Hypothesis: reduced renal mass with glomerular hyperfiltration, a cause of renal hyperechogenicity in children.

A group of 10 pediatric patients had renal hyperechogenicity and reduced renal mass. The authors wish to suggest a relationship between renal hyperechogenicity and glomerular hyperfiltration according to Brenner's theory on the progressive nature of kidney disease. Reduced renal mass was related to multicystic dysplastic kidney (3 cases) nephrectomy (3 cases) and to reflux nephropathy (4 cases). The hyperechogenicity was diffuse in 6 cases with the preservation of cortico-medullary differentiation and was localized in all four cases of reflux nephropathy producing a "pseudotumoral" appearance. Hyperfiltration was confirmed by isotope studies in all 3 cases where it was performed. This condition together with secondary glomerulosclerosis could explain hyperechogenicity. The predictive value of such patterns are still unclear; yet such findings should lead to appropriate radiolocal, functional, clinical and dietary measures.