Abstract: The invention relates to radiation detection with a directly converting semiconductor layer for converting an incident radiation into electrical signals. Sub-band infra-red (IR) irradiation considerably reduces polarization in the directly converting semi-conductor material when irradiated, so that counting is possible at higher tube currents without any baseline shift. An IR irradiation device is integrated into the readout circuit to which the crystal is flip-chip bonded in order to enable 4-side-buttable crystals.

Abstract: Calibration methods and related calibration controllers (CC) for calibrating imaging apparatuses (102) such as a 3D computed tomography imager or a 2D x-ray imager. The imaging apparatuses (102) are equipped with a dynamic beam shaper (RF). The dynamic beam shaper (RF) allows adapting the energy profile of a radiation beam (PR) used in the imaging apparatuses (102) to a shape of an object (PAT) to be imaged. A plurality of gain images are acquired in dependence on a shape of the object and the view along which the gain images are acquired or a target gain image is synthesized from a plurality of basis gain images (BGI).

Abstract: A radiation detector (10) includes a semiconductor element (1) for generating positive holes and electrons, a cathode (2) formed on a first surface of the semiconductor element (1) and a plurality of segmented anodes (3) formed on a second surface of the semiconductor element (1), the second surface being in opposed relation to the first surface. Additionally, a plurality of segmented steering electrodes (5a) are positioned adjacent the plurality of segmented anodes (3). Moreover, a plurality of doping atoms are located above at least a portion of the plurality of segmented anodes (3) for reducing the voltage difference between the plurality of segmented anodes (3) and the plurality of segmented steering electrodes (5a).

Abstract: The invention relates to a radiation detector (100) and an associated method for the detection of (e.g. X or ?-) radiation. The detector (100) comprises a converter element (110) in which incident photons (X) are converted into electrical signals, and an array of anodes (130) for generating an electrical field (E) in the converter element (110). At least two anodes are associated with two steering electrodes (140) to which different potentials can be applied by a control unit (150). Preferably, each single anode or small group of anodes is surrounded by one steering electrode. The potentials of the steering electrodes (140) may be set as a function of the potentials that are induced in these electrodes when an operating voltage is applied between the anodes and a cathode (120). Moreover, a grid electrode (160) may be provided that at least partially encircles anodes (130) and their steering electrodes (140).

Abstract: The present invention discloses a pixilated direct conversion photon counting detector with a direct conversion material layer and a pixilated electrode. Individual electrode pixels are segmented into three segments (510, 520, 530), wherein one of the segments (520) is operated at a more electrically repellant value than that of the other two (510, 530). Said other two segments are connected to electric circuitry (610, 611, 620, 630) that is arranged to generate signals which are indicative of a count of electrons or holes that approach each of the respective electrode pixel segments and to subtract the generated signals from each other.

Abstract: The present invention relates to a detection device (6) for detecting photons emitted by a radiation source (2). The detection device (6) is configured to detect the photons during a first time period. The detection device (6) comprises a sensor (10) having an intermediate direct conversion material for converting photons into electrons and holes, a shaping element (20), and a compensation unit (450, INT, 950). The compensation unit (450, INT, 950) is adapted to provide a compensation signal based on the electrical pulse and on a photoconductive gain of said sensor (10). The core of the invention is to provide circuits to reduce artifacts due to inherent errors with direct conversion detectors in spectral computed tomography by determining a compensation current, by detecting or monitoring a baseline restorer feedback signal, or by ignoring signals above the baseline level.

Abstract: The present invention relates to a detection device (6) for detecting photons emitted by a radiation source (2) and capable of adjusting ballistic deficit. The detection device (6) comprises a pre-amplifying unit (11) (such as, e.g., a charge-sensitive amplifier), a shaping unit (60) comprising a feedback discharge unit (13, I) (such as, e.g., a feedback resistor or a feedback current source), and a feedback discharge control unit (50) coupled to the feedback discharge unit (13, I). The feedback discharge control unit (50) is adapted to, e.g., adjust a resistance of a feedback resistor (and/or to adjust the current value of the feedback current source) if an electrical pulse generated by the shaping unit (60) does not exceed at least one energy comparison value (X1, X2, . . . , XN). The feedback discharge control unit (50) is adapted to not adjust the parameter of the feedback discharge unit (13, I) if the electrical pulse exceeds the at least one energy comparison value (X1, X2, . . . , XN).

Abstract: A wireless network with at least one base station and a plurality of associated terminals for the exchange of payload data and control data and at least one common transmission channel which is available for access to several terminals is described. The base station is configured to control access to the common transmission channel and the terminals are configured to send at least an access signal to the base station for the purpose of obtaining access to the common transmission channel. Different start moments and different preambles can be assigned to the terminals for transmitting their respective access signals.

Abstract: The invention relates to a wireless network with at least one base station and a plurality of associated terminals for the exchange of payload data and control data, and with at least one common transmission channel which is available for access to several terminals, wherein the base station is provided for controlling the access to the common transmission channel, wherein the terminals are provided for sending at least an access signal to the base station for the purpose of obtaining access to the common transmission channel, and wherein at least two different start moments can be assigned to the terminals for transmitting their respective access signals.

Abstract: An apparatus includes an integrator (120) that produces a pulse having a peak amplitude indicative of the energy of a detected photon. First discharging circuitry (136) discharges the integrator (120) at a first discharging speed, and second discharging circuitry (124) discharges the integrator (120) at a second discharging speed. The first discharging speed is less than the second discharging speed.

