Online measurement of the vasodilation of peripheral arteries on ultrasound images

The online measurement of the vasodilation of a peripheral artery is useful in many clinical applications. Moreover, ultrasound imaging is recommended because of the advantages of this technique such as non-invasivity and feasibility. However, an algorithm with a subpixel resolution is required to obtain a useful plot of the vasodilation when using ultrasound images since the temporal changes of the vascular diameter on these images are usually not greater than 1-2 pixels. The algorithm we propose in this paper is based on the first absolute central moment, a mathematical operator which is used as an edge detector. The performances of the algorithm are analysed both on test discontinuities and on the online analysis of the brachial artery in in-vivo studies