DIAGNOSTIC-SIGNIFICANCE OF TC-99M-DIMERCAPTOSUCCINIC ACID (DMSA) SCINTIGRAPHY IN URINARY-TRACT INFECTION

A total of 106 children with symptomatic urinary tract infection (73 girls and 33 boys, 0-15.9 years of age) were studied by means of a dimercaptosuccinic acid (DMSA) scan, renal ultrasound, and a desmopressin test during infection and at follow up approximately two months later. At follow up they were also investigated by means of intravenous urography (IVU) and micturition cystourethrography (MCU). During infection 23 children had a normal DMSA scan while 83 children had an abnormal one. The median C reactive protein and SD score for renal concentration capacity in the former group were 15 (range <10-178) mg/l and -1.0 SD score (range -2.4 to 1.8), respectively, and in the latter group 98 (range <10-320) mg/l and -3.1 SD score (range -5.7 to 1.1), respectively. In the former group there was no significant finding in any child on ultrasound or IVU and only one had significant vesicoureteric reflux (VUR) (grade 3). At follow up 51 children had a normal DMSA scan while 55 children showed persistent changes. The median SD score for renal concentration capacity in the former group was -0.9 SD score (range -3.2 to 1.4) and in the latter group -1.6 SD score (range -4.6 to 2.5). No significant changes were found in the former group on ultrasound or IVU and only two children had significant VUR (grade 3). In the latter group 20 children showed changes on ultrasound, 15 showed changes on IVU, and 23 had VUR. These results suggest that a normal DMSA scan during or approximately two months after urinary tract infection in children indicates a low risk of finding significant pathology of the urinary tract.