CT And Gray Histogram Features Of Pure Ground Glass Nodule Lung Adenocarcinoma And Their Applications In Differential Diagnosis

Objective:To explore the value of the general CT and the gray histogram features of pure ground-glass nodule(pGGN)lung adenocarcinoma in differential diagnosis of preinvasive lesions[atypical adenomatous hyperplasia(AAH)and adenocarcinoma in situ(AIS)],minimally invasive adenocarcinoma(MIA)of the lung,invasive adenocarcinoma(IA)of the lung.Materials and methods:A retrospective analysis was made on general clinical data(gender,age)and the CT characteristics(including location,size,density,shape,tumor boundary,internal signs and pleural depression signs)of148 pGGNs of 135 patients admitted to the first hospital of jilin university from December 2016 to November 2018 and examined by preoperative CT examination.All lesions were resected and conformed by pathology.The region of interest(ROI)was drawn from the pGGNs maximum level image and the gray histogram was generated by Image J software.c~2test or Fisher's exact test was used for counting data,and measurement data which conformed to the normal distribution use one-way ANOVA,LSD was used for comparison between the two groups;Kruskal-Wallis H test was used for non-normal distribution;P?0.05is considered as statistically significant difference.And the best threshold,sensitivity and specificity of the size of the lesion,StdDev and Max of gray histogram were analyzed by receiver operating characteristic curve(ROC).Result:Among 148 pGGNs,there were 49 cases of preinvasive lesions(6 cases of AAH,43 cases of AIS),56 cases of MIA and 43 cases of IA.There was no significant difference in gender and location between different pathological types.There were significant differences in age,size,density,shape,tumor boundary,internal signs and pleural depression signs among pathological types,P values were 0.001,0.001,0.008,<0.001,<0.001,0.001,0.014,P<0.05,respectively.CT gray histogram parameters:Area,Perimeter,Mean gray value,Maximum and Minimum gray value,Median,Standard Deviation and Skew showed statistically significant differences among pathological types.There was no significant difference in Kurt.ROC analysis showed that 0.65cm was the optimal critical value to differentiate the size between preinvasive and invasive lesions,The sensitivity and specificity of diagnosis were86.9%and 51.0%respectively,The area under curve(AUC)was 0.752.15.454 was the best threshold for StdDev differentiating from preinvasive lesions,The sensitivity and specificity of diagnosis were70.7%and 65.3%respectively,AUC was 0.725.The best critical value of Max for differentiating preinvasive lesions from invasive lesions was 144.5,The sensitivity and specificity were 76.8%and 63.3%respectively,and the AUC was 0.752.Conclusion:The general CT features of pGGNs lung adenocarcinoma,including size,density,shape,tumor boundary,internal signs and pleural depression signs,have certain guiding significance in differentiating preinvasive lesions(AAH+AIS),MIA and IA.As a quantitative analysis method,the parameters of CT gray histogram can objectively reflect the differences of three groups of lesions,and provide more references for clinical diagnosis and treatment combined with preoperative CT features.