Reproducibility Of Brachial And Femoral Arterial Diameter And Flow-mediated Dilation Via Automatic Edge-detection Software

Abstract

BACKGROUND: Flow-mediated dilation (FMD) is a non-invasive protocol to examine blood flow and arterial diameter via an endothelial-dependent NO-mediated response in vivo. New technologies such as automatic edge-detection software help to reduce subject variability when measuring vessel diameter. However, this variability has to be assessed. PURPOSE: To evaluate the variability of brachial and femoral artery diameters and FMD assessment using an automatic edge-detection software. METHODS: Subjects between 19-33 years of age were recruited for this study and tested twice within 4 days. Ischemia was elicited using suprasystolic pressure-cuff inflation placed around the forearm and lower thigh for brachial and femoral FMD assessments, respectively. Ultrasound imaging was performed with the ultrasound probe fixed approximately 5 cm above the antecubital fossa and the inguinal space for brachial and femoral measurement sites, respectively. Data acquisition at resting and post-deflation measurements was directly saved on a server hard-drive as digital AVI file format. Resting and post-deflation measurements were recorded for 30 and 120 seconds, respectively. Changes in vessel diameter were analyzed via automatic edge-detection software (Vascular Research Tools; Medical Imaging Applications LLC) that uses an algorithm to determine mean diameter through a series of repeated measures.TableRESULTS: CONCLUSION: The present results show that the assessment of brachial and femoral diameters and FMD is reproducible. The overall variability using this new technology in our Lab is approximately 8%, thereby making it considerably lower than other coefficients of variation reported in the literature.