Poor bladder filling is a condition where the bladder is not held and is usually suggested by ultrasound, CT and other imaging examinations. It is a condition where the bladder is collapsed and the structures within the bladder cannot be seen clearly due to failure to fill well and not holding urine under ultrasound and CT examinations, suggesting poor bladder filling. It is not a pathological manifestation, it is just that when doing ultrasound and CT examinations of the urinary system, the bladder is required to be in a state of holding urine for the examination. If the bladder is not held, ultrasound and CT will not be able to detect microscopic lesions in the bladder in an unfilled state, which can easily lead to a missed diagnosis. Therefore, ultrasound and CT examinations need to be performed in the state of holding urine. If the bladder is not held during ultrasound and CT imaging, it will indicate poor filling in the bladder, and the patient is advised to hold urine again for examination, or when a review is needed, the bladder needs to be filled with a large amount of urine again for examination, so as not to cause a missed diagnosis of the disease.