14-year-old female with cerebral cyst. Follow up exam at 3 Tesla. Redemonstrated is a focal intraparenchymal cystic appearing structure involving the left periatrial white matter right just cranial to the atrium of the left lateral ventricle. This currently measures up to 10 mm (previously 13 mm and 18 mm) demonstrating continued retraction. 3D FLAIR as well as FIESTA thin cuts through this reveal a small T2 hyperintense focus laterally, as well as adjacent perivascular spaces, both of which were present previously. There is no associated abnormal enhancement.The remaining images redemonstrates prominence of the perivascular spaces. The ventricles and sulci are normal in size. The cerebellar tonsils are in normal position. There are no masses, mass effect or midline shift. The pituitary gland is normal in size. There is no evidence for intracranial hemorrhage or acute cerebral, brainstem or cerebellar infarction. No diffusion-weighted abnormalities are identified. There are no extraaxial fluid collections or subdural hematomas. Flow voids are present within the major vessels indicating patency. The paranasal sinuses and mastoid air cells are clear.
Redemonstrated is a focal intraparenchymal cystic appearing structure involving the left periatrial white matter right just cranial to the atrium of the left lateral ventricle. This currently measures up to 10 mm (previously 13 mm in 2009 and 18 mm in 2006) demonstrating continued retraction. 3D FLAIR as well as FIESTA thin cuts reveal a small T2 hyperintense focus laterally, as well as adjacent perivascular spaces, both of which were present previously. There is no associated abnormal enhancement. Given the continued retraction and lack of enhancement now over a 9 year time interval, this is felt to represent a benign lesion, most likely a dilated perivascular space. A postinflammatory cyst remains in the differential diagnosis. Given the lateral T2 hyperintense focus, neuroglial cyst is felt to be unlikely. Given the retraction over an extended period of time, without associated enhancement, cystic neoplasm is also felt to be unlikely.