 There is diffuse prominence of the cortical sulci in proportion to the cerebral ventricles consistent with mild diffuse cerebral atrophy. There is an approximately 1.3 cm septated subdural fluid collection anterior to the left frontal lobe. A 7 mm superficial component of this fluid collection adjacent to the calvarium demonstrates small amount of intrinsic T1 signal and T2/FLAIR hyperintensity with respect to the CSF, while the remainder of the collection demonstrates CSF intensity. Additionally, there is prominence of the subarachnoid space overlying the somewhat flattened anterolateral left frontal lobe, possibly related to posttraumatic arachnoid cyst formation, with a prominent vessel coursing anteriorly. Scattered superficial siderosis is demonstrated along the paramedian frontal lobes near the vertex, as well as along the left anterolateral frontal lobe and minimally along the anterior right frontal lobe. There are also a few foci of susceptibility along the mesial left temporal lobe inferiorly. There is no diffusion restriction to suggest acute ischemia. The basal cisterns are visualized.
1. Chronic appearing septated 1.3 cm left frontal subdural collection may be related to prior hematoma. A 7 mm component of this collection demonstrates signal intensity slightly different from CSF.2. There is prominence of the subarachnoid space anterior to the left frontal lobe with hemosiderin deposition within the left frontal cortical sulci suggestive of possible posttraumatic arachnoid cyst formation.3. There is superficial siderosis along the left greater than right frontal lobes. This is favored to relate to prior trauma. Recommend correlation with history. If there is no history of prior trauma, further imaging of the spine may be considered as a potential source of subarachnoid hemorrhage.