Method for adjustment of the Doppler angle in echography, and arrangement for carrying out the method

摘要

The method entails first isotropic tracing of rays from initial point, with rays traversing the echographic image to provide histogram of the grey levels of selected points distributed along the rays. An algorithm is applied to the histogram to classify the grey levels into two classes, with adjoining ones separated by thresholds expressed in grey levels. One class is bounded by the lower threshold representative of the grey levels of the walls of the blood vessels in the image. A second tracing has as its first point for each ray the grey level equal to or higher than a threshold yielding a representation of the blood vessel in the form of a set of pixels with given co-ordinates, x and y. The slope of the inertial axis is determined from the set of pixels from a given formula, and the Doppler angle calculated.