CAN TECHNETIUM-99M-MERCAPTOACETYLTRIGLYCINE REPLACE TECHNETIUM-99M-DIMERCAPTOSUCCINIC ACID IN THE EXCLUSION OF A FOCAL RENAL DEFECT

The presence of focal renal damage dictates different management of a child with urinary tract infection (UTI) compared with children who have normal kidneys. Technetium-99m-dimercaptosuccinic (DMSA) has a high sensitivity in the detection of a focal defect, and allows estimation of differential function. The introduction of Tc-99m-MAG3 with high renal extraction suggests that this may be useful in children with UTI but its role remains speculative. Fifty-nine children with previous UTI underwent both Tc-99m-DMSA and MAG3 within 4 wk of each other. Differential function and assessment of the images were undertaken. There is close correlation (R2 = 0. 97) between the differential function. Analysis of the Tc-99m-DMSA and functional MAG3 images showed that the functional image had a specificity of 88% and a sensitivity of 88% in the detection of a focal parenchymal defect. Technetium-99m-MAG3 in the clinical setting of a child with UTI allows accurate assessment of differential function and a high probability of detecting a focal renal abnormality.