MR imaging diagnosis and differential diagnosis of intramedullary spinal cord metastasis

Objective To analyze the MRI appearance of intramedullary spinal cord metastasis (ISCM) and the difference between ISCM and other common tumors of inner spinal cord for improving the knowledge of the disease. Methods Eleven cases of ISCM were analyzed retrospectively. MR examinations including pre-contrast and Gd-DTPA enhancement were performed in all the cases. Results MRI appearance of 4 cases clinically and 7 cases pathologically proved were analyzed (average age of onset was 46.4±2.8 years). Multiple lesions occurred in 6 cases distributing in cervical cord, thoracic cord, conus or cauda equina. Mono-lesion occurred in 5 cases: 3 occurred in conus, 1 occurred in cervical cord, 1 occurred in the boundary of cervical cord and bulbus medullae. ISCM mainly displayed hypointensity or isointensity on T1WI and heterogeneousc hyperintensity on T2WI. On contrast study, all tumors showed marked enhancement, appearing patching, ring-shaped, mottling and nodosity enhancement. Affiliated signs included spinal cord thickening, peripheral edema, spinal cord cavity et al. Conclusion MRI can well demonstrate the inner structure and signal character of ISCM, identify the extension and development of lesion, thus can contribute the diagnosis and differential diagnosis; however ISCM have no characteristic manifestations on MRI, clinical data should be analyzed comprehensively to draw the final diagnosis.