What are Duret hemorrhages, and how are they identified on imaging in the context of brain herniation?

Duret hemorrhages are midline hematomas located within the tegmentum of the rostral pons and midbrain, typically associated with descending transtentorial herniation. They occur due to the stretching or tearing of penetrating arteries. On imaging, they appear as linear or flame-shaped hemorrhages in the brainstem. Clinically, they indicate severe brain injury and poor prognosis. A common pitfall is confusing them with other brainstem hemorrhages, such as those from hypertension or vascular malformations.