Table 2. Association between STAS and CT characteristics.
| Characteristics | Center I | Center II | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Nodules (n=462) | STAS status | P value | Nodules (n=116) | STAS status | P value | ||||
| Positive (n=90) | Negative (n=372) | Positive (n=28) | Negative (n=88) | ||||||
| Maximum diameter (mm) | 20.00 (12.70, 30.20) | 18.23 (11.59, 28.12) | 24.53 (18.99, 37.51) | <0.001 | 23.40 (16.60, 37.63) | 37.78 (20.78, 49.23) | 21.98 (15.13, 33.46) | 0.002 | |
| Maximum area (mm2) | 223.69 (89.67, 474.77) | 172.04 (75.68, 426.30) | 385.02 (222.47, 719.88) | <0.001 | 302.295 (150.30, 781.53) | 727.80 (284.07, 1,239.99) | 251.83 (130.20, 626.61) | 0.001 | |
| Area of the solid component (mm2) | 114.08 (10.25, 384.46) | 68.50 (0.00, 297.72) | 336.88 (193.56, 674.67) | <0.001 | 254.91 (52.97, 705.17) | 585.88 (220.75, 1,160.43) | 181.40 (49.70, 523.56) | 0.001 | |
| Ratio of solid component (%) | 58.97±42.88 | 85.17±30.04 | 52.64±43.15 | <0.001 | 69.89±37.20 | 79.67±32.25 | 60.77±38.28 | 0.014 | |
| Nodule type, n (%) | <0.001 | 0.096 | |||||||
| GGN | 102 (22.1) | 3 (3.3) | 99 (26.6) | 11 (9.5) | 0 (0.0) | 11 (12.5) | |||
| Part-solid | 141 (30.5) | 17 (18.9) | 124 (33.3) | 41 (35.3) | 9 (32.1) | 32 (36.4) | |||
| Solid | 219 (47.4) | 70 (77.8) | 149 (40.1) | 64 (55.2) | 19 (67.9) | 45 (51.1) | |||
| Pleural thickening, n (%) | 0.002 | 0.186 | |||||||
| Present | 287 (62.1) | 69 (76.7) | 218 (58.6) | 84 (72.4) | 23 (82.1) | 61 (69.3) | |||
| Absent | 175 (37.9) | 21 (23.3) | 154 (41.4) | 32 (27.6) | 5 (17.9) | 27 (30.7) | |||
| Pleural retraction, n (%) | 0.001 | 0.142 | |||||||
| Present | 275 (59.5) | 67 (74.4) | 208 (55.9) | 78 (67.2) | 22 (78.6) | 56 (63.6) | |||
| Absent | 187 (40.5) | 23 (25.6) | 164 (44.1) | 38 (32.8) | 6 (21.4) | 32 (36.4) | |||
| Mediastinal lymph node enlargement, n (%) | 0.002 | 0.350 | |||||||
| Present | 54 (11.7) | 19 (21.1) | 35 (9.4) | 22 (19.0) | 7 (25.0) | 15 (17.0) | |||
| Absent | 408 (88.3) | 71 (78.9) | 337 (90.6) | 94 (81.0) | 21 (75.0) | 73 (83.0) | |||
| Hilar lymphatic enlargement, n (%) | 0.058 | 0.277 | |||||||
| Absent | 51 (11.0) | 15 (16.7) | 36 (9.7) | 21 (18.1) | 7 (25.0) | 14 (15.9) | |||
| Present | 411 (89.0) | 75 (83.3) | 336 (90.3) | 95 (81.9) | 21 (75.0) | 74 (84.1) | |||
| Vascular cluster sign, n (%) | <0.001 | 0.162 | |||||||
| Present | 161 (34.8) | 46 (51.1) | 115 (30.9) | 45 (38.8) | 14 (50.0) | 31 (35.2) | |||
| Absent | 301 (65.2) | 44 (48.9) | 257 (69.1) | 71 (61.2) | 14 (50.0) | 57 (64.8) | |||
| Lobulation, n (%) | <0.001 | 0.274 | |||||||
| Present | 205 (44.4) | 55 (61.1) | 150 (40.3) | 60 (51.7) | 17 (60.7) | 43 (48.9) | |||
| Absent | 257 (55.6) | 35 (38.9) | 222 (59.7) | 56 (48.3) | 11 (39.3) | 45 (51.1) | |||
| Specula, n (%) | <0.001 | 0.590 | |||||||
| Present | 234 (50.3) | 62 (68.9) | 172 (46.2) | 57 (49.1) | 15 (53.6) | 42 (47.7) | |||
| Absent | 228 (49.4) | 28 (31.1) | 200 (53.8) | 59 (50.9) | 13 (46.4) | 46 (52.3) | |||
| Air bronchogram, n (%) | 0.912 | 0.446 | |||||||
| Present | 93 (20.1) | 23 (25.6) | 70 (18.8) | 27 (23.3) | 8 (28.6) | 19 (21.6) | |||
