Abstract: Various configurations for scatter reduction and control are provided for CT imaging. These configurations include an imaging system having a stationary detector extending generally around a portion of an imaging volume and a distributed X-ray source placed proximal to the stationary detector for radiating an X-ray beam toward the stationary detector. A scatter control system is further provided that is configured to adaptively operate in cooperation with the stationary detector and the distributed X-ray source to focally align collimator septa contained therein to the X-ray beam at a given focal point and to provide X-ray beam scatter control.

Abstract: Raw cone beam tomography projection image data are taken from an object and are denoised by a wavelet domain denoising technique and at least one other denoising technique such as a digital reconstruction filter. The denoised projection image data are then reconstructed into the final tomography image using a cone beam reconstruction algorithm, such as Feldkamp's algorithm.

Abstract: A method for reconstructing image data from acquired tomographic projection data measurements is provided. The projection data measurements comprise one or more missing data measurements. The method comprises generating a coarse-resolution projection data set from the acquired projection data measurements and performing an iterative reconstruction on the coarse-resolution projection data set to generate a coarse-resolution reconstructed data set. Then, the method comprises reprojecting the coarse-resolution reconstructed data set to obtain one or more estimates for the one or more missing data measurements. The one or more estimated missing data measurements are then recombined with the acquired projection data measurements, to generate a recombined data set. Then, a direct reconstruction algorithm is applied to the recombined data set to generate the reconstructed image data.

Abstract: A method, system, and computer program product for compensating for the unavailability of projection data of a scanned object at a selected point, the selected point located outside a detection range of a detector. The method include the steps of obtaining projection data of the scanned object, and compensating for the unavailability of the projection data at the selected point based on the obtained projection data and coordinates of the selected point relative to the detector. The compensating step includes determining at least one complementary projection angle and coordinates of at least one complementary point based on a source projection angle and the coordinates of the selected point relative to the detector, and estimating the projection data value at the selected point based on the acquired projection data, the at least one complementary projection angle, and the coordinates of the at least one complementary point.

Abstract: In a method for reconstructing a CT image from data acquired from an examination subject, a reconstruction algorithm is employed that is based on an ideal short-scan circle-and-line trajectory. To adapt the reconstruction algorithm to a “real world” scan trajectory, data are acquired with a C-arm CT apparatus wherein the focus is moved through an actual short-scan circle-and-line trajectory. For each position of the focus in the actual trajectory, a projection matrix is electronically generated and the reconstruction algorithm with the ideal trajectory is adapted to the actual trajectory using the projection matrices.

Abstract: A method and apparatus for reducing image noise, increasing image resolution, and facilitating reduced exposure to a subject to be imaged or improved apparatus life. A radiation tomographic imaging apparatus comprises, as image producing means, inter-imaging-plane filtering processing means for acquiring image data for a plurality of planes generated corresponding to imaging planes that are a plurality of cross-sectional planes of a subject to be imaged, and conducting filtering processing on the image data across the plurality of imaging planes. The filtering processing across the imaging planes that are a plurality of cross-sectional planes facilitates discrimination between a specific shape present in the cross-sectional plane and noise.

Abstract: A method and apparatus for quality assurance of an image guided radiation treatment delivery system. A quality assurance (“QA”) marker is positioned at a preset position under guidance of an imaging guidance system of a radiation treatment delivery system. A radiation beam is emitted from a radiation source of the radiation treatment delivery system at the QA marker. An exposure image of the QA marker due to the radiation beam is generated. The exposure image is then analyzed to determine whether the radiation treatment delivery system is aligned.

Abstract: An imaging system 10 is provided comprising an x-ray source 12, a detector 14, and an alignment device 38 adapted to align the detector 14 with the x-ray source 12 using an x-ray beam transmitted from the x-ray source 12. A method of positioning and aligning an imaging system is also provided.

Abstract: An artifact correcting image reconstruction apparatus includes a reconstruction processor (70) that reconstructs acquired projection data (60) into an uncorrected reconstructed image (74). A classifying processor (78) classifies pixels of the uncorrected reconstructed image (74) at least into high, medium, and low density pixel classes. A pixel replacement processor (88) replaces pixels of the uncorrected reconstructed image (74) that are of the high density and low density classes with pixel values of the low density pixel class to generate a synthetic image (90). A forward projecting processor (94) forward projects the synthetic image (90) to generate synthetic projection data (96). A projection replacement processor (100, 110) replaces acquired projection data (60) contributing to the pixels of the high density class with corresponding synthetic projection data (96) to generate corrected projection data (112).

Abstract: A method for correcting scatter in multi-slice imaging wherein, a projection p and a scatter correction factor R(d, do) are stored in association with each other, a projection p is determined from data D0 collected by imaging a subject with an X-ray beam with a beam thickness d using a detector with a detector thickness do, the scatter correction factor R(d, do) associated with the projection p is determined, and the data D0 is multiplied by the scatter correction factor R(d, do) to obtain scatter-corrected data D1.

