[Comparative study of differential renal function by DMSA and MAG-3 in congenital unilateral uropathies].

UNLABELLED

In congenital obstructed hydronephrosis, the assessment of the differential renal function (DRF) is essential to provide a prognosis or to determine surgical treatment. The most reliable method to measure the differential renal function is the isotopic study with DMSA. The MAG-3 is employed to evaluation renal elimination, although in the minutes 1-3 it also measures the differential renal function.

OBJECTIVE

We compared the estimation of differential renal function by 99Tc-dimercapto-succinic acid (DMSA) and 99Tc-mercaptoacetyltriglycyne (MAG-3) methods in congenital unilateral uropathies.

MATERIALS AND METHODS

We reviewed the results of 138 isotopic studies of children (age range: 0-9 years) with congenital unilateral uropathies: 67 cases were obstructed and 71 non-obstructed. In all of them were carried out match tests pairs with DMSA and MAG-3. Both series were divided into 4 groups: 1) DRF < 40%, 2) DRF 40-45%, 3) DRF 46-50% and 4) DRF > 50%. The measurement differential renal function correlation by DMSA and MAG-3 were analysed.

RESULTS

The coefficient of correlation was 0.96 (P < 0.01) in obstructed unilateral uropathy and 0.92 (P < 0.01) in non-obstructed serie.

CONCLUSIONS

The differential renal function measured with DMSA and MAG-3 has a close correlation in congenital unilateral uropathies. Therefore in obstructed types, differential renal function and half-time elimination can be reliable and sure studied with MAG-3, being unnecessary DMSA test, avoiding additional radiation to the children.