UW Emergency Radiology
Normal Adult Craniocervical Measurements on CT
| Measure | Mean (SD) (mm) | MDCT Normal Value (mm) |
| Basion-axial interval | 3.4 (4.64) | Not reliable |
| Basion-dens interval | 5.7 (1.39) | < 8.5 |
| Powers Ratio (a/b) | 0.8 (0.08) | < 0.9 |
| Atlanto-dental interval | 1.3 (0.37) | <2.0 |
| Atlanto-occipital interval | 1.0 (0.23) | <1.4 |
Reference:
Rojas, C. A., et al. (2007). “Reassessment of the craniocervical junction: normal values on CT.” AJNR Am J Neuroradiol 28(9): 1819-1823.