Medullary sponge kidney is due to congenital developmental abnormalities resulting in renal malformations, with a low incidence, mainly manifested as renal calcium deposits or kidney stones, abnormal urinary acidification and concentration function, medullary collecting duct cystic lesions and urinary tract infection and renal failure, or no clinical symptoms, but due to its anatomical features and functional changes, patients are prone to recurrent kidney stones and renal calcium deposits, so it should attract the attention of clinicians. The spongy kidney lacks specific imaging. The spongy kidney lacks specific diagnostic imaging criteria, and ultrasound mainly shows hyperechoic medullary images caused by renal calcium deposits, i.e., radiating hyperechoes in the renal cone, which is due to the small collecting duct cystic cavity, shaped in a large number of reflective interfaces, which can have clusters of small stones inside, so it is hyperechoic, and no echogenic cystic cavity is shown. The renal cortex is uniformly echogenic and thinner than normal, and the morphology of the kidney is close to normal in size. When the stone penetrates the cyst wall or enters the calyx and pelvis through the enlarged papillary duct, the collecting system can be seen as an intense cluster with acoustic shadow (less than 0.3 cm without acoustic shadow), and when the stone enters the ureter through the pelvis, it can be accompanied by hydronephrosis, and the renal cone can be deformed by pressure, and only the peripheral edge of the dilated calyx can be seen as a petal-like echogenic enhancement without acoustic shadow. The spongy kidney needs to be differentiated from renal calcium deposits, polycystic kidney, and multiple small kidney stones. Ultrasonography is the test of choice for spectral investigation or long-term follow-up of this disease.