Abstract: A photon-counting imaging system is provided. The system includes a photon-counting detector and processing circuitry. The detector acquires, from an imaging object, projection data for a plurality of projection views. The detector has a plurality of detector pixels that are arranged in both a channel direction and a segment direction on a surface of the detector. The processing circuitry obtains the projection data acquired by the detector. The projection data includes first and second projection data. The processing circuitry processes, with a first energy bin setting, the first projection data, the first energy bin setting having m energy bins, and processes, with a second energy bin setting, the second projection data, the second energy bin setting having n energy bins, where n>m. The processing circuitry generates, based on the processed first projection data and the processed second projection data, a material decomposition image of the imaging object.

Abstract: A method of determining a position offset includes receiving a first detection result from a first pixel of a plurality of pixels of a radiation detector, wherein the plurality of pixels are disposed on an incident side of the radiation detector on which an anti-scatter grid (ASG) is arranged, the plurality of pixels being aligned in at least a channel direction; receiving a second detection result from a second pixel of the plurality of pixels, wherein a septa of the ASG is arranged over a portion of the first pixel but is not arranged over any portion of the second pixel as viewed from the incident side of the radiation detector; estimating a positional offset of the septa of the ASG, based on the first detection result and the second detection result.

Abstract: An X-ray scanner system is provided. The system includes a photon-counting detector, a memory, and processing circuitry. The detector has a plurality of detector pixels in a channel direction. The memory stores a detector response forward model of the photon-counting detector. The detector response forward model is to be used during image reconstruction of an imaging object. The processing circuitry estimates an attenuation profile of the imaging object, determine, with respect to each of the plurality of detector pixels, a set of spatial weights, based on the estimated attenuation profile, and update, based on the determined set of spatial weights, the detector response forward model stored in the memory.

Abstract: An apparatus and a method for detection of defective pixels for a photon-counting detector-based computed tomography (CT) system is disclosed. In particular, the apparatus and the method disclosed herein, detect detector pixels that have intermittent behavior using on-the-fly defective pixel screening based on various criteria during an object scan. The defective pixels are discarded using a defective pixel map before image reconstruction.

Abstract: A photon counting computed tomography (CT) method including receiving a first forward model including a set of first parameters and a set of second parameters corresponding to a plurality of materials and path lengths by scanning a slab at plural tube voltages and plural tube currents of an X-ray tube; evaluating an image quality of a material decomposition image reconstructed by the set of first parameters and the set of second parameters; and updating at least one second parameters from the set of second parameters if the image quality of the material decomposition image does not satisfy a predetermined threshold, wherein the updating is achieved by updating the at least one second parameter from the set of second parameters to an energy dependent parameter from a constant value.

Abstract: Data acquired from a scan of an object can be decomposed into frequency components. The frequency components can be input into a trained model to obtain processed frequency components. These processed frequency components can be composed and used to generate a final image. The trained model can be trained, independently or dependently, using frequency components covering the same frequencies as the to-be-processed frequency components. In addition, organ specific processing can be enabled by training the trained model using image and/or projection datasets of the specific organ.

Abstract: A photon counting detector (PCD) apparatus includes a PCD array including a plurality of micro-pixels positioned in at least one of a channel direction and a row direction; and processing circuitry configured to: receive signals from each of the plurality of micro-pixels; configure the PCD array to include (a) a first micro-pixel area including a first group of plural micro-pixels of the plurality of micro-pixels and (b) a second micro-pixel area including a second group of plural micro-pixels of the plurality of micro-pixels, such that a portion of the first and second groups of plural micro-pixels overlap between the first and second groups; bin the signals from the first group of plural micro-pixels into a first virtual bin value; and bin the signals from the second group of plural micro-pixels into a second virtual bin value.

Abstract: A deep learning (DL) network corrects/performs sinogram completion in computed tomography (CT) images based on complementary high- and low-kV projection data generated from a sparse (or fast) kilo-voltage (kV)-switching CT scan. The DL network is trained using inputs and targets, which respectively generated with and without kV switching. Another DL network can be trained to correct sinogram-completion errors in the projection data after a basis/material decomposition. A third DL network can be trained to correct sinogram-completion errors in reconstructed images based on the kV-switching projection data. Performance of the DL network can be improved by dividing a 3D convolutional neural network (CNN) into two steps performed by respective 2D CNNs. Further, the projection data and DLL can be divided into high- and low-frequency components to improve performance.

Abstract: A photon counting computed tomography (CT) method including, but not limited to, receiving a first forward model including a set of first parameters and a set of second parameters corresponding to a plurality of materials and path lengths by scanning a slab at plural tube voltages and plural tube currents of an X-ray tube; evaluating an image quality of a material decomposition image reconstructed by the set of first parameters and the set of second parameters; and updating at least one second parameters from the set of second parameters if the image quality of the material decomposition image does not satisfy a predetermined threshold, wherein the update of the at least one second parameter from the set of second parameters is achieved by updating the at least one second parameter from the set of second parameters to an energy dependent parameter from a constant value. Processing circuitry that is part of a photon counting computed tomography (CT) can implement the method.

Abstract: Data acquired from a scan of an object can be decomposed into frequency components. The frequency components can be input into a trained model to obtain processed frequency components. These processed frequency components can be composed and used to generate a final image. The trained model can be trained, independently or dependently, using frequency components covering the same frequencies as the to-be-processed frequency components. In addition, organ specific processing can be enabled by training the trained model using image and/or projection datasets of the specific organ.

Abstract: A deep learning (DL) network corrects/performs sinogram completion in computed tomography (CT) images based on complementary high- and low-kV projection data generated from a sparse (or fast) kilo-voltage (kV)-switching CT scan. The DL network is trained using inputs and targets, which respectively generated with and without kV switching. Another DL network can be trained to correct sinogram-completion errors in the projection data after a basis/material decomposition. A third DL network can be trained to correct sinogram-completion errors in reconstructed images based on the kV-switching projection data. Performance of the DL network can be improved by dividing a 3D convolutional neural network (CNN) into two steps performed by respective 2D CNNs. Further, the projection data and DLL can be divided into high- and low-frequency components to improve performance.

Abstract: A deep learning (DL) network corrects/performs sinogram completion in computed tomography (CT) images based on complementary high- and low-kV projection data generated from a sparse (or fast) kilo-voltage (kV)-switching CT scan. The DL network is trained using inputs and targets, which respectively generated with and without kV switching. Another DL network can be trained to correct sinogram-completion errors in the projection data after a basis/material decomposition. A third DL network can be trained to correct sinogram-completion errors in reconstructed images based on the kV-switching projection data. Performance of the DL network can be improved by dividing a 3D convolutional neural network (CNN) into two steps performed by respective 2D CNNs. Further, the projection data and DLL can be divided into high- and low-frequency components to improve performance.

Abstract: A deep learning (DL) network corrects/performs sinogram completion in computed tomography (CT) images based on complementary high- and low-kV projection data generated from a sparse (or fast) kilo-voltage (kV)-switching CT scan. The DL network is trained using inputs and targets, which respectively generated with and without kV switching. Another DL network can be trained to correct sinogram-completion errors in the projection data after a basis/material decomposition. A third DL network can be trained to correct sinogram-completion errors in reconstructed images based on the kV-switching projection data. Performance of the DL network can be improved by dividing a 3D convolutional neural network (CNN) into two steps performed by respective 2D CNNs. Further, the projection data and DLL can be divided into high- and low-frequency components to improve performance.

Abstract: A method includes obtaining spectral computed tomography (CT) information via an acquisition unit having an X-ray source and a CT detector. The method also includes, generating, with one or more processing units, using at least one image transform, a first basis image and a second basis image using the spectral CT information. Further, the method includes performing, with the one or more processing units, guided processing on the second basis image using the first basis image as a guide to provide a modified second basis image. Also, the method includes performing at least one inverse image transform using the first basis image and the modified second basis image to generate at least one modified image.

Abstract: Methods and systems for model-based image processing are provided. One method includes selecting at least one reference image from a plurality of reference images, partitioning the at least one reference image into a plurality of patches, generating a probability distribution for each of the patches, and generating a model of a probability distribution for the at least one reference image using the probability distributions for each of the patches.

Abstract: A method includes obtaining spectral computed tomography (CT) information via an acquisition unit having an X-ray source and a CT detector. The method also includes, generating, with one or more processing units, using at least one image transform, a first basis image and a second basis image using the spectral CT information. Further, the method includes performing, with the one or more processing units, guided processing on the second basis image using the first basis image as a guide to provide a modified second basis image. Also, the method includes performing at least one inverse image transform using the first basis image and the modified second basis image to generate at least one modified image.

Abstract: A method includes obtaining spectral computed tomography (CT) information via an acquisition unit having an X-ray source and a CT detector. The method also includes, generating, with one or more processing units, using at least one image transform, a first basis image and a second basis image using the spectral CT information. Further, the method includes performing, with the one or more processing units, guided processing on the second basis image using the first basis image as a guide to provide a modified second basis image. Also, the method includes performing at least one inverse image transform using the first basis image and the modified second basis image to generate at least one modified image.

Abstract: Methods and systems for model-based image processing are provided. One method includes selecting at least one reference image from a plurality of reference images, partitioning the at least one reference image into a plurality of patches, generating a probability distribution for each of the patches, and generating a model of a probability distribution for the at least one reference image using the probability distributions for each of the patches.

Abstract: A method for reconstructing image component densities of an object includes acquiring multi-spectral x-ray tomographic data, performing a material decomposition of the multi-spectral x-ray tomographic data to generate a plurality of material sinograms, and reconstructing a plurality of material component density images by iteratively optimizing a functional that includes a joint likelihood term of at least two of the material decomposed sinograms. An x-ray tomography imaging system and a non-transitory computer readable medium are also described herein.

Abstract: A method for reconstructing image component densities of an object includes acquiring multi-spectral x-ray tomographic data, performing a material decomposition of the multi-spectral x-ray tomographic data to generate a plurality of material sinograms, and reconstructing a plurality of material component density images by iteratively optimizing a functional that includes a joint likelihood term of at least two of the material decomposed sinograms. An x-ray tomography imaging system and a non-transitory computer readable medium are also described herein.