Table 4 CT scan characteristics for chest CT among 155 patients in 7 selected facilities
Facility | A (n = 20) | B (n = 30) | C (n = 27) | D (n = 21) | E (n = 20) | F (n = 21) | G (n = 16) | Total (N = 155) |
|---|---|---|---|---|---|---|---|---|
kVp n (%) | ||||||||
120 | 16 (100.0) | 16 (10.3) | ||||||
130 | 20 (100.0) | 30 (100.0) | 27 (100.0) | 21 (100.0) | 20 (100.0) | 21 (100.0) | 139 (89.7) | |
Total mAs | 1283.1 (289.6) | 1781 (1325, 2884)** | 4400 (3658, 9224)** | 4958 (1648.6) | 2772.5 (2215.5, 3728**) | 1271 (940, 1812)** | – | 2220 (1197, 3895)** |
Exam mAs | 59.0 (15.0) | 54 (0) | 56 (36, 88) | 44.5 (16.3) | 46.1 (10.9) | 55 (45, 77)** | 198.5 (151.5, 295)** | 55.8 (23.8) |
Reference mAs | 78.5 (6.7) | 52.8 (0) | 78.9 (13.1) | 61.9 (8.7) | 70 (0) | 72.9 (9.0) | – | 68.4 (14.6) |
Scan length (mm) | 318.6 (56.1) | 397.8 (108.3) | 302.8 (48.4) | 281.0 (36.8) | 513 (0) | 287.2 (48.1) | 29.4 (19.8, 55.8)** | 318.8 (134.2) |
Scan time (s) | 6.0 (0.9) | 15.3 (0) | 23.8 (5.5) | 27 (24, 31) | 21.7 (6.7) | 12.8 (1.3) | 6.6 (0.8) | 19.0 (17.1) |
Slice thickness (mm) n (%) | ||||||||
1 | 30 (100.0) | 30 (19.4) | ||||||
2.5 | 16 (100.0) | 16 (10.3) | ||||||
3 | 21 (100.0) | 21 (13.5) | ||||||
5 | 20 (100.0) | 27 (100.0) | 20 (100) | 88 (56.8) | ||||
Image quality n (%) | ||||||||
2 | 2 (7.4) | 1 (4.8) | 1 (6.3) | 3 (1.9) | ||||
3 | 7 (23.3) | 5 (18.5) | 1 (4.8) | 8 (40.0) | 2 (9.5) | 10 (62.5) | 24 (15.5) | |
4 | 1 (5.0) | 12 (40.0) | 14 (51.9) | 11 (52.3) | 5 (25.0) | 5 (23.8) | 5 (31.2) | 58 (37.4) |
5 | 10 (95.0) | 11 (36.7) | 6 (22.2) | 38.1) | 7 (35.0) | 14 (66.7) | 3.8 (1.6) | 70 (45.2) |