Automated system for anatomical vessel characteristic determination

1. An anatomical blood vessel detection and display system, comprising:

a user interface enabling a user, via a display of an image presenting anatomical vessels, to,

mark a region of interest of a vessel identified by detected boundaries in said image and

extend the marked region of interest of said vessel by extending the marking of the detected boundaries in the direction of a point selected by a user on the vessel into a bifurcation via the user interface, by extending a marked vessel boundary in said region of interest by marking a new center point facilitating switching vessel detection from a non-bifurcation to a bifurcation;

a detector for automatically detecting a boundary comprising an outline of edges of said vessel in the extended marked region of interest by detecting an edge representing a change in luminance in data representing said image in the extended marked region and in the direction of a point selected by a user in said display image and by tracing the edges by including neighbouring edge pixels having substantially the same direction of edge representative luminance gradient as starting edge pixels; and

an image data processor for identifying a minimum vessel diameter in the extended marked region of interest between the detected boundaries and for initiating identification of the location of the minimum vessel diameter in said image.

2. A system according to claim 1 , wherein

said starting edge pixels are automatically determined pixels comprising a first pixel in a first boundary and a second pixel in a second boundary of said vessel and

the marked region of interest of said vessel is automatically extended into a bifurcation by extending the marking of said detected boundaries substantially in the direction of a point selected by a user on said vessel via said user interface.

3. A system according to claim 2 , wherein

the marked region of interest of said vessel is identified by visual attribute comprising at least one of, (a) highlighting, (b) different color, (c) different shading, (d) different pattern and (e) dashed line.

4. A system according to claim 2 , wherein

the marked region of interest of said vessel is automatically extended by,

identifying a first pixel on one of said detected boundaries closest to a point selected by a user using said user interface,

identifying a second pixel on the other of said detected boundaries closest to said point selected by said user and

extending marking of said detected boundaries beyond the marked region of interest into a bifurcation by determining vessel boundary pixels in said image adjacent to the first and second pixels using a curve fitting function.

5. A system according to claim 1 , wherein

said detector automatically identifies vessel boundaries having a luminance variation below a predetermined threshold and enhances said luminance variation by use of an enhancement factor and

detects a vessel boundary by detecting an edge representing a change in the enhanced luminance variation.

6. A system according to claim 1 , wherein

said detector detects said edge representing said change in luminance in response to determining a luminance gradient exceeding a predetermined threshold.

7. A system according to claim 1 , wherein

said detector automatically identifies vessel boundaries having a luminance variation below a predetermined threshold and enhances said luminance variation using a contrast stretching function employing an enhancement factor derived using a ratio of a maximum luminance intensity range to a predetermined portion of the maximum luminance intensity range.

8. A system according to claim 7 , wherein

said contrast stretching function comprises,

Pstretch=(Pin− C )( b−a/d−c )+ a

where, a and b are the lower and upper limit of allowed intensity,

c and d are the intensities at selected percentiles of pixel count,

Pin input pixel intensity for stretching and

Pstretch is stretched output pixel intensity.

9. A system according to claim 1 , wherein

said detector detects individual pixels comprising said edge representing said change in luminance in response to determining a luminance gradient exceeding a predetermined threshold and by fitting a curve to individual segmented groups of substantially adjacent pixels.

10. A system according to claim 9 , wherein

a segmented group of substantially adjacent pixels comprises a predetermined number of pixels.

11. A system according to claim 1 , wherein

said user interface enables a user to extend the marked region of interest of said vessel into a bifurcation comprising a side branch of said vessel.

12. A method for anatomical blood vessel detection and display system, comprising the activities of:

enabling a user, via a display of an image presenting anatomical vessels, to,

mark a region of interest of a vessel identified by detected boundaries in said image and

extend the marked region of interest of said vessel by extending the marking of the detected boundaries in the direction of a point selected by a user on the vessel into a bifurcation via a user interface, by extending a marked vessel boundary in said region of interest by marking a new center point facilitating switching vessel detection from a non-bifurcation to a bifurcation;

automatically detecting a boundary comprising an outline of edges of said vessel in the extended marked region of interest by detecting an edge representing a change in luminance in data representing said image in the extended marked region and in the direction of a point selected by a user in said display image and by tracing the edges by including neighbouring edge pixels having substantially the same direction of edge representative luminance gradient as starting edge pixels; and

identifying a minimum vessel diameter in the extended marked region of interest between the detected boundaries and for initiating identification of the location of the minimum vessel diameter in said image.

