Acute Pyelonephritis (APN) is one of the most common bacterial infections seen in children that may lead to renal scarring. Vesicoureteral reflux (VUR) is an important risk factor of renal damage but not the only one.

Materials and Methods: In order to determine the association between dimercaptosuccinic acid (DMSA) scintigraphic and voiding cystourethrographic findings, a retrospective study was performed on 50 children (100 renal units) with APN that had been admitted to Bahrami Hospital from 1995 through 1998. Voiding cystourethrography (VCUG) and DMSA scan were performed in all patients within 1 to 2 weeks after termination of treatment and a second scan was performed 6 months later in patients whose kidneys showed cortical defects in the first one. The grade of reflux was based on international reflux classification (I-V). The DMSA scans were considered abnormal if one or more areas of decreased cortical uptake were noted (cortical defect). The scar was defined as persistence of these defects in the second scan. DMSA cortical defect and VUR were demonstrated in 42 (42%) and 26 (26%) of renal units respectively.
Results: Fourteen out of 26 renal units (54%) with reflux had cortical defects and 28 out of 74 renal units (38%) without reflux had cortical defects (P=0.15). Permanent renal scarring was noted in 25/ 42 of renal units (62 %) in second scan.

Conclusion: It seems that VCUG alone is insufficient as a screening modality to identity those kidneys at risk of damage and DMSA scan may provide additional information about this.