 There is normal anatomic alignment of the basion, C1 and C2/dens articulations on the neutral, flexion and extension views. There is trace anterolisthesis of C2 on C3 without evidence of dynamic instability. Postoperative findings related to Chiari decompression with suboccipital craniectomy and occiput-C2 posterior fusion are again seen. There is mild loss of T2 disk signal in the C2-3, C4-5 and C5-6 disks without significant herniation, spinal canal or neural foraminal narrowing.There is diminished CSF spaces at the foramina magnum ventrally related to mild retroversion of the dens. Dens abuts the medulla, unchanged from prior, without evidence of impingement on the medulla on the flexion or extension views. Dorsal CSF flow is not seen on the CSF flow sequence secondary to susceptibility artifact from the hardware. T2 sequences however do demonstrate good dorsal CSF space.
1.Stable postoperative findings of Chiari decompression and occiput to C2 fusion. No MR evidence of dynamic instability.2.No syrinx in the cervical cord.