Simultaneous ultrasound assessment of brachial artery shear stimulus and flow-mediated dilation during reactive hyperemia

Ultrasound Med Biol. 2011 Oct;37(10):1561-70. doi: 10.1016/j.ultrasmedbio.2011.06.001. Epub 2011 Aug 6.


In flow-mediated dilation (FMD) studies, brachial artery diameter changes due to reactive hyperaemia are typically measured through manual or automatic analysis of high resolution B-mode images while the stimulus of diameter change, i.e., the flow change, is qualitatively estimated by measuring the mean velocity in the vessel and assuming a parabolic velocity profile. This article describes an experimental approach to simultaneously measure the wall shear rate (WSR) and the diameter variations, through multigate spectral Doppler and B-mode image processing, respectively. By using an ultrasound advanced open platform (ULA-OP), experimental results from the brachial arteries of 15 presumed healthy volunteers have been obtained. The mean increments during reflow against baseline were 105% ± 22% for the peak WSR and 8% ± 3% for the FMD. The mean time interval between the WSR peak and the beginning of plateau of diameter waveform was 38 ± 8 s. The results confirm that in young healthy subjects the postischemic vasodilation of brachial artery is largely correlated to the WSR increase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Algorithms
  • Blood Flow Velocity
  • Brachial Artery / diagnostic imaging*
  • Female
  • Humans
  • Hyperemia / diagnostic imaging*
  • Hyperemia / physiopathology
  • Image Interpretation, Computer-Assisted
  • Male
  • Ultrasonography, Doppler*
  • Vasodilation / physiology