Impact of imaging modality, age, and gender on craniocervical junction angles in adults without structural pathology.

CONTEXT

Multiple angles of the craniocervical junction (CCJ) are associated with pathological conditions and surgical outcomes, including the clivo-axial angle (CXA), clival slope (CS), and sagittal axis (XS). However, there are varying normative ranges reported and a paucity of data analyzing the effects of imaging modality, age, and gender on these angles.

SETTING AND DESIGN

A retrospective review of computed tomographic (CT) and magnetic resonance imaging (MRI) scans in fifty adults without CCJ pathology from 2014 to 2019.

METHODS

Age, gender, indication, and hours between scans were recorded. Two-blinded observers measured all angles. Analysis between angles from the same patient was performed using the Wilcoxon signed-rank test. Multivariable linear regression was used to test for associations between average angles and age or gender.

RESULTS

Average age and time between scans were 41.3 and 14.3 h, respectively, with 94% performed due to trauma. On CT, average CXA, CS, and XS were 162.1°, 118.4°, and 81.3°, respectively. On MRI, they were 159.8°, 117.2°, 85.3°, respectively. There were statistically significant differences between CXA and XS ( < 0.01) based on imaging modality. On CT, there was a significant increase in XS by 1.93°° and decrease in CS by 1.88°° and on MRI, there was a significant increase in CXA by 1.93°° and decrease in CS by 2.75°° corresponding with a 10-year advancement of age. Gender did not have an effect.

CONCLUSION

There are significant differences in angular measurements of the CCJ between CT and MRI from the same patient, as well as changes in normative values based on age.