Correlation of cervical and thoracic inlet sagittal parameters by MRI and radiography in patients with cervical spondylosis

To investigate the relationship between cervical and thoracic sagittal alignment parameters measured by magnetic resonance imaging (MRI) and x-ray in patients with cervical spondylosis Data from 120 symptomatic patients who presented with cervical spondylosis between April 2015 and January 2016 were retrospectively analyzed. Patients received both a cervical MRI and a cervical radiograph during a single visit. The thoracic inlet angle (TIA), T1 slope (T1S), neck tilt (NT), C2-C7 angle (C2-C7), and C2-C7 sagittal vertical axis (C2–7 SVA) were assessed. Pearson correlation coefficient, paired t test, and linear regression models were used to analyze parameters obtained by cervical MRI and radiography. The difference in mean thoracic inlet angle x-ray (TIAX) and thoracic inlet angle MRI (TIAM) (TIAM–TIAX) (0.72 ± 5.82°) was not significant (P > .05). There were significant differences in mean T1 slope x-ray (T1SX) and T1 slope MRI (T1SM) (T1SM-T1SX) (-2.55 ± 6.14°), mean neck tilt x-ray (NTX) and neck tilt MRI (NTM) (NTM-NTX) (3.26 ± 6.01°), mean C2-C7 angle x-ray (C2–7X) and C2-C7 angle MRI (C2–7 M) (C2–7M-C2–7X) (−3.57 ± 10.00°), and mean C2-C7 sagittal vertical axis X ray (C2–7 SVAX) and C2-C7 sagittal vertical axis MRI (C2–7 SVAM) (C2–7 SVAM-C2–7 SVAX) (-4.50 ± 1.26 mm) (all P ≤ .001). There were positive correlations between TIAM and TIAX (r = 0.807), T1SM and T1SX (r = 0.581), NTM and NTX (r = 0.759), cervical loidosis MRI and cervical loidosis x-ray (r = 0.666), and SVAM and SVAX (r = 0.226). MRI may be useful to evaluate thoracic inlet and sagittal alignment parameters in patients with cervical spondylosis. Patients with cervical spondylosis may have a relatively low capacity for compensation in the cervical region.