Method for locating an element of interest contained in a three-dimensional object, in particular during a stereotactic investigation in the X-ray examination of the breast
First Claim
1. A method for locating an element of interest contained in a three-dimensional object comprising:
- providing a set of images having at least first and second digitized stereotaxic images having positions of homologous regions of interest corresponding to the element of interest and appearing in the set of stereotaxic images;
selecting in a first stereotaxic image a first target region of interest having a target pixel;
matching the first target region of interest with a second region of interest homologous to the first target region of interest and appearing in the second stereotaxic image;
generating a target window of chosen dimensional characteristics and containing the selected first target region of interest around pixels of the selected target pixel;
selecting a set of pixels in the second stereotaxic image according to a predetermined selection criterion so as to generate a second window around each selected pixel, the second window having the same dimensional characteristics as the generated target window;
processing a correlation between gray-scale levels of the pixels in each second window and the tray scale levels of the pixels in the target window to obtain a correlation for each second window; and
using the correlation values to identify the region of interest homologous to the target region of interest and thereby minimize the risk of matching error between the homologous regions of interest.
1 Assignment
0 Petitions
Accused Products
Abstract
The stereotaxic images being digitized, a target pixel in a target region of interest is selected, a target window of chosen dimensional characteristics and containing the said target region of interest is generated around the selected target pixel, a set of pixels is determined in a second image, according to a predetermined selection criterion, a second window, of the same dimensional characteristics as the said target window, is generated around each selected pixel, a correlation processing between the grey-scale levels of the pixels of each second window and the grey-scale levels of the pixels of the target window is carried out so as to obtain a correlation value for each second window, and the region of interest homologous to the target region of interest is identified on the basis of the analysis of the set of correlation values thus obtained, so as to minimize the risks of matching error between the homologous regions of interest. The element of interest is then located on the basis of the positions of the two homologous regions.
-
Citations
22 Claims
-
1. A method for locating an element of interest contained in a three-dimensional object comprising:
-
providing a set of images having at least first and second digitized stereotaxic images having positions of homologous regions of interest corresponding to the element of interest and appearing in the set of stereotaxic images; selecting in a first stereotaxic image a first target region of interest having a target pixel; matching the first target region of interest with a second region of interest homologous to the first target region of interest and appearing in the second stereotaxic image; generating a target window of chosen dimensional characteristics and containing the selected first target region of interest around pixels of the selected target pixel; selecting a set of pixels in the second stereotaxic image according to a predetermined selection criterion so as to generate a second window around each selected pixel, the second window having the same dimensional characteristics as the generated target window; processing a correlation between gray-scale levels of the pixels in each second window and the tray scale levels of the pixels in the target window to obtain a correlation for each second window; and using the correlation values to identify the region of interest homologous to the target region of interest and thereby minimize the risk of matching error between the homologous regions of interest. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for locating an element of interest contained in a three-dimensional object comprising:
-
providing a set of digitized stereotaxic images having positions of homologous regions of interest corresponding to the element of interest and appearing in the set of stereotaxic images; selecting in a first stereotaxic image a first target region of interest having a target pixel; matching the first region of interest with a second region of interest homologous to the first region of interest and appearing in a second stereotaxic image; generating a target window of chosen dimensional characteristics and containing the target region of interest around pixels of the selected target pixel; determining and storing a first set of numerical values, respectively representing predetermined characteristics of any region of interest for the target region of interest on the basis of the grey-scale values of the pixels in the target window; determining in the second image a set of pixels belonging respectively to candidate regions of interest appearing in the second image according to predetermined selection criterion; generating a second window, containing a corresponding candidate region of interest around each of the selected pixels; determining and storing a second set of numerical values, respectively representing the predetermined characteristics for each candidate region of interest, on the basis of the grey-scale values of the pixels in the associated second window; and identifying the region of interest homologous to the target region of interest on the basis of a comparison processing between the first set of numerical values and each second set of numerical values so as to minimize the risk of matching error between the homologous regions of interest. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A method for locating an element of interest contained in a three-dimensional object comprising:
-
providing a set of digitized stereotaxic images having positions of homologous regions of interest corresponding to the element of interest and appearing in the set of stereotaxic images; selecting in a first stereotaxic image of a first target region of interest; selecting in a second stereotaxic image on the basis of a first automatic matching at least one second region of interest which may be homologous to the first target region; determining the spatial position of a candidate pixel of a candidate element of interest corresponding to the two regions of interest; determining the position, in a third stereotaxic image, of a projected pixel corresponding to the projection into the third stereotaxic image of the candidate pixel; providing a second automatic matching between the target region of interest and a vicinity of the projected pixel; and defining a projected region of interest so as to minimize the risk of matching errors between the homologous regions of interest. - View Dependent Claims (18, 19, 20, 21, 22)
-
Specification