title: "Flip-flop" phenomenon on retrograde ureterography establishes diagnosis of ureteral tumor.
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014516:Ureteral Neoplasms / Q000000981:diagnostic imaging*; D014567:Urography