The diagnostic value of MSCT in the classification of of subtypes of lung adenocarcinoma less than or equal to 1 cm in maximum diameter

WANG Mei; CAO Hanbo; XU Huaquan

Abstract：Objective To investigate the diagnostic value of MSCT signs in the classification of subtypes of lung adenocarcinoma less than or equal to 1 cm in maximum diameter,so as to provide the basis for the selection of clinical treatment methods.Methods A retrospective analysis was conducted on 293 patients,who presented with pulmonary nodules (338 lesions) pathologically confirmed as lung cancer less than or equal to 1 cm in naximum diameter,from June 2014 to June 2016.All the patients had complete imaging,pathology and clinical data.Of those 338 lesions,191 were adenocarcinoma in situ (AIS),114 were minimally invasive adenocarcinoma (MIA),and 33 were invasive adenocarcinoma (IAC).The MSCT manifestations of three types were analyzed.The evaluation indexes by CT included the lesion size,shape,density (mean CT value),edge features (lobulation and burr),internal structure (vacuole sign and air bronchograms),adjacent structure change (pleural indentation) and whether lymph node metastasis or not.Results 1) Lesion size:the size distribution of AIS group and MIA group was uniform,but,the size of the IAC group focused on more than 0.7 cm;2) Morphalogy:the shape of AIS group was round in 139 cases (72.7％),while,that in MIA and IAC was oval or irregular shape in more cases (51.7％,51.5％);3) density (mean CT value):The AIS showed pure ground glass density (57.8％),the average value of CT was (-627.41 ± 71.65) HU;MIA mainly showed ground glass opacity (84.2％),the the average CT value was (-457.44 ± 87.38) HU;and IAC mainly showed ground glass (57.6％) and solid nodules (42.4％),the average value of CT was (-294.58 ± 165.46) HU.the average CT value of three was statistically significant;4) changes in the internal structure,edge features and adjacent tissue:the three changes in terms of internal structure,edge features and adjacent structure were increasing;5) lymph node metastasis:1 case of IAC appeared hilar lymph node metastasis.Conclusion MSCT signs have important value in the classification of subtypes of lung adenocarcinoma less than or equal to 1 cm in maximum diameter.The average CT value of lesions and internal solid components,air bronchogram,vacuole sign,lobulation,pleural indentation and spiculation contribute to the accurate typing.