Radiological instrument with pulse shaping circuit
By using a pulse shaper circuit with feedback capacitors and switching units in a direct conversion radiation detector, the noise problem caused by ballistic defect effects was solved, and the image quality of the X-ray imaging system was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KONINKLIJKE PHILIPS NV
- Filing Date
- 2020-12-23
- Publication Date
- 2026-05-26
Smart Images
Figure CN114902077B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the detection of ionizing radiation, and more particularly to a system using a direct conversion X-ray detector. Background Technology
[0002] A shaping circuit is used to convert current pulses used in direct-conversion radiation detectors (such as CZTs) into voltage pulses. When X-rays are detected using a direct-conversion radiation detector, the ballistic defect (BD) effect causes the output pulse from the shaping circuit to have a slightly different amplitude for X-rays with the same energy. In computed tomography (CT) systems, these slight variations in amplitude caused by BD can often increase noise or affect image quality.
[0003] US Patent Application Publication US 20160299002 A1 discloses a detection device for detecting photons emitted by a radiation source and capable of adjusting ballistic defects. The detection device includes a preamplifier unit (e.g., a charge-sensitive amplifier), a shaping unit including a feedback discharge unit, and a feedback discharge control unit coupled to the feedback discharge unit. The feedback discharge control unit is adapted to adjust the resistance of a feedback resistor (and / or adjust the current value of a feedback current source), for example, when the electrical pulse generated by the shaping unit does not exceed at least one energy comparison value. The feedback discharge control unit is adapted not to adjust the parameters of the feedback discharge unit when the electrical pulse exceeds at least one energy comparison value. By adjusting the operating point of the feedback resistor, the ballistic defect can be adjusted to a predefined expected value.
[0004] European patent application EP3385756A1 discloses a pulse shaper comprising an integrator and a feedback resistor for generating pulses with peak amplitudes indicating the energy of detected photons, a switchable discharge circuit for discharging the integrator, and a peak detector. The pulse shaper initiates the discharge of the integrator based on the detection of the peak value, connects the feedback resistor in parallel with the integrator during pulse generation, and disconnects the feedback resistor during another period of pulse generation.
[0005] U.S. Patent Application US2020 / 329425A1 discloses a data acquisition system including a charge-sensitive amplifier (CSA) configured to receive charge from an X-ray detector. The CSA includes a high-gain electronic voltage amplifier, an energy storage device coupled to the amplifier, and a resistor coupled to the amplifier. The data acquisition system includes: a baseline sampling circuit configured to receive an output from the CSA and sample a baseline signal from the CSA; at least one discriminator coupled to the output of the CSA and the output of the baseline sampling circuit, the at least one discriminator being configured to output a voltage if the output of the CSA exceeds a threshold; and a counter coupled to the output of the discriminator and configured to output a digital signal indicating a photon count received at the X-ray detector based on the output of the CSA and the signal from the CSA. Summary of the Invention
[0006] The present invention provides radiological instruments, imaging systems, computer program products, and methods in the independent claims. Embodiments are given in the dependent claims.
[0007] The embodiments can provide improved methods for reducing or eliminating ballistic defect effects in pulse shaper circuits. This can be achieved by providing a pulse shaper circuit that includes an amplifier configured as an integrator. A feedback capacitor may be present between the input and output of the amplifier. Additionally, a feedback circuit is present, connected in parallel with the feedback capacitor or the input and output of the amplifier. In some examples, the feedback circuit may be a current source or a discharge resistor. The discharge resistor may also be referred to as a feedback resistor. A first switching unit may be connected in parallel with the input and output of the amplifier. When the first switching unit is turned off, the feedback circuit is effectively removed from the circuit.
[0008] The second switching unit can be connected to both the input and output of the amplifier. When closed, the second switching unit acts as a short circuit to quickly reset the integrator or equivalently discharge the feedback capacitor (if present). The second switching unit can be connected in series with a short-circuit resistor. If present, the short-circuit resistor can be chosen such that it depletes the feedback capacitor faster than the feedback circuit.
[0009] In some examples, a control unit can be provided for controlling the first and second switching units. In this example, the control unit controls the second switching unit such that when the second switching unit is closed, a large portion of the signal is integrated.
[0010] A discrimination circuit can be connected to the amplifier's output. If the output voltage exceeds a controllable signal threshold, the discrimination circuit, in some examples, sends a discrimination signal to the timing circuit. The timing circuit can then immediately disconnect the first switching unit and remove the feedback circuit from the circuit. After a first delay, the timing circuit then closes the second switching unit to discharge the feedback capacitor. The first delay is long enough for the signal from the direct-conversion radiation detector to be collected. After the second switching circuit closes, the timing circuit waits for a second delay until the timing unit disconnects the second switching circuit. The second delay can be selected to allow the feedback capacitor to discharge or fully discharge. In some examples, the timing circuit closes the first switching circuit when the second switching unit closes.
[0011] Therefore, when the output signal exceeds the controllable signal threshold, the first switching unit is disconnected to eliminate the effect of the discharge resistor on the circuit, and the second switching unit, after a first delay, returns the feedback capacitor to a consistent state for the next pulse shaping event. The effect of using these two switching units is a significant reduction in BD (damping artifacts). The circuitry is simplified compared to other solutions for reducing BD. When used in imaging systems, such as medical systems like CT systems, the reduced BD can potentially decrease image artifacts.
[0012] In one aspect, the present invention provides a radiological instrument comprising at least one pulse shaping circuit. The at least one pulse shaping circuit is configured to receive an input signal from a direct conversion radiation detector. In a direct conversion radiation detector, ionizing radiation enters the detector and directly creates a current. Typically, a direct conversion radiation detector is a semiconductor.
[0013] The at least one pulse shaper circuit includes a shaper input configured to receive an input signal. Each of the at least one pulse shaper circuit includes a shaper input terminal. The at least one pulse shaper circuit also includes a shaper output terminal configured to provide an output signal in response to the input signal. Each of the at least one pulse shaper circuit includes a shaper output terminal. The at least one pulse shaper circuit also includes an amplifier having an amplifier input terminal connected to the shaper input terminal and an amplifier output terminal connected to the shaper output terminal. The amplifier is configured as an integrator. An amplifier is present for each of the at least one pulse shaper circuits.
