Changes in the Findings of 99mTc-dimercaptosuccinic Acid(DMSA) Scan after Acute Pyelonephritis in Childhood and Renal Scar

Ahn, Sang Hee; Yoon, So Young; Yoon, Chong Hyun; Moon, Dae Hyuk; Park, Young Seo

Abstract

PURPOSE: We evaluated the change in the findings of DMSA scan after acute pyelonephritis (APN), and the relationship between renal scar formation and risk factors such as vesicoureteral reflux (VUR), organism and inflammatory reaction.
METHODS
We examined 200 patients under the age of 5 years with first APN. DMSA scan, voiding cystourethrography (VCUG), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were performed initially. If the initial DMSA scan was abnormal, it was repeated after 6 months.
RESULTS
Median age was 1.1 years. Initial renal defects existed in 136 (68%) of 200 cases. At 6 months after initial infection, follow up DMSA scan was checked in 61 children with initial renal defects for evaluation of scar. Initial renal defects disappeared in 19 (31%)children. Initial renal defects were present in 60 (64%) of 94 kidneys with the VUR, however, they were present in 94 (31.0%) of 306 kidneys without VUR(P<0.05). Among 72 kidneys with initial renal defects, scar developed in 27 (75%) of 36 kidneys with VUR and 22 (61%) of 36 kidneys without VUR (P>0.05). CRP was 11.0+/-7.0mg/dL in 127 patients with initial renal defects and 4.4 5.5mg/dL in 53 patients without initial renal defects (P<0.05) and CRP was 13.0+/-4.7mg/dL in 39 patients with scar and 8.7+/-4.6 mg/dL in 19 patients without scar in follow up DMSA scan (P<0.05).
CONCLUSION
The presence of VUR and higher CRP level are risk factors for initial renal defects but renal scarring occured higher in the higher level of CRP, irrespective of VUR.