title: CT evaluation of the upper urinary tract in adults younger than 50 years with asymptomatic microscopic hematuria: is IV contrast enhancement needed?
abstract: OBJECTIVE
  The purpose of this study is to compare CT urography (CTU) with unenhanced CT in the evaluation of upper urinary tracts in adults younger than 50 years with asymptomatic microscopic hematuria.
  
  
  METHODS
  In this study, 1516 CTU examinations were reviewed in adults younger than 50 years. Inclusion criteria were no significant prior urologic disease and asymptomatic microscopic hematuria with at least one urinalysis with greater than or equal to 3 RBCs/high-power field and less than or equal to 50 RBCs/high-power field. Upper urinary tract findings on CTU were classified as malignancy-related or non-malignancy-related hematuria and incidental non-hematuria-related findings. A blinded radiologist reviewed the unenhanced images, recording upper urinary tract findings and recommendations for further contrast-enhanced imaging. The modified Wald equation at a 95% CI, the "Rule of Threes" equation, and binomial distribution were used for malignancy-related findings.
  
  
  RESULTS
  Four hundred forty-five examinations in 442 patients met inclusion criteria. CTU reports showed zero malignancy-related hematuria findings, 64 non-malignancy-related hematuria findings (62 renal calculi and two others), and 138 incidental non-hematuria-related findings. Unenhanced CT interpretation had a sensitivity of 100% (64/64) and a specificity of 89.2% (337/378). The theoretic risk of an upper urinary tract malignancy is 0-1.1%.
  
  
  CONCLUSIONS
  CTU added no additional diagnostic benefit versus unenhanced CT in evaluating the upper urinary tracts of adults younger than 50 years with asymptomatic microscopic hematuria. Using only unenhanced CT can reduce radiation and minimize contrast agent-associated risk, with a less than 1.0% risk of missing upper urinary tract hematuria-related malignancy.
authors.affiliation: 1 Department of Radiology, San Antonio Military Medical Center, 3851 Roger Brooke Dr, Fort Sam Houston, San Antonio, TX 78234.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lisanti
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Toffoli
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Stringer
authors.forename: Robert M
authors.initials: RM
authors.lastname: DeWitt
authors.forename: Ryan B
authors.initials: RB
authors.lastname: Schwope
mesh_terms: D000293:Adolescent; D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006417:Hematuria / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D007275:Injections, Intravenous; D007680:Kidney Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014516:Ureteral Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D014567:Urography / Q000379:methods
chemical_list: D003287:Contrast Media
keywords: CT urography; hematuria; kidneys; ureters