 Postoperative changes are again seen from Chiari decompression, with a widely patent neoforamen magnum, similar to the appearance on the most recent comparison MRI cervical spine. The ventricles and sulci are prominent, consistent with moderate age-related volume loss. The basal cisterns remain patent. There is no midline shift or mass effect. There are scattered punctate foci and patchy areas of abnormal T2/FLAIR hyperintensity within the periventricular and subcortical white matter, which are nonspecific but may represent mild chronic small vessel ischemic changes. There is no diffusion abnormality. No extra-axial fluid collection is identified.Normal flow-voids are demonstrated in the major intracranial vascular structures, although the flow-void associated with the right distal transverse and sigmoid sinuses appear slightly less conspicuous than on the contralateral side, with increased T2 signal at the level of the jugular bulb and caudally. On T1-weighted images, the sinus appears similar to prior exam, where previous postcontrast images demonstrated venous patency. There is no significant associated diffusion restriction or susceptibility along these venous structures, and therefore findings are felt to be artifactual related to flow. The midline structures and craniocervical junction are within normal limits. There is a persistent prominent mucosal retention cyst in the right maxillary sinus.The intracranial internal carotid arteries are normal in course and caliber. The middle and anterior cerebral arteries are unremarkable. The vertebral arteries, basilar artery, and posterior cerebral arteries are normal in course and caliber. There is no evidence of flow-limiting stenosis or aneurysm.
1. No acute abnormality. Stable probable minimal chronic small vessel ischemic changes.2. Stable postoperative changes from prior Chiari decompression with patent neoforamen magnum.3. Unremarkable MRA of the head.