Abstract: Calibration methods and related calibration controllers (CC) for calibrating imaging apparatuses (102) such as a 3D computed tomography imager or a 2D x-ray imager. The imaging apparatuses (102) are equipped with a dynamic beam shaper (RF). The dynamic beam shaper (RF) allows adapting the energy profile of a radiation beam (PR) used in the imaging apparatuses (102) to a shape of an object (PAT) to be imaged. A plurality of gain images are acquired in dependence on a shape of the object and the view along which the gain images are acquired or a target gain image is synthesized from a plurality of basis gain images (BGI).

Abstract: An imaging system (300) includes a detector array (314) with direct conversion detector pixels that detect radiation traversing an examination region of the imaging system and generate a signal indicative of the detected radiation, a pulse shaper (316) configured to alternatively process the signal indicative of detected radiation generated by the detector array or a set of test pulses having different and known heights that correspond to different and known energy levels and to generate output pulses having heights indicative of the energy of the processed detected radiation or set of test pulses, and a thresholds adjuster (330) configured to analyze the heights of the output pulses corresponding to the set of test pulses in connection with the heights of set of test pulses and a set of predetermined fixed energy thresholds and generate a threshold adjustment signal indicative of a baseline based on a result of the analysis.

Abstract: The invention relates to a method and a pulse processing circuit (100) for the processing of current pulses (CP) generated by incident photons (X) in a piece of converter material, for instance in a pixel (11) of a radiation detector. Deviations of the pulse shape from a reference are detected and used to identify pulse corruption due to pile-up effects at high count rates and/or charge sharing between neighboring pixels. The deviation detection may for instance be achieved by generating, with a pulse shaper (110), bipolar shaped pulses from the current pulse (CP) and/or two shaped pulses of different shapes which can be compared to each other.

Abstract: An apparatus includes a pulse shaper (120) for receiving signals indicative of detected photons and generating a plurality of pulses therefrom to form a pulse train (200) and a peak detector (150) for sampling the pulse train (200) at an output of the pulse shaper (120). The peak detector (150) includes a circuit (300) for selectively detecting and sampling a maximum (202a, b, c) and a minimum (204a, b) value of the pulse train (200). The maximum (202a, b, c) and minimum (204a, b) values sampled are then converted from analog-to-digital format via an analog-to-digital converter (160).

Abstract: The present invention relates to the correction of X-ray image information, e.g. the correction of X-ray image information regarding persistent currents in X-ray detector elements. X-ray detectors may be embodied as photoconductors with ohmic contacts, which output a photo current depending on the energy and amount of photons impinging on a respective photoconductor pixel. Such photoconductors may exhibit a photoconductive gain, i.e. the measured current when irradiated by X-ray is higher than the current, which would result from impinging photons only generating electron-hole pairs. To compensate for photoconductive gain a method (50) for image correction of X-ray image information is provided, comprising receiving (52) readout information of an X-ray detector element (14), wherein the readout information is dependent on impinging X- radiation (20) generating a photo current and compensating (54) the readout information for a photoconductive gain employing compensation information.

Abstract: The invention relates to a detection device (6) for detecting photons emitted by a radiation source (2). A signal generation unit (20) generates a detection signal indicative of the energy of a detected photon while photons strike the detection device (6), and a baseline signal, which is affected by photons that previously struck the detection device (6), while photons are prevented from striking the detection device (6). A baseline shift determination unit (40) determines a baseline shift of the detection signal depending on the baseline signal. An energy determination unit (30) determines the energy of a detected photon depending on the detection signal and the determined baseline shift. Since the baseline shift of the detection signal is determined from a baseline signal that is generated while photons are prevented from striking the detection device (6), the baseline shift can be determined with higher accuracy, resulting in an improved energy determination.

Abstract: The invention relates to radiation detection with a directly converting semiconductor layer for converting an incident radiation into electrical signals. Sub-band infra-red (IR) irradiation considerably reduces polarization in the directly converting semi-conductor material when irradiated, so that counting is possible at higher tube currents without any baseline shift. An IR irradiation device is integrated into the readout circuit to which the crystal is flip-chip bonded in order to enable 4-side-buttable crystals.

Abstract: Device and method for synchronously switching activating a first and second charge accumulation section (31, 32) for a duration of a first and second predetermined sub-frame and a first and second X-ray source until lapse of a predetermined time frame for each of the first and second charge accumulation section (31, 32) for the accumulation of a plurality of temporally distributed partial charges according to an origin of a respective one of the plurality of spatially distributed X-ray sources so as to establish a specific relation between the focal spot position and a rule for accumulating the respective partial measurements, e.g. temporally distributed partial charges, belonging to the same focal spot positions, and to keep the focal spot temperature low by only activating the focal spot for a limited time according to a sub-frame.

Abstract: The present invention discloses a pixilated direct conversion photon counting detector with a direct conversion material layer and a pixilated electrode. Individual electrode pixels are segmented into three segments (510, 520, 530), wherein one of the segments (520) is operated at a more electrically repellant value than that of the other two (510, 530). Said other two segments are connected to electric circuitry (610, 611, 620, 630) that is arranged to generate signals which are indicative of a count of electrons or holes that approach each of the respective electrode pixel segments and to subtract the generated signals from each other.

Abstract: A radiation detector (10) includes a semiconductor element (1) for generating positive holes and electrons, a cathode (2) formed on a first surface of the semiconductor element (1) and a plurality of segmented anodes (3) formed on a second surface of the semiconductor element (1), the second surface being in opposed relation to the first surface. Additionally, a plurality of segmented steering electrodes (5a) are positioned adjacent the plurality of segmented anodes (3). Moreover, a plurality of doping atoms are located above at least a portion of the plurality of segmented anodes (3) for reducing the voltage difference between the plurality of segmented anodes (3) and the plurality of segmented steering electrodes (5a).