[0014] The at least one pulse shaper circuit may further include a feedback capacitor connected between the amplifier input and the amplifier output. Each of the at least one pulse shaper circuits may include a different or separate feedback capacitor. The at least one pulse shaper circuit also includes a feedback circuit connected in parallel with the feedback capacitor, the feedback circuit being configured to continuously reset the integrator, for example, by continuously discharging the feedback capacitor. The feedback circuit is selected to allow the amplifier to still function as an integrator while gradually discharging the feedback capacitor. A feedback circuit is present for each of the at least one pulse shaper circuits. The feedback circuit may be, for example, a current source or a discharge resistor.
[0015] The at least one pulse shaper circuit further includes a first switching unit connected in series with the feedback circuit and configured to disable the feedback circuit when disconnected. In some examples, the first switching unit is a solid-state switching unit or a switch. A first switching unit is present for each of the at least one pulse shaping circuits. The at least one pulse shaping circuit also includes a second switching unit connected in parallel with the amplifier. For example, the second switching unit may be connected between the input and output of the amplifier, or across a feedback capacitor (if present). A second switching unit is present for each of the at least one pulse shaping circuits. The second switching unit may also be implemented as a solid-state switch or a switching unit.
[0016] The at least one pulse shaper circuit further includes a discrimination circuit connected to the amplifier output. The discrimination circuit is configured to provide a discrimination signal when the amplifier output exceeds a controllable signal threshold. A discrimination circuit is present for each of the at least one pulse shaper circuits. The controllable signal threshold may be, for example, programmable, controllable, or adjustable.
[0017] The at least one pulse shaping circuit may include a control unit for controlling the first switching unit and the second switching unit, wherein the control unit controls the second switching unit such that when the second switching unit is closed, most of the signal is integrated.
[0018] In another embodiment, the at least one control unit includes a timing circuit configured to control the first switching unit and the second switching unit. The timing circuit may be implemented as a controller, or it may be implemented as an analog electronic device. The timing circuit is configured to receive the authentication signal. The timing circuit is configured to open the first switching unit upon receiving the authentication signal or in response to receiving the authentication signal. The timing circuit is also configured to close the second switching unit after a first delay. The timing circuit is configured to open the second switching unit after a second delay following the closing of the second switching unit. In some examples, the timing circuit is configured to close the first switching unit after a third delay. In other examples, the timing circuit is configured to close the first switching unit when the second switching unit is closed or while the second switching unit is closing.
[0019] This embodiment may be advantageous because it provides a pulse shaper that more accurately provides an output pulse proportional to or correlated with the energy of the incoming or detected ionizing radiation. When the timing circuit receives the discrimination signal, the first switching unit is disconnected, effectively removing the feedback circuit (e.g., a discharge resistor or current source) from the circuit. The feedback circuit is no longer connected in parallel with the feedback capacitor, thus eliminating the filtering effect of the discharge resistor.
[0020] For large incoming pulses, the signal has less BD. A first delay can be selected to allow sufficient time to collect all or substantially all of the current from the direct-conversion radiation detector. After this first delay, the second switching unit closes and effectively short-circuits the feedback capacitor. This helps the integrator of the pulse shaper to form a narrow pulse. After a second delay, the feedback capacitor has been effectively discharged or sufficiently depleted. After the second delay, the second switching unit opens, causing the amplifier to operate as an integrator again.
[0021] In another embodiment, the first delay is controllable and / or programmable.
[0022] In another embodiment, the second delay is controllable and / or programmable.
[0023] In another embodiment, the third delay is controllable and / or programmable.
[0024] In another embodiment, the control unit includes a maximum value detector connected to the amplifier output and configured to detect a maximum value of the output signal. The control unit is configured to close the second switching unit upon detecting the maximum value. The control unit is configured to open the first switching unit in response to receiving the discrimination signal. The control unit is configured to close the first switching unit after a fourth delay. The control unit is further configured to open the second switching unit after a fifth delay.
[0025] In another embodiment, the fourth delay is controllable and / or programmable.
[0026] In another embodiment, the fourth delay is a delay between detecting the maximum value of the output signal. In some embodiments, the fourth delay is configured such that the first switching unit closes immediately after the maximum value of the output signal is detected. In other embodiments, the delay is configured such that the first switching unit closes after the second switching unit has already closed or while the second switching unit is closing.
[0027] In another embodiment, the fifth delay is controllable and / or programmable. In some embodiments, the fifth delay is configured such that the second switching unit closes once the maximum value of the output signal is detected.
[0028] In another embodiment, the radiological instrument includes a direct conversion radiation detector for each of the at least one pulse shaper circuit. This embodiment may be advantageous because the pulse shaper circuit can be tuned to operate optimally with its direct conversion radiation detector.
[0029] In another embodiment, the direct conversion radiation detector is a zinc cadmium telluride detector.
[0030] In another embodiment, the direct conversion radiation detector is a cadmium telluride detector.
[0031] In another embodiment, the direct conversion radiation detector is an amorphous selenium detector.
[0032] In another embodiment, the direct conversion radiation detector is a lithium-doped silicon detector.
[0033] In another embodiment, the direct conversion radiation detector is a lithium-doped germanium detector.
[0034] In another embodiment, the at least one pulse shaper circuit is a plurality of pulse shaper circuits. In other words, there are multiple pulse shaper circuits, not just one. The radiological instrument includes a radiation detector array that includes or is connected to the plurality of pulse shaper circuits. This can be used, for example, to manufacture various imaging systems, such as CT systems, digital X-ray systems, etc.
[0035] In another embodiment, the radiological instrument further includes a pulse height analyzer connected to the shaper output. This embodiment may be advantageous because the pulse height analyzer is used to count the number of pulses within a specific voltage or energy range. The use of at least one pulse shaper circuit can provide more accurate counting in different channels.
[0036] As used herein, a pulse height analyzer includes an instrument configured to count the number of pulses falling into each of one or more predetermined or adjustable amplitude ranges. A pulse height analyzer may also be referred to as a kick sorter or a multichannel analyzer (MCA).
[0037] In another embodiment, the first delay is between 5 ns and 30 ns. This embodiment may be advantageous because, depending on the type of direct conversion radiation detector, the full current from the detector can be collected after the ionizing radiation has caused an event in the detector.
[0038] In another embodiment, the first delay is between 8 ns and 30 ns. This embodiment may be advantageous because it can provide a better measurement of the current generated by the direct-conversion radiation detector.
