Method and system for roentgenography-based modeling

• US 9,443,302 B2
• Filed: 08/20/2010
• Issued: 09/13/2016
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: Orthofix SRL (Orthofix Medical Inc.), Texas Scottish Rite Hospital for Children
• Original Assignee: AMER Technology Limited (AMER International Group Company Limited), Texas Scottish Rite Hospital for Children
• Inventors: Vvedenskiy, Petr Stanislavovich, Mikheev, Konstantin Evgenevich, Sivachev, Dmitry Alexandrovich, Morenko, Alexander Alexandrovich, Cherkashin, Alexander, Samchukov, Mikhail
• Primary Examiner(s): BROOME, SAID A
• Application Number:
  US13/817,778
• Publication Number:
  US 20130215114A1
• Time in Patent Office: 2,216 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61B 17/62 Ring frames, i.e. devices extending around the bones to be positioned A61B17/6433 , A61B17/66 take precedence
• CPC Class Codes: A61B 6/584 determining position of components of the apparatus or device using images of the phantom
• CPC Class Codes: G06T 2200/08 involving all processing steps from image acquisition to 3D model generation
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/30008 Bone
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/564 from contours

Abstract

Modeling an object in 3-D space may be accomplished various embodiments disclosed herein. An exemplary method of creating a 3-D model includes receiving roentgenograms of an object and at least one reference marker. In some embodiments, the roentgenograms may each include an image of at least one object marker. The exemplary method may further include determining 3-D positions of the x-ray source using the images of the at least one reference marker. The location of the 3-D positions of the x-ray source may allow a 3-D model of the imaged object to be created.

Claims

1. A method of transforming a plurality of roentgenograms of an object into a 3-D model of the object using a data transformation server, the method comprising:

receiving, using one or more processing devices of the data transformation server and from an x-ray imager, a first roentgenogram of an object disposed between an x-ray source and the x-ray imager in a first orientation, wherein the first roentgenogram is generated using the x-ray imager, wherein the first orientation comprises a first angular position of the object relative to an imaging axis, wherein the first roentgenogram includes a first image of;

the object; and

at least one reference marker having at least two fiducials, wherein the fiducials are separated by a fixed distance;

receiving, using the one or more processing devices and from the x-ray imager, a second roentgenogram of the object disposed between the x-ray source and the x-ray imager in a second orientation, wherein the second roentgenogram is generated using the x-ray imager, wherein the second orientation comprises a second angular position of the object relative to the imaging axis, and wherein the second roentgenogram includes a second image of;

the object; and

the at least one reference marker;

receiving, using the one or more processing devices and from the x-ray imager, an angular displacement corresponding to the difference between the first and second angular positions of the object relative to the imaging axis;

determining, using the one or more processing devices, a first 3-D position of the x-ray source with respect to the x-ray imager in the first orientation using the first image of the at least one reference marker;

determining, using the one or more processing devices, a second 3-D position of the x-ray source with respect to the x-ray imager in the second orientation using the second image of the at least one reference marker;

identifying, using the one or more processing devices, a first object outline of the imaged object in the first roentgenogram;

identifying, using the one or more processing devices, a second object outline of the imaged object in the second roentgenogram;

generating, using the one or more processing devices, a first 3-D object projection from the first outline of the imaged object to the first 3-D position of the x-ray source;

generating, using the one or more processing devices, a second 3-D object projection from the second outline of the imaged object to the second 3-D position of the x-ray source;

aligning, using the one or more processing devices, the first and second 3-D projections of the imaged object in a 3-D reference frame using the angular displacement; and

transforming, using the one or more processing devices, the first and second 3-D object projections into a 3-D model of the imaged object in the 3-D reference frame.

