
Keywords: HMO، سازمان حفظ سلامت; diagnostic imaging; hydronephrosis; kidney; pediatrics; ureteral obstructionCT, computerized tomography; HMO, health maintenance organization; IVP, excretory urography; MAG3, 99mtechnetium mercaptoacetyltriglycine; MRI, magnetic resonance imaging; RS, ren