Radionuclide perfusion scans in the assessment of acute renal transplant rejection.

Acute renal transplant rejection is a diagnostic and management problem. In the oliguric patient clinical evaluation and biochemical tests are less helpful than in those with a functioning graft. The perfusion index derived from a 99mTc-diethylenetriamine penta-acetic acid scan may be a more reliable marker of acute rejection. We studied 20 consecutive renal transplant recipients with serial radionuclide imaging to assess the usefulness of the perfusion index. Seventy-two of 74 episodes of acute rejection were evaluated. Thirty-three (46%) episodes were predicted or supported by a change in the perfusion index. In the non-functioning transplant, 12 of 15 (80%) acute rejection episodes were predicted or supported. A scan obtained the day after transplantation confirmed graft artery patency in all patients. The perfusion index is a useful diagnostic test for the diagnosis and management of acute rejection, particularly in the non-functioning transplanted kidney.