Fig. 1

Magnetic resonance imaging of the thoracolumbar spine of case no. 6, displaying extra-dural spinal cord compression associated with T11–12 disc protrusion and concurrent bilateral T11 caudal articular process aplasia. From left to right; T2-weighted mid sagittal of thoracolumbar spine, T2-weighted transverse at the affected level T11–12 (transverse level marked with a dashed line), three-dimensional reconstruction of thoracolumbar junction on CT (T11–12 marked with dashed line; the normal articular processes of T12 are highlighted with an arrow head). There is a marked focal increase in T2-weighted signal within the spinal cord despite only mild ventral extra-dural spinal cord compression (arrowed on transverse image)