CN215894971U - Semiconductor detector and imaging device - Google Patents

Abstract

The embodiment of the specification provides a semiconductor detector and an imaging device. The semiconductor detector includes at least one set of detector modules, the detector modules including: the electrode strip-type touch screen comprises a photosensitive substrate, a back bottom electrode positioned on the first main surface of the photosensitive substrate, and a plurality of groups of electrode strips positioned on the second main surface of the photosensitive substrate, wherein at least one group of electrode strips in the plurality of groups of electrode strips comprises a signal collecting electrode and a non-collecting electrode; and the reading circuit is used for reading the electric signals output by the plurality of groups of electrode strips and converting the electric signals into digital data, wherein the electric signals comprise the electric signals collected by the signal collecting electrodes or the electric signals collected by the signal collecting electrodes and the non-collecting electrodes.

Description

Semiconductor detector and imaging device

Technical Field

The present disclosure relates to the field of medical technology, and in particular, to a semiconductor detector and an imaging device.

Background

A semiconductor detector (semiconductor detector) is a radiation detector that uses a semiconductor material as a detection medium. The semiconductor detector depends on charged particles to generate electron-hole pairs in a sensitive volume of the semiconductor detector, and the electron-hole pairs drift under the action of an external electric field to output signals. With the development and demand of science and technology, the semiconductor detector has been greatly improved in structure and material, and is widely applied in various fields such as high-energy physics, celestial physics, industry, safety detection, nuclear medicine, X-ray imaging, military and the like. For example, semiconductor detectors are used in CT (Computed Tomography) imaging devices to convert photon signals in detected radiation emitted by the CT device into electrical signals, which are transmitted or stored by electronics to a computer in order to generate medical images. The quality of the detector performance can affect the image quality of the medical image to some extent.

It is therefore desirable to provide a semiconductor detector.

SUMMERY OF THE UTILITY MODEL

One aspect of the present description provides a semiconductor detector. The semiconductor detector includes at least one set of detector modules, the detector modules including: the photosensitive substrate is positioned on a back bottom electrode of the first main surface of the photosensitive substrate; a plurality of sets of electrode strips on the second major surface of the photosensitive substrate, at least one of the electrode strips in the plurality of sets comprising a signal collecting electrode and a non-collecting electrode; and the reading circuit is used for reading the electric signals output by the plurality of groups of electrode strips and converting the electric signals into digital data, wherein the electric signals comprise the electric signals collected by the signal collecting electrodes or the electric signals collected by the signal collecting electrodes and the non-collecting electrodes.

In some embodiments, each of the electrode strips comprises at least two sets of sub-electrodes arranged longitudinally, and the difference between photon counting rates output by each of the at least two sets of sub-electrodes is within a preset range.

In some embodiments, each set of the electrode strips comprises three sets of sub-electrodes arranged longitudinally.

In some embodiments, the length of each of the at least two sets of sub-electrodes increases exponentially along the direction of incidence of the radiation.

In some embodiments, the length of each of the at least two sets of sub-electrodes increases or decreases exponentially along the longitudinal direction.

In some embodiments, one of the at least two sets of sub-electrodes near the edge of the detector module includes a signal collecting electrode and a non-collecting electrode.

In some embodiments, the longer of the at least two sets of sub-electrodes comprises a signal collecting electrode and a non-collecting electrode.

In some embodiments, the signal collecting electrode of the at least one set of electrode strips is surrounded by the non-collecting electrode, and/or the signal collecting electrode is connected to the non-collecting electrode by means of a finger.

In some embodiments, the semiconductor detector is an energy integrating detector; the readout circuits at least comprise charge integrators, and the number of readout circuits is the same as the number of sub-electrodes included in each group of the electrode strips.

Another aspect of the present specification provides an image forming apparatus. The device comprises a ray source, the semiconductor detector and an image processing device; the ray source is used for emitting X rays to a target object; the semiconductor detector system is used for converting X-rays passing through the target object into digital data; the image processing device is used for generating a medical image of the target object based on the digital data.

