Abstract: A system and method for performing a virtual endoscopy in a branching structure is provided. The method comprises the steps of: determining an initial viewpoint and viewing direction of a virtual endoscope in a branching structure; casting a plurality of rays from the initial viewpoint along the viewing direction; and determining an occurrence of a branch in the branching structure, wherein the occurrence is associated with a cluster that corresponds to the branch.

Abstract: A system and method for determining a location and a direction for viewing a protrusion, comprising: casting a plurality of rays in an outward direction from a point, wherein the point is inside a protrusion; selecting at least one of the plurality of rays for determining a location and a direction for viewing the protrusion; and determining the location and the direction for viewing the protrusion using the selected at least one of the plurality of rays.

Abstract: A system and method for endoscopic path planning is provided. The method comprises: identifying a target in a lung, wherein the target is located in a peripheral airway of the lung; generating an endoscopic path to the target, wherein a peripheral artery is used as a surrogate for the peripheral airway; and viewing the endoscopic path.

Abstract: A method for registration of virtual endoscopy images in first and second patient positions comprises performing colon segmentation and feature extraction, including centerline and colon surface data for each of the images; resampling the centerline and colon surface data; computing respective local descriptors; pairing point correspondences on the centerlines between the first and second images by minimal cost matching; extrapolating the centerline point correspondences to a 3-dimensional/3-dimensional (3D/3D) transformation between the first and second images. The method also includes selecting a position for a virtual endoscope in one of the images; associating an orthogonal reference frame with the virtual endoscope; and applying the 3D/3D transformation to the orthogonal reference frame so as to derive a corresponding transformed reference frame for the virtual endoscope in the other of the images.

Abstract: A method for automatic centerline extraction for a virtual endoscopy image of an organ having a boundary surface includes centering on selected points of an initial path through the image, which is derived from an endoscopy dataset, respective spheres exhibiting respective maximal diameters short of contacting the boundary surface; and forming a centered path consecutively joining centers of the spheres.

Abstract: A method for automatically setting a rendering parameter for a virtual endoscope for rendering images for virtual endoscopy, comprises deriving a data set corresponding to an inside view of a viewing frustum of the endoscope; calculating a histogram from the data set; correlating features of the histogram with known physical regions wherein the endoscope is situated; and selecting a transfer function positioned relative to the features of the histogram for providing image differentiation between respective rendered images of the physical regions in the images.

Abstract: In a method and apparatus for determining and documenting, from current x-ray image data, x-ray exposure values employed for producing an x-ray exposure or a sequence of x-ray exposures by irradiation of a radiation detector with x-rays form an x-ray diagnostic source, an exposed image region of the radiation detector is determined, and a region of interest within the exposed image region also is determined. An x-ray image exposure value is determined from the grey scale values of the pixels in the region of interest. The x-ray image exposure value is normalized with respect to a signal value. Measurement values employed for producing the exposed image region are independently measured, and, using these measurement values, the normalized value is converted into a physical unit. The physical unit is stored, associated with the measurement values, for documentation.

Abstract: A method is for the compensation of image disturbances in the course of a radiation image recording caused by a defocusing of an antiscatter grid, arranged in the beam path between a beam source and a digital radiation image receiver and focused with respect to a specific distance from the focus of the beam source. Such image disturbances are caused by a defocusing-dictated attenuation of the primary radiation incident on the radiation image receiver. A solid-state image detector includes radiation-sensitive pixels arranged in matrix form and a device for pixelwise amplification of the radiation-dependent signals. In the method, at least some of the signals supplied in pixelwise fashion are amplified by an amplifying device in a manner dependent on the actual distance of the antiscatter grid from the focus.

Abstract: A method for automatic local path planning for a virtual endoscope comprises the steps of defining a sub volume around a current endoscope position in a lumen; performing a region growing inside the lumen, starting from the current endoscope position; calculating and clustering the intersection of the region with the faces of a cube circumscribing the sub volume; calculating approximated centerline paths from the current endoscope position to the center of each cluster formed in the preceding step; comparing each of the centerline paths with a current path exhibited by the endoscope; and selecting an optimal centerline path based on the comparison.

Abstract: A system and method for performing a virtual endoscopy is provided. The method comprises the steps of: calculating a distance map using three-dimensional (3D) data of a lumen; calculating a multiplanar reconstruction (MPR) of the lumen, wherein the MPR is calculated orthogonal to the lumen at an endoscope position; performing a first region growing on the MPR of the lumen at the endoscope position, wherein data associated with the first region is marked; calculating a minimum distance and a maximum distance from the marked data of the first region growing using corresponding distances from the distance map; performing a second region growing on the MPR of the lumen for data outside the first region growing, wherein data associated with the second region is marked; and performing a 3D rendering of the marked data associated with the first region growing and the second region growing.

