Normal dimercaptosuccinic acid scintigraphy makes voiding cystourethrography unnecessary after urinary tract...

To test the hypothesis that infants with dilating vesicoureteral reflux (VUR) have abnormal acute dimercaptosuccinic acid (DMSA) scintigraphy results, as was suggested by an earlier retrospective study.

We conducted a prospective study of infants <1 year old with first diagnosed symptomatic urinary tract infection at the Children's Hospital of Göteborg, Sweden. Two hundred ninety consecutive children (161 boys and 129 girls) with complete records were examined. Renal ultrasound scanning and DMSA scintigraphy were performed within a few days from diagnosis, and VCU was performed within 2 months.

VUR was found in 52 children, of which 27 had dilating VUR (grade III-V). DMSA scintigraphy results were abnormal in 149 infants (51%), 105 of 238 (44%) without VUR, 18 of 25 (72%) with VUR grade I to II, and 26 of 27 (96%) with VUR grade III to V (P <.001).

DMSA scintigraphy results were abnormal in all 27 infants with dilating VUR except 1. This single false-negative finding should be compared with 140 unnecessary VCU investigations. This supports our hypothesis that DMSA scintigraphy results are abnormal when there is dilating VUR. Thus, a normal DMSA scan makes VCU unnecessary in the primary examination of infants with UTI.