200 premature and mature neonates with clinical evidence of hypoxia or traumatic encephalopathy were examined by cranial computerized tomography (CT) during the first two weeks postnatally. The findings were compared with those in a "control group" consisting of 14 neonates with extraneural malformations. Cerebral hemorrhages were easily identified by their high density, in CT images. Bilateral areas of lowered density within the periventricular white matter, however, could not always be attributed to irreversible tissue damage prior to about 14 days after the hypoxic event in term newborns, and in preterm infants even later. During this early period of life an apparent decrease of periventricular density was regularly observed that must not be mistaken for a pathological change. In two cases persistent periventricular areas of decreased density were caused by neuropathologically verified foci of incomplete leucomalacia.
