title: Harmonic voiding urosonography with a second-generation contrast agent for the diagnosis of vesicoureteral reflux.
abstract: BACKGROUND
  Voiding urosonography with harmonic imaging (VUS HI) has been introduced as a sensitive and radiation-free imaging method for the diagnosis and follow-up of vesicoureteral reflux (VUR) in children.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the sensitivity of VUS HI using a second-generation US contrast agent compared to standard voiding cystourethrography (VCUG).
  
  
  METHODS
  A total of 228 children with 463 kidney-ureter units (KUUs) underwent two cycles of VUS HI and two cycles of VCUG at the same session. VUS HI was performed after intravesical administration of 1 ml of a second-generation US contrast agent (sulphur-hexafluoride gas microbubbles, SonoVue, Bracco, Italy). For statistical analysis we used McNemar's test, Student's t-test and k coefficient tests.
  
  
  RESULTS
  VUR was shown in 161/463 (34.7%) KUUs, 57 by both methods, 90 only by VUS, and 14 only by VCUG. Concordance in findings regarding the presence or absence of VUR was found in 359/463 (77.5%) KUUs (k=0.40). The difference in the detection rate of reflux between the two methods was significant (P<0.01). More importantly, reflux missed by VCUG was of higher grade (2 grade I, 65 grade II, 19 grade III, 4 grade IV) than that missed by VUS (8 grade I, 5 grade II, 1 grade III).
  
  
  CONCLUSIONS
  VUS HI and a second-generation contrast agent improved the identification of reflux in children. Our data reveal a higher sensitivity of the method compared to VCUG. Thus it can be used as an alternative radiation-free imaging method.
authors.affiliation: Department of Radiology, University Hospital of Ioannina, P.O. Box 1186, University Avenue, Ioannina, 45110, Greece. frpapad@cc.uoi.gr
authors.forename: Frederica
authors.initials: F
authors.lastname: Papadopoulou
authors.forename: Amalia
authors.initials: A
authors.lastname: Anthopoulou
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Siomou
authors.forename: Stavros
authors.initials: S
authors.lastname: Efremidis
authors.forename: Constantinos
authors.initials: C
authors.lastname: Tsamboulas
authors.forename: Kassa
authors.initials: K
authors.lastname: Darge
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010743:Phospholipids; D011446:Prospective Studies; D011859:Radiography; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography; D014554:Urination; D014718:Vesico-Ureteral Reflux / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride