At what gestational age or older is gliosis in the periatrial region, best visualized on proton-density MRI scans, typically caused by injury to the developing brain?

28 weeks. Key diagnostic features include increased signal intensity in the periatrial white matter on proton-density MRI, often associated with periventricular leukomalacia. Clinical pearls: This condition is linked to hypoxic-ischemic injury in premature infants. Common pitfalls include confusing gliosis with normal myelination patterns or other white matter pathologies such as demyelinating diseases.