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 radiation detector (100) comprising a converter element (113) with an array (120) of first electrodes (121) for sampling electrical signals generated by incident radiation (X). With a connection circuit (130), at least two first electrodes (121) can selectively be coupled to a common readout unit (141) according to a given connection pattern (CP1). The effective pixel size along the path of incident radiation (X) can thus be adapted to the distribution of electrical signals, which is usually determined by the spectral composition of the incident radiation.

Abstract: The invention relates to a radiation detector that is particularly suited for energy resolved single X-ray photon detection in a CT scanner. In a preferred embodiment, the detector has an array of scintillator elements in which incident X-ray photons are converted into bursts of optical photons. Pixels associated to the scintillator elements determine the numbers of optical photons they receive within predetermined acquisition intervals. These numbers can then be digitally processed to detect single X-ray photons and to determine their energy. The pixels may particularly be realized by avalanche photodiodes with associated digital electronic circuits for data processing.

Abstract: The present invention relates to processing electronics (18) for a detector (12) of an X-ray imaging device (14), the processing electronics (18) with a pulse counter section (22) having at least one count output (30) and with an integrator section (24) having an intensity output (32), wherein the processing electronics (18) is adapted to be connected to a sensor (16) in such a manner that X-ray photons (58) arriving at the sensor (16) can be processed by the pulse counter section (22), by the integrator section (24), or both, and wherein the processing electronics (18) comprises a processor (34) adapted to be connected to the count output (30) and to the intensity output (32) and adapted to output a count result (K) that takes into account both count information (N) obtained at the count output (30) and intensity information (I) obtained at the intensity output (32), so that the count result (K) contains information (N) obtained from the pulse counter section (22) and information (M) obtained from the integr

Abstract: The invention relates to a radiation detector (200), particularly an X-ray detector, which comprises at least one sensitive layer (212) for the conversion of incident photons (X) into electrical signals. A two-dimensional array of electrodes (213) is located on the front side of the sensitive layer (212), while its back side carries a counter-electrode (211). The size of the electrodes (213) may vary in radiation direction (y) for adapting the counting workload of the electrodes. Moreover, the position of the electrodes (213) with respect to the radiation direction (y) provides information about the energy of the detected photons (X).

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 a radiation detector (100), particularly for X-rays (X) and for ?-rays, which comprises a combination of (a) at least one primary conversion layer (101a-101f) with a low attenuation coefficient for the photons and (b) at least one secondary conversion layer (102) with a high attenuation coefficient for the photons. In preferred embodiments, the primary conversion layer (101a-101f) may be realized by a silicon layer coupled to associated energy-resolving counting electronics (111a-111f, 121). The secondary conversion layer (102) may be realized for example by CZT or GOS coupled to energy-resolving counting electronics or integrating electronics. Using primary conversion layers with low stopping power allows to build a stacked radiation detector (100) for spectral CT in which the counting rates of the layers are limited to feasible values without requiring unrealistic thin layers.

Abstract: The invention relates to an X-ray imaging device, particularly a Spectral-CT scanner, that comprises an X-ray source for generating X-radiation with an energy spectrum which varies continuously during an observation period. In a preferred embodiment, the radiation is attenuated in an object according to an energy-dependent attenuation coefficient ?, the transmitted radiation is measured by sensor units of a detector, and the resulting measurement signal is sampled and A/D converted. This is preferably done by an oversampling A/D converter, for example a ??-ADC. The tube voltage that drives the X-ray source is sampled with high frequency. In an evaluation system, these sampled measurement values can be associated with corresponding effective energy spectra to determine the energy dependent attenuation coefficient ?.

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 invention relates to a radiation detector and a method for its production, wherein a series of converter plates (110) and interconnect layers (120), which extend into a border volume (BV) lateral of the converter plates (110), are stacked. By filling voids in the border volume (BV) with an underfill material and cutting through the border volume, a contact surface (CS) is generated in which electrical leads (123) of the interconnect layers (120) lie free. To allow a good contacting, said leads (123) are preferably provided with enlargements in the contact surface, for example by bonding wires (132) to them.

Abstract: The invention relates to a radiation detector and a method for producing such a detector, wherein the detector comprises a stack of the scintillator elements and photodiode arrays. The PDAs extend with electrical leads into a rigid body filling a border volume lateral of the scintillator elements, wherein said leads end in a contact surface of the border volume. Moreover, a redistribution layer is disposed on the contact surface, wherein electrical lines of the redistribution layer contact the leads of the PDAs.

Abstract: The present invention relates to an apparatus (10) for generating countable pulses (30) from impinging X-ray (12, 14) in an imaging device (16), in particular in a computer tomograph, the apparatus (10) comprising a pre-amplifying element (18) adapted to convert a charge pulse (20) generated by an impinging photon (12, 14) into an electrical signal (22) and a shaping element (26) having a feedback loop (28) and adapted to convert the electrical signal (22) into an electrical pulse (30), wherein a delay circuit (38) is connected to the feedback loop (28) such that a time during which the feedback loop (28) collects charges of the electrical signal (22) is extended in order to improve an amplitude of the electrical pulse (30) at an output (56) of the shaping element (26). The invention also relates to a corresponding imaging device (16) and a corresponding method.

