Contribution of Tc-99(m)-DMSA scintigraphy to aetiological diagnosis in renal transplant recipients with impaired renal function

Routine Tc-99(m)-dimercaptosuccinic acid (DMSA) scintigraphy was performed in a series of 24 kidney transplant recipients with impaired renal function . Diagnostic findings on planar and tomoscintigraphic acquisitions obtained 3 and 4 h after the injection of 130-140 MBq Tc-99(m)-DMSA were compared w ith the diagnosis established by fine-needle biopsy in 13 patients and by c linic:al course and other examinations (ultrasonography, bacteriology) in 1 1 patients. Renal scintigraphy demonstrated segmental defects in patients w ith rejection (n = 2/6), immunosuppressor nephrotoxicity (n = 2/6), acute p yelonephritis (n = 3/3), renal artery stenosis (n = 1/1) and obstructive ly mphocele (n = 1/1). Diffuse lack of uptake was observed in one patient with severe renal failure. The scintigram was normal in 14 patients, including three with lesions histologically compatible with graft rejection or immuno suppressor nephrotoxicity. Tc-99(m)-DMSA was thus found to contribute littl e to the differential diagnosis between graft rejection and immunosuppresso r nephrotoxicity. However, it may be useful for identifying specific diseas e states, particularly acute pyelonephritis, seen as well-delimited systema tized defects. Tc-99(m)-DMSA scintigraphy could also be used in late follow -up after pyelonephritis in renal transplant recipients. ((C) 2000 Lippinco tt Williams & Wilkins).