Table 3. Clinical data and HRCT features of IAC subtypes.
| Variable | Lepidic adenocarcinoma | Acinar adenocarcinoma | Papillary adenocarcinoma | P value |
|---|---|---|---|---|
| Number | 100 | 76 | 19 | N/A |
| Age | 57.3±10.3 | 55.5±9.0 | 54.7±6.4 | 0.334d |
| Sex | 0.700c | |||
| Male | 25 | 15 | 4 | |
| Female | 75 | 61 | 15 | |
| Location | 0.112c | |||
| RUL | 44 | 27 | 5 | |
| RML | 9 | 3 | 5 | |
| RLL | 11 | 12 | 3 | |
| LUL | 24 | 23 | 3 | |
| LLL | 12 | 11 | 3 | |
| Morphologic features | ||||
| Lobulated sign | 83 | 63 | 15 | 0.909c |
| Spiculated sign | 9 | 15 | 2 | 0.108c |
| Vacuole sign/air bronchogram | 34 | 40 | 10 | 0.032c |
| Pleural tag/pleural indentation sign | 47 | 30 | 11 | 0.305c |
| Mean diameter (mm) | 11.6 (5.0–25.6) | 11.6 (5.8–24.3) | 12.1 (7.7–17.0) | 0.887e |
| Mean CT value (HU) | −570 (−738 to 263) | −512 (−720 to 212) | −457 (−656 to 255) | <0.001e |
| Relative CT value | 0.65±0.11 | 0.59±0.12 | 0.54±0.13 | <0.001d |
| Volume (mm3) | 867.5 (89−7,430) | 981.5 (101–7,786) | 908 (234–3,801) | 0.866e |
| Mass (mg) | 373.8 (37.5–3,141.3) | 489.3 (50.1–3,706.1) | 559.8 (90.6–2,360.4) | 0.306e |
Sex, location and morphological features are expressed in terms of frequency; age and relative CT value are expressed as mean ± standard deviation; the mean diameter, mean CT value, volume and mass are expressed as median (range). c, Pearson χ2 test; d, one-way analysis of variance (ANOVA); e, Kruskal-Wallis test. RLL, right lower lobe; RML, right middle lobe; RUL, right upper lobe; LLL, left lower lobe; LUL, left upper lobe; CT, computed tomography; HU, Hounsfield units.