Abstract: A method for modeling a 2-dimensional tubular structure in a digitized image includes providing a digitized image of a tubular structure containing a plurality of 2D balls of differing radii, initializing a plurality of connected spline segments that form an envelope surrounding the plurality of 2D balls, each the spline segment Si being parameterized by positions of the ith and i+1th balls and contact angles ?i, ?i+1 from the center of each respective ball to a point on the perimeter of each the ball contacting the spline segment Si, each the ?i affecting spline segment Si and Si?1, and updating the angles by minimizing an energy that is a functional of the angles, where the updating is repeated until the energy is minimized subject to a constraint that the envelope is tangent to each ball at each point of contact, where the envelope is represented by the contact angles.

Abstract: A method for segmenting intravascular images includes acquiring a series of digitized images acquired from inside a vessel, each said image comprising a plurality of intensities corresponding to a 2-dimensional grid of pixels, providing a precomputed set of shapes for modeling contours of vessel wall boundaries, wherein a contour can be expressed as a sum of a mean shape and a inner product of shape modes and shape weights, initializing a boundary contour for one of said set of images, initializing said shape weights by projecting a contour into said shape modes, updating said shape weights from differential equations of said shape weights, and computing a contour by summing said mean shape and said inner product of shape modes and updated shape weights.

Abstract: A method and system for lymph node segmentation in computed tomography (CT) images is disclosed. A location of a lymph node in a CT image slice is received. Intensity constraints are determined based on a histogram analysis of the CT image slice, and a spatial analysis of the intensity constrained CT image slice is performed using edge detection. An initial contour is estimated based on the lymph node location and the spatial analysis. The lymph node is then segmented by propagating the initial contour using an evolving elliptical model to define the lymph node boundaries.

Abstract: Certain exemplary embodiments can comprise a method, which can comprise, automatically determining a target object from an image via an application of an iterative minimization algorithm to an energy function. Each iteration of the iterative minimization algorithm can comprise a comparison of a model with an estimated contour of the target object.

Abstract: A method identifying apertures of ear impressions is disclosed. A plurality of contour lines associated with an ear impression are determined and a difference value between a value of a characteristic, such as the diameter, of each contour line and that characteristic of an adjacent contour line is determined. The aperture is identified as being that contour line having the greatest difference value. The contour lines are determined by identifying where a plane intersects the surface of the graphical representations. In another embodiment, the contour lines are assigned a weight. A contour index is then calculated for each contour line as a function of the difference value and these weights. According to this embodiment, the aperture is identified as being a contour line that is adjacent to that contour line having the greatest contour index.

Abstract: A method of tracking a guidewire in video imagery includes: obtaining a first video image including pixels associated with features of a guidewire; selecting a set of parameters to define an open curve on the first video image; determining a feature map of the first video image using phase congruency; and updating the parameters of the open curve using the feature map to align the open curve to the pixels associated with the features of the guidewire.

Abstract: A method and apparatus for automatically detecting stent struts in an image is disclosed whereby the inner boundary, or lumen, of an artery wall is first detected automatically and intensity profiles along rays in the image are determined. In one embodiment, detection of the lumen boundary may be accomplished, for example, by evolving a geometric shape, such as an ellipse, using a region-based algorithm technique, a geodesic boundary-based algorithm technique or a combination of the two techniques. Once the lumen boundary has been determined, in another embodiment, the stent struts are detected using a ray shooting algorithm whereby a ray is projected outward in the OCT image starting from the position in the image of the OCT sensor. The intensities of the pixels along the ray are used to detect the presence of a stent strut in the image.

Abstract: A system and method for segmentation of anatomical structures in MRI volumes using graph cuts is disclosed. In this method, a template is registered to an MRI brain volume. The template identifies seed points of anatomical brain structures, such as the cerebrum, the cerebellum, and the brain stem, in the MRI brain volume. Any or all of the anatomical brain structures can be segmented using graph cuts segmentation initialized based on the seed points identified by the template. It is possible to segment each of the anatomical brain structures by performing a hierarchical three-phase segmentation process including brain/non-brain segmentation, cerebrum/cerebellum and brain stem segmentation, and cerebellum/brain stem segmentation.

Abstract: A method and apparatus for rounding a sharp edge of a model of an object is disclosed whereby a ball is propagated in a desired direction along the edge to be smoothed. The position of the ball at each point in its propagation is noted and, as a result, a virtual tunnel through which the ball passed may be constructed. Points on the sides of the surface of the object in proximity to the sharp edge are then projected onto the virtual tunnel by connecting with a line each point in proximity to the sharp edge to the center of the tunnel. New projected points are created at each position on the surface of the tunnel where the lines intersect that surface. The original points along the sharp edge are then hidden or deleted and the points along the virtual tunnel are connected via well-known surface reconstruction methods. In this way, a sharp edge of a triangle mesh model are advantageously smoothed.

Abstract: A method and apparatus for generating a three dimensional representation of an ear canal are disclosed whereby an ear canal of a patient is imaged using optical coherence tomography (OCT). In a first embodiment, cross-section images of an ear canal are taken by, for example, rotating an OCT imaging sensor about a predetermined axis at each of a plurality of positions. In accordance with another embodiment, a contour line is then identified in each of the cross section images and a flow algorithm is used to identify the boundary of the ear canal cross section. Once the boundaries of each cross section have been identified, all of the cross section images are combined to generate a three dimensional image of the ear canal.

