Valves of the ureter.
D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D014513:Ureter / Q000002:abnormalities* / Q000473:pathology / Q000601:surgery; D014517:Ureteral Obstruction / Q000209:etiology / Q000473:pathology; D014567:Urography