New methodological approach to improve reproducibility of brachial artery flow-mediated dilatation

Echocardiography. 2014 Feb;31(2):197-202. doi: 10.1111/echo.12307. Epub 2013 Jul 30.


Background: Measurement of flow-mediated dilation (FMD) is well known as a noninvasive method for an assessment of vascular endothelial function. However, the reproducibility is a major issue of FMD measurement. The purpose of this study is to examine the reproducibility of the new FMD measurement with medial epicondyle method.

Methods: First, to evaluate the variability of the brachial artery diameter, 23 volunteers recruited from 32 healthy volunteers were examined for a brachial artery diameter at rest using with FMD equipment. Second, to evaluate the reproducibility of the FMD measurement, all volunteers underwent the FMD measurement, which was repeated at 2-week interval using the traditional method and the medial epicondyle method. The reproducibility in both methods was evaluated by 2 independent observers who measured on the same subject to assess the inter-observer reproducibility, and 1 observer who measured the same subject twice to assess the intra-observer reproducibility regarding the baseline value of arterial diameter and FMD.

Results: The variability of brachial artery diameter was 0.57 ± 0.27 mm in 23 healthy volunteers. In the study of inter- and intra-observer reproducibility, 2 parameters including intra-class correlation coefficient and Pearson's correlation coefficient by medial epicondyle method are superior to those by traditional method.

Conclusions: These results suggest that medial epicondyle methodological approach to measure FMD is superior to traditional method.

Keywords: flow-mediated dilatation; reproducibility of brachial artery.

MeSH terms

  • Adult
  • Algorithms
  • Anatomic Landmarks / diagnostic imaging*
  • Blood Flow Velocity / physiology
  • Brachial Artery / diagnostic imaging*
  • Brachial Artery / physiology*
  • Echocardiography / methods*
  • Endothelium, Vascular / diagnostic imaging*
  • Female
  • Humans
  • Image Enhancement / methods*
  • Image Interpretation, Computer-Assisted / methods*
  • Male
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Vascular Resistance / physiology