[0039] In another embodiment, the second delay is between 1 ns and 10 ns. This embodiment may be advantageous because this amount of time may be sufficient for the feedback capacitor to discharge and for at least one pulse shaper circuit to prepare to receive another pulse.
[0040] In another embodiment, the second delay is between 3 ns and 5 ns. This embodiment may be advantageous because it provides a more accurate time range within which the actual feedback capacitor is exhausted.
[0041] In another embodiment, the first delay and / or the second delay is programmable and / or controllable. This can be achieved, for example, in some examples by a timing circuit that functions as a controller or microcontroller. In other examples, the timing circuit may be a configurable analog circuit. The ability to program the first delay and / or the second delay can be advantageous because it can provide an output pulse with a higher accuracy relative to the energy absorbed by the direct conversion radiation detector.
[0042] In another embodiment, the second switching unit is configured to be short-circuited. This embodiment may be advantageous because the short circuit can be used to quickly deplete the discharge resistor and prepare the pulse shaper circuitry to receive another input signal.
[0043] In another embodiment, the short circuit has a short-circuit resistance. The short-circuit resistance is smaller than the discharge resistance. This embodiment may be advantageous because it allows the feedback capacitor to deplete more quickly.
[0044] On the other hand, the present invention provides an imaging system comprising an array of radiation detectors. This embodiment may be advantageous because the use of a first switching unit and timing circuitry can provide an imaging system that images an object using less ionizing radiation. For example, this can reduce the health risks associated with scanning using the imaging system. This embodiment can also be further advantageous because the pulse shaping circuitry can achieve more accurate energy identification or the spectrum of ionizing radiation. This can, for example, provide improved quality of images generated or acquired by the imaging system.
[0045] In another embodiment, the imaging system further includes a memory and a processor. The memory contains machine-executable instructions and imaging system control commands. Execution of the machine-executable instructions also causes the processor to receive configuration commands. The configuration commands include control unit configuration data. In some embodiments, the control unit configuration data includes time delay configuration data. The configuration commands may also include data for configuring controllable signal thresholds.
[0046] The execution of the machine-executable instructions causes the processor to receive configuration commands—the configuration commands including control unit configuration data. The execution of the machine-executable instructions also causes the processor to configure the control unit using the control unit configuration data. Furthermore, the execution of the machine-executable instructions causes the processor to control the imaging system to acquire imaging data using the imaging system control commands.
[0047] In another embodiment, the control unit is implemented using a timing circuit. The control unit configuration data includes time delay configuration data. The execution of the machine-executable instructions causes the processor to control the timing circuit to configure the first delay and / or the second delay using the time delay configuration data. The third delay can also be configured using the time delay configuration data.
[0048] In this step, the controllable signal threshold can also be configured. The execution of the machine-executable instructions further enables the processor to acquire imaging data (e.g., medical imaging data) by controlling the imaging system using imaging system control commands. The imaging system control commands are instructions or data that can be translated into instructions for controlling the operation and function of the imaging system. This embodiment may be advantageous because it can provide a means of customizing the configuration of at least one pulse shaper circuit for a specific imaging protocol. This can, for example, result in a reduction in the object's exposure to radiation, and it can also provide an improvement in the spectral resolution of the imaging data.
[0049] In another embodiment, the imaging system is a computed tomography system.
[0050] In another embodiment, the imaging system is a positron emission tomography (PET) scanner.
[0051] In another embodiment, the imaging system is a single-photon emission computed tomography (SPECT) system or scanner.
[0052] In another embodiment, the imaging system is a digital X-ray system. For example, the digital X-ray system may be a digital fluorescence microscope system.
[0053] In another embodiment, the imaging system is a computed tomography (CT) system. The CT system includes a rotatable gantry. The rotatable gantry includes an X-ray source and a radiation detector array. The radiation detector array can be arranged such that it can measure the absorption distribution from the X-ray source as the gantry rotates around the object. The CT system is a spectral computed tomography (SCT) system. This embodiment may be advantageous because the use of at least one pulse shaper circuit can provide improved spectral resolution for the spectral computed tomography system.
[0054] In another aspect, the present invention provides a computer program product including machine-executable instructions for execution by a processor controlling an imaging system. The imaging system includes pulse shaper circuitry. Each pulse shaper circuit is configured to receive an input signal from a separate direct-conversion radiation detector. Each pulse shaper circuit includes a shaper input configured to receive the input signal. Each pulse shaper circuit includes a shaper output configured to provide an output signal in response to the input signal. Each pulse shaper circuit includes an amplifier having an amplifier input connected to the shaper input and an amplifier output connected to the shaper output. The amplifier is configured as an integrator.
[0055] Each pulse shaper circuit may include a feedback capacitor connected between the amplifier input and the amplifier output. Each pulse shaper circuit includes a feedback circuit, such as a discharge resistor or current source, connected in parallel with the amplifier, or, if a feedback capacitor is present, configured to continuously reset the integrator. This is done, for example, by discharging the feedback capacitor (if present). Each pulse shaper circuit includes a first switching unit connected in series with the feedback circuit and configured to disable the feedback circuit when disconnected.
[0056] Each pulse shaper circuit includes a second switching unit connected in parallel with an amplifier or a feedback capacitor. The second switching unit is configured to reset the integrator or to discharge the feedback capacitor when closed. Each pulse shaper circuit includes a discrimination circuit connected to the amplifier output. The discrimination circuit is configured to provide a discrimination signal when the amplifier output exceeds a controllable signal threshold. Each pulse shaper circuit includes a control unit configured to control the first and second switching units.
[0057] The imaging system also includes a direct-conversion radiation detector for each pulse shaper circuit. The imaging system also includes a radiation detector array that includes or is connected to multiple pulse shaper circuits. The imaging system further includes an imaging system. The imaging system also includes a memory and a processor. The memory contains machine-executable instructions and imaging system control commands. The execution of the machine-executable instructions causes the processor to receive configuration commands. The configuration commands include control unit configuration data.
[0058] The execution of the machine-executable instructions also causes the processor to control the timing circuitry to configure the control unit using the control unit configuration data. The execution of the machine-executable instructions also causes the processor to control the imaging system to acquire imaging data using the imaging system control commands. In some embodiments, the imaging data can be reconstructed into an image by the processor.
[0059] In another aspect, the present invention provides a method of operating an imaging system. The imaging system includes pulse shaper circuitry. Each pulse shaper circuit is configured to receive an input signal from a separate direct-conversion radiation detector.
