 Again seen is mild dilatation of the lateral and third ventricles which is stable to minimally worse in the interval. For example the third ventricle measures up to 12 mm in the transverse plane, previously 11 mm. There is mild interval increase in dilatation of the infundibular recess of the third ventricle. Obstruction at the cerebral aqueduct is again suspected and better appreciated on prior sagittal FIESTA sequence on examination from 1/31/2013. Cerebellar tonsils have a pointed configuration and extend caudally up to 6 mm below the foramen magnum and to a lesser degree on the right. Retroflexed dens also contributes to fairly mild crowding at the foramen magnum.No evidence of acute infarct or intracranial hemorrhage. No extra-axial collections. There is minimal periventricular T2/FLAIR hyperintensity similar to prior with minimal if any evidence of transependymal flow of CSF. Brain parenchyma appears otherwise unremarkable. There is no intracranial mass, midline shift, or herniation. No abnormal enhancement. Pituitary gland is grossly unremarkable.Flow voids are present within the major vessels indicating patency. Paranasal sinuses are grossly clear. Minimal opacification of the left-sided mastoid air cells is present.
1. Findings compatible with mild chronic hydrocephalus with likely obstruction at the level cerebral aqueduct, which is better appreciated on prior high-resolution 3-D T2 sequence. Findings are stable to minimally worse since 1/31/2013. There is minimal if any evidence of transependymal flow of CSF.2. Findings of mild Chiari I malformation with fairly mild crowding at the foramen magnum related to low cerebellar tonsils and retroflexed dens similar to prior.