NEW TECHNIQUE FOR 3D ARTERY MODELING BY NONINVASIVE ULTRASOUND

Three-dimensional (3D) modelling of arteries using noninvasive ultraso und is a further development of this modality which currently displays images in a two-dimensional format. The approach aims to improve visu alisation of the artery under consideration for later use in monitorin g disease within it. The technique is based on analysing a series of t ransverse noninvasive ultrasound scans. Other ultrasound techniques ha ve used invasive scans, flow information and noninvasive longitudinal scans. The advantages of the new method concern noninvasive transverse scanning which allows a circle to be used as an appropriate model to determine the arterial wall data in each slice. This circle is extract ed from the edge magnitude information provided by a version of the Ca nny edge-detection operator and is then located using an implementatio n of the Hough transform tailored to determine the contour which best fits the arterial data. The deviation from the circle provides the art erial wall template except where data is absent when the approximation itself is used. By extracting the template from successive ultrasound images in in vivo studies 3D pictures of vessels, initially of the ca rotid artery and the bifurcation, have been developed. These were init ially portrayed using oblique projection, but to improve visualisation more sophisticated voxel-based solid modelling has been used even tho ugh it incurs greater complexity and memory cost. The resulting images show that it is indeed possible to provide a realistic model via noni nvasive transverse scanning by capitalising on modern techniques of fe ature extraction in images. The model's accuracy has been validated by a test object study and research is ongoing to include stenosis depic tion.