[0060] Each pulse shaper circuit includes a shaper input configured to receive an input signal. Each pulse shaper circuit includes a shaper output configured to provide an output signal in response to the input signal. Each pulse shaper circuit includes an amplifier having an amplifier input connected to the shaper input and an amplifier output connected to the shaper output. The amplifier is configured as an integrator. Each pulse shaper circuit may include a feedback capacitor connected between the amplifier input and the amplifier output. Each pulse shaper circuit includes a feedback circuit, such as a discharge resistor or current source, connected in parallel with the feedback capacitor, configured to continuously discharge the feedback capacitor. Each pulse shaper circuit includes a first switching unit connected in series with the feedback circuit and configured to disable the feedback circuit when disconnected. Each pulse shaper circuit includes a second switching unit connected to the input and output of the amplifier or connected in parallel with the feedback capacitor.
[0061] Each pulse shaper circuit includes a discrimination circuit connected to the amplifier output. The discrimination circuit is configured to provide a discrimination signal when the amplifier output exceeds a controllable signal threshold. Each pulse shaper circuit includes a control unit configured to control a first switching unit and a second switching unit. The control unit receives the discrimination signal. The timing circuit disconnects the first switching unit, causing a majority of the signal to be integrated.
[0062] The imaging system also includes a direct-conversion radiation detector for each of the pulse shaper circuits. The imaging system includes radiation detectors that are included in or connected to the plurality of pulse shaper circuits and a direct-conversion radiation detector for each of the pulse shaper circuits. The imaging system also includes an imaging system. The imaging system further includes a memory and a processor. The memory contains machine-executable instructions and imaging system control commands.
[0063] The method includes receiving a configuration command. The configuration command includes control unit configuration data. The method further includes configuring the control unit using the control unit configuration data. The method also includes acquiring imaging data by controlling an imaging system using imaging system control commands.
[0064] It should be understood that one or more of the foregoing embodiments of the present invention may be combined, as long as the combined embodiments are not mutually exclusive.
[0065] As those skilled in the art will recognize, several aspects of the invention can be implemented as apparatus, method, or computer program product. Therefore, aspects of the invention can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, which can be collectively referred to herein as “circuit,” “module,” or “system.” Furthermore, aspects of the invention can take the form of computer program products implemented in one or more computer-readable media having computer-executable code implemented thereon.
[0066] Any combination of one or more computer-readable media can be used. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" includes any tangible storage medium that can store instructions executable by a processor of a computing device. The computer-readable storage medium may be referred to as a "computer-readable non-transient storage medium." The computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, the computer-readable storage medium may also be able to store data accessible by the processor of the computing device. Examples of computer-readable storage media include, but are not limited to: floppy disks, magnetic hard disk drives, solid-state drives, flash memory, USB thumb drives, random access memory (RAM), read-only memory (ROM), optical disks, magneto-optical disks, and processor register files. Examples of optical disks include compact optical disks (CDs) and digital multi-purpose optical disks (DVDs), such as CD-ROMs, CD-RWs, CD-Rs, DVD-ROMs, DVD-RWs, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media accessible by the computer device via a network or communication link. For example, data may be retrieved via a modem, via the Internet, or via a local area network. Computer-executable code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, or any suitable combination of the foregoing.
[0067] Computer-readable signal media may include propagated data signals having computer-executable code implemented therein, for example, in baseband or as part of a carrier wave. Such propagated signals may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and is capable of transmitting, propagating, or conveying a program for use by or in connection with an instruction execution system, apparatus, or device.
[0068] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that a processor can directly access. "Computer storage device" or "storage device" is another example of a computer-readable storage medium. A computer storage device is any non-volatile computer-readable storage medium. In some embodiments, a computer storage device may also be computer memory, or vice versa.
[0069] As used herein, the term "processor" encompasses any electronic component capable of executing programs or machine-executable instructions or computer-executable code. References to computing devices including "processor" should be interpreted as including more than one processor or processing core. A processor may, for example, be a multi-core processor. A processor can also refer to a collection of processors within a single computer system or distributed across multiple computer systems. The term computing device should also be interpreted as potentially referring to a collection or network of computing devices, each including one or more processors. The computer-executable code can be run by multiple processors, which may reside within the same computing device or even be distributed across multiple computing devices.
[0070] Computer executable code may include machine-executable instructions or programs that instruct a processor to perform aspects of the present invention. Computer executable code for performing operations relating to aspects of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as "C" or similar programming languages, and compiled into machine-executable instructions. In some cases, the computer executable code may be used in the form of a high-level language or in a pre-compiled form in conjunction with an interpreter that generates machine-executable instructions in flight.
[0071] The computer-executable code can run as a standalone software package entirely on the user's computer, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network (including a local area network (LAN) or a wide area network (WAN)) or via a connection to an external computer (e.g., via the Internet using an Internet service provider).
[0072] Various aspects of the present invention are described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block or portion of a block in a flowchart, illustration, and / or block diagram can be implemented, where applicable, by computer program instructions in the form of computer-executable code. It should also be understood that combinations of blocks in different flowcharts, illustrations, and / or block diagrams can be combined when not mutually exclusive. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that instructions executed via the processor of the computer or other programmable data processing apparatus create units for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram.
[0073] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus or other device to operate in a particular manner, such that the instructions stored in the computer-readable medium produce an article of writing comprising instructions that implement the functions / actions specified in flowcharts and / or one or more block diagrams.
[0074] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the instructions running on the computer or other programmable apparatus provide for implementing the functions / actions specified in the flowchart and / or one or more block diagram boxes.
[0075] As used herein, a "user interface" is an interface that allows a user or operator to interact with a computer or computer system. A "user interface" can also be referred to as a "human-machine interface device." A user interface can provide information or data to an operator and / or receive information or data from an operator. A user interface enables input from an operator to be received by the computer and can provide output from the computer to the user. In other words, a user interface allows an operator to control or manipulate a computer, and the interface allows the computer to indicate the effects of the operator's control or manipulation. The display of data or information on a monitor or graphical user interface is an example of providing information to an operator. Receiving data via a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, gamepad, webcam, helmet, pedal, wired gloves, remote control, and accelerometer are all examples of user interface components that implement the receiving of information or data from an operator.
