Table 3 CT scan characteristics for Head CT among 163 patients in 7 selected facilities
Facility | A (n = 25) | B (n = 23) | C (n = 23) | D (n = 21) | E (n = 22) | F (n = 24) | G (n = 22) | Total (N = 163) |
|---|---|---|---|---|---|---|---|---|
kVp n (%) | ||||||||
120 | 22 (100.0) | 22 (13.5) | ||||||
130 | 26 (100.0) | 24 (100) | 23 (100.0 | 21 (100.0) | 22 (100.0) | 25 (100.0) | – | 141 (86.5) |
Total mAs | 851 (801, 1218)** | 3628.5 (745.6) | 4626 (4452, 4727)** | 5506 (620.6) | 3600.5 (3396, 4440)** | 2626.6 (444.4) | – | 3519 (2446, 4626)** |
Exam mAs | 151 (140, 166)** | 185.4 (8.8) | 221 (6.3) | 232.3 (19.0) | 211.9 (28.6) | 240 (0) | 297 (0) | 218.7 (44.6) |
Reference mAs | 188 (9.6) | 165.3 (21.5) | – | 240 (0) | 270 (0) | – | – | 207.9 (45.5) |
Scan length (mm) | 146.0 (43.7) | 262 (161, 301)** | 223.6 (19.2) | 182.5 (13.1) | 253.6 (15.9) | 173.7 (19.9) | 104.6 (22.1) | 188.4 (61.0) |
Scan time (s) | 16.4 (4.8) | 37.9 (2.7) | 66.9 (5.8) | 87.2 (6.3) | 65.5 (10.3) | 29.3 (3.5) | 22.1 (6.5) | 45.6 (25.9) |
Slice thickness (mm) n (%) | ||||||||
1.25 | 1 (4.6) | 1 (0.6) | ||||||
2.5 | 21 (95.4) | 21 (12.9) | ||||||
4 | 9 (34.6) | 23 (100.0) | 32 (19.6) | |||||
4.8 | 22 (100.0) | 22 (13.5) | ||||||
5 | 17 (65.4) | 24 (100) | 41 (25.2) | |||||
6 | 25 (100.0) | 25 (15.3) | ||||||
8 | 21 (100.0) | 21 (12.9) | ||||||
Image quality, n (%) | ||||||||
3 | – | – | 5 (21.7) | 1 (5.0) | 5 (22.7) | 1 (4.0) | 12 (7.7) | |
4 | 1 (5.0) | 20 (83.3) | 18 (78.3) | 8 (40.0) | 15 (68.2) | 2 (8.0) | 22 (100.0) | 86 (55.1) |
5 | 19 (95.0) | 4 (16.7) | 11 (55.0) | 2 (9.1) | 22 (88.0) | 58 (37.2) | ||