Cystosonography and voiding cystourethrography in the diagnosis of vesicoureteral reflux

The availability of US (ultrasonography) contrast media in the last few years has prompted investigation into their use in the diagnosis of vesicoureteral reflux (VUR) in children, a common cause of urinary tract infections (UTI) or pyelonephritis. We performed voiding cystourethrography (VCUG) and cystosonography (CSG) in the same session in 158 children (M/F 97/61, mean age 3.9 years, age range 0.1-12.7 years) with clinical suspicion of VUR, studied over a year with an ATL plus 3000 real-time scanner (ATL Ultrasound, Bothell, USA), equipped with 2- to 4- and 4- to 7-MHz convex transducers. US contrast medium Levovist (Schering, Berlin, Germany) was used. VCUG and CSG diagnosed 74 (24.2%) and 77 (25.2%) cases of VUR, respectively. There was no agreement in 67 cases (22%). The percentage of false negatives was similar and high with both techniques. CSG seems to be more sensitive in detecting intermediate (second- and third-degree) VUR. In spite of the moderate relative diagnostic adequacy of both methods, we believe that CSG is an alternative to VCUG, avoiding the risk of ionizing radiation, in the following conditions: (1) first diagnosis in females (not in males, due to the poor vesical and urethral anatomical detail it provides), (2) VUR follow-up, (3) VUR diagnosis in megaureters and/or in ureteroceles, and (4) VUR diagnosis in transplanted kidneys. Further improvements of CSG, both in US contrast media and in US technique, could possibly increase its sensitivity.