Abstract: Acquisition of X-ray transmission data at three or more energy levels is described. Various implementations utilize generator waveforms that utilize fast-switching, slow-switching, or a combination of fast- and slow-switching to transition between X-ray energy levels. In addition, various sampling arrangements for sampling and/or binning three or more energy levels of X-ray transmission data are discussed. The use of these data in subsequent processing steps, such for material decomposition and/or improvement of dual-energy material decomposition processing, are also described.

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: 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: A detector is described having readout electronics integrated in the photodetector layer. The detector may be configured to acquire both energy-integrated and photon-counting data. In one implementation, the detector is also configured with control logic to select between the jointly generated photon-counting and energy-integrated data.

Abstract: A detector panel is described having readout circuitry integrated with the photodetectors, such as in the light imager panel. The detector is useful in high spatial resolution and low-dose or low-signal imaging contexts and may be used in adaptive 2D binning configurations. Adaptive binning of detector elements may be accomplished using control logic and X-ray intensity detector circuitry capable of assessing an incident X-ray intensity and controlling binning of an associated group of detector elements.

Abstract: Acquisition of X-ray transmission data at three or more energy levels is described. Various implementations utilize generator waveforms that utilize fast-switching, slow-switching, or a combination of fast- and slow-switching to transition between X-ray energy levels. In addition, various sampling arrangements for sampling and/or binning three or more energy levels of X-ray transmission data are discussed. The use of these data in subsequent processing steps, such for material decomposition and/or improvement of dual-energy material decomposition processing, are also described.

Abstract: Some embodiments are associated with an input signal comprising a first and a second photon event incident on a photon-counting semiconductor detector. A relatively slow charge collection shaping amplifier may receive the input signal and output an indication of a total amount of energy associated with the superposition of the first and second events. A relatively fast charge collection shaping amplifier may receive the input signal and output an indication that is used to allocate a first portion of the total amount of energy to the first event and a second portion of the total amount of energy to the second event.

Abstract: A method of generating an image in one embodiment includes acquiring, with a computed tomography (CT) acquisition unit, CT projection data from at least a region of interest (ROI), and concurrently acquiring, with a magnetic resonance (MR) acquisition unit, MR imaging information of at least a portion of the ROI. The method also includes determining a motion of the at least a portion of the ROI using the MR imaging information, and reconstructing the image using the CT projection data. Reconstructing the image includes motion correcting the CT projection data based on the motion determined using the MR imaging information.

Abstract: An imaging method includes executing a low-dose preparatory scan to an object by applying tube voltages and tube currents in an x-ray source, and generating a first image of the object corresponding to the low-dose preparatory scan. The method further includes generating image quality estimates and dose estimates view by view at least based on the first image. The method includes optimizing the tube voltages and the tube currents to generate optimal profiles for the tube voltage and the tube current. At least one of the optimal profiles for the tube voltage and the tube current is generated based on the image quality estimates and the dose estimates. The method includes executing an acquisition scan by applying the tube voltages and the tube currents based on the optimal profiles and generating a second image of the object corresponding to the acquisition scan. An imaging system is also provided.

Abstract: A method of generating an image in one embodiment includes acquiring, with a computed tomography (CT) acquisition unit, CT projection data from at least a region of interest (ROI), and concurrently acquiring, with a magnetic resonance (MR) acquisition unit, MR imaging information of at least a portion of the ROI. The method also includes determining a motion of the at least a portion of the ROI using the MR imaging information, and reconstructing the image using the CT projection data. Reconstructing the image includes motion correcting the CT projection data based on the motion determined using the MR imaging information.

Abstract: X-ray imaging systems are provided that include an X-ray source and an X-ray detector. A filtering device is positioned between the X-ray source and the X-ray detector and includes one or more micro-filters each adapted to transition between an X-ray filtering position and an X-ray non-filtering position. A controller is programmed to control operation of the micro-filters.

