Abstract: This invention describes an optimization and view dependency reduction method for multiplanar reformatting (MPR) of slice-based volume images. This method utilizes a traversal scheme that allows for efficient access of the computer memory layout of a sliced based volume, and therefore optimizes overall processing time. This method does not require changes to the volume memory layout or additional volume memory. Instead, efficient memory access is achieved by adaptive traversal patterns on the reformatting planes. The traversal pattern is adapted on-the-fly during rendering as the reformatting plane location and orientation is changed arbitrarily relative to the volume. In this way, the typical speed differences between various reformatting planes orientations caused by inefficient memory access is greatly reduced. Computer cache coherency, SIMD coherent implementation, and multiprocessing environments are also considered in the design of the traversal pattern.

Abstract: Multiplanar reformatting visualization is provided with multiple scrolling speeds. A plurality of buffers is provided. Each buffer stores composites of data from different planes. The amount of compositing to generate a total composite for a visualization may be less since the division into partial composites may reduce addition and subtraction or other compositing operations. One level of partial composite buffers may be used. The total is recomputed for each visualization. In other embodiments, a hierarchal buffer structure is used. For example, a total composite buffer is provided in addition to the partial composite buffers. By re-compositing the partial composites before and after adjustment for scrolling increment from the total composite buffer, the total composite is updated for scrolling. Two or more levels of buffers may be used.

Abstract: Rendering with a punching mask is performed without voxelization. A plurality of sub-volumes are identified as a function of the punching mask. The sub-volumes are generally layered in range. Each sub-volume is rendered separately or independently. The renderings from multiple passes or sub-volumes are composited together.

Abstract: A method for rendering a deformable object. The method includes: obtaining a 3D volumetric voxel dataset of a region, such region having therein an object to be rendered; building a tree hierarchical structure for the obtained volumetric dataset, such tree structure blocks as the nodes of a primary tree hierarchy and bricks being those blocks stored as textures in a video memory; augmenting the primary tree hierarchical structure with maximum and minimum values of the data contained within a block; creating a neighborhood tree hierarchy having for each leaf block of the neighborhood tree hierarchy a reference to the neighboring leaf blocks in the neighborhood tree hierarchy as well as references to neighboring bricks in the neighborhood tree hierarchy; updating the information about minimum and maximum in the primary tree hierarchy by saving for each block the minimum and maximum of the neighboring blocks; and rendering the leaf blocks in visibility order.

Abstract: A system and method for automatically segmenting bone regions from Computed Tomography Angiography (CTA) volume data is disclosed. A locally operated bone detector distinguishes between bone regions and contrast agent filled vessels. A filtering operator removes small noise from the detected bone regions. A dilator expands the filtered detected bone regions to adjacent trabecular bones. A processor applies the dilated detected bone regions to the CTA volume data. A display shows the applied CTA volume data.

Abstract: A method for detecting and removing small isolated fragments in a 3D segmented volume is disclosed. The 3D segmented volume is projected onto several 2D images from different viewing directions. Isolated 2D fragments are detected in the 2D images. Corresponding 3D fragments are found in the 3D volume by unprojecting corresponding detected 2D fragment locations. The unprojected detected 2D fragment locations are used as seed points for region growing of isolated 3D fragments. Any of the 3D fragments having a volume size below a user-defined threshold are discarded.

Abstract: A recognition pipeline automatically partitions a 3D image of the human body into regions of interest (head, rib cage, pelvis, and legs) and correctly labels each region. The 3D image is projected onto a 2D image using volume rendering. The 3D image may contain the whole body region or any subset. In a learning phase, training datasets are manually partitioned and labeled, and a training database is computed. In a recognition phase, images are partitioned and labeled based on the knowledge from the training database. The recognition phase is computationally efficient and may operate under 2 seconds in current conventional computer systems. The recognition is robust to image variations, and does not require the user to provide any knowledge about the contained regions of interest within the image.

Abstract: The rendering pipeline is divided into multiple components or modules in a scene graph based visual programming environment. Different stages of the rendering pipeline, such as data conversion, transform function, shading, and rendering, are grouped into independent conceptual modules, and each module is implemented by separate nodes in a scene graph. The user may select different nodes belonging to different modules for inclusion into the scene graph to program the rendering pipeline. The visual program is implicitly compiled and run using an application programming interface for hardware acceleration.

