Risk Factors of Renal Scar After Acute Pyelonephritis in Children

PURPOSE: In this study we re-evaluated the known risk factors of pyelonephritic scarring in children. METHODS: A prospective study was performed on 36 acute pyelonephritis(APN) patients who were diagnosed as first acute pyelonephritis on 99mTc-DMSA scan between September 1998 and March 2000 in Masan Samsung Hospital. According to the prescence of remnant lesions on the 99mTc-DMSA scan performed 6 months after the first 99mTc-DMSA scan, the patients were divided into scar(Group A, N=15) and non-scar groups(Group B, N=21). We compared known risk factors of renal scarring between the two groups. RESULTS: There were no differences in age, sex, cultured organisms and CRP level between the two groups. Most of the initial 99mTc-DMSA scan results were not different but bilateral multiple lesions were much more common in group A(40.0% of Group A patients) compared with group B (9.5% of Group B patients). Moderate to high grade vesicoureteral reflux was also much more commonly observed in group A(46.6% of Group A patients) compared with group B(4.8% of Group B patients). CONCLUSION: Bilateral multiple lesion on initial 99mTc-DMSA scan and moderate to high grade vesicoureteral reflux at diagnosis of acute pyelonephritis may be risk factors associated with renal scarring after acute pyelonephritis in children.

Diagnostic Value of 99mTc-DMSA Renal Scan for Early Diagnosis of Acute Pyelonephritis in Children with Febrile Urinary Tract Infection

PURPOSE: For prevention of renal scar, early diagnosis and treatement of acute pyelonephritis are important in children with febrile urinary tract infection. But it has been difficult to differentiate acute pyelonephritis from lower urinary tract infection. We have performed this study to evaluate the diagnostic value of 99mTc-DMSA renal scan and to clarify the relationship among acute pyelonephritis, vesico-ureteral reflux and renal scar. METHODS: We have studied 100 patients with febrile urinary tract infection, from September, 1993 to June, 1995 at the Pediatric department of Ewha Womans University, Mok-dong hospital. Acute phase reactants, causative organism, renal ultrasound, 99mTc- DMSA renal scan on the acute stage, voiding cystouretherogram after 1-2 weeks of treatement, and follow-up 99mTc-DMSA renal scan were evaluated. RESULTS: Ther results are as follows; 1) 57 patients (57%) had defect on 99mTc-DMSA renal scan and diagnosed as acute pyelonephritis. 2) Acute phase reactants, renal ultrasound had low accuracy. 3) VUR was found in 31 (56.1%) of 57 patients with defect which was significantly higher than the 4 (9.3%) of 43 patients without defect on 99mTc-DMSA renal scan. 4) On the follow up 99mTc-DMSA renal scan, 34.8% of defects recorvered, and 65.2% of defects developed renal scar. CONCLUSIONS: 99mTc-DMSA renal scan is a valuable method for early diagnosis of acute pyelonephritis in children with febrile urinary tract infection. It would contribute to evaluate the relationship between acute pyelonephritis, vesico-ureteral reflux and renal scar.