Renal ultrasonography - first imaging procedure in children with urinary infection

In order to analyse the value of renal ultrasonography (RUS) as the first imaging procedure consecutive cases of 331 children (108 boys, 223 girls) aged 0.1 to 15 years (mean 3.05 years) with the first documented urinary infection were evaluated. On clinical bases 61% of patients had acute pyelonephritis; 20% of patients had previous undiagnosed urinary infection (UI). The investigation program consisted of RUS obtained within three days followed by voiding cystography, intravenous urography and dynamic scintigraphy 99m-Tc MAG3 obtained within seven days to three months after admission. By imaging techniques renal anomalies were detected in 167 patients. Vesicoureteral reflux had 142 patients (43%), obstructive anomalies 14 patients (4%) and other anomalies 11 patients (3%). RUS was abnormal in 144 patients (47%) with renal inflammation changes in 29% and structural abnormalities in 18% of studied patients. The patients with RUS findings of inflammation were significantly older compared to younger patients with more structural abnormalities (p < 0.01). According to clinical diagnosis 40% of patients with acute pyelonephritis had RUS findings of inflammation and less structural abnormalities (11%). In patients with no evidence for acute pyelonephritis RUS disclosed structural abnormalities in 28% of patients. RUS in comparison with voiding cystography and urography was in good correlation for obstructive anomalies and other structural abnormalities, but was less favourable for vesicoureteral reflux and renal scars. RUS is an adequate method for investigation after first UI, but it should be followed by voiding cystography in patients less than five and by renal scintigraphy in older patients and all children with acute pyelonephritis.