2. The method according to claim 1, the method further comprising:

identifying, using the one or more processing devices, a tilt axis in the 3-D reference frame, wherein the tilt axis passes between a first 3-D position in the 3-D reference frame that corresponds to the first position of the x-ray source in the first orientation and a second 3-D position in the 3-D reference frame that corresponds to the second position of the x-ray source in the second orientation;

identifying, using the one or more processing devices, one or more intersection planes passing through the tilt axis and through the first and second 3-D projections of the imaged object in the 3-D reference frame;

for each of the one or more intersection planes, performing the following steps a) through c);

a) identifying, using the one or more processing devices, one or more intersection points between the first and second 3-D object projections, and said intersection plane in the 3-D reference frame;

b) generating, using the one or more processing devices, one or more polygons connecting the intersection points in said intersection plane;

c) generating, using the one or more processing devices, one or more closed curves within the each of the one or more polygons, wherein the one or more closed curves corresponds to a cross-sectional view of the imaged object in said intersection plane; and

generating, using the one or more processing devices, a surface in the 3-D reference frame that connects each of the closed curves to form a 3-D model of the imaged object.

3. The method according to claim 1, wherein the at least one reference marker comprises at least three fiducials, the method further comprising:

receiving, using the one or more processing devices, a first outline of the at least three fiducials in the first roentgenogram; and

receiving, using the one or more processing devices, a second outline of the at least three fiducials in the second roentgenogram;

wherein determining the first 3-D position of the x-ray source further comprises identifying a first plurality of paths from the x-ray source to the first outline of the at least three fiducials and determining an approximate intersection of the first plurality of light paths; and

wherein determining the second 3-D position of the x-ray source further comprises identifying a second plurality of paths from the x-ray source to the second outline of the at least three fiducials and determining an approximate intersection of the second plurality of light paths.

4. The method according to claim 3, wherein determining the approximate intersection of the first plurality of paths and the approximate intersection of the second plurality of paths further comprises using an approximation model.

5. The method according to claim 4, wherein using an approximation model further comprises determining the position of a first segment between the first plurality of paths and designating a point on the first segment to be the first 3-D position of the x-ray source.

6. The method according to claim 5, wherein the first segment is a common perpendicular of the first plurality of paths.

7. The method according to claim 5, wherein using an approximation model further comprises determining the position of a second segment between the second plurality of paths and designating a point on the second segment to be the second 3-D position of the x-ray source.

8. The method according to claim 7, wherein the second segment is a common perpendicular of the second plurality of paths.

9. The method according to claim 1, wherein the at least one reference marker comprises at least three fiducials disposed along a longitudinal axis of the at least one reference marker.

10. The method according to claim 1, wherein the first roentgenogram includes a first image of first and second reference markers, and the second roentgenogram includes a second image of the first and second reference markers.

11. The method according to claim 10, wherein the first reference marker comprises two fiducials disposed along a longitudinal axis of the first reference marker, and the second reference marker comprises two fiducials disposed along a longitudinal axis of the second reference marker.

12. The method according to claim 10, wherein the first reference marker comprises two fiducials disposed along a longitudinal axis of the first reference marker, and the second reference marker comprises first, second, and third fiducials, wherein first and second fiducials of the second reference marker define a first longitudinal axis parallel to the x-ray imager, and the second and third fiducials of the second reference marker define a second longitudinal axis orthogonal to the first longitudinal axis.

13. The method according to claim 1, wherein receiving an angular displacement further comprises receiving data from a measuring device coupled to the object or the imaging device, the measuring device being operable to determine the angular displacement.

14. The method according to claim 1, wherein the at least one reference marker is made of a radio-translucent material and the fiducials of the at least one reference marker are made of a radio-opaque material.

15. A method of transforming a plurality of roentgenograms of an object into a 3-D model of the object using a data transformation server, the method comprising:

receiving, using one or more processing devices of the data transformation server and from an x-ray imager, a first roentgenogram of an object disposed between an x-ray source and the x-ray imager in a first orientation, wherein the first roentgenogram is generated using the x-ray imager, wherein the first orientation comprises a first angular position of the object with respect to an imaging axis, wherein the imaging axis is parallel to the imager in the first orientation, wherein the first roentgenogram includes a first image of;

the object; and

at least one reference marker having at least two fiducials, wherein the fiducials are separated by a fixed distance;

receiving, using the one or more processing devices and from the x-ray imager, a second roentgenogram of the object disposed between the x-ray source and the x-ray imager in a second orientation, wherein the second roentgenogram is generated using the x-ray imager, wherein the second orientation comprises a second angular position of the object with respect to the imaging axis, wherein the imaging axis is parallel to the imager in the second orientation and the second angular position of the object is orthogonal to the first angular position of the object, and further wherein the second roentgenogram includes a second image of;

