Doppler evaluation of the renal transplant.

Well-established roles for Doppler ultrasound assessment of renal transplants include postoperative evaluation for vascular occlusion and detection of renal artery stenosis. Doppler studies can often differentiate rejecting transplants from those that normally function. While very high Doppler indices are specific for rejection, waveforms in acute tubular necrosis may be abnormal. Mild cases of rejection may have normal waveforms. Further investigation is needed to determine the role of Doppler methods in graft dysfunction and to establish methods to improve their specificity.