[0076] As used herein, "hardware interface" encompasses any interface that enables a computer system's processor to interact with or control external computing devices and / or apparatuses. A hardware interface allows the processor to send control signals or instructions to external computing devices and / or apparatuses. A hardware interface also enables the processor to exchange data with external computing devices and / or apparatuses. Examples of hardware interfaces include, but are not limited to: Universal Serial Bus (USB), IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connectivity, wireless LAN connectivity, TCP / IP connectivity, Ethernet connectivity, control voltage interface, MIDI interface, analog input interface, and digital input interface.
[0077] As used herein, the terms "display" or "display device" encompass output devices or user interfaces suitable for displaying images or data. Displays can output visual, audio, and tactile data. Examples of displays include, but are not limited to: computer monitors, television screens, touchscreens, haptic electronic displays, Braille screens, cathode ray tubes (CRTs), memory tubes, bistable displays, electronic paper, vector displays, flat panel displays, vacuum fluorescent displays (VFs), light-emitting diode (LED) displays, electroluminescent displays (ELDs), plasma display panels (PDPs), liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, projectors, and head-mounted displays.
[0078] Imaging data is defined in this paper as the recorded measurement results of data acquired by an imaging system. Imaging data may also be referred to in some cases as medical imaging data or in others as tomographic imaging data. Imaging data can be reconstructed into one or more images to visualize the structure of an object. This visualization can be performed using a computer.
[0079] In some examples, such as CT, tomographic reconstruction can be performed. For CT systems, the imaging data can be X-ray absorption curves that can be used to reconstruct tomographic images. Attached Figure Description
[0080] In the following description, preferred embodiments of the invention will be illustrated by way of example only and with reference to the accompanying drawings, in which:
[0081] Figure 1 An example of a radiological instrument is illustrated;
[0082] Figure 2 Another example of an imaging system is illustrated;
[0083] Figure 3 Another example of an imaging system is illustrated;
[0084] Figure 4 Another example of an imaging system is illustrated;
[0085] Figure 5 This is a flowchart illustrating an example of the operation method of the imaging system of claim 2, 3 or 4;
[0086] Figure 6 This illustration shows another example of a radiological instrument;
[0087] Figure 7 Another example of a radiological instrument is illustrated; and
[0088] Figure 8 Another example of a radiological instrument is illustrated.
[0089] List of reference numerals
[0090] 100 Radiographic Instruments
[0091] 102 Pulse Shaping Circuit
[0092] 104 Shaper Input Terminal
[0093] 106 Shaper Output Terminal
[0094] 108 Direct Conversion Radiation Detector
[0095] 110 amplifier
[0096] 112 Amplifier Input Terminal
[0097] 114 Amplifier Output Terminal
[0098] 116 Feedback capacitor
[0099] 118 Discharge resistor
[0100] 120 First Switching Unit
[0101] 122 Second Switching Unit
[0102] 124 Discrimination Circuit
[0103] 124' Discrimination Circuit
[0104] 126 Timing Circuit
[0105] 128 Discrimination Signal
[0106] 200 Imaging System
[0107] 202 CT System
[0108] 204 Computer
[0109] 206 Rotatable Frame
[0110] 208 axis of rotation or axis of symmetry
[0111] 210 Object Support
[0112] 212 Objects
[0113] 214 X-ray tube
[0114] 216 Radiation Detector Array
[0115] 218 X-rays
[0116] 220 Imaging Area
[0117] 230 processor
[0118] 232 Hardware Interface
[0119] 234 User Interface
[0120] 236 memory
[0121] 240 Machine-Executable Instructions
[0122] 242 Imaging System Control Commands
[0123] 244 Configuration Commands
[0124] 246 Imaging Data
[0125] 248 images
[0126] 300 Imaging System
[0127] 302 X-ray System
[0128] 400 Imaging System
[0129] 402 SPECT system
[0130] 404 Inspection Ring
[0131] 410 Radionuclides
[0132] 412 gamma radiation
[0133] 500 Receive configuration command
[0134] 502 controls the timing circuit to configure a first delay and / or a second delay using delay configuration data.
[0135] 504 Imaging data is acquired by controlling the imaging system using imaging system control commands.
[0136] 600 Radiographic Instruments
[0137] 602 Counter
[0138] 604 Pulse Height Analyzer
[0139] 700 Radiographic Instruments
[0140] 800 Radiographic Instruments Detailed Implementation
[0141] In these figures, similarly numbered elements are equivalent elements or perform the same function. If the functions are equivalent, elements that have been discussed previously will not necessarily be discussed in later figures.
[0142] Figure 1 An example of a radiological instrument 100 is illustrated. The radiological instrument 100 includes a pulse shaper circuit 102. The pulse shaper circuit 102 has a shaper input 104 for receiving signals and a shaper output 106 for outputting shaped signals. The radiological instrument 100 is shown connected to a direct conversion radiation detector 108. In some examples, the direct conversion radiation detector 108 will be part of the radiological instrument 100, while in other examples it is not. For example, multiple pulse shaper circuits can be used to fabricate a pixelated radiation detector with multiple direct conversion radiation detectors 108. In other examples, the pulse shaper circuit 102 can be provided in a separate circuit that can be used to construct various experiments. For example, the pulse shaper circuit 102 can be provided in the form of a nuclear instrument module (NIM).
[0143] The pulse shaper circuit 102 is shown as including an amplifier 110 having an amplifier input 112 and an amplifier output 114. The amplifier 110 is configured as an integrator. Therefore, a feedback capacitor 116 exists between the amplifier input 112 and the amplifier output 114. A discharge resistor 118 is also present, which acts as a feedback resistor, but in this application is also used to gradually discharge the feedback capacitor 116. A first switching unit 120 is present in series with the discharge resistor 118. The discharge resistor in this circuit and other circuits can be replaced by a current source. The current of this current source is then controlled by the voltage between the amplifier's input and output, and the supplied current may depend on this voltage. A second switching unit 122 is present in parallel with the feedback capacitor 116. The second switching unit 122 serves as a short circuit for discharging the feedback capacitor 116. In some cases, the second switching unit 122 may also be connected in series with a short-circuit resistor. In this case, the short-circuit resistor will be much smaller than the discharge resistor 118.
