Power Doppler imaging and resistance index measurement in the evaluation of acute renal transplant rejection

Purpose. This study was designed to test the hypotheses that power Doppler imaging has a predictive value in the assessment of acute renal allograft r ejection and that the information garnered from the combination of resistan ce index (RI) determination and power Doppler imaging has an even greater p redictive value in this assessment. Methods. Power Doppler images obtained prior to 96 sequential renal allogra ft biopsies in 92 patients with suspected renal transplant rejection were r etrospectively graded for parenchymal vascularity on a scale of 1 to 4: 1, normal, uniform cortical flow; 2, mild peripheral cortical hypoperfusion; 3 , vascular pruning in cortex and medulla; and 4, no visible parenchymal flo w, with flow seen only in central vessels. Power Doppler grades and Rls for these cases were compared to graft biopsy results. Results. No statistically significant association was observed between pare nchymal vascularity as graded by power Doppler imaging, RI, and the presenc e of acute transplant rejection. Conclusions. Neither grading of vascularity on power Doppler images, RI mea surement, nor the combination of these methods is an accurate means of dete cting renal allograft rejection. (C) 2001 John Wiley & Sons, Inc.