In some embodiments, the X-ray is incident along a sub-electrode arrangement direction of one group of electrode strips of the semiconductor detector.

In some embodiments, the sub-electrodes near the X-ray incidence direction include signal collecting electrodes and non-collecting electrodes.

In some embodiments, the one or more sets of sub-electrodes away from the direction of incidence of X-rays comprise signal collecting electrodes and non-collecting electrodes.

Drawings

The present description will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a schematic diagram of an application scenario of a semiconductor detector according to some embodiments herein;

FIG. 2 is an exemplary schematic diagram of a detector module shown in accordance with some embodiments of the present description;

FIGS. 3A and 3B are exemplary schematic diagrams of detector modules according to further embodiments herein;

FIG. 4 is an exemplary structural schematic of a detector module shown in accordance with some embodiments of the present description;

5A-5C are schematic diagrams of exemplary configurations of detector modules according to further embodiments herein;

6A-6B are schematic diagrams of exemplary configurations of detector modules according to further embodiments herein;

FIG. 7 is an exemplary schematic diagram of a semiconductor detector shown in accordance with some embodiments herein;

FIG. 8 is an exemplary flow chart of a medical imaging method according to some embodiments shown herein;

FIG. 9 is an exemplary block diagram of a medical imaging system shown in accordance with some embodiments of the present description.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the present description, and that for a person skilled in the art, the present description can also be applied to other similar scenarios on the basis of these drawings without inventive effort. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "system", "apparatus", "unit" and/or "module" as used herein is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

Flow charts are used in this specification to illustrate operations performed by systems according to embodiments of the specification, with relevant descriptions to facilitate a better understanding of medical imaging methods and/or systems. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

FIG. 1 is a schematic diagram of an application scenario of a semiconductor detector according to some embodiments of the present disclosure.

As shown in fig. 1, an imaging device 110, a processor 120, a display device 130, and a storage device 140 may be included in the medical imaging system 100.

The imaging device 110 may be configured to scan a target object within the examination region to obtain scan data of the target object. For the purpose of illustration, in the present embodiment, image data of a target object acquired using the imaging apparatus 110 is referred to as a medical image, and image data acquired using the image acquisition device thereof is referred to as an image. In some embodiments, the target object may include a biological object and/or a non-biological object. For example, the target object may include a particular part of the body, such as the head, chest, abdomen, etc., or a combination thereof. As another example, the target object may be an artificial composition of organic and/or inorganic matter, living or non-living. In some embodiments, the medical image data related to the target object may include projection data, one or more scan images, etc. of the target object.

In some embodiments, the imaging device 110 may be a non-invasive biomedical imaging apparatus for disease diagnosis or research purposes. For example, the imaging device 110 may include a single modality scanner and/or a multi-modality scanner. The single modality scanner may include, for example, an ultrasound scanner, an X-ray scanner, a Computed Tomography (CT) scanner, a Magnetic Resonance Imaging (MRI) scanner, an ultrasound tester, a Positron Emission Tomography (PET) scanner, an Optical Coherence Tomography (OCT) scanner, an Ultrasound (US) scanner, an intravascular ultrasound (IVUS) scanner, a near infrared spectroscopy (NIRS) scanner, a Far Infrared (FIR) scanner, or the like, or any combination thereof. The multi-modality scanner may include, for example, an X-ray imaging-magnetic resonance imaging (X-ray-MRI) scanner, a positron emission tomography-X-ray imaging (PET-X-ray) scanner, a single photon emission computed tomography-magnetic resonance imaging (SPECT-MRI) scanner, a positron emission tomography-computed tomography (PET-CT) scanner, a digital subtraction angiography-magnetic resonance imaging (DSA-MRI) scanner, or the like. The scanners provided above are for illustration purposes only and are not intended to limit the scope of the present application. As used herein, the term "imaging modality" or "modality" broadly refers to an imaging method or technique that collects, generates, processes, and/or analyzes imaging information of a target object.

