Abstract
Normal sonograms on 50 infants admitted to the Johns Hopkins Hospital Neonatal Intensive Care Unit were reviewed as to the echogenicity of the caudate nucleus relative to the thalamus. The infants were divided into two populations according to gestational age and birth weight. A review of sequential follow-up examinations showed that the caudate nucleus of those infants whose gestational ages were less than 32 weeks or who weighed less than 1,500 g increased in echogenicity as the infants matured. The caudate nucleus of those infants whose gestational ages were greater than 32 weeks or who weighed more than 1,500 g decreased in echogenicity as the infants matured. The author observed that the variation in caudate nucleus echogenicity was a normal finding, not pathologic, and was dependent on maturation and gestational age. Also noted was the incidence of a band of occipital echogenicity posterior to the occipital horns of the lateral ventricles. Its presentation in a large percentage of infants in both populations demonstrated it to be a normal variant.