Correlation between the severity of myelopathy and cervical morphometric parameters on dynamic magnetic resonance imaging

Background To compare morphometric factors of cervical spine in the cervical stenosis on dynamic and static magnetic resonance imaging. To analyse the relationship between the severity of myelopathy and morphometric parameters. Methods Patients with cervical canal stenosis scanned with MRI in neutral (N), flexion (F) and extension (E) positions were retrospectively reviewed. All cases were evaluated in Nurick and Muhle grades. Following parameters were measured: anterior and posterior length of the cervical cord (aLCC, pLCC), mid-cord distance ( L value), cervical cord angle (CCA), cervical lordosis, spine/cord (S/C) angle ratio, spinal cord (SC) area, cerebrospinal fluid (CSF) area, and CSF reserve ratio (CSF/CSF plus SC). Univariate multiple regression for Nurick grade as dependent factor was used. Results Sixty-three patients and 34 men, with the mean age of 58.2 ± 11 years, were analysed. Significant differences were found for pLCC, SC area, C lordosis and CCA. The difference between F and E for C lordosis angle was 42.80° ± 14.4 and for CC angle 30.42° ± 9.6. The mean S/C angle ratio was calculated for 1.4 ± 1.3. Nurick grade positively correlated with age ( p = 0.041) and S/C angle ratio ( p = 0.011), negatively with SC area ( p = 0.006) and flexion-extension difference of L value (0.004). Conclusions Severity of myelopathy correlates with age, spinal cord area on extension and reduced mobility of spinal cord. An association between spine/cervical cord angle mismatch and Nurick grade was found.