摘要:
A method for creating a variable slice thickness for displaying an imaged object is disclosed. The method includes acquiring a plurality of projection images from a plurality of different projection angles within a defined sweep angle, reconstructing a plurality of object images from the plurality of projection images, each object image having a first slice thickness, and applying a function rule to combine images, whole images or portions thereof or attributes thereof, of the plurality of projection images, of the plurality of object images, or of both, thereby providing for the display of the object utilizing a second slice thickness that varies from the first slice thickness.
摘要:
An imaging system includes a two-dimensional detector having a plurality of cells wherein each cell is configured to detect energy or signal passing through an object. The imaging system includes a computer programmed to acquire imaging data for the plurality of cells, identify a cell to be corrected, based on the imaging data, interpolate Ix and Iy for the identified cell based on neighbor cells, and calculate local gradients gx and gy between the identified cell and its neighbor cells based on the interpolation. The computer is further programmed to calculate weighting factors wx and wy based on the local gradients, calculate a corrected final value I(0,0) for the identified cell, and correct the identified cell with the corrected final value.
摘要:
A system, method, and apparatus includes a computed tomography (CT) system having a rotatable gantry, an x-ray source, a generator, a detector having pixels and positioned to receive x-rays, and a computer. The computer is programmed to acquire CT data representative of an object, determine a first subset of the CT data, determine a second subset of the CT data, and determine a difference between the first and second subsets of the CT data to identify a motion region in the object. The computer is also programmed to update image data reconstructed from a first portion of the first subset of the CT data and corresponding to the region and reconstruct an image based on the updated image data and non-updated image data. The non-updated image data is reconstructed from a second portion the first subset of the CT data.
摘要:
Systems, methods and apparatus are provided through which a specialized back-projection process reconstructs a finely detailed and crisp three-dimensional image (3-D) from a series of two-dimensional (2-D) images by pre-filtering the 2-D images with a first group of settings before back-projecting the 2-D images into a 3-D image, and then post-filtering the 3-D image with another group of settings. In some embodiments, the first group of settings and the second group of settings are synergistically optimized in relation to each other to provide emphasis on a structure of interest in the object.
摘要:
A method of providing an automatic protocol assistance includes determining a number of exposures for a scan of an object, acquiring a low dose AEC exposure of the object or acquiring at least one of a PA and an AP view, calculating an initial technique, and automatically determining whether to use the initial technique to perform the scan or to not perform the scan.
摘要:
Systems, methods and apparatus are provided through which in one aspect, a three-dimensional (3D) image of an object is constructed from a plurality of two-dimensional (2D) images of the object using a specialized filter. The specialized filter implements a linear ramp function, a windowing function, and/or a polynomial function. The 3D image is back-projected from the filtered two-dimensional images, yielding a 3D image that has improved visual distinction of overlapping anatomic structures and reduced blurring.
摘要:
A technique is provided for non-uniform weighting in back-projection calculations in tomosythesis. The non-uniform weighting may include weighting based on a count map of the number of times pixels of individual slices are traversed by radiation in different projections. Weighting may also include non-uniform functions for contributions of features at different slice level to the sensed X-ray attenuation system response inconsistencies are accounted for by further weighting based upon projection maps which may be created in separate system calibration or configuration routines.
摘要:
Systems and methods that utilize asymmetric geometry to acquire radiographic tomosynthesis images are described. Embodiments comprise tomosynthesis systems and methods for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images. These systems comprise: an x-ray detector; and an x-ray source capable of emitting x-rays directed at the x-ray detector; wherein the tomosynthesis system utilizes asymmetric image acquisition geometry, where θ1≠θ0, during image acquisition, wherein θ1 is a sweep angle on one side of a center line of the x-ray detector, and θ0 is a sweep angle on an opposite side of the center line of the x-ray detector, and wherein the total sweep angle, φasym, is φasym=θ1+θ0. Reconstruction algorithms may be utilized to produce reconstructed images of the object from the plurality of two-dimensional x-ray projection images.
摘要:
An imaging system includes a rotatable gantry having an opening therein to receive a subject to be scanned and configured to rotate about a central axis in a rotation direction. The imaging system also includes a first x-ray source coupled to the rotatable gantry at a first position, wherein the first position is offset from the central axis of the rotatable gantry by a first distance. Further, the imaging system includes a second x-ray source coupled to the rotatable gantry at a second position, wherein the second position is offset from the central axis of the rotatable gantry by a second distance, wherein the second position is offset from the first position in a direction coincident with the rotation direction, and wherein the second position is offset from the first position in a direction parallel to the central axis.