MRI Findings in Acute Hyperammonemic Encephalopathy: Three Cases of Different Etiologies: Teaching Point: To recognize MRI findings in acute hyperammonemic encephalopathy.

Acute hyperammonemic encephalopathy is a rare but life-threatening condition that might complicate liver disease as well as non-hepatic conditions. It can lead to coma and death, secondary to brain edema and intracranial hypertension. We present three cases of acute hyperammonemic encephalopathy of different etiologies and the observed brain MRI findings. Symmetrical extensive cortical signal abnormalities, typically involving the insular and cingulate cortices, often showing restricted diffusion, are commonly described. These specific imaging features should be recognized by the radiologist since prompt treatment of the condition is paramount.