Estimation of flow mediated vasodilation of the radial artery

Preceding atherosclerosis is endothelial dysfunction. There is therefore interest in the application of non-invasive clinical tools to assess endothelial function. There are commercially available ultrasound scanners to measure flow-mediated vasodilatation (FMD) of the brachial artery using 10-12 MHz linear array probes, however the attainable precision in estimating the changes in artery dilation does not exceeds 0.2 mm, far beyond the required one. We have introduced a high frequency scanning schemes 25-35MHz encoded (Golay) wobbling type imaging without Doppler (uScan developed in our lab, thick film wide bandwidth transducer, 50 microns axial resolution) and 20 MHz ultrasound (Ultrasonix) with 20 MHz pulsed Doppler attached to the linear array. The FMD results were normalized using AUC of shear rate at the radial artery wall.