Other specified disorders of muscle [M62.89], Reason for Study: ^Reason: assess hypodense lesion History: AMS Bilateral confluent FLAIR high signal intensity lesions bilateral hemispheres especially involving bilateral occipital lobes, bilateral thalami, bilateral frontal, posterior parietal and temporal lobes as well as cerebellar hemispheres. The left basal ganglia and left mesial temporal lobe also show FLAIR high signal intensity lesion. Comparing to prior scan, these lesions are likely to be new interval development or progression of prior scattered FLAIR high signal lesions.Constellation of above findings suggest MR evidence of PRES (posterior reversible encephalopathy syndrome) and differential diagnosis include HIV encephalitis.The ventricles, sulci and cisterns are symmetric and unremarkable. There is no mass, mass effect, midline shift, intra or extra-axial fluid collection/hemorrhage, restricted diffusion/acute ischemia, or abnormal contrast enhancement. The midline structures and cranial-cervical junction are normal. Normal flow voids are identified in the major intracranial vessels. The mastoid air cells are clear.The left maxillary and ethmoid sinus show opacification which are related to prior traumatic fractures, grossly unchanged since prior scan.
1. Confluent bilateral supra and infra tentorial involvement of FLAIR high signal intensity lesions as described above, indicating possible diagnosis of PRES. Differential diagnosis include HIV encephalopathy, other white matter disease or low grade glioma but could be less likely.2. No evidence of acute ischemic or hemorrhagic lesion. No abnormal enhancement.3. No change of left basal ganglia and mesial temporal lobe abnormal FLAIR signal intensity lesions.