role of imaging tools in diagnosis of vesicoureteral reflux in children

vesicoureteral reflux (vur) is a relatively common and important entity in children. vur can expose patient to risk of pyelonephritis, permanent renal damage or scar. vur itself has no deleterious effect on kidney parenchyma until the development of infection or increased intravesical pressure.   the diagnosis of vur could lead to appropriate therapy and prevention of long term complications. there are several diagnostic procedures for diagnosis of vur, conventional voiding cystourethrography (vcug) and direct radionuclide cystography (drc) are most popular of them. although drc has advantages such as higher sensitivity and lower radiation, conventional vcug remain as a helpful diagnostic tool both for excellent anatomical image and quantitave subjective grading system. most physicians suggest performing vcug for male patient in first assessment and drc for later studies. in females, some advice to follow same as male children but most clinicians tends to apply drc at start of assessment. there are some limitations for two mentioned test despite such advantages. insertion of urinary catheter had some potential hazards for patient and distress for parents and child. two special studies microwave radiometry and indirect radionuclide cystography is newer tools that could diagnose vur without catheterization. these two tests are not standardized yet and remained to be less popular. another limitation is exposure even low dose to radiation. mr vcug and cystosonography are two new procedures that had lowest if any radiation exposure. however these two tests also need further investigation and subjective standardization.