Hospital-level characteristics
| Total facilities (n=395) | Total admissions | MRI N (%) | No MRI N (%) | P value |
| Total | 32 125 | 3185 (9.91) | 28 940 (90.09) | |
| Hospital type | ||||
| For profit (n=39) | 2725 | 215 (7.89) | 2510 (92.11) | <0.01 |
| Non-profit (n=355) | 29 186 | 2969 (10.17) | 26 217 (89.83) | |
| Teaching status | ||||
| Community (n=173) | 10 273 | 1211 (11.79) | 9062 (88.21) | <0.01 |
| Non-teaching (n=70) | 2667 | 298 (11.17) | 2369 (88.83) | |
| University (n=152) | 19 167 | 1675 (8.74) | 17 492 (91.26) | |
| Trauma center level | 2667 | 298 (11.17) | 2369 (88.83) | |
| Level 1 (n=178) | 23 722 | 2489 (10.49) | 21 233 (89.51) | <0.01 |
| Level 2 (n=217) | 8385 | 695 (8.29) | 7690 (91.71) | |
| Geographic region | ||||
| Midwest (n=108) | 6342 | 663 (10.45) | 5679 (89.55) | <0.01 |
| Northeast (n=80) | 5408 | 1182 (21.86) | 4226 (78.14) | |
| South (n=120) | 14 501 | 1010 (6.97) | 13 491 (93.03) | |
| West (n=80) | 5662 | 325 (5.74) | 5337 (94.26) | |