In some embodiments, imaging device 110 may include modules and/or components for performing imaging and/or correlation analysis. In some embodiments, imaging device 110 may include a radiation generating device, an accessory device, and an imaging device. The radiation generating device is a device that generates and controls radiation (e.g., X-rays). The radiation attachment means is various facilities designed to meet the needs of clinical diagnosis and treatment, and may include, for example, mechanical equipment such as an examination bed, a diagnostic bed, a catheter bed, a photographic bed, and the like, various supports, suspensions, stoppers, holders, a grid, a filter, a shutter, and the like. In some embodiments, the radiographic imaging device may take many forms, for example, the digital imaging device may include a detector, a computer system, image processing software, and the like; other imaging devices may include a fluorescent screen, a film cassette, an image intensifier, a video television, and the like.

In the embodiments of the present specification, description will be mainly given taking an example in which an image forming apparatus includes a digital image forming device. Wherein the detector may be adapted to convert the collected optical signals into electrical signals. In some embodiments, the detector may include one or more sets of detector modules, for example, as shown in fig. 7, each strip may represent a set of detector modules, and the detector may be comprised of a plurality of corresponding detector modules of the strip. In some embodiments, each set of detector modules may include a photosensitive module and readout circuitry, such as the detector module shown in FIG. 2. The photosensitive module can be used for collecting photon signals in rays passing through a target object and converting the collected photon signals into electric signals, and the reading circuit can be used for reading the electric signals collected in the photosensitive module and converting the electric signals into digital data so as to generate medical images. In some embodiments, the detector may include a semiconductor detector, a photovoltaic type detector, and the like, which are not limited by this specification. Further details regarding the detector can be found elsewhere in this specification, for example, fig. 2-fig. 7 and their related descriptions, which are not repeated herein.

In some embodiments, data acquired by imaging device 110 (e.g., a medical image of a target object) may be transmitted to processor 120 for further analysis. Additionally or alternatively, data acquired by imaging device 110 may be sent to a terminal device (e.g., display device 130) for display and/or a storage device (e.g., storage device 140) for storage.

The processor 120 may process data and/or information obtained from the imaging device 110, the storage device 140, or other components of the medical imaging system 100 (e.g., a user terminal). For example, the processor 120 may acquire medical image data of the target object from the imaging device 110. For another example, the processor 120 may acquire a photographed image of the target object from the image pickup device and perform analysis processing thereon. In some embodiments, the processor 120 may be a single server or a group of servers. The server groups may be centralized or distributed. In some embodiments, the processor 120 may be local or remote. For example, processor 120 may access information and/or data from imaging device 110 and/or storage device 140 over a network. As another example, processor 120 may be directly connected to imaging device 110 and/or storage device 140 to access information and/or data. In some embodiments, processor 120 may be implemented on a cloud platform. For example, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud, a multi-cloud, and the like, or any combination thereof.

In some embodiments, processor 120 may include one or more processors (e.g., a single chip processor or a multi-chip processor). Merely by way of example, the processor 120 may include a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), an application specific instruction set processor (ASIP), an image processing unit (GPU), a physical arithmetic processing unit (PPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a micro-controller unit, a Reduced Instruction Set Computer (RISC), a microprocessor, or the like, or any combination thereof. In some embodiments, the processor 120 may be part of the imaging device 110. For example, the processor 120 may be integrated within the imaging device 110 for processing the digitized data output by the detector system to generate a medical image of the target object.

Display device 130 may be coupled to imaging device 110 and/or processor 120 for input/output of information and/or data. For example, a user may interact with imaging device 110 via display device 130 to control one or more components of imaging device 110. For another example, the imaging device 110 may output the generated medical image to the display device 130 for presentation to the user. In some embodiments, display device 130 may include an input device. The input device may be selected from keyboard input, touch screen (e.g., with tactile or haptic feedback) input, voice input, eye tracking input, gesture tracking input, brain monitoring system input, image input, video input, or any other similar input mechanism. Input information received via the input device may be transmitted, for example, via a bus, to the processor 120 for further processing. Other types of input devices may include cursor control devices, such as a mouse, a trackball, or cursor direction keys, among others. In some embodiments, an operator (e.g., a medical professional) may input instructions reflecting the medical image category of the target subject via an input device. In some embodiments, the display device 130 may be part of the imaging device 110.