[0144] Amplifier output 114 is connected to discrimination circuit 124. When the voltage output at amplifier output 114 rises above a controllable signal threshold, discrimination circuit 124 provides discrimination signal 128. This causes first switching unit 120 to immediately open, and timing circuit 126 subsequently causes second switching unit 122 to close after a first delay. Timing circuit 126 can then be configured to open again after a second delay from when second switching unit 122 was initially closed. Timing circuit 126 can also be configured to close first switching unit 120 while second switching unit 122 is still closed.
[0145] The opening of the first switching unit 120 has the effect of temporarily removing the discharge resistor 118 from the circuit. This helps reduce ballistic defect effects. When the voltage signal at output terminal 114 rises rapidly, the output signal may be distorted, which may cause changes in the height of the output voltage pulse. Removing the discharge resistor 118 from the circuit helps reduce ballistic defects because the incoming charge is no longer discharged via the discharge resistor from the point when the first switching unit is turned on. The timing circuit 126 can be programmed for a first delay to wait until all or most of the current from the direct conversion radiation detector 108 has been collected. Then the closing of the second switching unit 122 causes the feedback capacitor 116 to discharge rapidly. This helps prepare the pulse shaper circuit 102 to quickly receive another pulse from the direct conversion radiation detector 108.
[0146] Figure 2An imaging system 200 is shown. In this example, the imaging system 200 is shown as including a CT system 202 and a computer 204. The CT or computed tomography system 202 has a rotating gantry 206 having a rotation axis or axis of symmetry 208. An object support 210 is present, which supports an object 212 within the rotating gantry 206. Within the rotating gantry 206 is an X-ray tube 214, which is opposite to a radiation detector array 216. The radiation detector array 216 consists of a pixelated array of direct-conversion radiation detectors 108 connected to a pulse shaper circuit 102, such as... Figure 1 As shown.
[0147] In some examples, the radiation detector array 216 may also include a pulse height analyzer for outputting large amounts of data to the computer 204. The X-ray tube 214 is shown generating X-rays 218 that pass through an object within the imaging region 220. The X-rays are then received by the radiation detector array 216. The use of the pulse shaping circuit 102 can reduce the amount of radiation required to generate a computed tomography (CT) image. The computed tomography system 200 can also be a multispectral computed tomography system. In this case, the high voltage of the X-ray tube 214 can be varied. Typically, the high voltage oscillates between two voltages. The X-ray spectra of these two voltages are then compared to create a multispectral CT image. The use of the pulse shaping circuit 102 can increase the accuracy of the multispectral CT image.
[0148] The computed tomography system 202 is shown as a hardware interface 232 connected to the computer system 204. The hardware interface 232 is connected to a processor 230. The processor 230 is also shown connected to an optional user interface 234 and memory 236. The hardware interface 232 enables the processor 230 to send and receive commands and data from the computed tomography system 202. The hardware interface 232 can also be used to network the computer 204 with other computer systems.
[0149] Memory 236 is shown to contain machine-executable instructions 240. The machine-executable instructions 240 contain commands that enable processor 230 to control the operation and functions of imaging system 200 and to perform various data analysis and image processing tasks.
[0150] Memory 236 is also shown to contain imaging system control commands 242. These are commands or data that can be translated into sequential operations controlling the computed tomography loop 202 to acquire imaging data. Memory 236 is also shown to contain configuration commands 244 including time delay configuration data. The time configuration data can be used to program a first delay and / or a second delay.
[0151] Memory 236 is shown containing imaging data 246 obtained by controlling the computed tomography system 202 using imaging system control commands 242 and programming the timing circuit 126 using timing configuration data. Finally, memory 236 is shown having an image 248 reconstructed from the imaging data 246. In this example, the imaging data 246 will be the X-ray absorption distribution and the image 248 will be a computed tomography image.
[0152] Figure 3 Another example of the imaging system 300 is illustrated. Figure 3 The imaging system 300 shown in the middle diagram is similar to Figure 2 The imaging system 200, except that the computed tomography system 202 has been replaced by an X-ray system 302. The X-ray system includes an X-ray tube 214 that emits X-rays 218 that pass through the object 212 to reach a radiation detector array 216. The X-ray system 302 is therefore a digital X-ray system. For example, the X-ray system 302 could be a digital fluorescence microscope system. The X-ray tube 214 and the radiation detector array 216 are shown as being controlled by a hardware interface 232 of the computer system 204.
[0153] Figure 4 Another example of the imaging system 400 is illustrated. Figure 4 The imaging system 400 is similar to Figure 2 and Figure 3 The imaging system shown is, in this case, a single-photon emission computed tomography (SPECT) system 402. SPECT system 402 includes a detector ring 404 with an axis of symmetry 208. Detector ring 404 includes multiple detector rays 216 arranged within the ring. Object 212 has ingested a radionuclide 410. The radionuclide undergoes decay and emits a single gamma photon 412. The system uses detector array 216 to acquire multiple gamma radiation events 412. When sufficient data has been collected in imaging data 246, image 248 is reconstructed. Although not depicted, a similar arrangement can be used to construct a positron emission tomography (PET) system.
[0154] Figure 5 The illustrated operation is shown. Figure 2 , Figure 3 or Figure 4A flowchart of a method for any of the imaging systems 200, 300, and 400 shown. First, in step 500, a configuration command 244 is received. In some cases, the configuration command 244 may be part of the imaging system control command 242. For example, for a specific imaging protocol, the configuration of first and second delays may be programmed into the imaging system control command 242. Next, in step 502, the timing circuit 126 is controlled by the configuration command 242. The configuration command 242 controls time delay configuration data used to set or configure the first and / or second delays. In step 502, the time delay configuration data is used to configure the first and second delays. Finally, in step 504, the imaging systems 202, 302, and 402 are controlled using the imaging system control command 242 to acquire imaging data 246. In some further examples, the imaging data 246 is reconstructed into an image 248.
[0155] The example can provide shaping circuitry to support a high count rate with a sufficiently good SNR and adequate uniformity across pixel channels. To address both the SNR issue and adequately meet the count rate requirements, it's necessary to ensure complete charge collection is achieved before allowing the feedback capacitors to discharge. This prevents ballistic defects.
[0156] Due to the high X-ray flux in human CT scans, in so-called “paralyzable” analog front-ends (AFEs), in addition to integrating over capacitance, they exhibit resistive feedback (so-called “continuous reset,” see below) that leads to pulse shaping. The observed count rate (OCR) as a function of the event count rate (ICR) decreases after reaching a maximum (OCRmax), thus there is no monotonic relationship between OCR and ICR. This is because, with reasonable power requirements, such AFEs can achieve a relatively long dead time of approximately 30 ns and a choice of pixel size (e.g., 500 μm), which should not be too small to avoid charge sharing compromising energy resolution.
