Reliability of brachial artery flow-mediated dilatation measurement using ultrasound.
OBJECTIVE
To determine the reliability of the baseline (BBAB) and post occlusion (POBAD) brachial artery diameters, brachial artery flow-mediated dilatations (BAFMD) measurements, and to quantify the typical error of the measurements (TEM).


METHODS
Internal consistency (2 measurements on the same day) was determined in 10 volunteers, whereas stability (2 measurements on separate days) was determined in 13 volunteers. All the volunteers looked healthy and were nonsmokers. The brachial artery images were obtained using a two dimensional Doppler ultrasound instrument: a 14 MHz transducer was used. The distances between the intima-lumen interfaces were measured before and after the blood flow had been stopped by means of a cuff on the arm for five minutes. BAFMD was considered as the percentile increase of POBAD in relation to BBAD.


RESULTS
ANOVA did not identify any significant differences between the measurements taken on the same and separate days. For BAFMD, the intraclass correlation coefficients between the measurements taken on the same and separate days were: R = 0.7001 and R = 0.8420, respectively (p < 0.05). The variation coefficients were 5.8% and 12.4% and the relative SMEs were 13.8% and 14.9%, respectively, for the measurements taken on the same and separate days. Analysis of the Bland-Altman graphs indicated that the variables did not present heteroscedastic errors.


CONCLUSIONS
The BBAD, POBAD and BAFMD measurements using the manual ultrasound technique were highly reliable for both the same and separate day measurements and therefore can be used to diagnose and monitor endothelial function.
Meirelles
Cláudia de Mello
Cde M
Centro de Pesquisas Interdisciplinares em Saúde, Universidade Gama Filho, Departamento de Nutrição do UNIBENNETT.
Leite
Sandra Pereira
SP
Montenegro
Carlos Antonio Barbosa
CA
Gomes
Paulo Sergio Chagas
PS
D000328:Adult; D000704:Analysis of Variance; D001132:Arm / Q000098:blood supply*; D001916:Brachial Artery / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology; D013997:Time Factors; D018608:Ultrasonography, Doppler; D014664:Vasodilation / Q000502:physiology*