Storage device 140 may store data, instructions, and/or any other information. For example, the storage device 140 may store medical image data of a target object acquired by the imaging device 110, an image taken by an image acquisition apparatus, and the like. In some embodiments, storage device 140 may store data obtained from imaging device 110 and/or processor 120. In some embodiments, storage device 140 may store data and/or instructions for processor 120 to perform or use to perform the exemplary methods described in this application. In some embodiments, storage device 140 may include mass storage, removable storage, volatile read-write memory, read-only memory (ROM), etc., or any combination thereof. In some embodiments, the storage device 140 may be implemented on a cloud platform.

In some embodiments, the storage device 140 may be connected to a network to communicate with at least one other component (e.g., imaging device 110, processor 120) in the medical imaging system 100. At least one component in the medical imaging system 100 may access data stored in the storage device 140 (e.g., medical image data of a target object, etc.) over a network. In some embodiments, the storage device 140 may be part of the imaging device 110 and/or the processor 120.

It should be noted that the foregoing description is provided for illustrative purposes only, and is not intended to limit the scope of the present application. Many variations and modifications will occur to those skilled in the art in light of the teachings herein. The features, structures, methods, and other features of the example embodiments described herein may be combined in various ways to obtain additional and/or alternative example embodiments. For example, the storage device 140 may be a data storage device comprising a cloud computing platform (e.g., public cloud, private cloud, community and hybrid cloud, etc.). However, such changes and modifications do not depart from the scope of the present application.

FIG. 2 is an exemplary schematic diagram of a detector module shown in accordance with some embodiments of the present description.

The basic principle of the semiconductor detector is that charged particles generate electron-hole pairs in a sensitive volume of the semiconductor detector, and the electron-hole pairs drift under the action of an external electric field to output signals. In some embodiments, the electron-hole pairs in a semiconductor detector may also be referred to as the information carriers of the detector. In some embodiments, the semiconductor detector may include a P-N junction type semiconductor detector, a lithium drift type semiconductor detector, a high purity germanium semiconductor detector, a compound semiconductor detector, a special type semiconductor detector, or the like.

The semiconductor detector has the advantages of good energy linearity, high resolution, quick time response, adjustable thickness of a sensitive area, simple structure, small volume, light weight and the like, and is widely applied to the field of medical imaging. For example, when X-rays emitted by the imaging device 110 pass through a target object and irradiate a semiconductor detector, if the energy of photons of the X-rays is equal to or greater than the forbidden bandwidth of the semiconductor, electrons in the valence band absorb the photons and enter the conduction band, electron-hole pairs (carriers of this type may also be referred to as photogenerated carriers) are generated, the electron-hole pairs are separated and drift to corresponding electrodes under the action of high voltage, induced charges are generated on the electrodes, and the semiconductor detector may output the induced charges to a processor (e.g., the processor 120) for processing or a storage device (e.g., the storage device 140) for storage. In some embodiments, the semiconductor detector may collect the induced charge and convert it into digitized data, e.g., to obtain photon counts for different energy intervals based on the induced charge, which may be output to a processor (e.g., processor 120) for processing or a storage device (e.g., storage device 140) for storage.

The movement speed and energy of the electrons are changed due to the action of the electric field force on the electrons, and the energy of the electrons changes from one energy level to another energy level when viewed from the energy band wheel. In the valence band, the energy level is occupied by electrons, and the electrons do not form current and do not contribute to the conduction when an external electric field is applied. In the conduction band, the energy level is occupied by the electron part, and under the action of an external electric field, the electron jumps from the energy absorbed by the external electric field to the energy level which is not occupied by the electron to form current to play a role in conduction. The forbidden region between the valence and conduction bands is called the forbidden band.

In some embodiments, the detector module may include a photosensitive module and readout circuitry. Where the photosensitive module can be used to convert photons to electrical signals (e.g., electron-hole pairs), the readout circuitry can be used to read out the electrical signals from the photosensitive module and convert them to digitized data. In some embodiments, the photosensitive module and readout circuitry may be integrated on a data acquisition board to form a wafer-type detector module.

In some embodiments, as shown in FIG. 2, a photosensitive module can include a photosensitive substrate, a back electrode on a first major surface of the photosensitive substrate, and a plurality of sets of electrode strips on a second major surface of the photosensitive substrate. In some embodiments, each set of electrode strips may include a set of sub-electrodes, and at least one of the sets of electrode strips may include a signal collecting electrode and a non-collecting electrode, such as shown in fig. 4. In some embodiments, each set of electrode strips may comprise at least two sets of sub-electrodes having lengths that increase or decrease exponentially along the longitudinal direction. For example, as shown in fig. 2, the direction indicated by the black arrow may represent the incident direction of the radiation, the black rectangle may represent the sub-electrodes, and each group of the electrode stripes may include a first sub-electrode 201, a second sub-electrode 203, and the like, the lengths of which increase exponentially in the Z direction. In some embodiments, at least one of the sets of sub-electrodes may be comprised of a signal collecting electrode and a non-collecting electrode, such as shown in fig. 5A-6B.

In some embodiments, the photosensitive substrate can employ a compound as the photosensitive material, for example, crystalline Si (silicon), CdTe, GaAs, HgI₂And CdZnTe (CZT), etc. By way of example only, the semiconductor detector may employ an N-type Si substrate as the photosensitive material. In some embodiments, the photosensitive substrate may include a PN-type, PIN-type, or the like structure.

In some embodiments, the readout circuitry may comprise an integrated circuit, for example, an Application Specific Integrated Circuit (ASIC). In some embodiments, the detector module may include one or more readout circuits. In some embodiments, the number of readout circuits of a detector module may correspond to the number of groups of electrode strips, or to the total number of sub-electrodes, or to the number of sub-electrodes included in each group of electrode strips. For example, each group of electrode strips may correspond to one ASIC circuit, or each group of sub-electrodes may correspond to one ASIC circuit, or sub-electrodes of the same length in all electrode strip groups may correspond to one ASIC circuit, etc. In some embodiments, the readout circuitry may be located anywhere on the semiconductor detector. Preferably, the readout circuitry may be located on either side of the detector module parallel to the direction of incidence of the radiation, for example in the position shown in fig. 2, to avoid that photons enter the semiconductor detector and affect the readout circuitry. In some embodiments, the sensing circuit may be configured to sense electrical signals output by the electrode strips, for example, to sense electrical signals collected by the signal collecting electrodes of at least one set of electrode strips, or electrical signals collected by the signal collecting electrodes and non-collecting electrodes of at least one set of electrode strips.

It should be appreciated that the term Application Specific Integrated Circuit (ASIC) should be construed broadly to mean any general integrated circuit used and configured for a particular application. For example, in a photon counting detector, the ASIC may include a pre-amplifier circuit, a shaping filter circuit, a pulse comparator circuit, and a digital signal output circuit. Also for example, in a photon energy integrating detector, the ASIC may include a shaping filter, a charge integrator.

In some embodiments, the readout circuit and the photosensitive module can be integrated into a chip, that is, the photosensitive module and the readout circuit can be processed on the same wafer. In some embodiments, the readout circuitry can be coupled to the photosensitive module by photon effect and by compton scattering, for example, to electrode strips and/or back bottom electrodes of the photosensitive substrate by photon effect and/or compton scattering.

