General Electric Company

Geng Fu

Jianjun Guo

Peter Michael Edic

Yannan Jin

Brian David Yanoff

Xue Rui

Sergei Ivanovich Dolinsky

Hua Qian

Adrian Ivan

Xiao Jin

David Leo McDaniel

Floribertus P M Heukensfeldt Jansen

Hao Lai

Hewei Gao

Vladimir Anatolievich Lobastov

Bruno Kristiaan Bernard De Man

Ravindra Mohan Manjeshwar

Lin Fu

Feng Chen

Mingye Wu

Fredrik Gronberg

Mikiko Ito

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.

Energy-discriminating photon-counting detector and the use thereof

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.

Reference detector elements in conjunction with an anti-scatter collimator

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.

System and method for statistical iterative reconstruction and material decomposition

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.

Dual-mode radiation detector

A SiPM tile includes SiPM arrays on a detector die, each of the SiPM arrays including a first plurality of microcells and a second plurality of reference microcells dispersed on the die, each reference microcell including an optically-opaque mask, a readout circuit each including a respective charge sensitive amplifier (CSA) connected to one of the reference microcells, each CSA configured to accumulate the dark current of the reference microcell during a selected time window, a hybrid temperature control circuit configured to receive an output signal from each CSA, and to determine the real-time temperature of the die based on the received output signal, to provide the real-time temperature to a temperature compensation and correction control unit that adjusts a cooling/heating system flow provided to the die, the adjustment based on the real-time temperature. A method for compensating the operating temperature variation of the SiPM tile is also disclosed.

Temperature compensation for silicon photomultiplier based detector

There is set forth herein a method including performing with an X-ray detector array of a CT imaging system one or more calibration scans, wherein the one or more calibration scans include obtaining for each element of the first through Nth elements of the X-ray detector array one or more calibration measurements; and updating a spectral response model for each element of the first through Nth elements using the one or more calibration measurements. In another aspect, a CT imaging system can perform imaging, e.g. including material decomposition (MD) imaging, using updated spectral response models for elements of an X-ray detector array. The spectral response models can be updated using a calibration process so that different elements of an X-ray detector array have different spectral response models.

Spectral calibration of spectral computed tomography (CT)

A silicon photomultiplier (SiPM) based detection system includes a plurality of scintillators, SiPMs, a front end circuit, adjustment circuits, and an energy and position processing unit. The SiPMs have a non-linear response to energy deposition corresponding to radiation detection. The adjustment circuit is configured to receive an analog signal from SiPMs, and to provide an adjusted analog signal, which is configured to simulate a signal corresponding to a linear response. The energy and position processing unit utilizes the adjusted signal to provide energy and position information of detected events in the detector block.

Systems and methods for detector output adjustment

A silicon photomultiplier array including a plurality of microcells arranged in rows and columns. A plurality of circuit traces connecting microcell output ports to the array pixel output port, with one or more impedance matching networks connected to at least one of the circuit traces. The impedance matching networks can be connected between each row circuit trace and the pixel output port. Impedance matching networks can be located between junctions of adjacent microcell output ports and row circuit traces.

Microcell interconnection in silicon photomultipliers

A method for determining depth-of-interaction correction in a PET system. The method includes modifying crystal and readout configuration to improve depth-dependent arrival profile of scintillation photons, creating a photon dispersion model within a scintillator crystal, measuring photon arrival profile of individual gamma ray event, deriving an estimated depth-of-interaction, and deriving a gamma ray event time based on a time stamp corrected with the estimated depth-of-interaction. The method further includes modeling dispersion at different depths of interaction within the scintillator crystal, providing a reflector layer to delay back-reflected photons, providing two respective readouts for the same gamma ray event from two respective pixels optically coupled by a backside reflector or modified crystal configuration, calculating a time difference of the photon arrival at the two pixels, and estimating the depth-of-interaction by applying a statistical weighting.

Method for improving timing resolution using depth of interaction correction in PET detector

The present approach relates to the use of reference pixels provided between the primary pixels of a detector panel. Coincidence circuitry or logic may be employed so that the measured signal arising from the same X-ray event may be properly, that is the signal measured at both a reference and primary pixel may be combined so as to provide an accurate estimate of the measured signal, at an appropriate location on the detector panel.

Pixel-design for use in a radiation detector

The present approach relates to the use of energy-resolved, photon-counting detectors, such as CZT- or CdTe-based detectors, to acquire spectral information that is not available with conventional energy-integrating detectors. In certain embodiments, the present approach discussed reduces or eliminates spectral contamination incurred by transient signals in neighboring pixels in designs employing coincidence logic and shaping amplifiers with short shaping times.

Coincidence-enabling photon-counting detector

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.

Apparatus and method for pile-up correction in photon-counting detector

The present approach relates to a detector design that allows detector-based wobble using an electronic control scheme. In one implementation, each detector pixel is divided into sub-pixels. The readout of the sub-pixels can be binned with minimal noise penalty to enable the detector wobble without physically shifting the detector or alternating the physical focal spot location, though, as discussed herein alternation of the focal spot location may be used in conjunction with the present approach to further improve radial and longitudinal imaging resolution as well as suppressing artifacts resulted by limited spatial sampling.

Computed tomography with detector wobble

A SiPM readout circuit includes a front-end circuit having amplifiers coupled to SiPM analog outputs, pixel readout channels coupled to amplifiers provide a timing signal representing gamma ray photon detection in individual SiPM, a block timing channel that creates a summed signal from all SiPMs, and generates a block timing signal and a validation signal, an energy channel that generates a summed energy signal and a two-dimensional position of the gamma ray photon detection in the block, and a control logic/processing circuit that performs a time stamp estimation method. Methods of determining the radiation event timing and a non-transitory computer-readable medium containing computer-readable instructions to implement the methods are disclosed.

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Rexford, NY, United States of America

Geng Fu