Abstract: A method and apparatus are provided for three dimensional computerized tomographic imaging of an object, wherein cone beam energy from a cone beam source is applied to at least a portion of an object to be imaged by causing relative rotational motion between the source and the object at a plurality of source positions along a path scanning trajectory. An area detector receives cone beam energy from the source on a plurality of detector elements arranged in an array of rows and columns, so that its detector elements develop a set of measurement signals at each of the plurality of source positions. Derivative Radon transform data is directly developing by multiplication of the measurement signals of each set by pre-calculated and stored weight factors. Thereafter, an image of the object is reconstructed using the directly developed Radon derivative data.

Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of an object, wherein a plurality of line integral derivatives for a respective plurality of line segments L formed in cone beam projection data acquired on a detector at a plurality of source positions, are calculated. The extent of line segments L in the data acquired at each of the source positions is determined by a mask formed by cone beam projections onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the cone beam data in which the line integral derivatives for line segments L are being calculated. The line integral derivatives calculated for a plurality of the line segments L are then backprojected onto a 2D space corresponding to the plane of the detector. Finally, the results of the 2D backprojecting step are 3D backprojected into a 3D space, thereby reconstructing a 3D image of the object.

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 method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of cone beam projection data, each set being acquired on a detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data to form masked data sets. The mask for each data set is formed by cone beam projections onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the data set being masked.

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 computed tomography apparatus has a surface X-ray detector composed of detection elements, with all detectors being usable in a spiral scan wherein the detector and an X-ray radiator are rotated around a system axis. The detector has a symmetry axis tilted relative to the system axis by a non-zero acute angle, this angle can be adjustable, including being settable to a value of zero for conducting a conventional spiral scan.