Contrast enhanced voiding urosonography (ce-VUS) as a radiation-free technique in the diagnosis of vesicoureteric reflux: Our early experience

OBJECTIVE: Contrast-enhanced ultrasound has become increasingly utilised as an alternative imaging modality for the diagnosis of vesicoureteric reflux (VUR) in paediatric patients. The study objective is to evaluate the efficacy of contrast enhanced Voiding Urosonography (ce-VUS) compared with fluoroscopic micturating cystourethrography (MCU) in the detection of VUR.
METHODS: This prospective study was carried out between July 2011 and January 2013 on paediatric patients who underwent MCU. All consented patients would undergo ce- VUS prior to MCU. We documented the epidemiology details, the number of Kidney-Ureter (K-U) unit studied, baseline renal and bladder sonogram, as well as presence of VUR on ce-VUR. The technique for ce-VUS was standardized using normal saline to fill the bladder prior to administration of SonoVue® (2.5 ml) to assess the kidney-ureter (K-U) unit. Dedicated contrast detection software was used to discern the presence of microbubbles in the pelvicaliceal system (PCS). The findings were then compared with MCU.
RESULTS: 27 paediatric patients were involved in the study [17 males (63%) and 10 females (37%)] involving 55 K-U units (one patient had a complete duplex system). MCU detected VUR in 10 K-U units while ce-VUS detected VUR in 8 out of the 10 K-U units. There were 2 false negative cases (both Grade 1) with ce-VUS. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of ce-VUS were 80%, 98%, 95%, 89% and 96%, respectively.
CONCLUSION: ce-VUS is a sensitive and specific radiation-free alternative for the detection of VUR in the paediatric population.