[Ultrasonography in urinary tract infection in infancy]

In a prospective study 77 infants (35 boys) with a mean age of 5.23 months were studied to determine the value of sonography for detection of renal parenchymal involvement in urinary tract infection (UTI). Sonography was performed during UTI and about one month later. UTI was classified as upper and lower UTI according to the clinical and laboratory findings; radiological investigations (voiding cystoureterography = MCU) were performed in all infants. 40 infants were classified to have upper UTI. There was a high sensitivity (80%) and specificity (97%) for detection of renal involvement by sonography. Incidence for vesicoureteral reflux (VUR) was significantly higher in infants with repeated pathological findings on sonography. In contrast, no VUR was detected on MCU in all 12 infants with normal findings in both sonographic examinations. Yet, sonography without catheterization could not detect VUR in all infants with radiologically confirmed reflux. Our results show, that sonography is of definite value in infants with UTI, but cannot replace radiological work up.