Hyperechogenic "rings" in the periphery of renal medullary pyramids as a sign of renal disease.

A rare sign of medullary abnormality, hyperechogenic "rings" in the peripheries of renal medullary pyramids, was detected in both kidneys in 21 patients, being associated with normally hypoechogenic medullary centers in 20 of these patients. Our results with 2 cases studied histologically suggest that fibrosis with and without calcifications is one reason for the hyperechogenicity of these medullary pyramids. The clinical history and laboratory tests (serum creatinine, proteinuria) showed signs of kidney disease in 52%, and a renal disease was suspected in an additional 38%. Eight of the patients had disturbances in blood potassium, calcium, or uric acid equilibrium, and 2 of them had a parathyroid abnormality. Calcifications were found on plain radiographs of the abdomen in 1 of the 13 patients. Two were totally asymptomatic and had normal laboratory findings. Hyperechogenic rings in the peripheries of renal medullary pyramids proved nonspecific and showed a poor correlation with the severity of renal disease.