Objective  To explore the correlation between pathological grading of ground-glass nodules and high resolution CT signs.

  Methods  A total of 127 patients diagnosed as ground-glass nodules were selected, and correlation between CT manifestation and pathological grading was analyzed.

  Results  There was no significant difference in age among patients with atypical adenomatoid hyperplasia (AAH), adherent adenocarcinoma in situ (AIS) growing completely along alveolar septum, microinvasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA) (P>0.05). There was no significant difference in gender among AAH group, AIS group and MIA group (P>0.05), but there were significant differences between IA group and AAH group, AIS group (P < 0.05). There was no significant difference in the incidence rate of burr sign between IA group and MIA group (P>0.05), but both were significantly higher than AIS group and AAH group (P < 0.05), and the incidence rate of burr sign in AIS group was significantly higher than that in AAH group (P < 0.05). There was no significant difference in the incidence rate of leaf sign among AAH group, AIS group and MIA group (P>0.05), but the incidence rate of leaf sign in IA group was significantly higher than that in AAH group, AIS group and MIA group (P < 0.05). There was no significant difference in the incidence rate of vacuole sign among AAH group, AIS group and MIA group (P>0.05), but the incidence rate of vacuole sign in IA group was significantly higher than that in AAHgroup, AIS group and MIA group (P < 0.05). The incidence rate of bronchial inflation sign in AIS group, MIA group and IA group was significantly higher than that in AAH group (P < 0.05), and which in IA group was significantly higher than that in AIS group (P < 0.05), but there was no significant difference between MIA group and IA group (P>0.05). The incidence rate of pleural indentation in IA group was significantly higher than that in AAH group, AIS group and MIA group (P < 0.05), and which in MIA group was significantly higher than that in AAH group (P < 0.05), but there was no significant difference between MIA group and AIS group (P>0.05).

  Conclusion  Burr sign, lobulation sign, vacuole sign, bronchial pneumatic sign and pleural indentation sign are the important basis for differentiating pathological grading of ground-glass nodules. The analysis of CT imaging features of ground-glass nodules is helpful for differentiating pathological grading.