Fig. 13. Atypical imaging features of longitudinally extensive transverse myelitis related to neuromyelitis optica in a 10-year-old patient presenting with lower limb weakness and gait ataxia. A, B: Sagittal (A) and axial (B) T2 images reveal a multicystic, mildly expansile lesion extensively involving the lower cervical and thoracic cord (arrows). C: Sagittal CE-T1 image reveals mild, nodular enhancement predominantly along the posterior aspect of the lesion (arrow). A glioma was initially considered, however active demyelination was confirmed on biopsy of the lesion and anti-aquaporin 4 immunoglobulin G was identified on the serum. D, E: Sagittal (D) and axial (E) T2 images obtained after 4 weeks of immunosuppressive therapy reveals marked reduction in the extent of the lesion and the associated cord expansion (arrows). CE-T1 image (not shown) was motion degraded; however, there was considerable reduction in the degree of enhancement. CE = contrast-enhanced.