TABLE 3.
Univariate analysis of clinical and imaging features in the training and test sets.
| Characteristic | Training set (219) | p | Test set (93) | p | ||
|---|---|---|---|---|---|---|
| Non-IAC group (n = 86) | IAC group (n = 133) | Non-IAC group (n = 43) | IAC group (n = 50) | |||
| Male | 63 (71.6%) | 86 (65.6%) | 0.355 | 26 (60.5%) | 34 (68.0%) | 0.449 |
| Age, year | 57 (49–62) | 61 (52–66) | 0.009 | 55 (46–60) | 60 (54–65) | 0.027 |
| Diameter, mm | 11 (8–14) | 17 (13–20) | ＜0.001 | 11 (8–15) | 17 (14–21) | ＜0.001 |
| Volume, mm³ | 509 (238–1,047) | 1,351 (796–2,639) | ＜0.001 | 552 (248–1,184) | 1,517 (816–3,104) | ＜0.001 |
| Ratio of consolidation | 0.04 (0–0.22) | 0.24 (0.10–0.45) | ＜0.001 | 0.04 (0–0.14) | 0.28 (0.13–0.54) | ＜0.001 |
| Mean CT value, HU | −588 (−660–489) | −442 (−566–361) | ＜0.001 | −593 (−675–530) | −445 (−553–322) | ＜0.001 |
| Mass, mg | 199 (104–393) | 775 (322–1,352) | ＜0.001 | 256 (101–520) | 755 (420–1725) | ＜0.001 |
| Location | 0.201 | 0.411 | ||||
| RUL | 30 (34.1%) | 51 (38.9%) | 12 (27.9%) | 22 (44.0%) | ||
| RML | 2 (2.3%) | 10 (7.6%) | 4 (9.3%) | 3 (6.0%) | ||
| RLL | 20 (22.7%) | 20 (15.3%) | 5 (11.6%) | 8 (16.0%) | ||
| LUL | 26 (29.5%) | 41 (31.3%) | 15 (34.9%) | 11 (22.0%) | ||
| LLL | 10 (11.4%) | 9 (6.9%) | 7 (16.3%) | 6 (12.0%) | ||
| pGGN | 47 (53.4%) | 32 (24.4%) | ＜0.001 | 24 (55.8%) | 9 (18.0%) | ＜0.001 |
| Margin | 0.106 | 0.377 | ||||
| Clear | 30 (34.1%) | 59 (45.0%) | 22 (51.2%) | 21 (42.0%) | ||
| Unclear | 58 (65.9%) | 72 (55.0%) | 21 (48.8%) | 29 (58.0%) | ||
| Shape | ＜0.001 | 0.008 | ||||
| Round or oval | 60 (68.2%) | 54 (41.2%) | 29 (67.4%) | 20 (40.0%) | ||
| Irregular | 28 (31.8%) | 81 (58.8%) | 14 (32.6%) | 30 (60.0%) | ||
| Pleural indentation sign | 27 (30.7%) | 74 (56.5%) | ＜0.001 | 15 (34.9%) | 22 (44.0%) | 0.371 |
| Bubble-like lucency | 21 (23.9%) | 34 (26.0%) | 0.727 | 6 (14.0%) | 14 (28.0%) | 0.1 |
| Air bronchus sign | 15 (17.0%) | 66 (50.4%) | ＜0.001 | 14 (32.6%) | 31 (62.0%) | 0.005 |
| Spiculation | 33 (37.5%) | 72 (55.0%) | 0.011 | 13 (30.2%) | 28 (56.0%) | 0.013 |
| Lobulation | 24 (27.3%) | 89 (67.9%) | ＜0.001 | 14 (32.6%) | 27 (54.0%) | 0.038 |
| Vascular change | 31 (35.2%) | 97 (74.0%) | ＜0.001 | 17 (39.5%) | 37 (74.0%) | 0.001 |
LLL, left lower lobe; LUL, left upper lobe; RLL, right lower lobe; RML, right middle lobe; RUL, right upper lobe.