Abstract: Artifact quantification is provided in volume rendering. Since the visual conspicuity of rendering artifacts strongly influences subjective assessments of image quality, quantitative metrics that accurately correlate with human visual perception may provide consistent values over a range of imaging conditions.

Abstract: Perception-based visual quality metrics are used in volume rendering. A perception-based visual quality metric is measured from one or more three-dimensional representations. For example, people tend to notice edges, so a numeric value representing the noticeable edges is calculated. The perception-based metric is used for developing volume renderers, calibrating across different renderers, calibrating across different rendering platforms, determining rendering parameter values as a function of rendering speed, selecting rendering parameter values for a given situation, providing a range of rendering options associated with gradual perception changes, and/or combinations thereof. The perception-based visual quality metric provides a quantifiable representation of importance to the user for a given application, assisting optimization of volume rendering.

Abstract: Multiplanar reformatting visualization is provided with multiple scrolling speeds. A plurality of buffers is provided. Each buffer stores composites of data from different planes. The amount of compositing to generate a total composite for a visualization may be less since the division into partial composites may reduce addition and subtraction or other compositing operations. One level of partial composite buffers may be used. The total is recomputed for each visualization. In other embodiments, a hierarchal buffer structure is used. For example, a total composite buffer is provided in addition to the partial composite buffers. By re-compositing the partial composites before and after adjustment for scrolling increment from the total composite buffer, the total composite is updated for scrolling. Two or more levels of buffers may be used.

Abstract: A region-based push-relabel formulation is disclosed that removes the requirement that the entire graph should fit into the computer memory and yields an implementation that can reduce the required size and redundancy of accesses to the data memory, thus improving speed performance, while allowing for an efficient parallel processing implementation. The algorithm assigns all vertices that are not part of the sources or sinks with a value of 1. Sinks are assigned with zeros and sources are assigned a label equal to the number of their vertices. The preflow is then pushed from the sources to their neighbors, if any. When the preflow has all reached the boundaries, an adjacent region of the neighboring set is selected and preflow is pushed within this region. When the values of the preflow have been exhausted, region relabeling is done to update the label values. This is repeated within the region until all preflow has exited to the boundary of this region.

Abstract: Rendering with a punching mask is performed without voxelization. A plurality of sub-volumes are identified as a function of the punching mask. The sub-volumes are generally layered in range. Each sub-volume is rendered separately or independently. The renderings from multiple passes or sub-volumes are composited together.

Abstract: This invention describes an optimization and view dependency reduction method for multiplanar reformatting (MPR) of slice-based volume images. This method utilizes a traversal scheme that allows for efficient access of the computer memory layout of a sliced based volume, and therefore optimizes overall processing time. This method does not require changes to the volume memory layout or additional volume memory. Instead, efficient memory access is achieved by adaptive traversal patterns on the reformatting planes. The traversal pattern is adapted on-the-fly during rendering as the reformatting plane location and orientation is changed arbitrarily relative to the volume. In this way, the typical speed differences between various reformatting planes orientations caused by inefficient memory access is greatly reduced. Computer cache coherency, SIMD coherent implementation, and multiprocessing environments are also considered in the design of the traversal pattern.

Abstract: A method for detecting and removing small isolated fragments in a 3D segmented volume is disclosed. The 3D segmented volume is projected onto several 2D images from different viewing directions. Isolated 2D fragments are detected in the 2D images. Corresponding 3D fragments are found in the 3D volume by unprojecting corresponding detected 2D fragment locations. The unprojected detected 2D fragment locations are used as seed points for region growing of isolated 3D fragments. Any of the 3D fragments having a volume size below a user-defined threshold are discarded.

Abstract: A system and method for automatically segmenting bone regions from Computed Tomography Angiography (CTA) volume data is disclosed. A locally operated bone detector distinguishes between bone regions and contrast agent filled vessels. A filtering operator removes small noise from the detected bone regions. A dilator expands the filtered detected bone regions to adjacent trabecular bones. A processor applies the dilated detected bone regions to the CTA volume data. A display shows the applied CTA volume data.