title: Acute ureterolithiasis: incidence of secondary signs on unenhanced helical CT and influence on patient management.
abstract: OBJECTIVE
  The purpose of this study was to determine the incidence of secondary signs associated with ureteral stones on unenhanced helical computed tomography (CT) of patients with acute renal colic, and to correlate these with patient management and outcome.
  
  
  METHODS
  One hundred and ten patients with ureterolithiasis were evaluated prospectively for the secondary signs of obstruction on unenhanced helical CT. Our attention was focused primarily on the presence or absence of seven secondary signs on unenhanced helical CT, including hydronephrosis, unilateral renal enlargement, perinephric oedema, unilateral absence of the white pyramid, hydroureter, periureteral oedema and lateroconal fascial thickening.
  
  
  RESULTS
  Of the 110 patients, 91 (82.7%) had hydroureter, 88 (80%) had hydronephrosis, 65 (59%) had periureteric oedema and 63 (57.2%) had unilateral renal enlargement. Ninety stones passed spontaneously and 21 required intervention.
  
  
  CONCLUSIONS
  Secondary signs of urinary tract obstruction are useful and supportive findings in interpretation of the CT examination. In our experience, the most reliable signs indicating ureteral obstruction are hydroureter, hydronephrosis, periureteral oedema and unilateral renal enlargement, respectively. In addition, stones larger than 6 mm, located within the proximal two thirds of the ureter, and seen associated with five or more the secondary signs of obstruction, are more likely to require endoscopic removal and/or lithotripsy.
authors.affiliation: Department of Radiology, Istanbul International Hospital, Istanbul, Turkey. gurkanege@yahoo.com
authors.forename: G
authors.initials: G
authors.lastname: Ege
authors.forename: H
authors.initials: H
authors.lastname: Akman
authors.forename: K
authors.initials: K
authors.lastname: Kuzucu
authors.forename: S
authors.initials: S
authors.lastname: Yildiz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D004487:Edema; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014514:Ureteral Calculi / Q000000981:diagnostic imaging* / Q000628:therapy; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy