摘要:
A computed tomography imaging system includes a source of a conical beam of radiation and a two-dimensional detector array arranged on opposite sides of an axis of rotation. Projection data is acquired in a conventional manner as the source and detector array make a full rotation about an object. A conventional half-scan image reconstruction algorithm is applied to the projection data at a plurality of different center-view angles to produce a plurality of sub-images. Image segments, which are centered in each sub-image along the axis of the respective center-view angle, are selected and combined to form a cross-sectional image of the object. The regions of each sub-image preferably are defined by a weighting function.
摘要:
A method for weighting projection data includes selecting a region that includes a plurality of projection data samples, dividing the region into a plurality of equally sized sub-regions, and weighting the equally sized sub-regions using a location dependent z-smoothing weighting function.
摘要:
A method for generating an adaptively interpolated projection of an object with an imaging system includes generating a first projection using a first interpolation kernel, generating a second projection using a second interpolation kernel, different from the first interpolation kernel, and taking a difference between the first projection and the second projection to generate a differential signal.
摘要:
The invention provides a technique for acquiring subsequent image data in a medical diagnostic context based upon analysis of initial image data. The initial image data is processed via a computer aided diagnosis algorithm to determine whether additional image data acquisition is appropriate. Subsequent acquisition processes may be performed on the same imaging system from which the initial image data originated, or a different imaging system. The imaging systems may also be of different modalities. The subsequent acquisition of image data may be performed automatically without operator intervention, or the prescribed subsequent acquisition sequence may be outputted by the system for execution upon command of an operator.
摘要:
A method and system for reducing noise in an x-ray image generated by an imaging system using an adaptive projection filtering scheme including generating system information, obtaining original projection data, determining a data characteristic of the original projection data, processing the original projection data responsive to the system information and the data characteristic so as to create filtered projection data and calculating resulting projection data responsive to the filtered projection data. Also claimed is a medium encoded with a machine-readable computer program code for reducing noise in an x-ray image generated by an imaging system, the medium including instructions for causing controller to implement the aforementioned method.
摘要:
A method for facilitating a reduction in reconstructed image noise in a computed tomography imaging system. The method includes generating projection data, characterizing a noise distribution of the projection data, performing an adaptive noise reduction operation on the projection data using the noise distribution characterization, and filtering the projection data.
摘要:
To reduce the computational load in comparison to the iso-center shift described above, instead of selecting the z-axis of the coordinate system as the iso-center for reconstruction, the gantry iso-center of one of the detector rows (e.g., one of the center rows) is selected as the reconstruction iso-center. In this arrangement, the detector row for which the iso-center is based need not to undergo protection shift, since the defined reconstruction iso-center is the row iso-center. Data from the other detector rows is shifted relative to the selected detector row. When the gantry iso-center of one of the detector rows (e.g., one of the center rows) is selected as the reconstruction iso-center, the reconstructed image will be shifted along y′-axis relative to the original compensation schemes described above. To ensure the images generated with both schemes are identical in location, an adjustment can be added in the backprojection process.
摘要:
One aspect of the present invention is a method for imaging a volume of a patient with a computed tomographic (CT) imaging system. The method includes steps of: scanning a volume of a patient with a first, full field of view (FOV) scan to acquire first projection data; scanning a smaller volume of the patient with a second, restricted FOV scan to acquire second projection data; estimating an amount of shift between the first projection data and the second projection data resulting from patient movement; and blending first projection data with second projection data in accordance with the estimated amount of shift to estimate projections of the second scan.
摘要:
A method for generating an image of an object using a computed tomography (CT) imaging system, which includes at least one x-ray detector array and at least one rotating x-ray source projecting an x-ray beam, includes the steps of identifying a physiological cycle of the object (the cycle comprising a plurality of phases); selecting at least one phase of the object; collecting at least one segment of projection data for each selected phase of the object during each rotation of each x-ray source; generating a projection data set by combining the projection data segments; generating a cross-sectional image of the entire object from the projection data set; and communicating the image or data associated with the image to a remote facility. The remote facility provides remote services over a network.