[Limits of ultrasonics in the study of urinary tract malformations].

Ultrasound is limited by the fact it gives no direct information about kidney function. Ultrasound does not allow fine structural analysis of minor calyces. It shows only secondary signs of important vesico-ureteric reflux. Normal ureters are not usually pictured by ultrasound. Bowel gas can impede good visualization of ectopic kidneys. Nevertheless ultrasound is the first test to do when searching for kidney malformations and it is important as a follow-up examination.