title: Echo-Tracking Method Improves the Reliability in Flow-Mediated Dilation Assessment by Measuring Brachial Artery Reactivity.
abstract: The purpose of the study was to compare the intraobserver and interobserver reliability and agreement for measurement of flow-mediated dilation (FMD) between B-mode method and echo-tracking (ET) method. Twenty healthy volunteers (mean age, 31.6 ± 9.2 years) underwent ultrasound examination by both B-mode and ET methods. Baseline brachial artery diameter, post-cuff release diameter, and FMD percent were assessed by each sonologist on 2 consecutive days. Reliability was assessed by intraclass correlation coefficients, and Bland-Altman plots were used to visually compare measurement bias and agreement by the 2 ultrasound methods. A total of 40 pairs of data were available for analysis. Excellent intraobserver and interobserver reliability values were found for all variables assessed by the 2 methods. The intraclass correlation coefficient values were higher for ET in both intraobserver and interobserver evaluations, but only for interobserver evaluations for post-cuff release diameter and FMD was there no overlap in the 95% confidence interval. The Bland-Altman plots showed that in 95% of the measurements, the percentage difference between ET and B-mode ultrasound techniques was within 18.1%, 19.4%, and 17.3% for baseline brachial artery diameter, post-cuff release diameter, and FMD percent, respectively. The results suggest that ET and B-mode methods are reproducible in assessing the FMD. The ET method improves the reliability of FMD assessment, but we cannot determine which measurement is better for FMD.
authors.affiliation: *Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University; and †Department of Ultrasound, The Military General Hospital of Beijing, Beijing, China.
authors.forename: Li-juan
authors.initials: LJ
authors.lastname: Du
authors.forename: Wen
authors.initials: W
authors.lastname: He
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiao-lu
authors.initials: XL
authors.lastname: Liang
authors.forename: Jiang-xia
authors.initials: JX
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001916:Brachial Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D014463:Ultrasonography