System and method for image segmentation in generating computer models of a joint to undergo arthroplasty

A method of partitioning an image of a bone into a plurality of regions, the method comprising the acts of:

• using a medical imaging machine to obtain a plurality of volumetric image slices of the bone;
• using at least one computer to generate a plurality of spline curves associated with the bone;
• verifying that at least one of the plurality of spline curves follow a surface of the bone;
• and using at least one computer to generate a three dimensional (3D) mesh representation based upon the at least one of the plurality of spline curves, wherein at least one image slice within the plurality includes voxels that are distorted through voxel volume averaging.

A method of generating a representation of a model bone, the method comprising the acts of:

• obtaining an image scan of the representation as a plurality of slices;
• segmenting each slice in the plurality using one or more segmentation curves, wherein the act of segmenting excludes segmenting cartilage associated with the representation of the model bone;
• using at least one computer to generate a mesh of the representation;
• adjusting each slice in the plurality to include areas where the boundary area of the bone is stable between successive image scans;
• and using at least one computer to generate an anchor segmentation such that the anchor segmentation follows a boundary of the representation of the model bone.

A method of generating a representation of a model bone, the method comprising the acts of:

• obtaining an image scan of the representation as a plurality of slices;
• segmenting each slice in the plurality using one or more segmentation curves;
• using at least one computer to generate a mesh of the representation;
• adjusting each slice in the plurality to include areas where the boundary area of the bone is stable between successive image scans;
• and using at least one computer to generate an anchor segmentation such that the anchor segmentation follows a boundary of the representation of the model bone, wherein at least a portion of the representation of the model bone exists between two segmentation curves.

A method of generating a representation of a model bone, the method comprising the acts of:

• obtaining an image scan of the representation as a plurality of slices;
• segmenting each slice in the plurality using one or more segmentation curves;
• using at least one computer to generate a mesh of the representation;
• adjusting each slice in the plurality to include areas where the boundary area of the bone is stable between successive image scans;
• and using at least one computer to generate an anchor segmentation such that the anchor segmentation follows a boundary of the representation of the model bone, wherein osteophytes are excluded from the anchor segmentation.

A method of generating a representation of a model bone, the method comprising the acts of:

• obtaining an image scan of the representation as a plurality of slices;
• segmenting each slice in the plurality using one or more segmentation curves;
• using at least one computer to generate a mesh of the representation;
• adjusting each slice in the plurality to include areas where the boundary area of the bone is stable between successive image scans;
• using at least one computer to generate an anchor segmentation such that the anchor segmentation follows a boundary of the representation of the model bone;
• and repositioning a point on the one or more segmentation curves by comparing point placement of adjacent segmentation curves.

A method of segmenting a target bone using a representation of a model bone, the method comprising the acts of:

• registering a segmented form of the representation to an image scan of the target bone;
• refining the registration of the segmented form of the representation near a boundary of the target bone;
• using at least one computer to generate a mesh from the segmented form of the representation;
• and using at least one computer to generate a plurality of spline curves that approximate the intersection of the mesh and one or more slices from the image scan of the target bone, wherein the act of refining comprises averaging one or more voxels of adjacent slices.

A method for refining registration of a representation of a model bone to a target bone, the method comprising the acts of:

• using at least one computer to transform an anchor segmentation mesh;
• using at least one computer to generate a plurality of random points around the transformed anchor segmentation mesh;
• determining if each point in the plurality lies inside one or more of the following meshes:
• Inpark-OutLight, InLight-Outpark, or Dark-In-Light determining whether one or more of the plurality of points lie within a threshold distance of the surface of the transformed anchor segmentation mesh;
• and adding each point in the plurality as a dark point or light point depending upon whether the point lies within the Inpark-OutLight, InLight-Outpark, or Dark-In-Light meshes and to determine of the point lies inside or outside of the transformed anchor segmentation mesh, wherein the act of determining if each point lies within a threshold distance comprises the acts of:
• intersecting the anchor segmentation mesh with each image slice;
• noting one or more pixels of the image slice that intersect with the anchor segmentation mesh;
• and filtering the one or more pixels outside the threshold distance.