Fig. 1

Sagittal fat suppressed T1-weighted (a) and T2-weighted (b) magnetic resonance images of the lumbosacral spine. A heterogeneous, predominantly cystic, intramedullary space-occupying lesion measuring 2.5 × 1.2 cm is present within the filum terminale at L2/3 level (green arrow). Additional findings include a transitional lumbosacral vertebra (lumbarisation of S1), dehydration of the L5/S1 intervertebral disc with a posterior disc bulge, and a hemangioma in the vertebral body of L5. The remainder of the spinal cord and conus medullaris, lower thoracic and lumbosacral vertebrae, intervertebral disc spaces, and paraspinal soft tissues appear normal