Niu R, et al. - Data of people with lung adenocarcinoma with ground-glass opacity nodules (GGNs) that were 3 cm or smaller was retrospectively reviewed between November 2011 and November 2018 in order to assess high-resolution CT (HRCT) combined with PET/CT for preoperative distinction of invasive adenocarcinoma (IAC) from preinvasive lesions and minimally invasive adenocarcinoma (MIA) (the combination of which is hereafter referred to as preinvasive-MIA) in lung adenocarcinoma presenting as GGNs 3 cm or smaller. A total of 89 patients (24 men and 65 women) with lung adenocarcinoma were included. The combined HRCT and PET/CT modality was found out to be an efficient approach to preoperatively recognize IAC in lung adenocarcinoma presenting as GGNs 3 cm or smaller.