A non-transitory computer-readable medium stores instructions readable and executable by a workstation (18) including at least one electronic processor (20) to perform an image reconstruction method (100) to reconstruct list mode data acquired over a frame acquisition time using a plurality of radiation detectors (17) in which the events of the list mode data is timestamped. The method includes: for the sub-frame bins of a plurality of sub-frame bins into which the frame acquisition time is divided, determining a sub-frame singles rates map for the plurality of radiation detectors from the list mode data whose time stamps reside in the sub-frame bin; determining a singles rate for the singles events of the list mode data using the sub-frame singles rates maps wherein the singles rates for the singles events are determined at a temporal resolution that is finer than the frame acquisition time; determining correction factors for the list mode data using the determined singles rates for the singles events of the list mode data; and reconstructing the list mode data of the frame acquisition time using the determined correction factors to generate a reconstructed image for the frame acquisition time.

A method and apparatus is provided to decompose spectral computed tomography (CT) projection data into material components using singles-counts and total-counts projection data. The singles-counts projection data more accurately solves the material decomposition problem, but can produce multiple results only one of which is correct. The total-counts projection data generates a unique result, but is less precise. The total-counts projection data is used to disambiguate the multiple results of the singles-counts projection data providing a unique results that is also precise. The unique and precise material decomposition can be achieved by limiting a search region for the singles-counts result to a neighborhood surrounding the total-counts result, choosing a singles-counts result that is closest to the total-counts result, choosing a singles-counts result that minimizes a total-counts cost function, or using a combined cost function that includes a singles-counts projection data and energy-integrated projection data.

A method for x-ray photon-counting data correction. The method includes generating, by a training data generation module, training input spectral projection data based, at least in part, on a reference spectral projection data. The training input spectral projection data includes at least one of a pulse pileup distortion, a charge splitting distortion, and/or noise. The method further includes training, by a training module, a data correction artificial neural network (ANN) based, at least in part, on training data. The data correction ANN includes a pulse pileup correction ANN, and a charge splitting correction ANN. The training data includes the training input spectral projection data and the reference spectral projection data.

The radiation detector according to the present invention is always able to calculate the summation value accurately, regardless of the intensity of the fluorescent emission that is produced in the scintillator. That is, if the method for calculating the summation value set forth in the present invention is used, then the number of instantaneous intensity data d that are added together each time a fluorescent emission is produced in the scintillator will be larger the greater the intensity of the fluorescent emission. Doing this prevents the intensity of an intense fluorescent emission from being understated. Moreover, the summing portion in the present invention is able to calculate the summation value with high reliability. This is because the instantaneous intensity data used in calculating the summation value are above a threshold value a, causing the signal-to-noise ratios to be adequately high and the reliability to be high as well.

Systems, methods, and devices for evaluating an earth formation intersected by a borehole. Apparatus may include at least one radiation detector configured to generate an analog electrical signal responsive to a plurality of radiation events, comprising absorption of incident ionizing radiation at a corresponding energy level, and an ionizing radiation spectrometer configured to convert each analog electrical signal from the at least one radiation detector into a plurality of digital signal pulses corresponding to the radiation events and resolve the plurality of digital signal pulses into radiation count information representative of the radiation events. Spectrometers include an input channel for each detector of the at least one radiation detector comprising an analog-to-digital converter (ADC) and configured to convert the analog electrical signal for each detector into the plurality of digital signal pulses; and at least one processor configured to generate the radiation count information.

Various embodiments described herein may include a detector array for a CT imaging system. The detector array includes a pixel array in which each pair of adjacent pixels in the pixel array may be separated by a collimator (e.g., located between each row and column of the pixel array) that absorbs photons and each pixel in the pixel array includes a sub-pixel array. The collimator absorbs photons that strike at a boundary between adjacent pixels. Each sub-pixel may have an anode that is connected to an ASIC channel When a sub-pixel in a pixel detects a photon, signals of a plurality of sub-pixels in the pixel are automatically summed, including the sub-pixel that detected the photon.

A photon counting detector of an embodiment includes X-ray detection elements, a capacitor, and generating circuitry. The X-ray detection elements detect an X-ray and generate an electrical signal. The capacitor is provided for each of the X-ray detection element, and accumulates an electrical signal generated in each of the X-ray detection element. The generating circuitry has low sensitivity to radiation, and generates a digital signal by using an accumulation result of the electrical signal in the capacitors, and reference information that is stored in advance.

The invention provides a method of estimating an input count rate of a radiation pulse detector from a detector signal where some individual signal pulses making up the detector signal are closely spaced in time less than a minimum reliable detection gap. In one aspect, the individual signal pulses are detected using a detection algorithm and a plurality of interval start times are defined each interposed with at least one of the detected individual signal pulse arrival times, each interval start time being later by at least the minimum reliable detection gap than a corresponding most recent detected individual signal pulse arrival time. A corresponding plurality of individual signal pulse arrival intervals are calculated between each of the interval start times and a corresponding next detected individual signal pulse arrival time.

The present invention relates to photon counting. In particular, a photon-counting data acquisition module is provided. The photon-counting data acquisition module comprises a signal input unit and one or more data acquisition channels, each channel adapted for converting at least one train of pulses received from the signal input unit to a counter signal. Each data acquisition channel comprises a pulse maximum identifier and a discriminator/counter pair comprising a discriminator and a counter. The pulse maximum identifier is configured to identify a maximum of a pulse in the at least one received train of pulses. The discriminator is configured to be triggered, by a detection of a maximum of a pulse in the at least one received train of pulses, to compare the pulse with at least one signal threshold to generate the counter signal. Alternatively, the counter is configured to be enabled in response to a detection of a maximum of a pulse to generate the counter signal.

A system for charge sharing compensation for a photon counting detector. A plurality of comparators, each configured to generate comparator output data based on a threshold value, a plurality of energy bins, each of the plurality of energy bins coupled to one of the plurality of comparators, and a coincidence logic coupled to two or more of the plurality of comparators and configured to receive comparator output data associated with two or more of a plurality of pixels. The comparator output data for each pixel indicates when a signal associated with the pixel crosses a threshold value. The coincidence logic is configured to generate a coincidence output when the comparator output data for a first pixel is received within a predetermined time interval of the comparator output data for a second pixel. The system includes a coincidence counting bin coupled to the coincidence logic and configured to receive the coincidence output and generate count data based on the coincidence output.