Table 2 CT scanning characteristics.
| Ā | All CT scans | Train cohort | Test cohort | p |
|---|---|---|---|---|
Number of scans | 3193 | 2141 | 1052 | Ā |
Manufacturer (n (%)) | Ā | Ā | Ā | 0.26 |
āGE MEDICAL SYSTEMS | 1059 (33.2) | 694 (32.4) | 365 (34.7) | Ā |
āPhilips | 445 (13.9) | 315 (14.7) | 130 (12.4) | Ā |
āSIEMENS | 1314 (41.2) | 889 (41.5) | 425 (40.4) | Ā |
āTOSHIBA | 312 (9.8) | 204 (9.5) | 108 (10.3) | Ā |
āFive other manufacturers | 63 (2.0) | 39 (1.8) | 24 (2.3) | Ā |
Manufacturer models (n (%)) | Ā | Ā | Ā | <0.05 |
āAquilion | 243 (7.6) | 157 (7.3) | 86 (8.2) | Ā |
āBrilliance 64 | 166 (5.2) | 114 (5.3) | 52 (4.9) | Ā |
āDefinition | 161 (5.0) | 124 (5.8) | 37 (3.5) | Ā |
āHiSpeed NX/i | 132 (4.1) | 104 (4.9) | 28 (2.7) | Ā |
āLightSpeed VCT | 240 (7.5) | 136 (6.4) | 104 (9.9) | Ā |
āLightSpeed16 | 197 (6.2) | 128 (6.0) | 69 (6.6) | Ā |
āSensation 16 | 303 (9.5) | 196 (9.2) | 107 (10.2) | Ā |
āSensation 64 | 309 (9.7) | 216 (10.1) | 93 (8.8) | Ā |
āSeventy-three other models | 1442 (45.2) | 966 (45.1) | 476 (45.2) | Ā |
āCT image reconstruction algorithms (n (%)) | Ā | Ā | Ā | <0.05 |
āB | 249 (7.8) | 165 (7.7) | 84 (8.0) | Ā |
āB30f | 332 (10.4) | 226 (10.6) | 106 (10.1) | Ā |
āB31f | 233 (7.3) | 172 (8.0) | 61 (5.8) | Ā |
āLUNG | 118 (3.7) | 82 (3.8) | 36 (3.4) | Ā |
āSTANDARD | 623 (19.5) | 399 (18.6) | 224 (21.3) | Ā |
āSTD+ | 141 (4.4) | 108 (5.0) | 33 (3.1) | Ā |
āFifty-nine other algorithms | 1497 (46.9) | 989 (31.0) | 508 (15.9) | Ā |
Slice thickness (n (%)) | Ā | Ā | Ā | 0.301 |
āā¤3āmm | 531 (16.6) | 340 (15.9) | 191 (18.2) | Ā |
ā3~5āmm | 2335 (73.1) | 1582 (73.9) | 753 (71.6) | Ā |
ā>5āmm | 327 (10.2) | 219 (10.2) | 108 (10.3) | Ā |
Voltage (n (%)) | Ā | Ā | Ā | 0.52 |
ā120ākVp | 2751 (86.2) | 1841 (85.9) | 910 (86.5) | Ā |
āOthers | 442 (13.8) | 300 (14.0) | 142 (13.5) | Ā |
Product of tube current and time (n (%)) | Ā | Ā | Ā | <0.05 |
āā¤100āmAs | 654 (20.5) | 449 (21.0) | 205 (19.5) | Ā |
ā100~200āmAs | 1196 (37.5) | 782 (36.5) | 414 (39.4) | Ā |
ā200~400āmAs | 757 (23.7) | 515 (24.0) | 242 (23.0) | Ā |
ā>400āmAs | 261 (8.2) | 70 (3.3) | 191 (18.2) | Ā |
āNAN | 325 (10.2) | 325 (15.2) | 0 (0.0) | Ā |
Pixel spacing (n (%)) | Ā | Ā | Ā | 0.408 |
ā0.5~0.75āmm | 1528 (47.9) | 1010 (47.2) | 518 (49.2) | Ā |
ā0.75~1.00āmm | 1640 (51.4) | 1112 (51.9) | 528 (50.2) | Ā |
ā>1āmm | 25 (0.8) | 19 (0.9) | 6 (0.6) | Ā |
