Abstract: Various methods and systems are provided for stationary CT imaging. In one embodiment, an imaging system comprises a stationary distributed x-ray source unit comprising a plurality of emitters positioned to emit x-ray beams through the imaging volume, one or more detector arrays extending around at least a portion of an imaging volume, each detector array comprising a plurality of detector elements, each detector element configured to receive x-ray beams from more than one emitter, and an anti-scatter device configured to be positioned between one or more emitters of the plurality of emitters and an object in the imaging volume.

Abstract: A control circuit accesses a memory having stored therein total detected computed tomography image signal information in a projection domain for an object, a first model representing object scatter, a second model representing background scatter, and a third model representing detector crosstalk. Prior to a reconstruction step, the control circuit processes the total detected computed tomography image signal information in the projection domain for the object as a function of each of the first model, the second model, and the third model to thereby compensate for object scatter, background scatter, and detector crosstalk by providing scatter and crosstalk-corrected computed tomography image signal information in the projection domain for the object. The control circuit can then carry out a reconstruction step using the scatter and crosstalk-corrected computed tomography image signal information in the projection domain for the object.

Abstract: Various methods and systems are provided for stationary CT imaging. In one embodiment, a method for an imaging system includes activating an emitter of a plurality of emitters of a stationary distributed x-ray source unit to emit an x-ray beam toward an object within an imaging volume, where the x-ray source unit does not rotate around the imaging volume, receiving the x-ray beam at a subset of detector elements of a plurality of detector elements of one or more detector arrays, sampling the plurality of detector elements to generate a total transmission profile, an attenuation profile, and a scatter measurement, generating a scatter-corrected attenuation profile by entering the total transmission profile, the attenuation profile, and the scatter measurement as inputs to a model, and reconstructing one or more images from the scatter-corrected attenuation profile.

Abstract: Various methods and systems are provided for multi-material decomposition for computed tomography. In one embodiment, a method comprises acquiring, via an imaging system, projection data for a plurality of x-ray spectra, estimating path lengths for a plurality of materials based on the projection data and calibration data for the imaging system, iteratively refining the estimated path lengths based on a linearized model derived from the calibration data, and reconstructing material-density images for each material of the plurality of materials from the iteratively-refined estimated path lengths. By determining path-length estimates in this way without modeling the physics of the imaging system, accurate material decomposition may be performed more quickly and with less sensitivity to changes in physics of the system, and furthermore may be extended to more than two materials.

Abstract: Methods and systems are provided for dual energy imaging. In one embodiment, a method for a dual energy imaging system comprises determining a first tube potential and a second tube potential according to a size of a subject, and controlling the dual energy imaging system with the first tube potential and the second tube potential to generate lower energy x-rays and higher energy x-rays respectively to image the subject. In this way, image quality may be increased while minimizing dose during dual energy imaging of a particular imaging subject.

Abstract: Various methods and systems are provided for stationary CT imaging. In one embodiment, a method for an imaging system includes activating an emitter of a plurality of emitters of a stationary distributed x-ray source unit to emit an x-ray beam toward an object within an imaging volume, where the x-ray source unit does not rotate around the imaging volume, receiving the x-ray beam at a subset of detector elements of a plurality of detector elements of one or more detector arrays, sampling the plurality of detector elements to generate a total transmission profile, an attenuation profile, and a scatter measurement, generating a scatter-corrected attenuation profile by entering the total transmission profile, the attenuation profile, and the scatter measurement as inputs to a model, and reconstructing one or more images from the scatter-corrected attenuation profile.

Abstract: Various methods and systems are provided for stationary CT imaging. In one embodiment, an imaging system comprises a stationary distributed x-ray source unit comprising a plurality of emitters positioned to emit x-ray beams through the imaging volume, one or more detector arrays extending around at least a portion of an imaging volume, each detector array comprising a plurality of detector elements, each detector element configured to receive x-ray beams from more than one emitter, and an anti-scatter device configured to be positioned between one or more emitters of the plurality of emitters and an object in the imaging volume.

