Sonographic detection of vesicoureteral reflux with fluid and air cystography. Comparison with VCUG

Purpose: Attempt to find out an effective and reliable alternative method for the diagnosis of vesicoureteral reflux (VUR), without irradiation, in children, and the comparison of its results with those of voiding cystourethrography (VCUG). Methods: In a prospective comparative study we examined 88 children (176 units) (average age = 2.8 years) sonographically and with VCUG, in order to detect VUR. First we examined sonographically the kidney's morphology on an empty bladder. Then we examined them sonographically after filling the urinary bladder with fluid (fluid-cystorenography, fluid-CRG), and after filling it with air (air cystorenography, air CRG). Within the following 2-5 days the standard VCUG was performed. We compared the results of these three methods. Results: Fluid CRG showed fluid reflux to the pelvicalyceal system in 25/176 kidneys (sensitivity = 94.4%, specificity = 94.9%, accuracy = 94.9%). Air CRG showed air reflux in 19/176 kidneys (sensitivity = 83.3%, specificity = 96.8%, accuracy = 95.4%). VCUG showed VUR in 18/176 pelvicalyceal systems and/or ureters. Conclusion: Fluid CRG and/or air CRG can be used as complementary methods to the VCUG, or during the follow up of patients with known VUR: VCUG cannot be replaced completely by fluid CRG or air CRG, especially the first and the last one, because of the false negative results of these methods and because none of them can show the renal collecting system, the urinary bladder and the urethra in the standard way