13. A method according to claim 12 , wherein

said starting edge pixels are automatically determined pixels comprising a first pixel in a first boundary and a second pixel in a second boundary of said vessel and

the marked region of interest of said vessel is automatically extended by extending the marking of said detected boundaries substantially in the direction of a point selected by a user on said vessel.

14. A method according to claim 13 , wherein

the marked region of interest of said vessel is identified by visual attribute comprising at least one of, (a) highlighting, (b) different color, (c) different shading, (d) different pattern and (e) dashed line.

15. A method according to claim 13 , wherein

the marked region of interest of said vessel is automatically extended by,

identifying a first pixel on one of said detected boundaries closest to a point selected by a user,

identifying a second pixel on the other of said detected boundaries closest to said point selected by said user and

extending marking of said detected boundaries beyond the marked region of interest by determining vessel boundary pixels in said image adjacent to the first and second pixels using a curve fitting function.

16. A method according to claim 12 , including the activities of

automatically identifying vessel boundaries having a luminance variation below a predetermined threshold and enhances said luminance variation by use of an enhancement factor and

detecting a vessel boundary by detecting an edge representing a change in the enhanced luminance variation.

17. An anatomical blood vessel detection and display system, comprising:

a user interface enabling a user, via a display of an image presenting anatomical vessels, to,

mark a region of interest of a vessel identified by detected boundaries in said image and

extend the marked region of interest of said vessel by extending the marking of the detected boundaries in the direction of a point selected by a user on the vessel into a bifurcation via the user interface, by extending a marked vessel boundary in said region of interest by marking a new center point facilitating switching vessel detection from a non-bifurcation to a bifurcation and preventing a user from marking said region of interest outside a vessel boundary by extending the marking of said detected boundaries in the direction of a point selected by a user on said vessel via said user interface;

a detector for automatically detecting a boundary comprising an outline of edges of said vessel in the extended marked region of interest by detecting an edge representing a change in luminance in data representing said image in the extended marked region and in the direction of a point selected by a user in said display image and by tracing the edges by including neighbouring edge pixels having substantially the same direction of edge representative luminance gradient as starting edge pixels; and

an image data processor for identifying a minimum vessel diameter in the extended marked region of interest between the detected boundaries.

18. A system according to claim 17 , wherein

said image data processor identifies the location of the minimum vessel diameter in said image,

the marked region of interest of said vessel is extended by,

identifying first pixels on adjacent detected vessel boundaries and

extending marking of the detected adjacent vessel boundaries by identifying pixels adjacent to said first pixels on the boundaries in the direction of said point selected by said user.

19. A system according to claim 18 , wherein

said detector detects individual pixels comprising said edge representing said change in luminance in response to determining a luminance gradient exceeding a predetermined threshold and by fitting a curve to individual segmented groups of substantially adjacent pixels.

20. A system according to claim 17 , wherein

the marked region of interest of said vessel is identified by visual attribute comprising at least one of, (a) highlighting, (b) different color, (c) different shading, (d) different pattern and (e) dashed line,

said detector automatically identifies vessel boundaries having a luminance variation below a predetermined threshold and enhances said luminance variation by use of an enhancement factor and

detects a vessel boundary by detecting an edge representing a change in the enhanced luminance variation.

21. A system according to claim 17 , wherein

said detector detects said edge representing said change in luminance in response to determining a luminance gradient exceeding a predetermined threshold.

22. A system according to claim 17 , wherein

said user interface enables a user to extend the marked region of interest of said vessel into a bifurcation comprising a side branch of said vessel.