Diagnosis: The human ureter, because of its narrow lumen, is difficult to be directly visualized by traditional imaging methods including CT and MRI for its internal structure. In contrast, ureteroscopy, as a precise and slim endoscope, is used to find the opening of the ureter in the bladder after reaching the bladder via the urethra, and can enter the ureter, which is only 0.2cm~0.5cm in diameter, and clearly observe various lesions in the ureter under direct vision, including stones, tumors, strictures, etc. The images can be photographed or videoed for retention. Therefore, it is not an exaggeration to say that ureteroscopy is a good diagnostic tool for ureteral lesions.