Discordant [99mTc]Tc-MAG3 and [99mTc]Tc-DMSA Findings in Renal Transplant Dysfunction

A 7-year-old boy with end-stage kidney disease secondary to posterior urethral valves underwent deceased donor renal transplantation complicated by suspected vascular thrombosis and delayed graft function. A [ 99m Tc]Tc-MAG3 renogram on day 2 post-transplant demonstrated absent perfusion and uptake, suggesting graft nonfunction, with no improvement on repeat imaging despite thrombectomy. However, [ 99m Tc]Tc-DMSA SPECT/CT demonstrated cortical tracer uptake within the graft, indicating residual viable renal tissue. Biopsy confirmed extensive necrosis with focal preserved glomeruli. The graft was deemed nonsalvageable and nephrectomy performed. This case highlights discordant functional and cortical imaging findings and underscores the value of multimodality imaging in complex renal transplant dysfunction.