title: Correlation between ultrasonographic bladder measurements and urodynamic findings in children with recurrent urinary tract infection.
abstract: OBJECTIVE
  To evaluate the role of bladder variables measured by ultrasonography (US) in assessing bladder dysfunction in children with urinary tract infections (UTIs).
  
  
  METHODS
  Children presenting with recurrent UTI (with or with no vesico-ureteric reflux) were prospectively recruited. At entry, each patient had US and both natural- filling (NFC) and conventional-filling (CFC) cystometry. Bladder volume and wall thickness index (BVWI) was calculated, and based on US studies and the bladder pattern on US, were classified as thick (BVWI <70), normal (70-130) and thin (>130) as previously reported. The criteria for diagnosing urodynamic patterns included normal, overactive and hypocontractile, as reported previously. The correlation between the US measured variables and urodynamic findings were then evaluated. Sixty-one children (38 boys and 23 girls; mean age 4.82 years, range 1-11) were selected for further evaluation.
  
  
  RESULTS
  Of the 61 children, 16 had a normal BVWI, 36 a 'thick' value and nine 'thin'. When the BVWI was correlated with the urodynamic findings, 14 of 16 with a normal BVWI had a normal bladder pattern, whereas 92% of the patients with a BVWI of <70 had overactive bladder (P < 0.001). Among children with a BVWI of >130, six of nine had a hypocontractile pattern. The mean (sd) bladder capacity (on CFC) compared to that expected for age was significantly lower, at 56.7 (32.3)% in 'thick' bladders, vs children with normal and thin bladders, at 91.3 (23.8)% and 98.7 (31.8)%, respectively (P < 0.001). A high voiding detrusor pressure was significantly associated with children who had a thick bladder rather than normal or thin bladder (P < 0.001).
  
  
  CONCLUSIONS
  This study further confirmed that the BVWI is a sensitive tool for diagnosing bladder dysfunction in children, and it can be used as a reliable guide for the appropriate choice of further invasive urodynamic studies.
authors.affiliation: Division of Paediatric Surgery, Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China. ckyeung@surgery.cuhk.edu.hk
authors.forename: Chung-Kwong
authors.initials: CK
authors.lastname: Yeung
authors.forename: Biji
authors.initials: B
authors.lastname: Sreedhar
authors.forename: Yee-Fong V
authors.initials: YF
authors.lastname: Leung
authors.forename: Kam-Yee F
authors.initials: KY
authors.lastname: Sit
mesh_terms: D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging*; D014552:Urinary Tract Infections / Q000000981:diagnostic imaging*; D014563:Urodynamics