 Redemonstrated is a heterogeneous T2/FLAIR hyperintense lesion within the cerebellar vermis, with areas of intrinsic T1 shortening and several foci of susceptibility artifact corresponding to previously noted calcifications as well as minimal patchy enhancement. Mild mass effect on the posterior wall of the fourth ventricle is again noted, without associated hydrocephalus. The mass is best delineated on the T2-weighted FLAIR images. It again measures 2.4 cm transverse x 3.0 cm AP dimension. These findings are unchanged.Low-lying cerebellar tonsils again extend 7 mm below the foramen magnum with associated crowding, unchanged in appearance. CSF flow analysis is nondiagnostic secondary to technical factors.No evidence of diffusion restriction or midline shift. No new pathological enhancement is identified. There is no extra-axial fluid collection. Normal flow voids are identified in the major intracranial vessels. There is mild mucosal thickening in the maxillary sinuses, unchanged, with an increase in ethmoid and frontal sinus mucosal thickening. There are no air-fluid levels. Mastoid air cells are clear.
1.No significant interval change in heterogeneous midline cerebellar vermian lesion with foci of calcification and enhancement.2.Stable low lying cerebellar tonsils, possibly relating to the mass effect from the cerebellar vermian lesion.