In some embodiments, the length, width, and thickness of the detector module 200 (e.g., the length, width, and thickness of the photosensitive substrate) may be any reasonable value, and are not limited herein. For example only, the detector module 200 may have a length (Z direction) greater than 30mm, a width (Y direction) greater than 40mm, and a thickness (X direction) in the range of 0.5mm to 1 mm. The detector module is set to be longer than 30mm, wider than 40mm and thick within the range of 0.5mm-1mm, so that the ray absorption efficiency of the semiconductor detector can be improved.

In some embodiments, the radiation may be incident from an edge, or surface, of the detector. For example, the X-rays may enter the semiconductor detector from the direction of the black arrow in fig. 2, or enter the semiconductor detector from the depth direction of the vertical electrode strip. Preferably, the radiation can be injected into the semiconductor detector along the depth direction of the electrode strip.

Fig. 3A and 3B are exemplary schematic diagrams of detector modules according to further embodiments herein. Fig. 3A is a schematic front view, and fig. 3B is a schematic side view.

As shown in fig. 3A or 3B, in some embodiments, the detector module 300 may be a strip detector, i.e. the electrode strips are strip electrodes, wherein a set of strip electrodes (one set for each column) may constitute one pixel. In some embodiments, the pixel size of the detector may be determined based on the spacing between the strip electrodes and the thickness of the photosensitive substrate. For example, when the thickness h of the photosensitive substrate and the spacing s between the laterally arranged strip electrodes are both 0.5mm, the pixel size of the detector module is 0.5mm by 0.5 mm. In some embodiments, the distance between each group of strip electrodes and the thickness of the photosensitive substrate can be set according to actual conditions. For example, if the width of the detector module is 40mm, and the detector module is divided into 80 groups of strip electrodes, the distance between each group of strip electrodes may be 0.5mm, that is, the detector includes 80 pixels. For example, the thickness of the photosensitive substrate may be in the range of 0.5mm to 1 mm.

In some embodiments, each set of electrode strips may include at least two sets of sub-electrodes. For example, as shown in fig. 3A or 3B, each set of electrode stripes may include three sets of sub-electrodes, a first sub-electrode 201, a second sub-electrode 203, and a third sub-electrode 205, arranged longitudinally. In some embodiments, the difference between the photon count rates output by each of the at least two sets of sub-electrodes of the electrode strip may be within a predetermined range. In some embodiments, the predetermined range may include any reasonable range from 0-1, 0-10, 1-10, etc. For example, the difference between the photon counting rates output by each of the at least two groups of sub-electrodes may be 0, i.e. the photon counting rates output by each group of sub-electrodes are the same. In some embodiments, the length of each of the at least two sets of sub-electrodes may increase or decrease exponentially along the longitudinal direction. In some embodiments, during the application, the length of each of the at least two groups of sub-electrodes may increase exponentially along the incident direction of the radiation, for example, the lengths of the first sub-electrode 201, the second sub-electrode 203, and the third sub-electrode 205 may increase exponentially along the incident direction of the radiation. In some embodiments, the length ratio of at least two groups of sub-electrodes (e.g., the first sub-electrode 201, the second sub-electrode 203, and the third sub-electrode 205) of each group of electrode strips may be any value that enables the photon counting rate output by each group of sub-electrodes to be similar or identical, for example, the ratio in the incident direction of the radiation (i.e., the Z direction) may be 1: 2: 4, the specification does not limit the same.

In some embodiments, the three sub-electrodes of the detector module 300 may correspond to three different readout circuits, respectively. For example, three dashed boxes in fig. 3A correspond to three sub-electrodes, all the first sub-electrodes 201 in a first dashed box may correspond to the same readout circuit 1, all the second sub-electrodes 203 in a second dashed box may correspond to the same readout circuit 2, and all the third sub-electrodes 205 in a third dashed box may correspond to the same readout circuit 3. This is equivalent to dividing the count of one pixel equally over the three sub-electrodes and then reading out separately.

