Abstract: Various methods and systems are provided for stationary computed tomography (CT) imaging. In one embodiment, a stationary CT system includes one or more detector arrays extending around at least a portion of an imaging volume, a stationary distributed x-ray source unit comprising a plurality of emitters including a first set of emitters configured to operate at a first voltage and a second set of emitters configured to operate at a second voltage, different than the first voltage, and a source controller for triggering the first set of emitters for acquiring first projection data by the one or more detector arrays and triggering the second set of emitters for acquiring second projection data by the one or more detector arrays, the first projection data and the second projection data usable to reconstruct one or more basis material composition images or monochromatic images of an object within the imaging volume.

Abstract: A computer-implemented method includes generating, via a processor, synthetic vessels. The method also includes performing, via the processor, three-dimensional (3D) computational fluid dynamics (CFD) on the synthetic vessels for different flow rates to generate 3D CFD data. The method further includes extracting, via the processor, 3D image patches from the synthetic vessels. The method even further includes obtaining, via the processor, pressure drops across the 3D image patches from the 3D CFD data. The method yet further includes training, via the processor, a deep neural network utilizing the 3D image patches, the pressure drops, and associated flow rates to generate a trained deep neural network.

Abstract: A system and method for estimating vascular flow using CT imaging include a computer readable storage medium having stored thereon a computer program comprising instructions, which, when executed by a computer, cause the computer to acquire a first set of data comprising anatomical information of an imaging subject, the anatomical information comprises information of at least one vessel. The instructions further cause the computer to process the anatomical information to generate an image volume comprising the at least one vessel, generate hemodynamic information based on the image volume, and acquire a second set of data of the imaging subject. The computer is also caused to generate an image comprising the hemodynamic information in combination with a visualization based on the second set of data.

Abstract: The present disclosure relates to fabrication and use of a phase-contrast imaging detector that includes sub-pixel resolution electrodes or photodiodes spaced to correspond to a phase-contrast interference pattern. A system using such a detector may employ fewer gratings than are typically used in a phase-contrast imaging system, with certain functionality typically provided by a detector-side analyzer grating being performed by sub-pixel resolution structures (e.g., electrodes or photodiodes) of the detector. Measurements acquired using the detector may be used to determine offset, amplitude, and phase of a phase-contrast interference pattern without multiple acquisitions at different phase steps.

Abstract: The present disclosure relates to the use of prior images acquired of the patient and acoustic signature from a vascular region of interest to create a patient-specific model of sound propagation from the vascular region. This model is then used to monitor the progression of disease in the vascular region of interest, using subsequently-acquired acoustic signals. In an alternate embodiment, population-based images and/or population-based acoustic signatures are used to generate predictive data when a priori patient-specific imaging information is not available and this data is used to characterize or categorize at-risk patients suspected of coronary artery disease, but without prior cardiac events.

Abstract: Various methods and systems are provided for stationary computed tomography (CT) imaging. In one embodiment, a stationary CT system includes one or more detector arrays extending around at least a portion of an imaging volume, a stationary distributed x-ray source unit comprising a plurality of emitters including a first set of emitters configured to operate at a first voltage and a second set of emitters configured to operate at a second voltage, different than the first voltage, and a source controller for triggering the first set of emitters for acquiring first projection data by the one or more detector arrays and triggering the second set of emitters for acquiring second projection data by the one or more detector arrays, the first projection data and the second projection data usable to reconstruct one or more basis material composition images or monochromatic images of an object within the imaging volume.

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 disclosure relates to fabrication and use of a phase-contrast imaging detector that includes sub-pixel resolution electrodes or photodiodes spaced to correspond to a phase-contrast interference pattern. A system using such a detector may employ fewer gratings than are typically used in a phase-contrast imaging system, with certain functionality typically provided by a detector-side analyzer grating being performed by sub-pixel resolution structures (e.g., electrodes or photodiodes) of the detector. Measurements acquired using the detector may be used to determine offset, amplitude, and phase of a phase-contrast interference pattern without multiple acquisitions at different phase steps.

Abstract: There is provided an x-ray detector having a number of x-ray detector sub-modules. Each detector sub-module is an edge-on detector sub-module having an array of detector elements extending in at least two directions, wherein one of the directions has a component in the direction of incoming x-rays. The detector sub-modules are stacked one after the other and/or arranged side-by-side. For at least part of the detector sub-modules, the detector sub-modules are arranged for providing a gap between adjacent detector sub-modules, where at least part of the gap is not directed linearly towards the x-ray focal point of an x-ray source.

Abstract: The present disclosure relates to training one or more neural networks for vascular vessel assessment using synthetic image data for which ground-truth data is known. In certain implementations, the synthetic image data may be based in part, or derived from, clinical image data for which ground-truth data is not known or available. Neural networks trained in this manner may be used to perform one or more of vessel segmentation, decalcification, Hounsfield unit scoring, and/or estimation of a hemodynamic parameter.

Abstract: The present disclosure relates to determining the position of an X-ray focal spot in real time during an imaging process and using the focal spot position to ensure alignment of the focal spot and high-aspect detector elements or to correct for focal spot misalignment, thereby mitigating image artifacts. For example, the focal spot position may be monitored and may be adjusted in real-time using electromagnetic electron beam steering during a scan. Alternatively, previously determined functional relationships between focal spot position and measured data may be applied to address or correct for focal spot misalignment in the acquired data.

Abstract: The present approaches relates to the use of silicon-based energy-discriminating, photon-counting detectors, such as for use in X-ray based imaging including computed tomography. The described approaches address the resolution and classification of X-ray photons affected by Compton scatter, which may be detected as having energy levels below their proper level due to collision or deflection events.

Abstract: The present approach relates to the use of detector elements (i.e., reference detector pixels) positioned under septa of an anti-scatter collimator. Signals detected by the reference detector pixels may be used to correct for charging-sharing events with adjacent pixels and/or to characterize or correct for focal spot misalignment either in real time or as a calibration step.

Abstract: The present disclosure relates to determining the position of an X-ray focal spot in real time during an imaging process and using the focal spot position to ensure alignment of the focal spot and high-aspect detector elements or to correct for focal spot misalignment, thereby mitigating image artifacts. For example, the focal spot position may be monitored and may be adjusted in real-time using electromagnetic electron beam steering during a scan. Alternatively, previously determined functional relationships between focal spot position and measured data may be applied to address or correct for focal spot misalignment in the acquired data.

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: The present approach provides a non-invasive methodology for estimation of coronary flow and/or fractional flow reserve. In certain implementations, various approaches for personalizing blood flow models of the coronary vasculature are described. The described personalization approaches involve patient-specific measurements and do not assume or rely on the resting coronary flow being proportional to myocardial mass. Consequently, there are fewer limitations in using these approaches to obtain coronary flow and/or fractional flow reserve estimates non-invasively.

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 disclosure relates to training one or more neural networks for vascular vessel assessment using synthetic image data for which ground-truth data is known. In certain implementations, the synthetic image data may be based in part, or derived from, clinical image data for which ground-truth data is not known or available. Neural networks trained in this manner may be used to perform one or more of vessel segmentation, decalcification, Hounsfield unit scoring, and/or estimation of a hemodynamic parameter.

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.