Holm first reported the manifestation of renal calcium breast in 1948, and Howell named it as renal calcium breast in 1959, which is divided into two types, cystic type and hydronephrosis type. The cystic type occurs in the diverticula or cysts of the calyces; the hydronephrosis type occurs in the hydronephrosis of the calyces and is combined with renal calculi, and the calcium milk is present in the middle and lower group of calyces. The pelvic diverticulum is a cystic lesion within the renal parenchyma, which is connected to the collection system by a narrow channel. The particles vary in size, most are the size of a grain of rice, and most are smooth, brown, brown, or black in color, with a hard texture. The number of calcium milk particles varies, from less than a hundred to more than 20,000. The chemical composition is mainly composed of calcium oxalate, calcium carbonate, calcium phosphate, hydroxyapatite or a mixture of these compounds. The biopsy samples avoided by renal calcium breast cysts are sclerotic fibrous tissue rather than uroepithelium. Therefore, it is mostly believed that the formation of hydronephrosis-type renal calcium breast is associated with inflammation and obstruction. Inflammation and obstruction can cause the kidney unit secretion and reabsorption to be impaired, and the long-term retention of urine in the renal calyces gradually concentrates, so that crystalline substances containing calcium and phosphorus salts are saturated and precipitated, forming calcium milk particles. The cystic calcium milk is usually located in the diverticulum of the renal calyces, and the calcium milk is formed due to the obstruction of the isthmus connecting the renal calyces, which causes the retention of urine. Ultrasound shows strong echogenicity in the cyst around the calyx, followed by acoustic tail or acoustic shadow, or a strong echogenic plane composed of sediment-like stones can be seen at the bottom of the cyst, with a faint acoustic shadow visible behind. X-ray signs: 1.Standing film can show the plane of calcium breast, showing a disk or semicircular hyperdensity shadow (disk sign or hemimelia sign). 2, supine radiographs show a granular or inhomogeneous high-density shadow in the form of a mass. The edges are blurred (pancake sign). The presence of these signs and is a reliable basis for the diagnosis of renal calcium breast. The degree of typicality is related to the number, size and composition of calcium breast particles, the degree of hydronephrosis, and the size of renal cysts. The CT scan shows a heterogeneous round lesion of about 1 to 2 cm in size in the kidney, and when the body is turned, the hemimelon high-density shadow formed by the calcium breast is always located at the lowest part of the lesion and parallel to the examination bed.CT can also adequately show the anatomical structures and pathological patterns associated with renal calcium breast, i.e. hydronephrosis, thinning renal parenchyma, etc. At one CT level, two calcium mammograms are sometimes seen. This is due to the fact that the calcium breast can accumulate in separate anatomical locations within the kidney, in most cases deposited in the adjacent calyces and captured at one scan level. Renal calcium breast is often misdiagnosed as renal stone, high density renal cyst, and tuberculosis because of the following reasons 2, clinicians do not know enough about its pathogenesis, I clinical manifestations, imaging diagnosis, etc. 3, Conventional X-ray and CT examination, calcium breast with body position changes produce different features. 4, Calcium breast can be transmissive or partially transmissive. For asymptomatic, lesions <25 mm, or those with concomitant diabetes mellitus or other organ insufficiency, they can be followed up and observed, and surgery is not urgent. For those with symptoms and lesions >25 mm, early surgery should be performed. IVU shows that the contrast agent does not enter the calcium emulsion, suggesting that the calcium emulsion cavity is not connected to the renal collecting system and there is no possibility of self-healing.