Abstract
In recent years brain ultrasonography has become a simple, useful and almost indispensable examina-tion for the neurological diagnosis of newborns and young infants. A pulsatility index (PI) calculated from the formula (S-D) /S for the cerebral arteries such as basilar artery (BA) or anterior cerebral artery (ACA) decreased at the stage of elevated intracranial pressure in the infants with acute encephalopathy and subdural hemorrhage. Using two-dimensional Doppler ultrasonography (color flow mapping system), the blood flow of BA or ACA was observed as a continuous line of warm color along the course of the arteries. To obtain PI of these arteries, the sampling site could be easily decided using this system. Brain ultrasonograms of 515 cases of 1-month-old infants whose birth weights were more than 2500gm. were observed at their health 1-month-examination. Subependymal cysts (SEC) were observed in 51 infants (9.9%), and choroid plexus cysts (CPC) in 31 infants (6.0%) . Since the rate of neonatal asphyxia was 15.7% in SEC, 0% in CPC and 1.9% in normal controls, SEC was correlated with neonatal asphyxia statically. SEC was suspected of subependymal hemorrhage (SEH) and the occurrence of SEH in mature neonates was indicated in this study.
