Objective: 1. To evaluate the diagnostic accuracy of contrast enhanced ultrasound cystography (CUSC) with ascending administration of Levovist for the detection of vesicoureteral reflux (VUR) in children; 2. to evaluate the ability of CUSC to grade VUR. Materials and methods: Between September 1998 and August 2000, authors perfomed 71 CUSC examinations in 70 children, where micturating x-ray cystouretrography (MCUG) was indicated due to either intermittent urinary tract infection or unexplained dilatation of pyeloureteral systems. Based on the results of MCUG, which served as the gold standard in this prospective comparative study, they evaluated 141 pyeloureteral units (PUU). According to ultrasonographic findings, authors subdivided the cohort into two subgroups: group A with and group B without dilatation of pyelocalyceal systems (PCS) prior to CUCS. Results: MCUG revealed 65 PUU with reflux. CUSC detected 54, there were 2 false positive results. Among the group of 11 false negative subjects, they encountered 1 case of grade I, 6 cases of grade II, and 4 cases of grade III VUR. The sensitivity of CUSC in VUR was 83 %, the specificity 97 %, positive predictive value 96 %, negative predictive value 87 %, and the diagnostic accuracy 92 %. Within group A, the sensitivity was 96 % and specificity 100 %. Compared with the group B, the difference is statistically significant (p = 0.0176). In term of grading VUR by means of CUSC, it is possible to divide the finding into low (grades I and II) and advanced (grades III to V) categories. Conclusion: Contrast enhanced ultrasound cystography is a clinically applicable method for detection of VUR with slightly limited sensitivity for low grade VUR. The highest accuracy was found in children with initial dilatation of PCS. Further studies are mandatory to evaluate the capacity of CUSC to grade the vesicoureteral reflux more precisely.

        Key words: vesicoureteral reflux, children, ultrasonography, ultrasound contrast agents