Objective:

To analyze the computed tomography (CT) features of pre-invasive lesions and stage ⅠA pulmonary adenocarcinomas

in order to improve the differential diagnosis level.

Methods:

A total of 147 patients with 18 atypical adenomatous hyperplasia (AAH)

86 adenocarcinoma in situ (AIS) and 43 minimally invasive adenocarcinoma (MIA) co

nfirmed by surgery and pathology were selected from December 2011 to January 2020. CT imaging features were analyzed including lesions size

density

lobulation

bubble sign

pleural indentation and tumor microangiogram sign. The statistical differences among and in groups were analyzed.

Results:

The average size of AAH was (8.63.2) mm

AIS was (9.72.9) mm and which of MIA was (12.13.8) mm. The average CT value of AAH was (592.260.1) Hu

AIS was (510.5135.5) Hu and which of MIA was (408.9127.4) Hu. Among CT morphology features

AAH showed pure ground-glass opacity (pGGO)

the percentage of mixed ground-glass opacity (mGGO) in AIS and MIA was 20.9% and 48.8% respectively. The pleural indentation and tumor microangiogram sign was not showed in AAH. The percentage of them in AIS and MIA were rising gradually which was 69.8% in MIA.

Conclusion:

There is relatively difficult to distinguish AAH from AIS with CT morphology features. The MIA morphology appearances have some extent characteristics. The integrated imaging features should be considered as diagnosing of specific cases. The single feature which to be a differential diagnosis method is not advisable.