MR imaging features of conus medullaris and filum terminale myxopapillary ependymomas at cauda equina and filum terminale

Objective:To study the MR imaging features of myxopapillary ependymomas at cauda equina and filum terminale.Methods:12 cases of myxopapillary ependymomas at cauda equina and filum terminale histologically proved were retrospectively reviewed in terms of length,pattern of growth and signal intensity.Results:The average number of vertebral units involved with tumors was 2~9.Myxopapillary ependymomas at cauda equina and filum terminale in our study were classified into vertebra involved(n=3) and non-vertebra involved(n=9) type.The former was generally accompanied by expansion of spinal canal and neural foraminae,bone destruction,while the latter usually presented central growth.On MR T1WI,tumors presented iso-or slight hypointensity,patchy high signal appeared in 8 cases.On T2WI,tumors presented hyperintensity,cystic component was shown in 3 cases,and reactive cysts were shown in the head-side of the spinal cord in 2 cases.All tumors showed marked heterogeneous enhancement.Conclusion:MRI findings of conus medullaris and filum terminale myxopapillary ependymomas have certain characteristics,understanding these features will help to make correct diagnosis.