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 nega tive. When comparing the two procedures and taking into consideration the age of the patients we find that radionuclide cystography is more sensitive to det ect vesico-ureteric reflux in the younger population (p<0.02). This advanta ge is less clear for older children who more often present a low-grade refl ux, Low radiation exposure is also a great advantage of radionuclide cystog raphy, but anatomic definition is better with contrast cystography. It seem s thus that the two procedures complement rather than rival each other. Their respective interest for evaluation of repeated urinary tract infectio n in children therefore depends on age, attainability 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 respect ive role in repeated urinary tract infection exploration.