Value of Ultrasound in Evaluation of Infants With First Urinary Tract Infection

Abstract

We evaluated the role of ultrasound in diagnosing and treating infants with a first urinary tract infection with a focus on important structural abnormalities. In a setting of limited prenatal ultrasound screening this population based, prospective, 3-year study included 161 male and 129 female infants. Ultrasound and dimercapto-succinic acid scintigraphy were performed as initial investigations and voiding cystourethrography was conducted within 2 months. Ultrasound revealed dilatation in 15% of patients and increased kidney length in 28%. Sensitivity for detecting scintigraphic abnormality was 48%. Renal length was significantly correlated to inflammatory parameters, including scintigraphic abnormalities. Important structural abnormalities were detected in 40 cases, with 30 on ultrasound, while 10 of 27 cases of dilating reflux (mostly grade III) were missed. Outside the study there were 28 additional cases of structural abnormality, of which 15 were detected prenatally. Ultrasound detected most structural abnormalities except grade III reflux. Since it is noninvasive, ultrasound has a place in the evaluation of infants with urinary tract infection, especially in the absence of prenatal ultrasound during late pregnancy. Kidney length in infants with acute infection correlated with inflammatory parameters, and the clinical importance of this finding needs to be studied further.