Echogenic renal medullary pyramids in this neonate may be the result of Tamm-Horsfall protein deposition from dehydration or from transient, physiologic hyperechogenicity of the renal pyramids in neonates. There is maximal hyperechogenicity at the apex with a decreasing gradient toward the base of the pyramid. There is also a readily identifiable "red, blue, white" sign on ultrasound. This finding is not indicative of intrinsic renal disease, and will subside without intervention if physiologic, or with rehydration if due to hypernatremic dehydration. However, it can also be due to a number of other concerning differentials. 

This case was submitted with supervision and input from:

Soni C Chawla, MD
Associate Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Olive View - UCLA Medical Center