Patent ID: 7343031

Claim:
A method of tracking position and velocity of objects' borders in two or three dimensional digital images, particularly in echographic images, comprising the following steps: acquiring a sequence of at least two consecutive ultrasound image frames of a moving tissue or a moving object, said ultrasound image frames being timely separated by a certain time interval; automatically or manually defining a certain number of reference points of a border of said moving tissue or object on a first image frame of said sequence of image frames; automatically tracking said border on at least one frame following said first frame by determining the new position of said reference points by estimating the position of said reference points on the basis of the ultrasound image data of the acquired sequence of image frames, wherein the sequence of image frames acquired is a sequence of consecutive B-mode, grey scale ultrasound images; drawing either manually or by means of an automatic border detection algorithm on a first frame a border line being defined by a trace of pixels of the image frame coinciding with said border line, said trace of pixels coinciding with said manually or automatically drawn border line is followed by searching the maximum likelihood of said trace of pixels in said following image frame with said trace of pixels in said first image frame by analyzing the image pixels in the neighborhood of said trace of pixels; tracking the position displacements of one or more representative reference points over the entire sequence of consecutive image frames; rescaling the border line drawn on said first image frame and at least on of said following image frames of said sequence of image frames according to the corresponding position tracked of said representative reference points; defining a certain number of further reference points distributed along said border line on said first image frame; tracking the position of each point independently from said other points along said sequence of image frames; tracking the position of said representative reference points and of said other reference points by defining a transmural cut line comprising a line which crosses said border line drawn and passing through said reference point; and wherein for images having a low signal-to noise-ratio, the space-time representation along said transmural cuts is built using a line for said transmural cut having a thickness greater than that of a single pixel, and by extracting the average value across said thickness.