the object; and

the at least one reference marker;

determining, using the one or more processing devices, a first 3-D position of the x-ray source with respect to the x-ray imager in the first orientation using the first image of the at least one reference marker;

determining, using the one or more processing devices, a second 3-D position of the x-ray source with respect to the x-ray imager in the second orientation using the second image of the at least one reference marker;

identifying, using the one or more processing devices, a first object outline of the imaged object in the first roentgenogram;

identifying, using the one or more processing devices, a second object outline of the imaged object in the second roentgenogram;

generating, using the one or more processing devices a first 3-D object projection from the first outline of the imaged object to the first 3-D position of the x-ray source;

generating, using the one or more processing devices, a second 3-D object projection from the second outline of the imaged object to the second 3-D position of the x-ray source;

aligning, using the one or more processing devices, the first and second 3-D projections of the imaged object in a 3-D reference frame according to the orthogonal first and second angular positions of the object; and

transforming, using the one or more processing devices, the first and second 3-D object projections into a 3-D model of the imaged object in the 3-D reference frame.

16. The method according to claim 15, the method further comprising:

identifying, using the one or more processing devices, a tilt axis in the 3-D reference frame, wherein the tilt axis passes between a first 3-D position in the 3-D reference frame that corresponds to the first position of the x-ray source in the first orientation and a second 3-D position in the 3-D reference frame that corresponds to the second position of the x-ray source in the second orientation;

identifying, using the one or more processing devices, one or more intersection planes passing through the tilt axis and through the first and second 3-D projections of the imaged object in the 3-D reference frame;

for each of the one or more intersection planes, performing the following steps a) through c);

a) identifying, using the one or more processing devices, one or more intersection points between the first and second 3-D object projections, and said intersection plane in the 3-D reference frame;

b) generating, using the one or more processing devices, one or more polygons connecting the intersection points in said intersection plane;

c) generating, using the one or more processing devices, one or more closed curves within the each of the one or more polygons, wherein the one or more closed curves corresponds to a cross-sectional view of the imaged object in said intersection plane; and

generating, using the one or more processing devices, a surface in the 3-D reference frame that connects each of the closed curves to form a 3-D model of the imaged object.

17. The method according to claim 15, wherein the at least one reference marker comprises at least three fiducials in total, the method further comprising:

receiving, using the one or more processing devices, a first outline of the at least three fiducials in the first roentgenogram; and

receiving, using the one or more processing devices, a second outline of the at least three fiducials in the second roentgenogram;

wherein determining the first 3-D position of the x-ray source further comprises identifying a first plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the first plurality of paths; and

wherein determining the second 3-D position of the x-ray source further comprises identifying a second plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the second plurality of paths.

18. A method transforming a plurality of roentgenograms of an object into a 3-D model of the object using a data transformation server, the method comprising:

receiving, using one or more processing devices of the data transformation server and from an x-ray imager, a first roentgenogram of an object disposed between an x-ray source and the x-ray imager in a first orientation, wherein the first roentgenogram is generated by the x-ray imager, wherein the first orientation comprises a first angular position of the object relative to an imaging axis, wherein the first roentgenogram includes a first image of;

the object;

at least one reference marker having at least two fiducials, wherein the fiducials are separated by a fixed distance; and

at least one object marker attached to the object, wherein the object marker includes at least one fiducial of fixed dimensions;

receiving, using the one or more processing devices and from the x-ray imager, a second roentgenogram of the object disposed between the x-ray source and the x-ray imager in a second orientation, wherein the second roentgenogram is generated by the x-ray imager, wherein the second orientation comprises a second angular position of the object relative to the imaging axis, and wherein the second roentgenogram includes a second image of;

the object;

the at least one reference marker; and

the at least one object marker;

determining, using the one or more processing devices, a first 3-D position of the x-ray source with respect to the x-ray imager in the first orientation using the first image of the at least one reference marker;

