Ultrasonographic evaluation of the renal parenchyma in infancy and childhood.

Abstract

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.

Increased Echogenicity of Renal Cortex: A Transient Feature in Acutely Ill Children

“…None of these patients had a history of renal disease, nor did they develop a renal disorder after one year follow-up. Because previous articles [3,5] have shown that in healthy pediatric subjects (neonates and infants excluded) echogenicity of the renal parenchyma is not increased, we believe that hyperechogenicity of renal parenchyma can be a nonspecific finding, a sign of (abdominal) illness varying from appendicitis to ileocecitis, infectious gastroenteritis or otherwise, rather than an indicator of renal disease. Only one study reported that renal echogenicity equal to the liver parenchyma is a nonspecific finding and does not suggest renal disease; that study, however, included only adults [10].…”

“…Increased renal echogenicity of infants changes gradually in the adult pattern [7]. Several reports have stated that increased echogenicity of the renal parenchyma is an indicator of renal disease [3,4]. However, we have encountered increased echogenicity in patients with various abdominal diseases but no concurrent renal disease.…”

“…Evaluation of the kidneys is a routine part of abdominal US. The normal renal cortex in older infants, children, and adults should be less echogenic than the liver parenchyma [3][4][5][6][7]. Only in neonates and infants is increased echogenicity of the renal parenchyma a normal finding [6].…”

Fetal renal hyperechogenicity in intrauterine growth retardation: importance and outcome

“…It has been noted in intrauterine growth-retarded fetuses, presumably as a result of the associated hyperechogenicity. In transient hyperechogenic cases, the cause is transient renal insufficiency [3,10,16,17]. Increased echogenicity may represent a tubular blockage caused by Tamm-Horsfall protein precipitation [18].…”

“…Hyperechogenic medullae were diagnosed when the fetal renal medullae displayed an echogenicity similar to that of the surrounding bone, but higher than that of the liver or spleen [10].…”