Fig. 2

Different CT manifestations of the BLL sign in GGNs. (a) The density of BLL in the GGN (MIA) is lower than that of peripheral normal lung tissue and is similar to that of air attenuation. (b) The density of BLL in the GGN (AIS) is lower than that of peripheral tumor tissue, and which is similar to that of adjacent normal lung tissue. BLL: bubble-like lucency; GGNs: ground glass nodules; MIA: minimally invasive adenocarcinoma; AIS: adenocarcinoma in situ