|T1 pre-gad||T2 FSE||T2 FSE|
On imaging, spinal arachnoid cysts have CSF signal characteristics and if small may be difficult to differentiate asymmetry in the sizes of the ventral vs. dorsal subarachnoid spaces. Communication of arachnoid cysts with the subarachnoid space may be demonstrated on CT myelography if the lesion is intradural. A late finding may be cord atrophy from the progressive mass effect of the arachnoid cyst. In this case, the phase contrast cine MR was diagnostic since it demonstrated that the tiny residual subarachnoid space has different flow characteristics than the CSF within the arachnoid cyst. At surgery, an intradural arachnoid cyst was found and was treated with cysto- peritoneal shunt.
Rabb CH, McComb JG, Raffel C, et al. Spinal arachnoid cysts in the pediatric group: an association with neural tube defects. J Neurosurg, Sep 1992; 77(3):p369-72.
Mirich DR, Hall JT, Carasco CH. MR imaging of traumatic spinal arachnoid cyst. J Comput Assist Tomogr, Sep-Oct 1988; 12(5):p862-5.