 Corresponding to the recent development of findings on the noncontrast CT, there has been interval worsening of burden of intracranial metastatic disease. There are innumerable round enhancing nodules throughout the parenchyma, with some areas of more gyriform enhancement along the cerebral hemispheres. The associated pattern of FLAIR hyperintense vasogenic edema appears similar to the outside MRI from June 2016, except for prominent progression of paramedian frontal parietal abnormal signal. There is also increased extent of FLAIR abnormality involving a left parietal metastasis and a lateral right frontal lobe metastasis. Diffuse cerebral sulcal effacement is also worsened.Compared to the more remote postcontrast exam from 4/26/2016, there has been severe progression of disease. Reference lesion in the right posterior medial temporal lobe is increased in size, now measuring 13 mm on 1001/169, previously 6 mm. The referenced treated right lateral inferior frontal lobe lesion demonstrates decreased degree of enhancement, measuring 7 mm on 1001/151, previously 6 mm. The referenced left occipital lobe lesion is also been treated, increased central low signal and decreased peripheral enhancement. This measures 7 mm on 1001/122, compared to previous 8 mm. However, many other lesions have significantly enlarged, for example a right caudate head lesion measures 12 x 10 mm on 1001/176, compared to previous 7 x 6 mm. Dorsal left midbrain lesion is also present now.Within the posterior fossa, there is extensive progression of tumor burden, with significant increased extent of FLAIR abnormality in the left cerebellar hemisphere. There is now near complete effacement of the fourth ventricle, measuring 6 mm transverse compared to previous 9 mm in June 2016. There is also mild posterior midline shift to the right, not previously present. In addition, a focal enhancing lesion is identified within the anterior cerebellum just distal to the cerebral aqueduct measuring 5 x 4 mm on 1001/119. A bilobed appearing lesion in the midline cerebellum measures up to 2.0 cm transverse x 1.7 cm AP. As described on the CT, there is significant effacement of CSF space in the posterior fossa and crowding of the foramen magnum, although there is no frank cerebellar tonsillar herniation at this time. Third ventricle is also mildly increased in caliber, now measuring 4 mm transverse compared to previous 2 mm.There is no significant susceptibility identified. There is redemonstration of a calcified lesion along the left anterior falx which may represent a small calcified meningioma. There is no diffusion abnormality to suggest recent ischemia. No extra-axial fluid collection is identified. Normal flow-voids are demonstrated in the major intracranial vascular structures. The midline structures are within normal limits. There is prominent T2 hyperintense fluid signal throughout left mastoid air cells, middle ear, and aerated petrous apex. There is also mild mucosal thickening in the left frontal ethmoidal recess.
1.Interval worsened intracranial metastatic disease burden, with increased extent of vasogenic edema especially within the cerebellum and also along the paramedian frontal parietal region.2.Interval decreased fourth ventricular caliber due to surrounding mass effect from extensive cerebellar tumor, including the presence of a small lesion just distal to the cerebral aqueduct along the anterior cerebellum. Interval effacement of CSF spaces in the posterior fossa even when compared to 6/11/2016, without frank cerebellar tonsillar herniation at this time.3.Slight increased prominence of the third ventricle which could in part relate to the more distal compromise of the ventricular outflow due to surrounding increased mass effect.4.Evidence of posttreatment changes involving right lateral frontal and left occipital pole metastatic lesions.