The ultrasound presentation of the duplicated kidney mainly shows two sets of renal sinus echos in the kidney. The long diameter of the kidney is larger than the average kidney, and the scattered renal tracings are shorter, especially in the upper kidney where the sinuses are smaller, and are often accompanied by mild pelvic effusion and a slight dilatation of the adjacent ureter, the end of which protrudes into the bladder. Small cystic foci are not echogenic, but are sometimes easily confused with a double pelvis malformation, in which the upper and lower sets of kidneys fuse prematurely to form two renal pelvises, the ureters do not overlap, and the sinus echogenicity is divided into two non-adjacent parts, but there is no hydronephrosis or ureteral dilatation, and the size and shape of the kidneys are normal.