44 years, Female, follow-up of a left retrocerebellar arachnoid cyst. Again seen is a left posterior fossa CSF signal lesion measuring approximately 7.0 x 3.3 x 5.5 cm (TV x AP x CC), which is unchanged when measured with a similar technique. Mild associated mass effect on the adjacent cerebellum. Mild scalloping of the occipital calvarium is also again noted. No restricted diffusion to suggest acute ischemia. No intracranial hemorrhage. Unchanged 4 mm pineal cyst. No suspicious intracranial mass. The ventricles are within normal limits in size and configuration. No abnormal parenchymal or meningeal enhancement. Major flow-voids are preserved.Sella and orbits are grossly within normal limits. Paranasal sinuses and mastoid cells are clear. Bone marrow signal and extracranial soft tissues are within normal limits.
Compared to outside MRI from 12/2/2013, left retrocerebellar arachnoid cyst is unchanged.