Abstract: A method and apparatus is disclosed whereby a point on an ear impression model to be labeled is selected and a shape context is determined for that point. This shape context is then compared to average shape contexts for different regions on a reference ear impression model, also referred to herein as an ear impression shape atlas. A cost function is used to determine the minimum cost between the shape context for the selected point and one of the average shape contexts. Once the minimized cost is determined, the region label corresponding to the average shape context having a minimized cost is assigned to that point. In this way, points on the surface of an ear impression are classified and labeled as being located in regions corresponding to the regions on the ear impression shape atlas.

Abstract: Disclosed is a method and system for propagating information about an image to segment a target structure. An input to denote a region of interest of the image containing the target structure is received. A first seed is set outside of the target structure and a second seed is set inside the target structure. A first partial differential equation (PDE) associated with the first seed is solved and a second PDE associated with the second seed is solved to segment the image.

Abstract: A method for registering two three-dimensional shapes is disclosed whereby the two shapes are represented as zero level set of signed distance functions and the energy between these two functions is minimized. In a first embodiment two undetailed ear impression models are rigidly registered with each other. In another embodiment, a detailed ear impression is initially aligned with an undetailed ear impression model and, then, the detailed ear impression model is rigidly registered with the undetailed ear impression model as a function of said signed distance functions. In accordance with another embodiment, an undetailed ear impression model is non-rigidly registered with a template ear impression model as a function of said signed distance functions.

Abstract: A method of designing hearing aid molds is disclosed whereby skeletons, o r simplified models, of two ear impressions are used to register the graphical representations of the molds to facilitate the joint design of hearing aid shells. The center points of at least a portion of contour lines on the surface of each ear impression are identified. Then, for each ear impression, by connecting these center points to each adjacent center point, a skeleton that represents a simplified model of an ear impression is generated. Vectors describing the distance and direction from the points of each skeleton to an anatomical feature of each ear impression are identified to obtain a correspondence between the points of each skeleton. Three-dimensional translations and rotations of a feature vector of at least one of the skeletons are determined to achieve alignment of the skeleton of one ear impression with the skeleton of another impression.

Abstract: A method of designing hearing aid molds is disclosed whereby two shapes corresponding to graphical images of ear impressions are registered with each other to facilitate joint processing of the hearing aid design. In a first embodiment, a first graphical representation of a first ear impression is received and a feature, such as the aperture of the ear impression, is identified on that graphical model. A first vector is generated that represents the orientation and shape of that first feature. The three-dimensional translation and rotation of that first vector are determined that are necessary to align the first vector with a second vector representing the orientation and a shape of a feature, once again such as the aperture, of a second ear impression. In another embodiment, this alignment is then refined by minimizing the sum of the distances between points on the first and second graphical representations.

Abstract: An improved method of designing hearing aid molds is disclosed whereby regions of an ear impression model are identified as a function of a geodesic distance measure. According to a first embodiment, a canal point of an ear impression model is identified as that point having a maximum normalized geodesic distance as compared to all other points on the surface of the ear impression model. According to a second embodiment, a helix point of the ear impression model is identified as that point having a maximum normalized geodesic distance as compared to all points except those points in the canal region of said ear impression model. Finally, in accordance with another embodiment, a geodesic distance between a canal point and a helix point of an ear impression model is identified and a percentage threshold, illustratively 65%, is applied to that geodesic distance to identify a crus region.

Abstract: A system and method for graph cut image segmentation using a shape prior is provided. In this method, an initial shape is applied to a portion of an image to be segmented. A narrowband is formed around a border of the shape, and a minimized graph cut is calculated for a portion of the image within the narrowband. The shape is then adjusted using the shape prior to fit the minimized graph cut. This method can be iteratively performed so that the shape evolves to segment an object from an image. The shape prior can be a parametric shape, such as an ellipse, or a statistical shape eigenspace calculated based on one or more training shapes.

Abstract: A computer-implemented method for vertebrae segmentation includes providing an image of a plurality of vertebrae, and determining a seed in each of at least two adjacent vertebrae in the image. The method further includes mapping a unit square to the seeds in the image as corresponding shape constraints on a segmentation, evolving the shape constraints to determine the segmentation of the adjacent vertebrae, wherein evolutions of the shape constraints interact, and outputting a segmented image indicating a location of the vertebra.

Abstract: An exemplary method of detecting a structure in a three-dimensional (3D) computed tomography (“CT”) knee image is provided. An intensity prior mask is created based on a two-dimensional (2D) slice of the CT image. A seed point in the 2D slice is received or estimated. The seed point is in a Hoffa's pad region. A geometric prior mask is created based on the seed point. The intensity prior mask and the geometric mask are combined to form a region mask. A level-set contour is segmented from the 2D slice. The step of segmenting is constrained by the region mask.

Abstract: A method for joint segmentation and registration of a contour for detecting an object in image data includes initializing a segmentation, initializing a registration of the segmentation, updating the segmentation and the registration, outputting an updated segmentation and an updated registration, wherein the updated segmentation and updated registration delineates the object in the image data.