The renal pyramids are highly echogenic, strongly suggestive of medullary sponge kidney (MSK) with medullary nephrocalcinosis. Medullary sponge kidney occurs because of focal or diffuse dilation of the medullary collecting tubules with stasis of urine and may eventually lead to calculi deposits. On ultrasound exam it appears as hyperechoic calyces when stones begin to form in the dilated collecting tubules. Smaller calcifications do not shadow while larger stones can produce shadowing. Nephrocalcinosis is the formation of diffuse deposits of calcium throughout the kidneys.

Radiographer: TSRM Fabio Imola