title: Diagnosis of renal artery stenosis in transplanted kidneys: value of Doppler waveform analysis of the intrarenal arteries.
abstract: OBJECTIVE
  The objective of this study was to determine in renal transplant patients if the acceleration time and subjective assessment of dampening of the waveforms from the intrarenal arteries improves the accuracy of detecting a hemodynamically significant (> or = 50%) proximal arterial stenosis compared with measurements of peak systolic velocity from a main renal artery.
  
  
  METHODS
  In 15 patients, the findings of 19 Doppler sonograms and corresponding arteriograms of their renal transplants were reviewed, with arteriography serving as the gold standard. Four patients had a significant proximal arterial stenosis; three were of the main renal artery and one was of the adjacent external iliac artery proximal to the anastomosis with the renal artery.
  
  
  RESULTS
  We found a significant prolongation of the acceleration time in patients with a significant proximal arterial stenosis (p = .0004). Use of a threshold acceleration time of 0.10 sec or subjective assessment of dampening of the waveforms resulted in an accuracy of 95% in detecting a significant proximal arterial stenosis. This compared with an accuracy of 62% in detecting a significant proximal arterial stenosis using a peak systolic velocity threshold of 2.0 m/sec as the sole criterion. Using intrarenal arterial Doppler waveform parameters alone would have spared arteriography in 11 patients and would have detected three of four significant proximal arterial stenoses.
  
  
  CONCLUSIONS
  In this study, Doppler waveform analysis of the intrarenal arteries improved the accuracy of screening for a significant proximal arterial stenosis. The results suggest that such analyses can be used to spare many patients with suspected renal vascular hypertension from unnecessary arteriography.
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods / Q000706:statistics & numerical data; D001158:Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016030:Kidney Transplantation / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies; D013599:Systole; D018608:Ultrasonography, Doppler / Q000379:methods / Q000706:statistics & numerical data