 There is redemonstration of patient's known multifocal anaplastic astrocytoma with localized mass effect. An expansile infiltrating T1 hypointense and T2 hyperintense mass involves a majority of the left pons, left midbrain, and extends into the left thalamus. There is no enhancement of the tumor or restricted diffusion. Based on multiple different measurements on FLAIR and T2 sequences, this lesion is not significantly changed in size.There is minimal questionable FLAIR hyperintensity in the right ventral pons and some expansile convexity which may reflect subtle tumor infiltration. Abnormal T2 signal of the left lateral cerebellar hemisphere is unchanged. Review of rCBV maps does not demonstrated significant hyperperfusion of the tumor in any area.Again seen are postoperative changes of a small right occipital burr hole and a small area of encephalomalacia along the right lateral cerebellum which likely reflects site of prior biopsy. Again seen are a few scattered small foci of susceptibility which is nonspecific but may be related to microhemorrhage secondary to radiation therapy. Peripheral foci of susceptibility weighted abnormalities in the right lateral cerebellar hemisphere are likely post operative.The ventricles and sulci are unchanged. There is no herniation. There are no extraaxial fluid collections or subdural hematomas. Flow voids are present within the major vessels indicating patency. There is a small mucus retention cyst in the right maxillary sinus.
1. Multifocal anaplastic astrocytoma is unchanged in size compared to the most recent study as detailed above.2. Postoperative changes of a right lateral cerebellar biopsy.