determining, using the one or more processing devices, a second 3-D position of the x-ray source with respect to the x-ray imager in the second orientation using the second image of the at least one reference marker;

generating, using the one or more processing devices, a first 3-D object marker projection from the at least one object marker in the first roentgenogram to the first 3-D position of the x-ray source;

generating, using the one or more processing devices, a second 3-D object marker projection from the at least one object marker in the second roentgenogram to the second 3-D position of the x-ray source;

aligning, using the one or more processing devices, the first and second 3-D object marker projections in a 3-D reference frame using the first and second object marker projections;

identifying, using the one or more processing devices, a first object outline of the imaged object in the first roentgenogram

identifying, using the one or more processing devices, a second object outline of the imaged object in the second roentgenogram

generating, using the one or more processing devices, a first 3-D object projection from the first object outline to the first 3-D position of the x-ray source;

generating, using the one or more processing devices, a second 3-D object projection from the second object outline to the second 3-D position of the x-ray source;

aligning, using the one or more processing devices, the first and second 3-D object projections in the 3-D reference frame using the alignment of the first and second 3-D object marker projections in the 3-D reference frame; and

transforming, using the one or more processing devices, the first and second 3-D object projections into a 3-D model of the imaged object in the 3-D reference frame.

19. The method according to claim 18, the method further comprising:

identifying, using the one or more processing devices, a tilt axis in the 3-D reference frame, wherein the tilt axis passes between a first 3-D position in the 3-D reference frame that corresponds to the first position of the x-ray source in the first orientation and a second 3-D position in the 3-D reference frame that corresponds to the second position of the x-ray source in the second orientation;

identifying, using the one or more processing devices, one or more intersection planes passing through the tilt axis and through the first and second 3-D projections of the imaged object in the 3-D reference frame;

for each of the one or more intersection planes, performing the following steps a) through c);

a) identifying, using the one or more processing devices, one or more intersection points between the first and second 3-D object projections, and said intersection plane in the 3-D reference frame;

b) generating, using the one or more processing devices, one or more polygons connecting the intersection points in said intersection plane;

c) generating, using the one or more processing devices, one or more closed curves within the each of the one or more polygons, wherein the one or more closed curves corresponds to a cross-sectional view of the imaged object in said intersection plane; and

generating, using the one or more processing devices, a surface in the 3-D reference frame that connects each of the closed curves to form a 3-D model of the imaged object.

20. The method according to claim 18, wherein the at least one object marker includes at least three fiducials, wherein the fiducials are separated by fixed distances, and further wherein:

generating the first 3-D object marker projection further comprises generating a first 3-D projection of the at least three fiducials from the object marker in the first roentgenogram to the first 3-D position of the x-ray source;

generating the second 3-D object marker projection further comprises generating a second 3-D projection of the at least three fiducials from the object marker in the second roentgenogram to the second 3-D position of the x-ray source; and

aligning the first and second 3-D object marker projections in the 3-D reference frame further comprises determining 3-D locations of the at least three fiducials in the 3-D reference frame.

21. The method according to claim 20, wherein determining the 3-D locations of the at least three fiducials further comprises:

providing a plurality of mathematical solutions that may represent the 3-D locations of the at least three fiducials; and

receiving an instruction that selects one of the plurality of mathematical solutions to be the 3-D locations of the at least three fiducials.

22. The method according to claim 18, wherein the at least one object marker includes at least four fiducials, wherein the at least four fiducials are separated by fixed distances, and further wherein:

generating the first 3-D object marker projection comprises generating a first 3-D projection of the at least four fiducials from the object marker in the first roentgenogram to the first 3-D position of the x-ray source;

generating the second 3-D object marker projection comprises generating a second 3-D projection of the at least four fiducials from the object marker in the second roentgenogram to the second 3-D position of the x-ray source; and

aligning the first and second 3-D object marker projections in the 3-D reference frame further comprises determining 3-D locations of the at least four fiducials in the 3-D reference frame.

23. The method according to claim 22, wherein determining the 3-D locations of the at least four fiducials further comprises:

providing a plurality of mathematical solutions that may represent the 3-D locations of the at least four fiducials; and

determining the 3-D locations of the at least four fiducials according to a mathematical correlation between the plurality of mathematical solutions.

