The Value Of MDCT In The Diagnosis Of Lung Adenocarcinoma Presented As Pure Ground Glass Nodule

Objective: To discuss the pathologic classification and MDCT imaging characteristics of lung adenocarcinoma presented as pure ground-glass opacity in early stage,summarize the MDCT features of different pathological subtypes of pGGO in order to improve the diagnostic accuracy.Method: Analysis of CT imaging of 156 patients(156 lesions)of lung adenocarcinoma in early stage who were confirmed by surgery of complete resction and pathology from October 2012 to September 2016 in retrospectively.All the pathological results were classified by the new classification standard of lung adenocarcinoma which proposed by the World Health Organization(WHO)in 2015.The TNM staging were T1N0M0 in all patients.There were 50 male and 106 female included.Age ranged from 28 to 77 years,the average age was(57.92±9.72)years.CT characters were analyzed including lesion’s distribution(left lung,right lung),lesion’s shape(round/oval shape,irregular shape),size,density,and the lesion’s density was uniform or no(even and uneven),internal changes of lesion(vacuole sign,air bronchus sign,abnormal change of blood vessel),lung-tumor interface(clear,not clear),lesion’s margin(speculated,lobular,vascular convergence sign)and abnormal change of adjacent of lesion(pleural indentation).Patient’s gender,lesion’s distribution and lesion’s CT appearance were compared with(2 test between different pathological types,patient’s age,the size of lesions and the density of lesions were compared via analysis of variance between different pathological types,all the results had statistical significant differences if the P<0.05.Meanwhile,assessed the size of preinvasive group lesions {Atypical Adenomatous Hyperplasia(AAH)and Adenocarcinoma in Situ(AIS)included}and invasive group lesions {Minimally Invasive Adenocarcinoma(MIA)and Invasive Adenocarcinoma(IAC)included}using the ROC curves.Results: There were 16 AAH,42 AIS,32 MIA and 66 IAC in the 156 pGGO lesions.There were more female patients than male patients in the 156 patients,including 106 femaile patients and 50 male patients.The ratio of female to male is 2.12:1,there were more female patients than male patients in each pathologic substyles,the male patients in pre-invasive group,MIA group and IAC group were 17,12,21,while the female patients were 41,20,45,but there was no significant difference between different groups(P=0.727,P >0.05).There were 103 lesions located in the right lung,accounting for 66.03%of all 156 lesions.There lesions more located in the right lung in different subtype groups,the ratios were 67.24%,65.62% and 65.15% in the pre-invasive group,MIA group and IAC group respectively,but there were no signification difference in different subtype groups(P=0.969,P>0.05).There were not statistical significant difference in patient’s age and the lesion’s density,shape,internal vacuole sign,air bronchus,lobulation,pleural indentation during different pathological types(P value were 0.289,0.080,0.173,0.070,0.756,0.252 respectively,all P>0.05),while,there were statistical significant difference in lesion’s uneven density,abnormal change of the vascular passed through the lesion,lung-tumor interface clear,speculation and vascular convergence during different pathological types(all P <0.05).Compared the lesion’s average size found there was statistical significant differences on different subtype groups(P<0.05),compare the lesion’s size between different pathological types found that the lesion’s average size of preinvasive group smaller than the MIA group and invasive group(MIA and IAC included)(P all <0.001),there were not statistical significant difference between the MIA group and IAC group(P=0.385,P>0.05).Used the ROC curve analysis of all the lesions found that when the lesion larger than15.35 mm,the probability of invasive lesions was 75.9%.There were significant difference in the density of lesion’s during different pathological types(P=0.024,P<0.05),the higher incidence of uneven density as the increase of invasive degree of the pGGO lesions.The incidence of abnormal changes of the blood vessels passed through the pGGO lesions were also hadsignificant difference during the different pathological types(P<0.001),the incidence of pre-invasive group was the lowest,it was 1.72%,the incidence of MIA was 15.63%,while the incidence of IAC was the highest,it was34.85%.There was statistical significant difference in the lung-tumor interface during different pathological types(P<0.001),the significant difference also with the lesion’s speculation and vascular convergence sign(P=0.020,P<0.05;P<0.001),with the increase of invasive lesions,the more possible it with clear lung-tumor interface,speculation and vascular convergence sign.Conclusion: The size of lesions,lung-tumor interface clear,abnormal changes of the blood vessels in the lesions,speculation and vascular convergence sign had some predictive value to the pathological classification of the lung adenocarcinoma presented as pGGO on MDCT,as the malignancy of pGGO lesions was higher,it was more likely to be greater than 15.35 mm,with clear tumor-lung interface,the incidence of abnormal vascular changes,speculations sign and vascular converge sign was higher.