Assess extent of PML, history of AIDS, PML and altered mental status Extensive confluent high signal intensity lesion on bilateral hemispheres in particular, right frontal lobe and left fronto-parietal lobes. The lesions involve mainly white matter and subcortical u-fibers but saving gray matter. Especially the left hemispheric lesion generates mass effects thus demonstrates midline shift toward right side with the degree of about 11mm at the level of foramen of Monroe.Gad enhanced images show minimal abnormal enhancement of the lesion especially peripheral area of the lesion. There is no evidence of acute ischemic or hemorrhagic lesion.Above described findings with considering history of AIDS and active HAART treatment indicate diagnostic possibility of Progressive Multifocal Leukoencephalopathy with Immune Reconstitution Inflammatory Syndrome (PML-IRIS). However, differential diagnosis of HIV encephalopathy, JC virus encephalitis and other opportunistic encephalitis could be considered. Normal flow voids are identified in the major intracranial vessels. The paranasal sinuses and mastoid air cells are clear.
1. Extensive confluent bihemispheric white matter lesions with mass effect of left fronto-parietal lesion creating midline shift toward right side indicate diagnostic possibility of PML with IRIS. Differential diagnosis include HIV encephalopathy, progression of JV virus encephalitis and other opportunistic infection.2. No evidence of acute ischemic or hemorrhagic lesion. 