Abstract: The present invention relates to an apparatus (10) for counting X-ray photons (12, 14). The apparatus (10) comprises a sensor (16) adapted to convert a photon (12, 14) into a charge pulse, a processing element (18) adapted to convert the charge pulse (51) into an electrical pulse (53) and a first discriminator (20) adapted to compare the electrical pulse (53) against a first threshold (TH1) and to output an event (55) if the first threshold (TH1) is exceeded. A first counter (22) counts these events (55), unless counting is inhibited by a first gating element (24). The first gating element (24) is activated when the first discriminator (20) outputs the event (55), and it is deactivated, when the processing of a photon (12, 14) is found to be complete or about to be completed by a measurement or by the knowledge about the time that it takes to process a photon (12, 14) in the processing element (18). By activating and deactivating the first counter (22) pile-up events, i.e.

Abstract: The present invention relates to processing electronics (18) for a detector (12) of an X-ray imaging device (14), the processing electronics (18) with a pulse counter section (22) having at least one count output (30) and with an integrator section (24) having an intensity output (32), wherein the processing electronics (18) is adapted to be connected to a sensor (16) in such a manner that X-ray photons (58) arriving at the sensor (16) can be processed by the pulse counter section (22), by the integrator section (24), or both, and wherein the processing electronics (18) comprises a processor (34) adapted to be connected to the count output (30) and to the intensity output (32) and adapted to output a count result (K) that takes into account both count information (N) obtained at the count output (30) and intensity information (I) obtained at the intensity output (32), so that the count result (K) contains information (N) obtained from the pulse counter section (22) and information (M) obtained from the integr

Abstract: The invention relates to converter element (100) for a radiation detector, particularly for a Spectral CT scanner. The converter element (100) comprises at least two conversion cells (131) that are at least partially separated from each other by intermediate separation walls (135) which affect the spreading of electrical signals generated by incident radiation (X). The conversion cells (131) may particularly consist of a crystal of CdTe and/or CdZnTe. Said crystal is preferably grown by e.g. vapor deposition between preformed separation walls.

Abstract: The invention relates to a radiation detector (100) comprising a converter element (113) with an array (120) of first electrodes (121) for sampling electrical signals generated by incident radiation (X). With a connection circuit (130), at least two first electrodes (121) can selectively be coupled to a common readout unit (141) according to a given connection pattern (CP1). The effective pixel size along the path of incident radiation (X) can thus be adapted to the distribution of electrical signals, which is usually determined by the spectral composition of the incident radiation.

Abstract: The invention relates to a radiation detector and a method for its production, wherein a series of converter plates (110) and interconnect layers (120), which extend into a border volume (BV) lateral of the converter plates (110), are stacked. By filling voids in the border volume (BV) with an underfill material and cutting through the border volume, a contact surface (CS) is generated in which electrical leads (123) of the interconnect layers (120) lie free. To allow a good contacting, said leads (123) are preferably provided with enlargements in the contact surface, for example by bonding wires (132) to them.

Abstract: The invention relates to a radiation detector (100) that is particularly suited for energy resolved single X-ray photon detection in a CT scanner. In a preferred embodiment, the detector (100) comprises an array of scintillator elements (S k) in which incident X-ray photons (X) are converted into bursts of optical photons (hn). Pixels (P k) associated to the scintillator elements (S k) determine the numbers of optical photons they receive within predetermined acquisition intervals. These numbers can then be digitally processed to detect single X-ray photons (X) and to determine their energy. The pixels may particularly be realized by avalanche photodiodes with associated digital electronic circuits for data processing.

Abstract: The invention relates to a radiation detector (100), particularly for X-rays (X) and for y-rays, which comprises a combination of (a) at least one primary conversion layer (101a-101f) with a low attenuation coefficient for the photons and (b) at least one secondary conversion layer (102) with a high attenuation coefficient for the photons. In preferred embodiments, the primary conversion layer (101a-101f) may be realized by a silicon layer coupled to associated energy-resolving counting electronics (111a-111f, 121). The secondary conversion layer (102) may be realized for example by CZT or GOS coupled to energy-resolving counting electronics or integrating electronics. Using primary conversion layers with low stopping power allows to build a stacked radiation detector (100) for spectral CT in which the counting rates of the layers are limited to feasible values without requiring unrealistic thin layers.

Abstract: The invention relates to a radiation detector and a method for producing such a detector, wherein the detector comprises a stack of the scintillator elements and photodiode arrays. The PDAs extend with electrical leads into a rigid body filling a border volume lateral of the scintillator elements, wherein said leads end in a contact surface of the border volume. Moreover, a redistribution layer is disposed on the contact surface, wherein electrical lines of the redistribution layer contact the leads of the PDAs.