Relevance of Tc-99m DMSA scintigraphy in renal transplant parenchymal imaging

Tc-99m DMSA renal scintigraphy was performed in 40 renal grafts. Cyclosporin A and glucocorticoids were given to all patients as antirejection therapy, and 11 also were given azathioprine. The kidneys were transplanted 1 to 97 months before the investigation. Seventy percent of kidneys had diffusely altered distribution of Tc-99m DMSA, and 43% had focal clear-cut parenchymal defects. The frequency of parenchymal defects observed on the DMSA scans was higher in patients who suffered manifest acute rejection episodes (8/16 versus 9/24 patients, borderline significance, P < 0.06), but had no relation to the living or cadaveric donor transplant or its function. A combination of peritubular edema and interstitial fibrosis is considered the most probable explanation of diffuse changes. The high frequency of clear-cut parenchymal defects most likely results from symptomatic or asymptomatic rejection episodes complicated by renal transplant infarcts.