Female, 33 years old, with Chiari malformation and large syrinx, normal neurologic exam. Assess syrinx length. Assess for cord tethering. The foramen magnum is crowded. The right cerebellar tonsil is pointed and descends 9 mm below the level of the foramen magnum. The left cerebellar tonsil also descends below the foramen magnum but to a lesser degree. Adequate CSF flow signal is seen along the ventral aspect of the brainstem through the foramen magnum. Posteriorly, flow is seen up to the level of the cerebellar tonsils but not around or above the tonsils.A spinal cord syrinx is evident beginning at the C2 level and continuing caudally to the T4 level. The syrinx cavity reaches its maximum caliber at C5 and C6 where it measures 9 mm TV and 5 mm AP. The syrinx cavity is largely positioned in the center of the cord, though at the C2 level, there is a linear slitlike component which completely traverses the right hemicord.The remainder of the spinal cord is unremarkable. The conus tip terminates at the mid L2 level which is still within normal limits. The nerve roots of the cauda equina disperse evenly through the thecal sac. No evidence of fatty filum or other intraspinal fatty lesions is seen. On prone imaging, the conus and cauda equina demonstrate clear anterior displacement.Spinal alignment is anatomic. Vertebral body height, morphology and signal characteristics are all within normal limits. The intervertebral discs are preserved and at no level is there any evidence of significant spinal canal or foraminal stenosis.
1.Findings compatible with Chiari I malformation. The foramen magnum is crowded and there is no detectable CSF flow posteriorly along the cerebellar tonsils.2.A spinal cord syrinx is evident extending from C2 down to the T4 level. The syrinx reaches its maximum caliber at C5 and C6 where it measures 9 x 5 mm.3.No evidence of tethered cord is seen. No other significant spinal abnormalities are detected.