Male 9 years old with cyst shown on CT, headache, dizziness.Additional history per EMR: CT demonstrates a fluid filled cyst over the right frontal region with possible bone remodeling around it. These findings are likely consistent with an arachnoid cyst, which can remodel the surrounding bone; however, the fluid within the cyst is not quite the same density as the fluid in the ventricles. There is cystic enlargement of the subarachnoid space along the right frontal cerebral convexity measuring up to 6 mm in thickness (series 601 image 17), which follows CSF signal on all sequences and does not demonstrate diffusion restriction or enhancement. There is overlying osseous remodeling and mild mass effect on the adjacent parenchyma. There is no evidence of intracranial hemorrhage, enhancing mass, or acute infarct. There is a prominent curvilinear vein in the right temporal lobe compatible with a dural venous anomaly. The brain parenchyma and pituitary gland otherwise appear unremarkable. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
Cystic enlargement of the subarachnoid space along the right frontal cerebral convexity compatible with an arachnoid cyst.