title: Renal tract abnormalities missed in a historical cohort of young children with UTI if the NICE and AAP imaging guidelines were applied.
abstract: OBJECTIVE
  In a historical cohort of children with a urinary tract infection (UTI) who had already undergone all the imaging procedures, the aim was to determine renal tract abnormalities which would have been missed had we implemented the new guidelines from the National Institute for Health and Care Excellence in the United Kingdom (NICE) or the American Academy of Pediatrics (AAP).
  
  
  METHODS
  After a UTI episode, forty-three children (28 females, 65%) aged between 2 months and 2 years presenting at two general hospitals with a febrile UTI before 2008 underwent all the recommended imaging studies predating the new guidelines. Hydronephrosis was defined and graded according to the Society for Fetal Urology (SFU) classification. Hydronephrosis grade II (mild pelvicalyceal dilatation), grade III (moderate dilatation), and grade IV (gross dilatation with thinning of the renal cortex), duplication, vesicoureteral reflux (VUR) grade II and above, renal scarring and reduced renal uptake (<45%) on technetium-99m-labeled dimercaptosuccinic acid (DMSA) scintigraphy were considered significant abnormalities. We calculated the proportion of abnormalities which would have been missed had the new guidelines been used instead.
  
  
  RESULTS
  The median of age was 7.6 months (mean 8.7, range 2-24 months), with the majority (n = 37, 86%) being under 1 year of age. Ultrasound (US) showed hydronephrosis in 14 (32%), all grade II. A voiding cystourethrogram (VCUG) was performed in all and showed VUR ≥ grade II in 16 (37%), including eight children (19%) where it was bilateral. DMSA scan showed scarring in 25 children (58%) of whom 11 (26%) had bilateral scars. Reduced differential renal uptake was present in 10 children (23%). Of the 29 children with normal US, 18 (62%) had renal scarring and nine (31%) had VUR ≥ grade II. The NICE guidelines would have missed 63% of the children with VUR ≥ grade II, including a high proportion of grades IV and V VUR, 44% of the children with renal scarring, and 20% of the children with decreased renal uptake, including some children with bilateral renal scarring and with decreased renal uptake. The AAP guidelines would have missed 56% of the children with VUR ≥ grade II, including a high proportion of grades IV and V VUR, and all children with renal scarring as well as those with decreased renal uptake.
  
  
  CONCLUSIONS
  The prevalence of renal tract abnormalities missed by the new guidelines is high. They should be used with full awareness of their limitations.
authors.affiliation: Department of Pediatrics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates. Electronic address: hassib.narchi@uaeu.ac.ae.
authors.forename: Hassib
authors.initials: H
authors.lastname: Narchi
authors.affiliation: Department of Pediatrics, Al Ain Hospital, Al Ain, United Arab Emirates.
authors.forename: Muhaned
authors.initials: M
authors.lastname: Marah
authors.affiliation: Department of Pediatrics, Al Ain Hospital, Al Ain, United Arab Emirates.
authors.forename: Asad Aziz
authors.initials: AA
authors.lastname: Khan
authors.affiliation: Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.
authors.forename: Abdulla
authors.initials: A
authors.lastname: Al-Amri
authors.affiliation: Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.
authors.forename: Amar
authors.initials: A
authors.lastname: Al-Shibli
mesh_terms: D002675:Child, Preschool; D003952:Diagnostic Imaging / Q000592:standards*; D005260:Female; D006801:Humans; D007223:Infant; D007668:Kidney / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008297:Male; D017410:Practice Guidelines as Topic; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000494:pharmacology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012955:Societies, Medical; D019783:Technetium Tc 99m Dimercaptosuccinic Acid / Q000494:pharmacology*; D006113:United Kingdom; D014481:United States; D014552:Urinary Tract Infections / Q000000981:diagnostic imaging / Q000209:etiology*; D014564:Urogenital Abnormalities / Q000150:complications / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid
keywords: Imaging; Outcome; Renal scarring; Vesicoureteral reflux