| Absent | 369 (79.9) | 67 (74.4) | 302 (81.2) | 89 (76.7) | 20 (71.4) | 69 (78.4) | |||
| Satellite lesions, n (%) | 0.988 | 0.501 | |||||||
| Present | 46 (10.0) | 9 (10.0) | 37 (9.9) | 20 (17.2) | 6 (21.4) | 14 (15.9) | |||
| Absent | 416 (90.0) | 81 (90.0) | 335 (90.1) | 96 (82.8) | 22 (78.6) | 74 (84.1) | |||
| Vacuolar sign, n (%) | 0.437 | 0.706 | |||||||
| Present | 99 (21.4) | 22 (24.4) | 77 (20.7) | 26 (22.4) | 7 (25.0) | 19 (21.6) | |||
| Absent | 363 (78.6) | 68 (75.6) | 295 (79.3) | 90 (77.6) | 21 (75.0) | 69 (78.4) | |||
| Void sign, n (%) | 0.513 | 0.806 | |||||||
| Present | 29 (6.3) | 7 (7.8) | 22 (5.9) | 15 (12.9) | 4 (14.3) | 11 (12.5) | |||
| Absent | 433 (93.7) | 83 (92.2) | 350 (94.1) | 101 (87.1) | 24 (85.7) | 77 (87.5) | |||
| Pleural effusion, n (%) | 0.383 | 0.011 | |||||||
| Present | 14 (3.0) | 4 (4.4) | 10 (2.7) | 2 (1.7) | 2 (7.1) | 0 (0.0) | |||
| Absent | 448 (97.0) | 86 (95.6) | 362 (97.3) | 114 (98.3) | 26 (92.9) | 88 (100.0) | |||
| Distribution within the lobe, n (%) | 0.334 | 0.321 | |||||||
| Center | 91 (19.7) | 69 (76.7) | 302 (81.2) | 98 (84.5) | 22 (78.6) | 76 (86.4) | |||
| Peripheral | 371 (80.3) | 21 (23.3) | 70 (18.8) | 18 (15.5) | 6 (21.4) | 12 (13.6) | |||
| Nodule location, n (%) | 0.415 | 0.239 | |||||||
| LUL | 116 (25.1) | 27 (30.0) | 89 (23.9) | 29 (25.0) | 11 (39.3) | 18 (20.5) | |||
| LLL | 65 (14.1) | 16 (17.8) | 49 (13.2) | 19 (16.4) | 3 (10.7) | 16 (18.2) | |||
| RUL | 164 (35.5) | 26 (28.9) | 138 (37.1) | 43 (37.1) | 7 (25.0) | 36 (40.9) | |||
| RML | 33 (7.1) | 5 (5.6) | 28 (7.5) | 6 (5.2) | 2 (7.1) | 4 (4.5) | |||
| RLL | 84 (18.2) | 16 (17.8) | 68 (18.3) | 19 (16.4) | 5 (17.9) | 14 (15.9) | |||
| Central low attenuation, n (%) | 0.201 | 0.321 | |||||||
| Present | 32 (6.9) | 9 (10.0) | 23 (6.2) | 18 (15.5) | 6 (21.4) | 12 (13.6) | |||
| Absent | 430 (93.1) | 81 (90.0) | 349 (93.8) | 98 (84.5) | 22 (78.6) | 76 (86.4) | |||
| Other pulmonary nodules, n (%) | 0.819 | 0.963 | |||||||
| Present | 236 (51.1) | 45 (50.0) | 191 (51.3) | 70 (60.3) | 17 (60.7) | 53 (60.2) | |||
| Absent | 226 (48.9) | 45 (50.0) | 181 (48.7) | 46 (39.7) | 11 (39.3) | 35 (39.8) | |||
| Emphysema, n (%) | 0.903 | 0.985 | |||||||
| Present | 79 (17.1) | 15 (16.7) | 64 (17.2) | 25 (21.6) | 6 (21.4) | 19 (21.6) | |||
| Absent | 383 (82.9) | 75 (83.3) | 308 (2.8) | 91 (78.4) | 22 (78.6) | 69 (78.4) | |||
| Pulmonary fibrosis, n (%) | 0.406 | 0.921 | |||||||
| Present | 41 (8.9) | 10 (11.1) | 31 (8.3) | 20 (17.2) | 5 (17.9) | 15 (17.0) | |||
| Absent | 421 (91.1) | 80 (88.9) | 341 (91.7) | 96 (82.8) | 23 (82.1) | 73 (83.0) | |||
| Calcification, n (%) | 0.912 | 0.967 | |||||||
| Present | 11 (2.4) | 2 (2.2) | 9 (2.4) | 4 (3.4) | 1 (3.6) | 3 (3.4) | |||
| Absent | 451 (97.6) | 88 (97.8) | 363 (97.6) | 112 (96.6) | 27 (96.4) | 85 (96.6) | |||
Distribution within the lobe: center, the nodule entirely located within the inner two-thirds of the lung; peripheral, a portion of the nodule residing in the outer third of the lung. STAS, spread through air space; LUL, left upper lobe; LLL, left lower lobe; RUL, right upper lobe; RML, right middle lobe; RLL, right lower lobe.