Should renal ultrasonography be done routinely in children with first urinary tract infection?

To reassess the impact of renal ultrasonography on the care of children wit h first febrile urinary tract infection (UTI) we conducted a computer searc h and review of medical records of (1) all children who were admitted to ou r hospital with first febrile urinary tract infection and underwent renal u ltrasonography during a 25-month period beginning February 1, 1995, (2) all children diagnosed by ultrasound to have hydronephrosis during the same ti me period. Of a total of 124 patients with UTI, renal ultrasound appeared n ormal or showed evidence of acute pyelonephritis in 105 (84.7%), and in ano ther nine (7.2%) it showed only minor findings. In 10 children (8.1%) ultra sound showed hydronephrosis and/or hydroureter. In eight of the latter 10, voiding cystourethrography showed vesicoureteral reflux; in one, posterior urethral valves; and in one, who had a unilateral nonobstructed dilatated s ystem, cystography appeared normal. Except for the last patient, who was gi ven prophylactic antibiotics and continued to have urinary tract infections , in no other case did ultrasound alone have any impact on the patient's ma nagement. Four children with both abnormal-appearing renal ultrasound and v oiding cystourethrography required surgical intervention. One hundred of th e 124 children had a voiding cystourethrogram. In 38 children it detected v esicoureteral reflux and, in another two, bladder abnormalities. Thirty-fiv e of those with abnormal-appearing cystogram but without an indication for surgery were given prophylactic antibiotics. During the same 25-month perio d, 63 children without urinary tract infection were diagnosed by ultrasound with hydronephrosis. In 45 of them (71.4%) the urologic abnormality had al ready been detected by prenatal ultrasound. Fourteen of these 45 children ( 31.1%) required surgery, all for congenital anomalies related to obstructiv e uropathy. We conclude that routine renal ultrasonography in children with first urinary tract infection has negligible influence on their clinical m anagement. This seems to be due to the recent widespread use, in industrial ized countries, of maternal-fetal ultrasonography, which already detects a significant number of children with congenital obstructive uropathy prenata lly On the other hand imaging of the lower urinary tract is of high yield a nd contributes significantly to patient care. Therefore, whereas imaging of the lower urinary tract should continue to be done routinely in children w ith first urinary tract infection, renal ultrasound may be reserved for mor e select cases.