An adaptive template-matching method and its application to the boundary detection of brachial artery ultrasound scans

We developed an adaptive template-matching method for vessel wall boundary detection in brachial artery ultrasound (US) scans. The computer-aided iden tification of lumen-intima and media-adventitia boundaries of the brachial artery US scan is a critical step for Bow-mediated vasodilator response mea surement, which has become an increasingly important tool in both clinical and research applications. The adaptive template we propose in this paper i s a combination of two parameterized Gaussian envelopes that approximates t he US pulse envelope. The algorithm for template matching is cast as a cons trained nonlinear least squares problem. A best match between the template and the observed US scan line signal results in a set of optimum parameters of the adaptive template, and the location of the boundaries is directly c omputed from these parameters. We present the results of applying our metho d to synthetic and clinical data, showing that the adaptive template-matchi ng method provides superior accuracy in detecting the media-adventitia boun daries of both the near wall and the far wall of the vessel to that of conv entional edge-detection methods. (C) 2001 World Federation for Ultrasound i n Medicine & Biology.