Method and system for image analysis

1. A system for assessing fracture risk of bone of a subject, the bone comprising a plurality of bone compartments, the system comprising:

a CT scanner configured to generate a CT image of a bone, wherein the CT scanner is configured to transmit the image to an image processor configured to perform an analysis of the image;

an output device configured to receive from the image processor at least one result of the analysis of the image;

wherein the at least one result of the analysis is generated by the image processor with a method comprising:

(i) automatically defining a plurality of regions of interest within the image that include junctions between a first and a second of the compartments, each of said regions of interest having a width of one or more pixels or voxels;

(ii) determining respective profiles of density, intensity or attenuation within the regions of interest, each of the respective profiles crossing the respective junctions;

(iii) automatically identifying the material of interest in the profiles;

(iv) analysing said profiles by automatically defining, for each of said profiles, a series of sections of said respective profile, each of said sections comprising at least one S-like portion of the respective profile, the S-like portion containing a respective junction; and

(v) locating the junction in each of the S-like portions, including: (a) identifying the greatest difference in values of the respective profile between an adjacent peak and trough in a segment of the respective profile that includes at least some of the first and second compartments; and (b) locating a point of inflexion in said segment.

2. A system as claimed in claim 1 , wherein the image processor is configured to determine any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2);

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico-trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or more indices or parameters so determined.

3. A system for assessing fracture risk of bone of a subject, the system comprising:

a CT scanner configured to generate a CT image of a bone, the bone comprising a plurality of bone compartments, wherein the CT scanner is configured to transmit the image to an image processor configured to perform an analysis of the image;

an output device configured to receive from the image processor at least one result of the analysis of the image;

wherein the at least one result of the analysis is generated by the image processor with a method comprising:

defining a plurality of regions of interest within the image that include junctions between a first and a second of the compartments, each of said regions of interest having a width of one or more pixels or voxels;

determining respective density, intensity or attenuation profiles within the regions of interest; and

determining a location of the junctions including defining a first reference point (xi, 0) within one of said first and second compartments and employing the first reference point as current reference point, and

(i) determining a closest point to said current reference point that is on said respective profile and in the other of said first and second compartments to that of the current reference point;

(ii) locating a greatest difference in values of the respective profile between an adjacent peak and trough in a segment of the respective profile between said current reference point and said closest point; and

(iii) locating a point of inflexion in said segment.

4. A system as claimed in claim 3 , wherein the image processor is configured to determine any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2);

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject to resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico-trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or more indices or parameters so determined.

5. A computer-implemented method of detecting fracture-vulnerable bone of a subject, of assessing a structure of bone of a subject, of diagnosing the effects of a disease or abnormality in a subject, of monitoring the effects of a disease or abnormality in a subject, of quantifying the effects of a treatment of a subject, of detecting fracture-vulnerable bone of a subject or of assessing a structure of bone of a subject, the bone comprising a plurality of bone compartments, the method comprising:

generating with a CT scanner a CT image of a bone;

transmitting the image to an image processor configured to perform an analysis of the image; and

receiving from the image processor at least one result of the analysis of the image;

wherein the at least one result of the analysis is generated by the image processor with a method comprising:

(i) automatically defining a plurality of regions of interest within the image that include junctions between a first and a second of the compartments, each of said regions of interest having a width of one or more pixels or voxels;

(ii) determining respective profiles of density, intensity or attenuation within the regions of interest, each of the respective profiles crossing the respective junctions;

(iii) automatically identifying the material of interest in the profiles;

(iv) analysing said profiles by automatically defining, for each of said profiles, a series of sections of said respective profile, each of said sections comprising at least one S-like portion of the respective profile, the S-like portion containing a respective junction; and

(v) locating the junction in each of the S-like portions, including: (a) identifying the greatest difference in values of the respective profile between an adjacent peak and trough in a segment of the respective profile that includes at least some of the first and second compartments; and (b) locating a point of inflexion in said segment.

6. A method as claimed in claim 5 , wherein said analysis includes determining any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2);

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject to resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or more indices or parameters so determined.

7. A method as claimed in claim 5 , including transmitting the image to the image processor via a communications link or network.

8. A method as claimed in claim 5 , including diagnosing an abnormality in the bone.

9. A system configured to implement the method of claim 5 , the system comprising:

a CT scanner configured to generate a CT image of a bone, wherein the CT scanner is configured to transmit the image to an image processor configured to perform said analysis of the image; and

an output device configured to receive from the image processor said at least one result of said analysis of the image.

10. A system as claimed in claim 9 , wherein the image processor is configured to determine any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2),

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject to resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico-trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or snore indices or parameters so determined.

11. A computer-implemented method of detecting fracture-vulnerable bone of a subject, of assessing a structure of bone of a subject, of diagnosing the effects of a disease or abnormality in a subject, of monitoring the effects of a disease or abnormality in a subject, of quantifying the effects of a treatment of a subject, of detecting fracture-vulnerable bone of a subject or of assessing a structure of bone of a subject, the bone comprising a plurality of bone compartments, the method comprising:

generating with a CT scanner a CT image of a bone;

transmitting the image to an image processor configured to perform an analysis of the image; and

receiving from the mage processor at least one result of the analysis of the image;

wherein the at least one result of the analysis is generated by the image processor with a method comprising:

defining a plurality of regions of interest within the image that include junctions between a first and a second of the compartments, each of said regions of interest having a width of one or more pixels or voxels;

determining respective density, intensity or attenuation profiles within the regions of interest; and

determining a location of the junctions including defining a first reference point (xi, 0) within one of said first and second compartments and employing the first reference point as current reference point, and

(i) determining a closest point to said current reference point that is on said respective profile and in the other of said first and second compartments to that of the current reference point;

(ii) locating a greatest difference in values of the respective profile between an adjacent peak and trough in a segment of the respective profile between said current reference point and said closest point; and

(iii) locating a point of inflexion in said segment.

12. A method as claimed in claim 11 , wherein said analysis includes determining any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2);

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject to resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico-trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or more indices so determined.

13. A method as claimed in claim 11 ; including transmitting the image to the image processor via a communications link or network.

14. A method as claimed in claim 11 , including diagnosing an abnormality in the bone.

15. A system configured to implement the method of claim 11 , the system comprising:

a CT scanner configured to generate a CT image of a bone, wherein the CT scanner is configured to transmit the image to an image processor configured to perform said analysis of the image; and

an output device configured to receive from the image processor said at least one result of said analysis of the image.

16. A system as claimed in claim 15 , wherein the image processor is configured to determine any one or more indices or parameters from the group consisting of:

a fat proportion;

a fat burden;

a ratio of total cross section area to endocortical perimeter;

decay of the compact cortex (CD1);

decay of the trabecularized cortex (CD2);

a thickness of a cortex of the bone, of a trabecularized cortex of the bone or of a transition zone therebetween;

a cortical area or an area of the trabecularized cortex;

a porosity of the cortex, of the trabecularized cortex, or of the transition zone;

whether the cortex or the trabecularized cortex is normal;

whether the cortex or the trabecularized cortex has been subject to resorption;

trabecular architecture and porosity;

percentage compact cortex;

percentage trabecularized cortex;

percentage cortico-trabecular junction;

apparent porosity of the compact cortex;

apparent porosity of the trabecularized cortex;

cortical fragility index; and

one or more indices indicative of at least a portion of the bone and adapted to identify abnormality within the bone;

wherein the at least one result of the analysis includes the one or more indices so determined.