Table 1.
Data sets and patient characteristics.
| Variable | Training set | Validation set | Test set |
|---|---|---|---|
| No. of MRI sets | 1023 (70) | 224 (15) | 207 (15) |
| No. of MRI sets with known onset-to-MRI delay | 723 (71) | 157 (70) | 143 (70) |
| Onset-to-MRI delay (h), per MRI set,* | 3.75 (2–28) | 3.6 (2–26) | 4.2 (1.9–29.3) |
| No. of patients | 885 | 218 | 207 |
| Age (y) | 71 (59–83) | 69 (59–97) | 70 (60–98) |
| No. of women | 524 (51) | 122 (54) | 116 (54) |
| NIHSS score at admission* | 13.5 (7–19) | 14 (9–20) | 14 (7–20) |
| Intravenous thrombolysis † | 403 (52) | 95 (54) | 86 (50) |
| Mechanical thrombectomy ‡ | 667 (89) | 151 (88) | 164 (96) |
| No. of MRI sets in each subset | |||
| Subset A: Manufacturer 1, 1.5 T | 242 (24) | 53 (24) | 48 (23) |
| Subset B: Manufacturer 2, 1.5 T blow = 0 s/mm2 | 375 (37) | 81 (36) | 77 (37) |
| Subset C: Manufacturer 2, 1.5 T blow = 50 s/mm2 | 105 (10) | 23 (10) | 21 (10) |
| Subset D: Manufacturer 3, 1.5 T | 67 (6) | 15 (7) | 13 (6) |
| Subset E: Manufacturer 1, 3 T | 62 (6) | 14 (6) | 12 (9) |
| Subset F: Manufacturer 2, 3 T | 92 (9) | 20 (9) | 19 (9) |
| Subset G: Manufacturer 3, 3 T | 80 (8) | 18 (8) | 17 (8) |
NIHSS: National Institutes of Health Stroke Scale.
Values are expressed as numbers of patients with percentages in parentheses, unless otherwise specified.
*
Data are expressed as median with interquartile range in parentheses. NIHSS data were missing in respectively 46 (5%), 16 (7%), and 9 (4%) patients in training, validation, and test sets.
†
Missing data in respectively 114, 43, and 34 patients.
‡
Missing data in respectively 135, 47, and 37 patients.