title: CAT scan of the month. Retroperitoneal fibrosis.
mesh_terms: D006801:Humans; D008297:Male; D008875:Middle Aged; D012185:Retroperitoneal Fibrosis / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging*