• Etiology: failure of dorsal induction of central nervous system, failure of closure of posterior neural tube
  • Imaging: meninges and spinal cord and nerve roots herniate into sac
  • Clinical: overt not skin covered spinal dysraphism

Radiology Cases of Myelomeningocele

MRI of Chiari II malformation and myelomeningocele
Sagittal T1 MRI without contrast of the brain (left) shows a small posterior fossa with downward cerebellar tonsil herniation and a small fourth ventricle. There is kinking of the spinal cord at the cervico-medullary junction. Sagittal (above right) and axial (below right) T2 MRI without contrast of the spine shows a low-lying conus medullaris with the spinal cord nerve roots terminating in a posteriorly located cerebrospinal fluid filled sac which is not covered by skin at the level of the L5-S1 vertebral bodies.
3D CT of myelomeningocele
3D reconstruction of CT without contrast of the lumbar spine shows lack of fusion of the posterior elements of the L4-S5 vertebral bodies.