[0157] To support higher count rates by reducing dead time, thereby increasing the ICR range as the ICR monotonically increases, a concept can be used to discharge the feedback capacitor Cfb (116) by closing a switch (second switching unit 122) after each event (commonly referred to as "Cfb reset"). This discharge is triggered when the integrator's output voltage exceeds the minimum energy threshold LT (controllable signal threshold). As a result of the reset, the resulting SHA output pulse is significantly shorter than 30 ns, ideally no longer than the maximum charge collection time of an X-ray event in the crystal (e.g., 13 ns). This Cfb reset must be combined with a feedback resistor Rfb (discharge resistor 118) to eliminate events with energy below the minimum energy threshold (below LT events). Without Rfb, Cfb only integrates charges below LT events, thus leading to incorrect energy estimates for events above LT. Because Rfb enables continuous reset of Cfb, Cfb is autonomously discharged by Rfb, and therefore the output voltage of the charge integrator always returns to the baseline below LT events.
[0158] The drawback of this method is that even with a large Rfb value, ballistic defects can occur, thus failing to completely eliminate the dependence of the charge integrator's output voltage on the CZT (or other direct conversion detector) pulse duration. Rfb cannot be chosen to be very large, otherwise events below LT will result in very long small pulses, leading to a long tail that distorts the energy estimate for events above LT, causing this tail accumulation. To eliminate this problem, a first switching unit is described, placed in series with Rfb, which disconnects Rfb when processing the aforementioned LT events.
[0159] Therefore, it is recommended to combine these two ideas to obtain a low ballistic defect SHA, where the OCR monotonically follows the ICR (so-called “non-paralyzing” count rate behavior).
[0160] A pulse shaper (SHA) may have one or more of the following characteristics:
[0161] a) Integrate the generated current pulse.
[0162] b) Detect that the energy of the input pulse is greater than the set minimum energy threshold.
[0163] c) Disconnect the feedback resistor Rfb until the feedback capacitor Cfb is discharged.
[0164] d) Wait for the maximum possible charge collection time given by the direct conversion material, then discharge the feedback capacitor Cfb to prepare SHA for the next CZT pulse. Near the reset operation time, Rfb is reconnected.
[0165] Alternatively, d) can be replaced by detecting that the output voltage of SHA has reached its maximum value, i.e., no longer changing, which indicates that charge collection for the event has been completed, and Cfb is discharged when the maximum value has been reached.
[0166] Due to the Cfb reset, the dead time of this AFE is determined by the maximum charge collection time (typically in the range of 13 ns), so the maximum possible OCR (observed count rate) can be pushed to greater than, for example, 15 Mcps / pixel.
[0167] Figure 6 Another example of a radiographic instrument 600 is shown. Figure 6 The radiology instrument 600 in the middle is similar to Figure 1 The circuit shown is radiologically illustrated. The radiological instrument is additionally shown as including a pulse height analyzer 604. It has additional discrimination circuitry 124'. All discrimination circuitry 124', including the discrimination circuitry for generating discrimination signal 128, is connected to counter 602. Discrimination circuitry 124 has a minimum energy threshold within pulse height analyzer 604.
[0168] Figure 6 One possible implementation is illustrated. A minimum energy threshold (controllable signal threshold) is used to determine whether a pulse higher than LT is being generated, and it must be counted without ballistic defects. Therefore, when LT is exceeded, Rfb disconnects from Cfb, and from then on, Cfb can be charged without any charge loss that would otherwise lead to (additional) ballistic defects, and thus to V. 输出 The small variation in V is caused by changes in the charge collection time of the same energy event. 输出 When LT is exceeded, a timer is also started (e.g., a digital counter or analog implementation for time increment). This timer is set to wait for the maximum possible (remaining) charge collection time until Cfb is discharged by closing SW2.
[0169] Alternatively, in addition to the normal energy threshold used for spectral acquisition, a specific minimum threshold can be specified (see below). Figure 7 In this case, the threshold does not need to be connected to the counter, because its sole purpose is to detect “real” pulses, i.e., those whose energy will be analyzed by the discriminator group connected to the counter.
[0170] Figure 7 Another example of a radiographic instrument 700 is shown. Figure 7 The circuit shown is similar to Figure 6The circuitry, except in this case, the discrimination circuit 124 used to generate the discrimination signal 128 is not part of the pulse height analyzer 604. This has the advantage of being able to set a threshold value lower than that analyzed by the pulse height analyzer 604. Figure 7 In this example, the threshold for detecting whether the feedback resistor is open is not used for energy measurement, therefore there is no counter. In another example, a charge pump method could be used to perform the reset to minimize charge loss, which might occur if another event occurs during the short circuit Cfb. Figure 6 and Figure 7 In the implementation, such events will be partially or completely lost.
[0171] Handling dark and continuous currents. Typically, sensors will exhibit dark current. When Rfb is off, this current no longer has a resistive path, meaning the dark current will charge Cfb, leading to incorrect energy readings for the event being processed. For example, a 100pA dark current during a 20ns duration of Rfb off will cause a change in collected charge of 100pA x 20ns = 0.002fC, which must be compared to the lowest energy photon (e.g., a 20keV photon to be collected, with a charge of 0.690fC) for evaluation; that is, the measured energy of the 20keV photon is 0.03% higher. This seems quite low, especially when the dark current is unchanged; such deterministic offsets can also be eliminated through calibration. For larger dark currents, a static leakage current compensation circuit can be used: the dark current is measured in each pixel before measurement, and during measurement, this measurement is subtracted from the current received from the sensor pixel. For larger continuous currents, i.e., additional background current due to charge injection, where X-ray photons interact with the sensor crystal, a baseline restorer will be required.
[0172] For continuous reset achieved by injecting current, the feedback current can be redirected from the input node to stop the discharge. This seems feasible in principle if it exceeds LT, but it is not as direct as disconnecting Rfb.
