Ultrasonographic evaluation of the renal parenchyma in infancy and childhood.

The authors evaluated 46 patients several hours to 10 years of age and found that in neonates and young infants, the renal cortex is normally as echogenic as the hepatic parenchyma. Within 2 to 3 months, the renal cortex becomes progressively less echogenic than the liver; however, in patients with renal parenchymal disease, cortical echogenicity increases. Sonography is very sensitive to this condition, especially in older children; however, the overall findings are nonspecific. The authors conclude that ultrasound is helpful in screening for renal parenchymal abnormalities in the pediatric patient, since (a) it is very sensitive in the detection of parenchymal disease, particularly in the neonatal period, and (b) older patients demonstrate a direct correlation between parenchymal abnormality and increased cortical echogenicity; this is not possible in the neonate because the renal cortex is normally as echogenic as the liver. However, ultrasound is relatively nonspecific except for renal cystic disease.