24. The method according to claim 18, wherein the at least one reference marker comprises at least three fiducials, the method further comprising:

receiving, using the one or more processing devices, a first outline of the at least three fiducials in the first roentgenogram; and

receiving, using the one or more processing devices, a second outline of the at least three fiducials in the second roentgenogram;

wherein determining the first 3-D position of the x-ray source comprises identifying a first plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the first plurality of paths; and

wherein determining the second 3-D position of the x-ray source comprises identifying a second plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the second plurality of paths.

25. The method according to claim 24, wherein determining the approximate intersection of the first plurality of paths and the approximate intersection of the second plurality of paths comprises using an approximation model.

26. The method according to claim 25, wherein using an approximation model further comprises determining the position of a first segment between the first plurality of paths and designating a point on the first segment to be the first 3-D position of the x-ray source.

27. The method according to claim 26, wherein the first segment is a common perpendicular of the first plurality of paths.

28. The method according to claim 26, wherein using an approximation model further comprises determining the position of a second segment between the second plurality of paths and designating a point on the second segment to be the second 3-D position of the x-ray source.

29. The method according to claim 28, wherein the second segment is a common perpendicular of the second plurality of paths.

30. The method according to claim 18, wherein the at least one object marker is directly attached to the object.

31. The method according to claim 18, wherein the at least one object marker is indirectly attached to the object.

32. The method according to claim 18, wherein the at least one reference marker is made of a radio-translucent material and the fiducials of the at least one reference marker are made of a radio-opaque material.

33. The method according to claim 18, wherein the at least one object marker is made of a radio-translucent material and the fiducial of the at least one object marker is made of a radio-opaque material.

34. A method of transforming a plurality of roentgenograms of an object into a 3-D model of the object using a data transformation server, the object being coupled to at least one ring of an orthopedic fixator, the at least one ring having a predetermined diameter, the method comprising:

receiving, using one or more processing devices of the data transformation server and from an x-ray imager, a first roentgenogram of an object disposed between an x-ray source and the x-ray imager in a first orientation, wherein the first roentgenogram is generated by the x-ray imager, wherein the first orientation comprises a first angular position of the object relative to an imaging axis, wherein the first roentgenogram includes a first image of;

the object;

at least one reference marker having at least two fiducials, wherein the fiducials are separated by a fixed distance; and

the ring;

receiving, using the one or more processing devices and from the x-ray imager, a second roentgenogram of the object disposed between the x-ray source and the x-ray imager in a second orientation, wherein the second roentgenogram is generated by the x-ray imager, wherein the second orientation comprises a second angular position of the object relative to the imaging axis, wherein the second roentgenogram includes a second image of;

the object;

the at least one reference marker; and

the ring;

determining, using the one or more processing devices, a first 3-D position of the x-ray source with respect to the x-ray imager in the first orientation using the first image of the at least one reference marker;

determining, using the one or more processing devices, a second 3-D position of the x-ray source with respect to the x-ray imager in the second orientation using the second image of the at least one reference marker;

receiving, using the one or more processing devices, a first ring outline of the imaged ring in the first roentgenogram;

generating, using the one or more processing devices, a first 3-D ring projection from the first ring outline in the first roentgenogram to the first 3-D position of the x-ray source;

determining, using the one or more processing devices, a first ring position from the x-ray imager in the first orientation using the first 3-D ring projection and the fixed diameter of the ring;

receiving, using the one or more processing devices, a second ring outline of the imaged ring in the second roentgenogram;

generating, using the one or more processing devices, a second 3-D ring projection from the second ring outline in the second roentgenogram to the second 3-D position of the x-ray source;

determining, using the one or more processing devices, a second ring position from the x-ray imager in the second orientation using the second 3-D ring projection and the fixed diameter of the ring;

determining, using the one or more processing devices, the 3-D position of the ring with respect to the x-ray imager in the first and second orientations using the first and second ring outlines and the first and second ring positions;

identifying, using the one or more processing devices, a first object outline of the imaged object in the first roentgenogram;

generating, using the one or more processing devices, a first 3-D object projection from the first outline of the imaged object to the first 3-D position of the x-ray source;

identifying, using the one or more processing devices, a second object outline of the imaged object in the second roentgenogram;

generating, using the one or more processing devices, a second 3-D object projection from the second outline of the imaged object to the second 3-D position of the x-ray source;

aligning, using the one or more processing devices, the first and second 3-D object projections in a 3-D reference frame using the 3-D positions of the ring with respect to the x-ray imager in the first and second orientations; and

transforming, using the one or more processing devices, the first and second 3-D object projections into a 3-D model of the imaged object in the 3-D reference frame.

