The State University of New York

Terarecon, Inc.

Hyland Switzerland Sarl

Viatronix Incorporated

Ingmar Bitter

Arie E Kaufman

Kevin Kreeger

Frank Dachille

Mark R Wax

Baoquan Chen

Ming Wan

Dongqing Chen

Randy B Osborne

Hanspeter Pfister

Hugh C Lauer

Zhengrong Liang

James M Knittel

Jerome Zhengrong Liang

Sameer Zaheer

Sarang Lakare

Zhenrong Liang

Sandra Stapleton

A method for segmenting a vessel from an image data that includes accessing the image data from which the vessel is segmented through a user display interface. A first seed point is then received from a user, the first seed point placed by the user on a first location on the image data. A second seed point is further received from the user, the second seed point placed by the user on a second location on the image data. The method further includes calculating a centerline for the vessel to be segmented, the centerline beginning at the first location and finishing at the second location as indicated by the first and the second seed points, respectively; calculating borders of the vessel to be segmented based on the centerline; and displaying an output of the vessel to be segmented using the centerline and the borders of the vessel, wherein the calculating the centerline comprises utilizing a minimum cost dual front propagation method that incrementally accumulates local vessel measures to determine a global optimal cost path and form the centerline.

System and methods of segmenting vessels from medical imaging data

Virtual navigation () and examination of virtual objects are enhanced using methods of insuring that an entire surface to be examined has been properly viewed. A user interface (FIG.) identifies regions which have not been subject to examination and provides a mechanism () to route the user to these regions in the 3D display. Virtual examination is further improved by the use of measuring disks () to enhance quantitative measurements such as diameter, distance, volume and angle. Yet another enhancement to the virtual examination of objects is a method of electronic segmentation, or cleaning, which corrects for partial volume effects occurring in an object.

Enhanced virtual navigation and examination

In accordance with the present invention, a method for determining a centerline through a region of interest in a 3D image dataset is provided. The method includes identifying the boundaries of the region of interest and identifying the endpoints of the region of interest. For those points within the boundaries, a penalty value which is a function of the proximity of the point to a boundary is determined. A centerline is then identified by the path connecting the endpoints which has the minimum penalized distance wherein the penalized distance reflects the actual accumulated pathlength and the penalties associated with the points along the path. From the centerline, branches of a complete skeleton can be established by determining branch endpoints and then finding the minimum penalized distance from each endpoint the centerline or another intersecting branch.

Centerline and tree branch skeleton determination for virtual objects

An apparatus and method for real-time volume processing and universal three-dimensional rendering. The apparatus includes a plurality of three-dimensional (3D) memory units; at least one pixel bus for providing global horizontal communication; a plurality of rendering pipelines; at least one geometry bus; and a control unit. The apparatus includes a block processor having a circular ray integration pipeline for processing voxel data and ray data. Rays are generally processed in image order thus permitting great flexibility (e.g., perspective projection, global illumination). The block processor includes a splatting unit and a scattering unit. A method for casting shadows and performing global illumination in relation to light sources includes sweeping a two dimensional array of rays through the volume can also be implemented with the apparatus. A method for approximating a perspective projection includes using parallel projection.

Apparatus and method for real-time volume processing and universal three-dimensional rendering

Methods for generating a centerline or skeleton structure within a 3D virtual object are provided. A first method defines a centerline based on distance from boundary values along points of the defined centerline. A second method uses a distance from boundary field to assign costs to voxels in the virtual object and defines a minimum cost spanning tree based on assigned costs. The centerline is defined along the minimum cost spanning tree. Branches along the centerline are identified and added to the centerline to define a skeleton.

Method of centerline generation in virtual objects

Apparatus and method for volume processing and rendering

An apparatus and method are provided for motion artifact detection and correction, where an apparatus includes a scanning device for receiving two-dimensional image slices of an object, a rendering device in signal communication with the scanning device for rendering a three-dimensional volume representation of the two-dimensional image slices, and a correction device in signal communication with the rendering device for correcting motion artifacts within the three-dimensional volume representation; and a corresponding method for detecting motion artifacts within scan data of a region comprising an object includes creating a three-dimensional representation with volume elements of the region based on the scan data, analyzing the volume elements along a boundary of the object, and determining the existence of a motion artifact in response to the analyzing.

