Ultrasound assessment of endothelial function in real-time (Honorable Mention Poster Award)

The characterization of the endothelial function is one of the most attractive research topics in modern vascular medicine. The evaluation of the flow-mediated vasodilation (FMD) of the brachial artery is a widely used measurement technique. Despite its widespread use, this technique has some limitations due to the difficulties in obtaining an accurate measurement of such a small vessel (3 to 5 mm) by using ultrasounds. The system we present in this paper can automatically measure the diameter of the artery with high accuracy on each image of a video sequence. Furthermore, it processes the data in real-time, thus providing the physician with an immediate response while the examination is still in progress. The main part of the system is a video processing board based on a state-of-the-art digital signal processor (DSP). The board acquires the video signal generated by the ultrasound equipment which furnishes a longitudinal section of the artery vessel. For each image, the DSP automatically locates the two borders of the vessel and subsequently computes the diameter. The algorithm used to automatically locate the borders of the vessel is based on a new operator of edge detection which was derived from the first absolute central moment. Tests in many clinical centers proved that the system provides very accurate measurements and is a remarkable step forward toward a more systematic evaluation of the FMD.