Abstract: A system includes an energy-discriminating, photon-counting X-ray detector, comprising a plurality of detector cells adapted to produce projection data in response to X-ray photons and to produce an electrical signal having a recorded count for the energy bins and a total energy intensity. The system also includes data processing circuitry adapted to receive the electrical signal, to generate a simulated count rate for each of the energy bins by using the total energy intensity, to determine a set of energy intensity dependent material decomposition vectors, and, for the measured projection data, to perform material decomposition.

Abstract: A filtering device includes an X-ray translucent substrate having a plurality of septa disposed therein at a plurality of fixed positions with respect to the substrate. A controller is programmed to acquire a first set of projection data at a first energy spectrum by controlling the X-ray source to emit the X-rays at the first energy spectrum and controlling the position of the filtering device to focally align the plurality of septa with the X-ray beam emitted from the focal spot, and to acquire a second set of projection data at a second energy spectrum with a mean energy greater than the mean energy of the first energy spectrum by controlling the X-ray source to emit the X-rays at the second energy spectrum and controlling a change in the position of the filtering device to focally misalign the plurality of septa with the X-ray beam emitted from the focal spot.

Abstract: X-ray imaging systems are provided that include an X-ray source and an X-ray detector. A filtering device is positioned between the X-ray source and the X-ray detector and includes one or more micro-filters each adapted to transition between an X-ray filtering position and an X-ray non-filtering position. A controller is programmed to control operation of the micro-filters.

Abstract: A system includes an energy-discriminating, photon-counting X-ray detector, comprising a plurality of detector cells providing measurements corresponding to at least two energy bins and being adapted to produce projection data in response to X-ray photons that reach the X-ray detector and to produce an electrical signal having a recorded count for the energy bins and a total energy intensity.

Abstract: A multi-energy X-ray imaging system includes an X-ray source and an X-ray detector. A filtering device includes an X-ray translucent substrate having a plurality of septa disposed therein at a plurality of fixed positions with respect to the substrate. A controller is programmed to acquire a first set of projection data at a first energy spectrum by controlling the X-ray source to emit the X-rays at the first energy spectrum and controlling the position of the filtering device to focally align the plurality of septa with the X-ray beam emitted from the focal spot, and to acquire a second set of projection data at a second energy spectrum with a mean energy greater than the mean energy of the first energy spectrum by controlling the X-ray source to emit the X-rays at the second energy spectrum and controlling a change in the position of the filtering device to focally misalign the plurality of septa with the X-ray beam emitted from the focal spot.

Abstract: An energy-sensitive system includes one or more processors configured to determine spectral attenuation curves for a first basis material and a second basis material, respectively. The one or more processors are configured to substitute a k-edge feature in the determined spectral attenuation curves with an approximation of the determined spectral attenuation curves lacking the k-edge feature. The one or more processors are also configured to construct a material decomposition model based on one of the determined or approximated first and second spectral attenuation curves. The one or more processors are additionally configured to decompose X-ray projection data into basis material projection data comprising first and second line integrals based, at least in part, on the model.

Abstract: Methods and systems for active resonant voltage switching are provided. One active resonant switching system includes a voltage switching system having one or more active resonant modules to provide a switching voltage output. Each of the resonant modules includes a plurality of switching devices configured to operate in open and closed states to produce first and second voltage level outputs from a voltage input. The resonant modules also include a capacitor connected to the switching devices and configured to receive a discharge energy during a resonant operating cycle when switching an output voltage from the first voltage level to the second voltage level, wherein the capacitor is further configured to restore system energy when switching from the second to first voltage level. The resonant modules further include a resonant inductor configured to transfer energy to and from the capacitor.

Abstract: An energy-sensitive system includes one or more processors configured to determine spectral attenuation curves for a first basis material and a second basis material, respectively. The one or more processors are configured to substitute a k-edge feature in the determined spectral attenuation curves with an approximation of the determined spectral attenuation curves lacking the k-edge feature. The one or more processors are also configured to construct a material decomposition model based on one of the determined or approximated first and second spectral attenuation curves. The one or more processors are additionally configured to decompose X-ray projection data into basis material projection data comprising first and second line integrals based, at least in part, on the model.