[0173] Figure 8 Another example of a radiographic instrument 800 is shown. The radiographic instrument 800 is similar to... Figure 1 The radiological instrument 100 is depicted. Besides the controller 126, which is shown to also have a direct connection to the output 106, the controller may additionally include a maximum value detector configured to detect the maximum value of the output signal. The control unit may, for example, be configured to disconnect the first switching unit in response to receiving an identification signal. The control unit may also be configured to close the first switching unit after a fourth delay. The control unit may also be configured to disconnect the second switching unit after a fifth delay.
[0174] Although the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary, and not restrictive. The invention is not limited to the disclosed embodiments.
[0175] Those skilled in the art, through studying the accompanying drawings, disclosure, and claims, will understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality. A single processor or other unit can perform the functions of several items recited in the claims. Although specific measures are recited in dissimilar dependent claims, this does not imply that combinations of these measures cannot be advantageously used. Computer programs can be stored / distributed on suitable media such as optical storage media or solid-state media provided with or as part of other hardware, but can also be distributed in other forms such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope.
Claims
1. A radiological instrument comprising at least one pulse shaper circuit, wherein, The at least one pulse shaper circuit is configured to receive an input signal from a direct conversion radiation detector, wherein the at least one pulse shaping circuit includes: The shaper input is configured to receive the input signal; The shaper output is configured to provide an output signal in response to the input signal; An amplifier having an amplifier input connected to the input of the shaper and an amplifier output connected to the output of the shaper, wherein the amplifier is configured as an integrator; A feedback circuit, connected in parallel with the amplifier, is configured to continuously reset the integrator; A first switching unit, which is connected in series with the feedback circuit, is configured to disable the feedback circuit when disconnected; A second switching unit, connected in parallel with the amplifier, is configured to reset the integrator when closed; A discrimination circuit, connected to the amplifier output, is configured to provide a discrimination signal when the amplifier output exceeds a controllable signal threshold; and A control unit for controlling the first switching unit and the second switching unit, wherein the control unit controls the second switching unit such that when the second switching unit is closed, most of the signal is integrated; Its features are, The control unit is a timing circuit configured to control the first switching unit and the second switching unit, wherein the timing circuit is configured to receive the identification signal, wherein the timing circuit is configured to disconnect the first switching unit upon receiving the identification signal, wherein the timing circuit is configured to close the second switching unit after a first delay, wherein the timing circuit is configured to disconnect the second switching unit after a second delay following the closure of the second switching unit, and wherein the timing circuit is configured to close the first switching unit after a third delay.
2. The radiological instrument according to claim 1, wherein, The radiological instrument includes a direct conversion radiation detector for each of the at least one pulse shaper circuit.
3. The radiological instrument according to claim 2, wherein, The direct conversion radiation detector is any one of the following: zinc cadmium telluride detector, cadmium telluride detector, amorphous selenium detector, lithium-doped silicon detector, and lithium-doped germanium detector.
4. The radiological apparatus according to any one of the preceding claims, wherein, The at least one pulse shaper circuit further includes a feedback capacitor connected between the amplifier input and the amplifier output, wherein the feedback circuit is configured to continuously reset the integrator by continuously discharging the feedback capacitor, and wherein the second switching unit is configured to reset the integrator by short-circuiting the feedback capacitor.
5. The radiological apparatus according to any one of claims 1-3, wherein, The second switching unit is configured for short circuit.
6. The radiological apparatus according to any one of claims 1-3, wherein, The feedback circuit is a current source.
7. The radiological apparatus according to any one of claims 1-3, wherein, The feedback circuit is a discharge resistor, wherein the second switching unit is connected in series with a short-circuit resistor, and the short-circuit resistor is smaller than the discharge resistor.
8. The radiological apparatus according to any one of claims 1-3, wherein, The at least one pulse shaper circuit is a plurality of pulse shaper circuits, and the radiological instrument includes at least one radiation detector array, the at least one radiation detector array including the plurality of pulse shaper circuits, or the at least one radiation detector array does not include the plurality of pulse shaper circuits but is connected to the plurality of pulse shaper circuits.
9. An imaging system, wherein, The imaging system includes the radiological instrument according to claim 8.
10. The imaging system according to claim 9, wherein, The imaging system further includes a memory and a processor, wherein the memory contains machine-executable instructions and imaging system control commands, and the execution of the machine-executable instructions causes the processor to: Receive a configuration command, wherein the configuration command includes control unit configuration data; Configure the control unit using the control unit configuration data; and Imaging data is acquired by controlling the imaging system using the imaging system control commands.
11. The imaging system according to claim 10, wherein, The control unit configuration data includes time delay configuration data, wherein the execution of the machine-executable instructions further enables the processor to configure the first delay and / or the second delay using the time delay configuration data.
12. The imaging system according to claim 9, 10 or 11, wherein, The imaging system is any of the following: computed tomography system, PET scanner, SPECT scanner, and digital X-ray system.
13. A method for operating an imaging system, wherein, The imaging system includes pulse shaper circuitry, wherein each pulse shaper circuit is configured to receive input signals from a separate direct-conversion radiation detector. Each of the pulse shaper circuits includes: The shaper input is configured to receive the input signal; The shaper output is configured to provide an output signal in response to the input signal; An amplifier having an amplifier input connected to the input of the shaper and an amplifier output connected to the output of the shaper, wherein the amplifier is configured as an integrator; A feedback circuit, connected in parallel with the amplifier, is configured to continuously reset the integrator; A first switching unit, which is connected in series with the feedback circuit, is configured to disable the feedback circuit when disconnected; A second switching unit, connected in parallel with the amplifier, is configured to reset the integrator when closed; A discrimination circuit, connected to the amplifier output, is configured to provide a discrimination signal when the amplifier output exceeds a controllable signal threshold; and A control unit for controlling the first switching unit and the second switching unit, wherein the control unit controls the second switching unit such that when the second switching unit is closed, most of the signal is integrated; Its features are, The control unit is a timing circuit configured to control the first switching unit and the second switching unit, wherein the timing circuit is configured to receive the identification signal, wherein the timing circuit is configured to disconnect the first switching unit upon receiving the identification signal, wherein the timing circuit is configured to close the second switching unit after a first delay, wherein the timing circuit is configured to disconnect the second switching unit after a second delay following the closure of the second switching unit, and wherein the timing circuit is configured to close the first switching unit after a third delay.
14. A computer program product storing a computer program including instructions for causing a radiological instrument according to claim 1 to perform the steps of the method according to claim 13.
15. A computer-readable medium having thereon a computer program according to claim 14.