Method and system for enhancing contrast of spatially-localized phenomena in mammography image

1. A computer-implemented method of enhancing a contrast of spatially localized phenomena in a medical image, the method comprising:

applying a multi-scale decomposition to a digital signal representation of the medical image to generate detail images at different scales;

after the multi-scale decomposition applying step, modifying detail signals in the detail images pertaining to the spatially localized phenomena having a first common polarity at at least one of the scales, a spatial extent of a region to which the modifying step is applied being limited to pixels within a neighborhood surrounding a position of the spatially localized phenomena, and the modifying step includes applying an amplification factor to the detail signals to be modified or applying a look up table operation to the detail signals to be modified; and

leaving unchanged ones of the detail signals pertaining to the spatially localized phenomena having a second common polarity.

2. The method according to claim 1 , wherein the modifying step is preceded by a thresholding step applied to the detail signals having common polarity.

3. The method according to claim 1 , wherein the spatial extent of the region to which the modifying step is applied has a fixed shape.

4. The method according to claim 1 , wherein the spatial extent of the region to which the modifying step is applied is determined by applying connected component analysis at the position(s) of the spatially localized phenomena.

5. The method according to claim 1 , wherein the spatial extent of the region to which the modifying step is applied is determined by a region growing method having the position(s) of the spatially-localized phenomena as seed point(s).

6. The method according to claim 1 , wherein the spatial extent of the region to which the modifying step is applied is computed by applying a segmentation algorithm to generate a binary mask signal and by interpolating or reducing the binary mask signal to a resolution at which the modifying step is performed.

7. The method according to claim 1 , wherein the modifying step includes applying the amplification factor to the detail signals to be modified.

8. The method according to claim 1 , wherein the modifying step includes applying the look up table operation to the detail signals to be modified.

9. The method according to claim 1 , where the scale at which the modifying step is applied corresponds with dimensions of the spatially localized phenomena of which the contrast is to be enhanced.

10. A computer program product embodied on a non-transitory computer readable medium adapted to carry out the method of claim 1 when the computer program product runs on a computer.

11. A non-transitory computer readable medium including computer executable program code adapted to perform a method of enhancing contrast of spatially localized phenomena in a medical image when the computer executable program code is executed on a computer, the method comprising:

applying a multi-scale decomposition to a digital signal representation of the medical image to generate detail images at different scales;

after the multi-scale decomposition applying step, modifying detail signals in the detail images pertaining to the spatially localized phenomena having a first common polarity at at least one of the scales; and

leaving unchanged ones of the detail signals pertaining to the spatially localized phenomena having a second common polarity, a spatial extent of a region to which the modifying step is applied being limited to pixels within a neighborhood surrounding a position of the spatially localized phenomena, and the modifying step includes applying an amplification factor to the detail signals to be modified or applying a look up table operation to the detail signals to be modified.

12. A system that generates medical images and enhances contrast of spatially localized phenomena in the medical images, the system comprising:

an imaging system configured to generate the medical images; and

a computer system programmed to enhance the contrast by applying a multi-scale decomposition to a digital signal representation of the medical images to generate detail images at different scales, after the application of the multi-scale decomposition, to modify detail signals in the detail images pertaining to the spatially localized phenomena having a first common polarity at at least one of the scales, and to leave unchanged ones of the detail signals pertaining to the spatially localized phenomena having a second common polarity; wherein

a spatial extent of a region to which the modifying step is applied is limited to pixels within a neighborhood surrounding a position of the spatially localized phenomena; and

the modifying step includes applying an amplification factor to the detail signals to be modified or applying a look up table operation to the detail signals to be modified.

13. The system according to claim 12 , wherein the computer system is programmed to apply thresholding to the detail signals having a common polarity.

14. The system according to claim 12 , wherein the computer system is programmed to limit the spatial extent of the region to which the modifying step has a fixed shape.

15. The system according to claim 12 , wherein the computer system is programmed to determine the spatial extent of the region to which the modifying step is applied by applying connected component analysis at the position(s) of the spatially localized phenomena.

16. The system according to claim 12 , wherein the computer system is programmed to determine the spatial extent of the region to which the modifying step is applied by a region growing method having the position(s) of the spatially-localized phenomena as seed point(s).

17. The system according to claim 12 , wherein the computer system is programmed to determine the spatial extent of the region to which the modifying step is applied by applying a segmentation algorithm to generate a binary mask signal and by interpolating or reducing the binary mask signal to a resolution at which the modifying step is performed.

18. The system according to claim 12 , wherein the imaging system is an x-ray system.

19. The system according to claim 12 , wherein the imaging system is a mammography system.