Increased renal medullary echogenicity in neonates.

The prevalence of increased renal medullary echogenicity in healthy neonates was looked for. A group of 178 neonates underwent renal ultrasound on the first and second days of life. On the first day of life 58% had hyperechoic material in their renal collecting system, whereas on the second day only 33% were found to have ultrasonographically demonstrable increased echogenicity in their kidneys. Urinary protein concentrations in infants with increased renal echogenicity were significantly higher than in those without increased renal echogenicity.