TC-99M DTPA PERFUSION SCINTIGRAPHY AND COLOR-CODED DUPLEX SONOGRAPHY IN THE EVALUATION OF MINIMAL RENAL-ALLOGRAFT PERFUSION

Aim: The clinical impact of perfusion scintigraphy versus color coded Duplex sonography was evaluated, with respect to their potential in as sessing minimal allograft perfusion in vitally threatened kidney trans plants, i.e. oligoanuric allografts suspected to have either severe re jection or thrombosis of the renal vein or artery. Methods: From July 1990 to August 1994 the grafts of 15 out of a total of 315 patients we re vitally threatened. Technetium-99m DTPA scintigraphy and color code d Duplex sonography were performed in all patients. For scintigraphic evaluation of transplant perfusion analog scans up to 60 min postinjec tion, and time-activity curves over the first 60 sec after injection o f 370-440 MBq Tc-99m diethylenetriaminepentaacetate acid (DTPA) were u sed and classified by a perfusion score, the time between renal and il iac artery peaks (TDiff) and the washout of the renogram curve. Additi onally, evaluation of excretion function and assessment of vascular or urinary leaks were performed. By color coded Duplex sonography the pe rfusion in all sections of the graft as well as the vascular anastomos es were examined and the maximal blood flow velocity (Vmax) and the re sistive index (RI) in the renal artery were determined by means of the pulsed Doppler device. Pathologic-anatomical diagnosis was achieved b y either biopsy or post-explant histology in all grafts. Results: Scin tigraphy and color coded Duplex sonography could reliably differentiat e minimal (8/15) and not perfused (7/15) renal allografts. The results were confirmed either by angiography in digital subtraction technique (DSA) or the clinical follow up. Conclusion: In summary, perfusion sc intigraphy and color coded Duplex sonography are comparable modalities to assess kidney graft perfusion. In clinical practice scintigraphy a nd color-coded Doppler sonography can replace digital subtraction angi ography in the evaluation of minimal allograft perfusion.