Differentiation between intramedullary spinal ependymoma and astrocytoma: comparative MRI analysis.

AIM: To investigate magnetic resonance imaging (MRI) findings that could be used to differentiate intramedullary spinal ependymoma from astrocytoma, and to determine predictors for this differentiation.

MATERIALS AND METHODS: MRI images of 43 consecutive patients with pathologically proven intramedullary spinal ependymoma (n = 24) and astrocytoma (n = 19) were comparatively evaluated with regard to size, location, margin, signal intensity, contrast enhancement, presence of syringohydromyelia, tumoural cyst, non-tumoural cyst, and haemorrhage. MRI findings and demographic data were compared between the two tumour groups using univariate and multivariate logistic regression analyses.

RESULTS: In patients with ependymoma, older age and a larger solid component were more often observed than in astrocytoma. Central location, presence of enhancement, diffuse enhancement, syringohydromyelia, haemorrhage, and cap sign were more frequently observed in ependymoma. However, multivariate analysis revealed that syringohydromyelia was the only variable able to independently differentiate ependymoma from astrocytoma, with an odds ratio of 62.9 (95% CI: 4.38-903.22; p = 0.002).

CONCLUSION: Among the various findings, the presence of syringohydromyelia is the main factor distinguishing ependymoma from astrocytoma.