Radionuclide studies in the evaluation of urinary tract infections.

ABSTRACT

OBJECTIVE: To estimate the prevalence of vesicoureteral reflux (VUR) and renal scarring in children presenting with culture proven urinary tract infections (UTI). DESIGN: Descriptive study. SETTING: Tertiary care hospital-based study. SUBJECTS: Thirty-two children with proven UTI were evaluated by means of an abdominal ultrasonogram (USG), Technetium-99m Dimercapto Succinic Acid (DMSA) scan and Direct Radionuclide Cystography (DRCG). A micturating cystourethrogram (MCU) was performed to rule out any structural abnormality and to grade VUR. RESULTS: A total of 64 renal units in 32 children were evaluated. DMSA scan showed scarring in 27 renal units (42.2%) in 16 patients. Bilateral renal scarring was more common in older (> 2 yr) children as compared to younger ones (89% Vs 43%; p < 0.05). USG detected abnormalities in 13 renal units (20.3%) in 7 cases. VUR was detected in 37.5% of children of all age group by DRCG. In contrast, MCU showed evidence of VUR in only 13/20 renal units with a sensitivity of 65% as compared to DRCG and did not pick up any additional VUR that could have been missed on the DRCG. Only 3/9 in < 2 yr, in contrast to 10/11 in > 2 yr were positive for VUR on MCU (p < 0.05). However, MCU detected evidence of cystitis in 3 children and a bladder diverticulum in one patient. CONCLUSION: Wherever available, DMSA scan should be considered as a part of the first line investigations in any patient presenting with UTI. DRCG can also be performed in the same sitting to screen for the presence of reflux particularly for girls.