Abstract: Various methods and systems are provided for multi-material decomposition for computed tomography. In one embodiment, a method comprises acquiring, via an imaging system, projection data for a plurality of x-ray spectra, estimating path lengths for a plurality of materials based on the projection data and calibration data for the imaging system, iteratively refining the estimated path lengths based on a linearized model derived from the calibration data, and reconstructing material-density images for each material of the plurality of materials from the iteratively-refined estimated path lengths. By determining path-length estimates in this way without modeling the physics of the imaging system, accurate material decomposition may be performed more quickly and with less sensitivity to changes in physics of the system, and furthermore may be extended to more than two materials.

Abstract: The techniques disclosed may be used to detect and correct channel gain errors resulting from X-ray focal spot mis-alignment during the course of a scan. One benefit of the present invention relative to conventional techniques is that additional hardware is not required for detection of focal spot drift. Instead, the static mis-alignment of each blade is taken into account as part of estimating and correcting X-ray focal spot drift or mis-alignment. In this manner, the risk of image artefacts due to focal spot motion is reduced and the need for costly hardware solutions to detect focal spot motion is avoided.

Abstract: A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.

Abstract: The techniques disclosed may be used to detect and correct channel gain errors resulting from X-ray focal spot mis-alignment during the course of a scan. One benefit of the present invention relative to conventional techniques is that additional hardware is not required for detection of focal spot drift. Instead, the static mis-alignment of each blade is taken into account as part of estimating and correcting X-ray focal spot drift or mis-alignment. In this manner, the risk of image artefacts due to focal spot motion is reduced and the need for costly hardware solutions to detect focal spot motion is avoided.

Abstract: Methods and systems are provided for dual energy imaging. In one embodiment, a method for a dual energy imaging system comprises determining a first tube potential and a second tube potential according to a size of a subject, and controlling the dual energy imaging system with the first tube potential and the second tube potential to generate lower energy x-rays and higher energy x-rays respectively to image the subject. In this way, image quality may be increased while minimizing dose during dual energy imaging of a particular imaging subject.

Abstract: The present disclosure relates to the design of phantoms configurable using one or more inserts and to their use in generating images that may be used to compare image quality between different imaging systems. Such phantoms may have a modular design with inserts that may be exchanged one for another within a phantom body.

Abstract: A method for imaging an object to be reconstructed includes acquiring projection data corresponding to the object. Furthermore, the method includes generating a measured sinogram based on the acquired projection data and formulating a forward model, where the forward model is representative of a characteristic of the imaging system. In addition, the method includes generating an estimated sinogram based on an estimated image of the object and the forward model and formulating a statistical model based on at least one of pile-up characteristics and dead time characteristics of a detector of the imaging system. Moreover, the method includes determining an update corresponding to the estimated image based on the statistical model, the measured sinogram, and the estimated sinogram and updating the estimated image based on the determined update to generate an updated image of the object. Additionally, the method includes outputting a final image of the object.

Abstract: A method for imaging an object to be reconstructed includes acquiring projection data corresponding to the object. Furthermore, the method includes generating a measured sinogram based on the acquired projection data and formulating a forward model, where the forward model is representative of a characteristic of the imaging system. In addition, the method includes generating an estimated sinogram based on an estimated image of the object and the forward model and formulating a statistical model based on at least one of pile-up characteristics and dead time characteristics of a detector of the imaging system. Moreover, the method includes determining an update corresponding to the estimated image based on the statistical model, the measured sinogram, and the estimated sinogram and updating the estimated image based on the determined update to generate an updated image of the object. Additionally, the method includes outputting a final image of the object.

Abstract: A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.

Abstract: The present approach relates to avoiding azimuthal blur in a computed tomography context, such as in dual energy imaging with fast kV switching. In accordance with certain aspects, the focal spot position is held stationary in the patient coordinate system within each respective view and the detector signals within the view are summed. In one embodiment, this results in the low and high energy views within the signal being collected from the same position within the patient coordinate system.

Abstract: A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.

Abstract: The present approach relates to avoiding azimuthal blur in a computed tomography context, such as in dual energy imaging with fast kV switching. In accordance with certain aspects, the focal spot position is held stationary in the patient coordinate system within each respective view and the detector signals within the view are summed. In one embodiment, this results in the low and high energy views within the signal being collected from the same position within the patient coordinate system.

Abstract: A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.