Small dotted hyperdense shadow of bladder on CT examination may be caused by bladder stones, calcified foci in the bladder wall, and foreign bodies in the bladder. 1. Bladder stones: CT shows small dots of sediment-like high-density shadows, mostly caused by kidney and ureteral stones entering the bladder, or by urate crystals caused by urine remaining in the bladder for a long period of time, which is difficult to be discharged. 2. Calcified foci in the bladder wall: CT shows small dots of irregular high-density shadows in the bladder wall, mostly caused by chronic cystitis, bladder tumors and other calcium deposits. 3. Foreign body in the bladder: If there is a foreign body in the bladder, it can also be shown as high density shadow in CT. CT examination of small dotted high-density shadow in the bladder, need to cooperate with the doctor in time to carry out related examinations, such as urinary ultrasonography, urine routine, routine blood tests, a clear diagnosis, and actively target the cause of the treatment.