 Again noted are postoperative findings related to left retrosigmoid craniotomy. Postoperative extra-axial collection with flattening of the left lateral aspect of the cerebellum is unchanged. There is persistent intermediate T2 signal with enhancement on postcontrast T1 images within the left internal auditory canal with adjacent dural thickening, which measures about 1 cm in length, as seen on image 11 of series 17, unchanged when compared to prior exam. Stellate areas of low signal in the left prepontine area minimally distorting the left trigeminal nerve and extending caudally is again noted and perhaps represents scarring from previous surgery, similar to prior exam. There is diminished normal T2 signal associated with left inner ear structures which appears less conspicuous as compared to the contralateral side, likely postoperative.Scattered foci of T2/FLAIR hyperintensity in the periventricular white matter is nonspecific but suggestive of chronic microvascular ischemic changes. There is mild symmetric smooth diffuse pachymeningeal thickening. Previous smooth pachymeningeal enhancement was seen along the ventral skull base at the level of surgery. The ventricles and sulci are normal in size. There is no significant mass effect or midline shift. No diffusion-weighted abnormalities are identified. Flow voids are present within the major vessels indicating patency. The left maxillary sinus and nasopharyngeal retention cysts are unchanged.
1.Postoperative findings with persistent intermediate T2 signal and enhancement within the left internal auditory canal, stable when compared to exam from 1/6/2016. This may represent posttreatment changes and/or residual tumor. 2.Diffuse symmetric pachymeningeal thickening which is nonspecific, but may be related to recent lumbar puncture or can be seen with idiopathic hypertrophic pachymeningitis.3.Scattered foci of T2/FLAIR hyperintensity in the periventricular white matter, which is nonspecific but suggestive of chronic microvascular ischemic changes.