508,0.544,0.338,and 0.559,respectively.Conclusions There is a correlation between the CT manifestations of m GGN and pathological classification.The probability of IAS is higher with larger m GGN size(threshold: 16.54 mm),larger solid component size(threshold: 4.83 mm),higher ratio of solid component(threshold: 46.76%)and higher CT value of the solid component(threshold:-39.66 HU).The analysis of different CT features is helpful in pathological diagnosis before the surgery and guiding clinical treatment.