Hypoxic brain damage: cortical laminar necrosis and delayed changes in white matter at sequential MR imaging.

PURPOSE

To report the findings of sequential magnetic resonance (MR) imaging in hypoxic encephalopathy.

MATERIALS AND METHODS

Three women and three men underwent repeated MR imaging studies. Sequential changes in signal intensity and morphologic features of the brain were evaluated.

RESULTS

Involvement of the watershed zones in the parietooccipitotemporal cortex was more frequent and more severe than that in the basal ganglia, thalami, hippocampus, pons, and cerebellum. Cerebral edema was seen in the acute stage. Enhanced T1-weighted images showed cortical laminar enhancement in the early subacute stage; unenhanced T1-weighted images revealed characteristic laminar hyperintense lesions of the cerebral cortex in the late subacute stage. Both of these findings seemed to reflect the progression of cortical laminar necrosis. In the chronic stage, cortical atrophy and delayed but progressive white matter changes were seen.

CONCLUSION

Changes in MR imaging features of hypoxic brain damage are complex but distinct. Cortical laminar necrosis, delayed white matter degeneration, and, probably, increased iron deposition in the white matter can be delineated.