title: Meaning of ureter dilatation during ultrasonography in infants for evaluating vesicoureteral reflux.
abstract: OBJECTIVE
  To investigate the meaning of ureter dilatation during ultrasonography (US) in infants for evaluating vesicoureteral reflux (VUR).
  
  
  METHODS
  We retrospectively reviewed abdominal US images of infants who were diagnosed with urinary tract infection (UTI group) or only hydronephrosis without UTI (control group). Hydronephrosis (graded 0-4) and ureter dilatation (present or absent) were evaluated on each side with US. Voiding cystourethrography (VCUG) within 3 months time interval with US was also reviewed and VUR was graded (0-5) on each side. Hydronephrosis, ureter dilatation, and VUR were then compared between the two groups.
  
  
  RESULTS
  Four hundred and three infants (142 in the UTI group and 261 in the control group) were included and VCUG was performed in 129 infants (68 in UTI and 61 in control groups). VUR grades were not different between the two groups (p=0.252). Hydronephrosis grade was not related to VUR in either group (p>0.05). However, ureter dilatation had a significant relationship with VUR in the UTI group (p=0.015), even among patients with a high-grade VUR (p=0.005). Whereas, ureter dilatation was not associated with VUR in the control group (p=0.744). The relationship between ureter dilatation and VUR was different between the two groups for both all grades (p=0.014) and high-grade (p=0.004) VUR. Ureter dilatation had 66.7% sensitivity, 80.3% specificity, and 79.4% accuracy for evaluating high-grade VUR in the UTI group.
  
  
  CONCLUSIONS
  Ureter dilatation on US can be a helpful finding for detecting VUR in infants with UTI, but not infants without UTI.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, 120-752 Seoul, Republic of Korea. Electronic address: yaewonpark@yuhs.ac.
authors.forename: Yae-won
authors.initials: YW
authors.lastname: Park
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, 120-752 Seoul, Republic of Korea. Electronic address: mjkim@yuhs.ac.
authors.forename: Myung-Joon
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Pediatric Urology, Severance Children's Hospital, Yonsei University College of Medicine, 120-752 Seoul, Republic of Korea. Electronic address: swhan58@yuhs.ac.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Han
authors.affiliation: Biostatistics Collaboration Unit, Yonsei University, College of Medicine, 120-752 Seoul, Republic of Korea. Electronic address: kimdw@yuhs.ac.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, 120-752 Seoul, Republic of Korea. Electronic address: mjl1213@yuhs.ac.
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Lee
mesh_terms: D004106:Dilatation; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging* / Q000473:pathology; D007223:Infant; D008297:Male; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014513:Ureter / Q000473:pathology*; D014552:Urinary Tract Infections / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D014554:Urination; D014567:Urography; D014718:Vesico-Ureteral Reflux / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Ultrasonography; Ureter; Urinary tract infection; Vesicoureteral reflux