The Significance of (99m)Technetium Dimercaptosuccinic Acid(DMSA) Scan as a Substitute for Voiding Cystourethrography(VCUG) in Evaluating Children with first Febrile Urinary Tract Infection

ABSTRACT

PURPOSE: We studied the value of clinical signs, laboratory findings and (99m)technetium dimercaptosuccinic acid(DMSA) scan in predicting the presence of vesicoureteral reflux(VUR) in children with first febrile urinary tract infection(UTI). METHODS: A retrospective analysis of 84 hospitalized children with first febrile UTI was performed. They underwent DMSA scan and voiding cystourethrography(VCUG) during the acute phase, and were divided into three groups according to the results of the VCUG: absence of VUR, mild(grade I-II) and severe VUR(grade III-V). We studied the relation of VUR to age, gender, fever duration, causative organism, white blood cell count, serum C-reactive protein and result of DMSA scan. RESULTS: Among 84 patients, 6 had mild and 17 had severe VUR. Thirty-eight had abnormal DMSA scan. results Patients with VUR were older than those without VUR(P<0.01). There was a lower probability of infection with Escherichia coli in patients with severe VUR than in those with mild and absent VUR(P<0.01). An abnormal DMSA scan correlated with the presence and severity of VUR(P<0.05). Severe VUR was present in 10.9% of patients with normal DMSA scan. The sensitivity, specificity, positive and negative predictive values of the DMSA scan in predicting the presence of VUR were 69.6%, 63.9%, 42.1%, and 84.8%, respectively. CONCLUSION: An abnormal DMSA scan correlated to the presence and severity of VUR, but the sensitivity, specificity and positive predictive value of the DMSA scan were low. Therefore, patient with an abnormal DMSA scan requires a VCUG. In order to prevent missing the 10.9% of patients with severe VUR but normal DMSA scans, a VCUG should be performed in patient with normal DMSA scan.