Table 3. The groups of the GGNs with progressive changes on the initial and latest preoperative CT images.
| Characteristics | Group 1 | Group 2 |
|---|---|---|
| Numbers (n=35) | 7 (20.0) | 28 (80.0) |
| Follow-up interval (days) | 42.0 [263.0] | 44.0 [281.0] |
| Diameter (mm) | ||
| Initial | 9.5±4.9 | 10.5 [5.2] |
| Follow-up | 9.5±4.9 | 11.7 [5.0] |
| P value | >0.99‡ | <0.001† |
| Volume (mm3) | ||
| Initial | 217.5±1,014.1 | 559.0 [645.0] |
| Follow-up | 253.1 [1,391.5] | 976.5 [944.2] |
| P value | 0.13† | <0.001† |
| VDT (days) | – | 167.9 [368.3] |
| Density (HU) | ||
| Initial | −526.0±178.8 | 569.8 ±141.3 |
| Follow-up | −255.7±189.0 | −482.7±205.8 |
| P value | 0.003‡ | 0.001‡ |
Data are presented as n (%), or mean ± standard deviation, or median [interquartile range]. †, calculated with the Wilkinson sign test; ‡, calculated with the paired t-test. Group 1 includes GGNs with changes of type I and III; Group 2 includes GGNs with changes of type II, IV, and V. – indicates no statistical data. GGNs, ground-glass nodules; CT, computed tomography; VDT, volume doubling time; HU, Hounsfield unit.