Age-related Radiological Imaging in Children with Acute Pyelonephritis

Han, Chang Hee; Cho, Su Yeon; Kang, Sung Hak

Abstract

PURPOSE: The accurate diagnosis of acute pyelonephritis(APN) using clinical and laboratory parameters is often difficult in children. The 99mTc-dimercaptosuccinic acid (DMSA) renal scan is utilized as a gold standard for renal involvement, and renal ultrasonography(RUS) and voiding cystourethrography(VCUG) are utilized to evaluate underlying urinary tract anomalies. In this study the radiological imaging in children of different age groups, with clinical APN, were retrospectively compared.
MATERIALS AND METHODS
Between May 1994 and April 2002, 375 children presented with a febrile urinary tract infection(UTI), and had a DMSA renal scan. Of the patients, 270 had RUS and 220 had contrast VCUG. The sensitivity of these tests in febrile UTI in three age groups was determined: group I less than 2 years; group II 2-5 years; group III older than 5 years.
RESULTS
The clinical and laboratory manifestations of APN correlated better with a positive DMSA renal scan in the older children than in the younger children; 76.1% of the DMSA renal scans were positive in group III; 68.3% in group II; 50.8% in group I(p<0.05). RUS had no correlation with a positive DMSA renal scan in any of the age groups. Vesicoureteral reflux was more prevalent in the older age groups. High grades of reflux(grade IV-V) correlated better with positive DMSA renal scans(p<0.05).
CONCLUSIONS
This study demonstrates that the clinical and laboratory manifestations of APN do not correlate with the findings of DMSA renal scans in young children. Therefore, a young child with a clinical suspicion of APN should be evaluated by a DMSA renal scan to confirm renal parenchymal involvement.