title: Interureteric ridge edema: incidence and etiology.
abstract: BACKGROUND
  Interureteric ridge edema may be seen at intravenous urography (IVU) and is related to acute lower ureteral obstruction, trauma, or calculi. The purpose of this study was to explore the relationship between interureteric ridge edema and acute distal ureteral obstruction caused by ureteral calculi.
  
  
  METHODS
  A total of 338 patients who had IVU for various indications during a 6-month period were reviewed for the presence of interureteric ridge edema.
  
  
  RESULTS
  Interureteric ridge edema was seen in 12 (4%) of 338 patients, all with acute lower ureteral obstruction from stones. Interureteric ridge edema was best demonstrated with the partially filled bladder film or post-void bladder film in all cases.
  
  
  CONCLUSIONS
  Interureteric ridge edema is most commonly caused by stone-induced distal ureteral obstruction and is less commonly seen with recent passage of a stone or other etiologies. Interureteric ridge edema was present in 26% of patients with acute lower ureteral obstruction.
authors.affiliation: Department of Radiology, Bowmann Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1088, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Chen
authors.forename: R J
authors.initials: RJ
authors.lastname: Zagoria
authors.forename: R B
authors.initials: RB
authors.lastname: Dyer
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage; D004487:Edema / Q000000981:diagnostic imaging / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007275:Injections, Intravenous; D007479:Iopamidol / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D014056:Tomography, X-Ray; D014514:Ureteral Calculi / Q000150:complications / Q000000981:diagnostic imaging; D014515:Ureteral Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D014517:Ureteral Obstruction / Q000150:complications / Q000000981:diagnostic imaging; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014567:Urography
chemical_list: D003287:Contrast Media; D007479:Iopamidol