35. The method according to claim 34, the method further comprising:

identifying, using the one or more processing devices, a tilt axis in the 3-D reference frame, wherein the tilt axis passes between a first 3-D position in the 3-D reference frame that corresponds to the first position of the x-ray source in the first orientation and a second 3-D position in the 3-D reference frame that corresponds to the second position of the x-ray source in the second orientation;

identifying, using the one or more processing devices, one or more intersection planes passing through the tilt axis and through the first and second 3-D projections of the imaged object in the 3-D reference frame;

for each of the one or more intersection planes, performing the following steps a) through c);

a) identifying, using the one or more processing devices, one or more intersection points between the first and second 3-D object projections, and said intersection plane in the 3-D reference frame;

b) generating, using the one or more processing devices, one or more polygons connecting the intersection points in said intersection plane;

c) generating, using the one or more processing devices, one or more closed curves within the each of the one or more polygons, wherein the one or more closed curves corresponds to a cross-sectional view of the imaged object in said intersection plane; and

generating, using the one or more processing devices, a surface in the 3-D reference frame that connects each of the closed curves to form a 3-D model of the imaged object.

36. The method according to claim 34, wherein the ring comprises a plurality of object markers being attached thereto, wherein the plurality of object markers each include at least one fiducial, and wherein:

receiving, using the one or more processing devices, the first ring outline comprises receiving an outline of the fiducial of each object marker in the first roentgenogram;

generating, using the one or more processing devices, the first 3-D ring projection comprises generating a projection of the fiducial of each object marker from the first ring outline in the first roentgenogram to the first 3-D position of the x-ray source;

determining, using the one or more processing devices, the first ring position comprises determining a first ring center location from the x-ray imager in the first orientation using the first 3-D ring projection and the fixed diameter of the ring;

receiving the second ring outline comprises receiving an outline of the fiducial of each object marker in the second roentgenogram;

generating, using the one or more processing devices, the second 3-D ring projection comprises generating a projection of the fiducial of each object marker from the second ring outline in the second roentgenogram to the second 3-D position of the x-ray source;

determining, using the one or more processing devices, the second ring position comprises determining a second ring center location from the x-ray imager in the second orientation using the second 3-D ring projection and the fixed diameter of the ring; and

determining, using the one or more processing devices, the 3-D position of the ring with respect to the x-ray imager in the first and second orientations comprises aligning the first and second ring center locations.

37. The method according to claim 36, wherein the plurality of object markers are disposed diametrically on the ring.

38. The method according to claim 36, wherein the at least one object marker is made of a radio-translucent material and the fiducial of the at least one object marker is made of a radio-opaque material.

39. The method according to claim 34, wherein the at least one reference marker comprises at least three fiducials in total, the method further comprising:

receiving, using the one or more processing devices, a first outline of the at least three fiducials in the first roentgenogram; and

receiving, using the one or more processing devices, a second outline of the at least three fiducials in the second roentgenogram;

wherein determining the first 3-D position of the x-ray source comprises identifying a first plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the first plurality of paths; and

wherein determining the second 3-D position of the x-ray source comprises identifying a second plurality of paths from the x-ray source to the first outline of the least three fiducials and determining an approximate intersection of the second plurality of paths.

40. The method according to claim 39, wherein determining the approximate intersection of the first plurality of paths and the approximate intersection of the second plurality of paths comprises using an approximation model.

41. The method according to claim 34, wherein the at least one reference marker is made of a radio-translucent material and the fiducials of the at least one reference marker are made of a radio-opaque material.