Motion artifact detection and correction

An apparatus and method for real-time volume processing and universal three-dimensional rendering. The apparatus includes a plurality of three-dimensional (3D) memory units; at least one pixel bus for providing global horizontal communication; a plurality of rendering pipelines; at least one geometry bus; and a control unit. The plurality of rendering pipelines each preferably include hardware for interpolation, shading, FIFO buffering, communication and table lookups. The apparatus of the present invention may be coupled to a geometry pipeline for mixing surfaces, images and volumes together in a single image. A method for performing volumetric ray casting of a 3D volume includes the steps of calculating a distance along a major projection axis from a predefined viewpoint; dividing the volume into a plurality of consecutive regions having exponentially increasing bounds; casting a plurality of rays from the viewpoint through the volume; either merging two or more rays or splitting one or more rays at the region boundaries; and repeating the ray casting and merging/splitting steps until the entire volume has been processed. The apparatus and methods of the present invention achieve true real-time performance for high-resolution volume rendering, mixing surfaces and volumes in a single image, and accelerating other imaging operations, including texture mapping and image-based rendering.

Apparatus and method for real-time volume processing and universal 3D rendering

A volume rendering processor renders a two-dimensional image from a volume data set of voxels constituting a three-dimensional representation of an object. Voxel memory interface logic retrieves the voxels from a voxel memory in a scanned order with respect to X, Y and Z coordinate axes, the Z axis being the axis most nearly parallel to a predefined viewing direction. The set of voxels having equal Z coordinate values are referred to as a &ldquo;slice&rdquo; of voxels. Interpolation logic calculates a sequence of samples from the retrieved voxels such that (i) each sample lies along a corresponding imaginary ray extending through the object parallel to the viewing direction, (ii) each sample results from interpolating the eight voxels surrounding the sample in the XYZ coordinate system. &ldquo;Supersampling&rdquo; in the Z dimension is performed such that the number of samples calculated for each ray is greater than the number of slices of voxels in the volume data set. Gradient calculation logic calculates for each sample respective gradients in the X, Y and Z directions for use by classification and illumination logic. The X and Y gradients are calculated from the samples emitted by the interpolation logic, and Z gradients are calculated by (i) calculating Z gradients at the voxel positions from voxel values retrieved from memory, and (ii) interpolating the voxel Z gradients to arrive at the Z gradients at the sample positions.

Super-sampling and gradient estimation in a ray-casting volume rendering system

An apparatus and method for parallel and perspective real-time volume visualization. The method employs ray-slice-sweeping and includes the steps of selecting viewing and processing parameters; initializing a compositing buffer; sampling voxel values from a three dimensional memory buffer onto a current slice of sample points; combining the sample point values with pixels of the compositing buffer along a plurality of interstice ray segments which extend only between the current slice and an adjacent slice associated with the compositing buffer; and repeating the sampling and combining steps by subsequentially sweeping through subsequent slices of sample points parallel to the first processing slice until the last processing slice is reached. Each of the subsequent slices in turn becomes the current slice. The apparatus includes a three dimensional buffer; a pixel bus; a plurality of rendering pipelines; and a control unit. The plurality of rendering pipelines each include a first slice unit; a compositing unit; a two dimensional slice compositing buffer; and a first (preferably bilinear) interpolation unit. Sample point values are combined with pixels of the compositing buffer in the compositing unit along the plurality of interslice ray segments which extend only between a current slice contained in the slice unit and a slice contained in the two-dimensional slice compositing buffer. In the apparatus and method of the present invention, gradients are computed at voxel positions, improving accuracy and allowing for a more compact implementation with less control overhead than prior methods and apparatuses.

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Maple, Canada

Ingmar Bitter