Distinct Imaging Patterns and Lesion Distribution in Posterior Reversible Encephalopathy Syndrome

A 50-year-old woman 6 months post liver transplant experienced a generalized seizure and unresponsiveness. Blood pressure at the time of the toxic event fluctuated markedly with a range between 106 and 200 mm Hg systolic and 54 and 80 mm Hg diastolic.

A–E, Brain MR imaging (FLAIR sequence) obtained the day of the toxic event demonstrates moderate vasogenic edema in the subcortical white matter of the frontal (white arrows), parietal (white curved arrows), and occipital regions (white open arrows) with some cortical involvement consistent with a milder expression of the holohemispheric pattern. Thalamic involvement is present (black arrowhead, 2B) along with the upper margin of vasogenic edema present in the pons (black arrow, 2A).

A 36-year-old man with severe type 1 diabetes and recurrent septic arthritis of the shoulder requiring frequent debridement presented with several days of headache, nausea, and visual changes along with hypertension. Blood pressure at toxicity was 184/111 mm Hg.

A–E, Brain MR imaging (FLAIR sequence) demonstrates moderate vasogenic edema in the parietal (white curved arrows) and occipital (white open arrows) cortex and white matter with linear involvement along the superior frontal sulcus (white arrows) in the mid to posterior frontal lobes bilaterally. The extreme frontal poles seem normal (3B). This pattern is consistent with the superior frontal sulcus pattern. Cerebellar involvement (white arrowheads) is also present along with vasogenic edema at the junction of the pons and midbrain on the right (black arrowhead, 3A).

A 48-year-old woman with acute myelogenous leukemia status post allogenic BMT had a seizure 19 days after transplantation. Baseline blood pressure was 134/84 mm Hg, and blood pressure at toxicity was 132/48 mm Hg.

A–B, Vasogenic edema is present in the occipital poles (open arrows) and thalamus (arrowheads) bilaterally along with deep white matter in the subinsular region (small arrow).

C–D, Vasogenic edema is present in the parietal region (curved arrows) and corona radiata and subinsular region (small arrows) bilaterally and caudate nucleus on the left (arrowhead).

E, Vasogenic edema is present in the parietal region (curved arrows) bilaterally with involvement along the superior frontal sulcus (large arrows) bilaterally. A linear “string-of-pearl” pattern is also present in the adjacent left centrum semiovale (small arrows). MR imaging is consistent with a more diminutive expression of the superior frontal sulcus pattern.

A 56-year-old diabetic man with a foot infection on antibiotic treatment experienced a headache and visual change. Baseline blood pressure was 191/88 mm Hg, and blood pressure at toxicity was 215/115 mm Hg.

A–B, Brain MR imaging (FLAIR sequence) obtained at toxicity demonstrates vasogenic edema in the occipital lobes (open arrows) and parietal region (curved arrows) bilaterally as well as involvement in the cerebellum bilaterally (not shown). This is representative and typical of the dominant parietal-occipital pattern. CSF hyperintensity is noted, likely related to ongoing oxygen administration.