Contribution of 99Tcm-DMSA scintigraphy to aetiological diagnosis in renal transplant recipients with impaired renal...

Routine 99Tcm-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 99Tcm-DMSA were compared with the diagnosis established by fine-needle biopsy in 13 patients and by clinical course and other examinations (ultrasonography, bacteriology) in 11 patients. Renal scintigraphy demonstrated segmental defects in patients with rejection (n = 2/6), immunosuppressor nephrotoxicity (n = 2/6), acute pyelonephritis (n = 3/3), renal artery stenosis (n = 1/1) and obstructive lymphocele (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 immunosuppressor nephrotoxicity. 99Tcm-DMSA was thus found to contribute little to the differential diagnosis between graft rejection and immunosuppressor nephrotoxicity. However, it may be useful for identifying specific disease states, particularly acute pyelonephritis, seen as well-delimited systematized defects. 99Tcm-DMSA scintigraphy could also be used in late follow-up after pyelonephritis in renal transplant recipients.