Tc-99m DTPA renography in children following renal transplantation - Its value in the evaluation of rejection

A retrospective analysis of the value of Tc-99m DTPA DRS in children requiring renal biopsy following transplantation. Thirty-one children following renal transplantation with possible rejection underwent thirty-nine DRS and biopsy within a 72-h period and clinical followed up for 12 months. The biopsy was classified according to the Banff 97. The DRS assessed semi-quantitatively images of renal perfusion and filtration, and the balance between these two images. The clinical notes were reviewed. Based on the biopsy results 15 children had acute rejection, three children chronic rejection, nine children a mixed appearance of both acute and chronic rejection while 12 children had no rejection. Based on the long-term clinical outcome, the DRS had an overall sensitivity of 76% and specificity of 86%. While renal biopsy remains the gold standard for the diagnosis of rejection, if the perfusion and filtration phases of the DRS are analysed separately and the results integrated, there is a possibility of suggesting that acute rejection is not the cause of the increase in creatinine. The DRS provides useful information to the nephrologist when taken in conjunction with the biopsy result and other investigations.