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: With a method for controlling the dose or dose rate when recording x-ray images by means of a detector comprising image elements which record a plurality of dose data values, an actual value is determined for the dose or dose rate from the totality of the data values recorded by the image elements of a predetermined image segment, said actual value being compared with a predetermined target value in order to control the dose or dose rate when recording a further x-ray image. In accordance with the invention, the actual value is determined such that on the basis of a frequency distribution of the dose data values of the image elements assigned to the dominant, a p-quantile is determined, and that the dose data value assigned to the p-quantile is used to determine the actual value.

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: A method and apparatus for guiding image reading for colon screening, includes calculating a centerline for a colon; scrolling through a succession of two dimensional (2D) cross-sectional images of a colon in respective image planes, such that a current image plane includes a respective current focus point formed by an intersection of the centerline with the current image plane. The method further includes performing a three-dimensional (3D) region growing process for growing a region of a suitable given thickness around a current seed point in a current image plane, the current seed point being at the respective current focus point in the current image plane, such that the region growing “floods” folds within a prescribed distance from the current seed point such that part of the region intersects the current image plane.

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 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 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 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 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: Apparatus for determining a proper insertion depth of a biopsy needle to be inserted at a selected point on the body of a patient so that a sampling end of the needle just reaches to a designated target area within the body, comprises at least one straight calibrated pointing device, having a pivot point at one end thereof, and aligned to point through the selected point in a straight line passing through the designated target region, an image of the pointing device being formed on each of first and second image planes by utilizing radiation from respective first and second radiation source positions, along with images corresponding to the selected point and the target area. Needles are provided for casting an image on one at least one of the image planes, the needles being pivotably mounted at a further pivot point different from the pivot point of the pointing device and being constrained for movement in plane defined by the pivot point, the further pivot point and by the pointing device.

Abstract: A method and system for displaying unseen areas in guided two dimensional (2D) colon screening, includes calculating segmentation and colon surface for a colon; calculating a centerline for the colon; designating as a current focus point a current point of intersection of a current portion of the centerline and a current cross-sectional image of a colon in a current image plane; and extracting a colon surface portion in a connected colon component containing the current focus point; and marking voxels of the colon surface portion as a “seen” area. Unseen areas of the colon surface are calculated by subtracting seen areas from the total colon area of observation. The unseen areas may then be displayed.

Abstract: A method and system for guiding imaging reading for colon screening includes scrolling through a succession of two dimensional (2D) cross-sectional images of a colon in respective image planes. A point of intersection with a current image plane with the centerline of the colon is marked in a first color in the current cross-sectional image. As the scrolling proceeds and a new current cross-sectional image in a respective image plane is observed. a new point of intersection is marked in the current cross-sectional image in the first color and the prior point of intersection is projected onto the new current cross-sectional image and marked in a second color.

Abstract: With a method for controlling the dose or dose rate when recording x-ray images by means of a detector comprising image elements which record a plurality of dose data values, an actual value is determined for the dose or dose rate from the totality of the data values recorded by the image elements of a predetermined image segment, said actual value being compared with a predetermined target value in order to control the dose or dose rate when recording a further x-ray image. In accordance with the invention, the actual value is determined such that on the basis of a frequency distribution of the dose data values of the image elements assigned to the dominant, a p-quantile is determined, and that the dose data value assigned to the p-quantile is used to determine the actual value.

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 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 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 virtual endoscopy in a lumen includes acquiring from a patient an imaging dataset exhibiting a lesion external to a lumen wall; deriving a three-dimensional (3-D) volume of the lesion; obtaining data on maximum bend characteristics for a given endoscope; and deriving projection criteria, based on the 3-D volume and the maximum bend, for projecting an endoluminal image of said lesion, indicating an optimal biopsy insertion point.

Abstract: Exemplary systems and methods for performing registration applications are provided. An exemplary system includes a central processing unit (CPU) for transferring a plurality of images to a graphics processing unit (GPU); wherein the GPU performs a registration application on the plurality of images to produce a registration result, and wherein the GPU returns the registration result to the CPU. An exemplary method includes the steps of transferring a plurality of images from a central processing unit (CPU) to a graphics processing unit (GPU); performing a registration application on the plurality of images using the GPU; transferring the result of the step of performing from the GPU to CPU.

Abstract: A system and method for creating a panoramic projection of a volumetric image of an object is disclosed. A virtual camera is placed in a center of a cubic space within the object. Images obtained from the camera are projected onto a single plane. A front image is mapped in a window at a center of the plane. A left, right, top and bottom image of the cubic space are mapped around the rectangular window such that the left, right, top and bottom images form a continuous image surrounding the rectangular window.