Findings:
Compared to the previous study newly appreciated areas of restricted diffusion are seen in the left middle cerebellar peduncle, the left anterolateral medulla, the left thalamus and the centrum semiovale and in the anterior aspect as well as the splenium of the corpus callosum bilaterally.
There are also areas of cortical diffusion restriction in both frontal lobes, extending to the postcentral region bilaterally.
Also, significant increase in the patchy areas of enhancement is noted, involving the frontal lobes, the cingulate gyri posterior to the splenium, the left thalamus and both cerebellar hemispheres, more significant on the right.
The diffuse bilateral white matter lesions remain relatively unchanged with no significant mass effect or midline shift.
Mild vertebrobasilar dolichoectasia is noted.
The pituitary gland is normal.
The orbits, paranasal sinuses and mastoid air cells are clear.
No bony abnormality is seen. The craniocervical junction is normal.
Conclusion:
Compared to the previous study newly appreciated areas of diffusion restriction as well as increase in the patchy areas of enhancement in both cerebral and cerebellar hemispheres, suspicious of PML with associated IRIS. Histopathological evaluation is advised.