Reason: Chiari malformation. Follow-up of cervical spine T2 hyperintensity, syrinx, follow up exam , evaluate for change History: chiari, syrinx , follow up. Images are slightly limited by patient motion. Stigmata of Chiari I malformation are again seen, with peglike tonsils extending up to 22 mm below the level of the foramen magnum. There is again severe crowding at the level the foramen magnum. CSF flow imaging again demonstrates diminished biphasic CSF flow at the level of the foramen magnum, more conspicuous posteriorly, although with focal attenuation along the slightly retroflexed dens tip as well. Overall, this appearance appears similar to prior exam.The ventricles and sulci are within normal limits. The cisterns remain patent. There is no midline shift or mass effect. There are no areas of abnormal signal or pathological enhancement. There is no diffusion abnormality. No extra-axial fluid collection is identified.Normal flow-voids are demonstrated in the major intracranial vascular structures. The midline structures and craniocervical junction are within normal limits. There is mild mucosal thickening throughout the visualized paranasal sinuses.CERVICAL SPINE
1.Redemonstration of stigmata of Chiari I malformation with significant caudal extension of the cerebellar tonsils. Retroflexed dens also contributes to narrowing at the level of the foramen magnum, with persistent decreased biphasic flow especially posteriorly at this level.2.Stable appearance of ill-defined T1-hypointense and T2 hyperintense signal at the lower C2 level within the cord, unchanged since baseline exam. Given the Chiari I malformation, this most likely relates to soft syrinx. No pathological enhancement identified, although continued follow-up is recommended to exclude possibility of space-occupying lesion.