Imaging after urinary tract infection in male neonates

Objective. To assess the frequency of urinary tract anomalies in male neona tes <8 weeks old who presented with urinary tract infection (UTI), and to e valuate a suitable imaging approach after the initial infection. Design. During a period of 4.5 years, from July 1994 through December 1998, 45 male neonates <8 weeks old (range: 5-56 days; mean: 23.77 days) with UT I were hospitalized. All patients had an ultrasound (US) and a voiding cyst ourethrogram (VCUG), except 1 neonate in whom VCUG was unsuccessful because of technical problems. A dimercaptosuccinic acid (DMSA) scan was recommended to all patients but w as performed only in 30 of 45, most of them with an abnormal VCUG. The rena l scan was performed at least 4 months after the UTI. Results. Urinary tract abnormalities were observed in 22 of 45 male neonate s. Nineteen had vesicoureteral reflux (VUR), 1 had VUR and a double collect ing system, 1 had VUR and a posterior urethral valve, and 1 had an ureterop elvic junction stricture. Renal atrophy or scars, as demonstrated by DMSA s can, were detected almost exclusively in neonates with VUR grade 3 and abov e. Only 1 neonate with VUR grade 1 had a pathologic DMSA, and the US of thi s male also demonstrated renal atrophy. Escherichia coli was the pathogen i n 62% (28 of 45), and 9 boys had bacteremia. Conclusion. We suggest that US and VCUG should be performed routinely after the initial UTI in male neonates. Renal scan should be reserved for those cases in which the US suggests renal parenchymal damage or when VCUG detect s VUR grade 3 and above.