Abstract: A method for determining the best entry point for a percutaneous procedure, such as with a biopsy needle, comprises selecting first and second arbitrary entry points on a patient; determining the three dimensional (3-D) orientation of the needle at the first arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the first arbitrary entry point for pointing the needle at the secondary target; determining the 3-D dimensional orientation of the needle at the second arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the second arbitrary entry point for pointing the needle at the secondary target; determining a 3-D line representing the intersection of a first plane containing the first arbitrary entry point, the primary target point, and the secondary target point, and a second plane containing the second arbitrary entry point, the primary target, and the secondary target point, whereb

Abstract: A method for determining the best entry point for a percutaneous procedure, such as with a biopsy needle, comprises selecting first and second arbitrary entry points on a patient; determining the three dimensional (3-D) orientation of the needle at the first arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the first arbitrary entry point for pointing the needle at the secondary target; determining the 3-D dimensional orientation of the needle at the second arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the second arbitrary entry point for pointing the needle at the secondary target; determining a 3-D line representing the intersection of a first plane containing the first arbitrary entry point, the primary target point, and the secondary target point, and a second plane containing the second arbitrary entry point, the primary target, and the secondary target point, whereb

Abstract: A method for determining the best entry point for a percutaneous procedure, such as with a biopsy needle, comprises selecting first and second arbitrary entry points on a patient; determining the three dimensional (3-D) orientation of the needle at the first arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle: at the first arbitrary entry point for pointing the needle at the secondary target; determining the 3-D dimensional orientation of the needle at the second arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the second arbitrary entry point for pointing the needle at the secondary target; determining a 3-D line representing the intersection of a first plane containing the first arbitrary entry point, the primary target point, and the secondary target point, and a second plane containing the second arbitrary entry point, the primary target, and the secondary target point, where

Abstract: A method for providing a virtual contrast agent for blood vessels in a body portion for angioscopy comprising deriving data from a 3D model using, for example, magnetic resonance imaging, computerized tomography (CT), and 3D angio. The data is segmented to provide a segmented 3D model of the blood vessels. A first procedure image is made with a contrast agent present. The 3D model is then registered with the first procedural image and “virtual camera parameters” are obtained. The 3D model is rendered and overlaid onto a second procedure image without contrast, whereby a virtual contrast is achieved.

Abstract: A method for navigating a viewpoint of a virtual endoscope in a lumen of a structure is provided. The method includes the steps of (a)determining an initial viewpoint of the virtual endoscope, the initial viewpoint having a first center point and first direction; (b)determining a longest ray from the initial viewpoint to the lumen, the longest ray having a first longest ray direction; (c)determining a second direction between the first direction of the initial viewpoint and the first longest ray direction; (d)turning the viewpoint to the second direction and moving the initial viewpoint a first predetermined distance in a first direction of the initial viewpoint; (e)calculating a second center point of the viewpoint; (f)moving the viewpoint to the second center point; and repeating steps (b) through (f) until the viewpoint reaches an intended target.

Abstract: A system for reviewing a plurality of images, at least one image including a marker, is provided. The system includes a display for displaying the plurality of images sequentially; a cursor control device for controlling a speed of the sequentially displayed images, the cursor control device including a feedback mechanism; and a processor for receiving a direction control signal from the cursor control device and presenting the sequence of images to the display in the determined direction, and for determining if any image in the sequence has a marker, wherein if a marker is detected, the processor outputs a feedback signal to the feedback mechanism of the cursor control device to indicate to a user to review the image. Similarly, a method for reviewing a plurality of images at high speed is also provided.

Abstract: A method for determining a gesture includes determining a change in a background of an image from a plurality of images, determining a object in the image, determining a trajectory of the object through the plurality of images, and classifying a gesture according to the trajectory of the object.

Abstract: A method for determining the best entry point for a percutaneous procedure, such as with a biopsy needle, comprises selecting first and second arbitrary entry points on a patient; determining the three dimensional (3-D) orientation of the needle at the first arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the first arbitrary entry point for pointing the needle at the secondary target; determining the 3-D dimensional orientation of the needle at the second arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the second arbitrary entry point for pointing the needle at the secondary target; determining a 3-D line representing the intersection of a first plane containing the first arbitrary entry point, the primary target point, and the secondary target point, and a second plane containing the second arbitrary entry point, the primary target, and the secondary target point, whereb

Abstract: A computer-controlled method for automatically positioning a guide for a biopsy needle for its proper insertion into the body of a patient from a selected point on a surface of the body, so as to enter in a straight line passing through a designated target region within the body, in conjunction with an imaging system utilizing radiation from first and second source positions for deriving first and second radiographic images.

Abstract: A method for rendering volume data as texture maps on top of polyhedral surfaces is provided. Initially, a region of interest (roi) to be rendered must be selected. The selection of a region of interest is done using simple segmentation. The polyhedral surface of this segmentation is used to sample the volume data at a specified depth. The result of the sampling is converted into texture maps that are rendered on the segmented surface.