Abstract: A two-step 3D Radon inversion processor for processing Radon data on a set of vertically oriented co-axial .phi.-planes that partition Radon space, wherein each of the .phi.-planes is sampled during the processing so as to have its own independent local Radon origin. In accordance with further principles of the present invention, a 3D Radon data generator generates Radon data on a set of vertically oriented co-axial .phi.-planes that partition Radon space, wherein each of the .phi.-planes is sampled so as to have its own independent local Radon origin, and a two-step 3D Radon inversion processor independently processes each of the .phi.-planes. Any shift of the local Radon origins with respect to a global coordinate system is compensated for during the 3D Radon inversion processing. Compensation for the origin shift may be made during or after a first step of the Radon inversion processing.

Abstract: A method and apparatus for reconstructing an image of an object using a three dimensional (3D) computerized tomographic (CT) imager having a cone beam radiation source and detector arrangement for acquiring measurement data. The source and detector arrangement is operated at a plurality of source positions along a spiral scan path so as to acquire a corresponding plurality of sets of measurement data representative of radiation attenuation caused by the object. Image reconstruction processing information required for processing of the acquired measurement data in a Radon space partitioned by plurality of vertically oriented coaxial .phi.-planes for reconstructing the image, is pre-calculated and stored in a hitlist. The stored information is pre-calculated on less that all of the .phi.-planes, but due to a symmetry that is induced in the reconstruction processing, the stored information can be used for calculating Radon data for all of the .phi.-planes that partition the Radon space.

Abstract: A scanning and data acquisition technique for three dimensional (3D) computerized tomographic (CT) imaging of an object, wherein scanning at a plurality of positions along a source scanning trajectory causes an area detector to acquire cone beam projection data corresponding to a shadow of said object at each of scanning positions and Radon derivative data is calculated by processing line integral values from cone beam projection data. In order to improve the calculation efficiency of the Radon derivative calculation, calculation of the Radon derivative data uses a determination of the left and right boundaries of the shadow for each of the scanning positions, and calculates the Radon derivative data only using projection data from within the determined boundaries.

Abstract: A method and apparatus for reconstructing an image of an object using a three dimensional (3D) computerized tomographic (CT) imager having a cone beam radiation source and detector arrangement for acquiring measurement data. Before the acquisition of measurement data during an imaging operation of the apparatus, image reconstruction processing information dependant on the geometric parameters of the imager and required for processing of the acquired measurement data for developing contributions to the final reconstruction of the image, is pre-calculated and stored. During an imaging operation of the apparatus, the acquired measurement data is processed using the pre-calculated image reconstruction processing information for reconstructing the image.

Abstract: A technique for object information extraction from images which retains fuzziness as realistically as possible. The technique is used for image segmentation of fuzzy objects for n-dimensional digital spaces based on the notion of "hanging togetherness" of image elements specified by their fuzzy connectedness. A specified fuzzy object is extracted and all fuzzy objects present in the image data are identified by segmenting the image using the notion of "hanging togetherness" of image elements specified by their fuzzy connectedness as defined herein. The technique is used in a preferred embodiment to quantify MS lesions of the brain via magnetic resonance imaging.