The segmentation of the ureter facilitates the localization of the stone and thus the selection of the best treatment option. Determining the segmentation of the ureter facilitates the localization of ureteral stones and thus guides the selection of the best treatment. 1. Anatomical segmentation The ureter has three physiological strictures. The first is located at the migration between the renal pelvis and ureter; the second stricture is located at the transiliac vessels of the ureter; and the third stricture is at the entry into the bladder lining. According to these three strictures, the ureter can be divided into ventral segment, pelvic segment, and bladder segment. The ventral segment is from the pelvic ureteral junction to the crossing of the iliac artery; the pelvic segment, from the iliac artery to the bladder wall; and the bladder segment, from the bladder wall to the bladder mucosa and ureteral opening obliquely. 2.Imaging segments For the purpose of describing the location of ureteral stones on imaging, the ureter is usually also divided into three segments. The first segment is the upper ureter, which runs from the ureteropelvic junction to the superior border of the sacroiliac joint; the second segment is the middle ureter, which runs from the superior border of the sacroiliac joint to the inferior border of the sacroiliac joint; and the third segment is the lower ureter, which starts from the inferior border of the sacroiliac joint and crosses the pelvis to the bladder.