Interest of direct radionuclide cystography in repeated urinary tract infection exploration in childhood.

108 children with repeated urinary tract infection were examined both with direct contrast cystography and radionuclide cystography. There was a good correlation between the two procedures in the majority of the cases (79), but in 21 cases, direct radionuclide cystography alone was positive and for 8 other children, direct contrast cystography showed a low-grade vesico-ureteric reflux even though radionuclide cystography was negative. When comparing the two procedures and taking into consideration the age of the patients we find that radionuclide cystography is more sensitive to detect vesico-ureteric reflux in the younger population (p < 0.02). This advantage is less clear for older children who more often present a low-grade reflux. Low radiation exposure is also a great advantage of radionuclide cystography, but anatomic definition is better with contrast cystography. It seems thus that the two procedures complement rather than rival each other. Their respective interest for evaluation of repeated urinary tract infection in children therefore depends on age, attain-ability of the procedure, and the possibility of a bladder or ureteral abnormality. Quite a few authors consider radionuclide cystography as at least as valid as contrast cystography, and even more sensitive. We have attempted to compare both procedures and to determine their respective role in repeated urinary tract infection exploration.