Abstract: Photon starvation causes streaks and noise and seriously impairs the diagnostic value of the CT imaging. To reduce streaks and noise, a new scheme of adaptive Gaussian filtering relies on the diffusion-derived scale-space concept in one embodiment of the current invention. In scale-space view, filtering by Gaussians of different sizes is similar to decompose the data into a sequence of scales. As the scale measure, the variance of the filter linearly relates to the noise standard deviation of a predetermined noise model in the new filtering method. The new filter has only one optional parameter that remains stable once tuned. Although single-pass processing using the new filter generally achieves desired results, iterations are optionally performed.

Abstract: Three or more materials are advantageously separated from dual energy data by using a material separation technique. To effectively separate material clusters, a density plot is introduced to automatically render cluster separations. Initially, the projection data optionally undergo data-domain dual energy decomposition. Then, the image data is plotted in a vector plot whose axes are the low HU values and the high HU values. For a given data point in the vector plot, a number of data points is counted within in a region of interest surrounding the given data point to generate a density plot where each point now represents a density level surrounding the data point. Thus, clustering of a certain material is visualized by a predetermined color assignment scheme. Furthermore, special image processing methods such as Gaussian decomposition are used to improve the accuracy of material separation.

Abstract: Embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index such as electrocardiogram gated reconstruction, view-based motion map and ray-based motion map. Other embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index and another index that is associated with certain geometric characteristics of a cone beam.

Abstract: A method of reconstructing a volume image of an object includes receiving circle projection data collected by a detector along a circular path with respect to the object; receiving line projection data collected by the detector along a linear path with respect to the object; producing a reconstructed circle path volume image of the object from the pre-processed circle projection data using a reconstruction algorithm that includes a ramp filter; producing a reconstructed line path volume image of the object from pre-processed line projection data using a reconstruction algorithm that includes a Hubert filter; and combining the reconstructed circle path volume image and the reconstructed line path volume image to produce the volume image of the object. An apparatus and computer program product are also described.

Abstract: The CT imaging system optimizes its image generation by adaptively weighting certain parameters during the iterations in an iterative reconstruction algorithm. The projection data is grouped into N subsets, and after each of the N subsets is processed by the ordered subsets simultaneous algebraic reconstruction technique (OSSART), the image undergoes total variation (TV) minimization process. During the iterative reconstruction algorithm, a combination of the parameters such as a total variation, a relaxation parameter and a step size parameter is assigned a respective value based upon the current value of the iteration.

Abstract: Embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index such as electrocardiogram gated reconstruction, view-based motion map and ray-based motion map. Other embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index and another index that is associated with certain geometric characteristics of a cone beam.

Abstract: The CT imaging system optimizes its image generation by substantially reducing artifacts caused by a known amount of readout time lag in the X-ray detectors or data acquisition system. Although each detector row takes the same amount of time to read out the signals, the time lag cumulates over the rows as each row is sequentially read out. The back-projection coordinates are correspondingly corrected based upon the above described delay.

Abstract: The CT imaging system optimizes its image generation by substantially reducing artifacts caused by a known amount of readout time lag in the X-ray detectors or data acquisition system. Although each detector row takes the same amount of time to read out the signals, the time lag cumulates over the rows as each row is sequentially read out. The back-projection coordinates are correspondingly corrected based upon the above described delay.

Abstract: A method of reconstructing a volume image of an object includes receiving circle projection data collected by a detector along a circular path with respect to the object; receiving line projection data collected by the detector along a linear path with respect to the object; producing a reconstructed circle path volume image of the object from the pre-processed circle projection data using a reconstruction algorithm that includes a ramp filter; producing a reconstructed line path volume image of the object from pre-processed line projection data using a reconstruction algorithm that includes a Hubert filter; and combining the reconstructed circle path volume image and the reconstructed line path volume image to produce the volume image of the object. An apparatus and computer program product are also described.