Abstract: An X-ray system has a patient examination table, an image acquisition unit under the surface of the patient examination table, and an X-ray radiator that can be positioned above the patient examination table, On the patient examination table a radiation protection device is disposed, which—during the operation—shields at least one zone on one side of the patient examination table from the radiation area between the X-ray radiator and the image acquisition unit. In addition, on the patient examination table an X-ray system operation unit is disposed that is accessible from the shielded zone.

Abstract: A method and apparatus for reducing the contrast of a tomographic image due to crosstalk and the occurrence of artifacts and improve the quality of the tomographic image. Detection data are subjected to fitting processing in such a manner that, of the data generated by an X-ray detected by X-ray detection elements disposed in array form in a plurality of X-ray detection modules disposed adjacent to one another, first detection data generated by the X-ray detected by X-ray detection elements adjacent to a boundary between the plurality of X-ray detection modules are adapted to waveform data based on second detection data generated by the X-ray detected by X-ray detection elements lying around the adjacent X-ray detection elements.

Abstract: A method of reconstructing an image includes combining a two-dimensional forward projection function and a three-dimensional stabilizing function to generate an iterative reconstruction algorithm, and using the obtained iterative reconstruction algorithm to perform a multislice Computed Tomography (CT) reconstruction to generate an image.

Abstract: A method for real-time target reconstruction from target image projections including dividing an object into external and internal sub-objects, acquiring external sub-object data, acquiring internal projections, each internal projection including an internal-internal projection which is the projection of the internal sub-object only as if the external sub-object is null, and an internal-external projection which is the projection of the external sub-object only as if the internal sub-object is null, using the external sub-object data to estimate internal-external projections, subtracting the estimated internal-external projections from the acquired internal projections to obtain internal-internal projections, and reconstructing the internal sub-object from the internal-internal projections.

Abstract: A single-leaf X-ray collimator comprises at least one collimating leaf member having at least one collimating aperture. The collimating leaf member is adapted to be configured to rotate about at least one of a vertical or horizontal plane. The collimator provides elliptical collimation and hence improved dosage efficiency.

Abstract: A method of reconstructing an image includes substantially minimizing a cost function of the form x ^ = arg ? ? min x ? { ? m = 0 M ? ? D m ? ( y m , F m ? ( x ) ) + S ? ( x ) } , where {circumflex over (x)} is the value of x which achieves the minimum summation, ym is an integral projection, Fm(x) is an forward projection function, and S(x) is a stabilizing function, to obtain {circumflex over (x)}, and using the obtained {circumflex over (x)} to perform a multislice Computed Tomography (CT) reconstruction to generate an image.

Abstract: Methods, systems and processes for providing efficient, accurate and exact image reconstruction using portable and easy to use C-arm scanning devices and rotating gantries, and the like, that combines both a circle and a curve scan. The invention can provide exact convolution-based filtered back projection (FBP) image reconstruction by combining two curved scans of the object. The curved scan can be less than or greater than a full circle about an object being scanned. The invention can be done by a first curve within a first plane followed by a second curve within a second plane that is transversal to the first plane.

Abstract: An X-ray generator of this invention has an X-ray monitor that monitors a state of an X-ray emitted from a target. Hence the state of the X-ray can be monitored in real time to maintain the X-ray in a constant state. The X-ray monitor is positioned off the path on which an X-ray transmitted from a first exit window travels. Hence, when the X-ray is emitted from the first exit window to an object to be inspected, the X-ray monitor does not obstruct the approaching of the object to the first exit window. This makes it possible to acquire X-ray images of high magnification.

Abstract: A method of using a radiation system having a multileaf collimator (“MLC”) to adjust for unevenness in the radiation emitted by the system is disclosed. By appropriately controlling the MLC in accordance with the invention the system can be operated without a flattening filter. In addition, the invention allows the system user to vary the radiation beam energy in the course of a single treatment, without the need to use or change flattening filters. A map of the uneven radiation beam intensity in the treatment area is obtained, and the map information is combined with a treatment plan to control movement of the leaves of the MLC such that each area receives the correct radiation dose.

Abstract: Reconstructing images of objects spirally scanned with two-dimensional detectors with a novel algorithm under a variable pitch (nonconstant speed), where the object is not restricted to moving at a constant velocity. The object can move at variable speeds(increasing, decreasing, combinations thereof) during the scan of the object. The image reconstruction process is proven to create an exact image of the object under the ideal circumstances. The algorithm can have a convolution-based FBP (Filtered Back Projection) structure and works very efficiently. The algorithm uses less computer power and combines the benefits of Exact Algorithms and Approximate algorithms. An object can be moved at a nonconstant speed through a rotating source and oppositely located detector. Additionally, at least one source and oppositely located detector can be mounted on a coil stand for generating the spiral scan.