Premature Destruction of Microbubbles during Voiding Urosonography in Children and Possible Underlying Mechanisms: Post Hoc Analysis from the Prospective Study

The aim of this study is to describe premature microbubbles destruction with contrast-enhanced voiding urosonography (ce-VUS) in children using 2nd-generation ultrasound contrast agents (UCA) and to hypothesize about the reason. 141 children (61 females and 80 males) were included in the study, with mean age of 3.3 years (range 4 weeks-16.0 years), who underwent ce-VUS examination between 2011 and 2014. Premature destruction of the microbubbles in the urinary bladder during ce-VUS was observed in 11 children (7.8%). In all these cases the voiding phase of ce-VUS examination could not be performed because of destroyed UCA microbubbles. This was noted in anxious, crying infants and children with restricted voiding. The premature destruction of ultrasound contrast agent during ce-VUS is an underreported, important limitation of ce-VUS, which prevents evaluation of the voiding phase and the establishment of vesicoureteric reflux (VUR). This was particularly noted in crying infants and children.