In some embodiments, the detector module 300 may include a photon counting type detector, an energy integrating type detector, or the like. Wherein the number of readout circuits is the same as the number of sub-electrodes in each set of strip electrodes (i.e. electrode strips). When photons are injected into a semiconductor detector and deposited in a certain pixel, electron-hole pairs are generated, and the electron-hole pairs are separated and drift to the corresponding electrode under the action of high voltage (for example, 100-. The readout circuit can output photon counting or charge integration of different energy intervals by collecting the induced charges on the electrodes. For example, the readout circuit of the photon counting detector may correspond to a counting integrated circuit composed of a front-end amplifier circuit, a shaping filter circuit, a pulse comparator and a digital signal output circuit. In this case, the semiconductor detector can output photon counts of 3 different energy intervals by pulse comparison of the shape-filtered signals. For another example, the readout circuit of the photon energy integration detector may correspond to an integration integrated circuit including a shaping filter circuit and a charge integration circuit. In this case, the semiconductor detector can perform charge integration of the amount of photo-generated charge by performing current integration on the shape-filtered photocurrent (i.e., the current signal generated by photon conversion). The processor can further calculate the light intensity information of the corresponding segmented energy spectrum according to the linear relation between the light intensity and the photo-generated charges based on the charge integration collected by each electrode.

Generally, after a ray enters a semiconductor detector from the edge, photons with lower energy are more easily deposited on the upper layer in the incident direction, and photons with higher energy are more easily deposited on the lower layer in the incident direction. Thus, the upper layer reads most low-energy photons, the middle layer reads most intermediate-energy photons, and the lowest layer reads most high-energy photons. In the embodiment of the present disclosure, each group of electrode strips is divided into multiple segments (for example, the first sub-electrode 201, the second sub-electrode 203, and the third sub-electrode 205) with exponentially increasing lengths, so that low, medium, and high-energy photons can be collected respectively, the efficiency of photon counting/integration calculation is improved, and the requirement of multi-energy spectrum image reconstruction is met, thereby reducing the radiation dose of a patient, improving the accuracy of imaging quantitative analysis, and realizing ultrahigh spatial resolution.

FIG. 3B is a side view of a detector module corresponding to FIG. 3A. In some embodiments, the side of the detector module 300 opposite the electrode strips (i.e., the first major surface) may include a back bottom electrode 213 that covers the entire detector sensitive area, as shown in FIG. 3B. The distance h between the electrode strips and the back bottom electrode 213 corresponds to the thickness of the photosensitive substrate. It should be noted that the thickness of the electrode strips and the back bottom electrodes 213 is only illustrated schematically, and in practical applications, the electrode strips and the back bottom electrodes 213 are relatively thin. In some embodiments, the back bottom electrode 213 may be a cathode or an anode. For more details of the photosensitive substrate and the electrode, reference may be made to other parts of this specification (for example, fig. 2 and the related description thereof), and details are not repeated here.

In some alternative embodiments, the number of sub-electrodes per group of electrode strips in the detector module 300 may be adjusted to other numbers as desired, for example, dividing each group of electrode strips into 5-6 groups of sub-electrodes. For a photon counting detector, the design can reduce the data reading time and bandwidth requirements of the reading circuit; for an energy integration type detector, the design can obtain more energy interval information, and further enables a spectrum image to be more accurate.

It should be noted that the above description of the detector modules 200 and 300 is for illustration and description only and is not intended to limit the scope of applicability of the present description. Various modifications and changes to the structure of the detector module 200 or 300 will be apparent to those skilled in the art in light of this disclosure. For example, the structure of the detector module 300 may be applied in a photovoltaic type detector. However, such modifications and variations are intended to be within the scope of the present description.

FIG. 4 is a schematic diagram of a detector module shown in accordance with some embodiments herein.

As shown in FIG. 4, in some embodiments, at least one of the sets of electrode strips of the detector module may be comprised of signal collecting electrodes and non-collecting electrodes. In some embodiments, the signal collecting electrodes of at least one set of electrode strips may be surrounded by one or more non-collecting electrodes, e.g. as shown in the lower dashed box of fig. 4, with the middle black circle representing the signal collecting electrode and the plurality of rectangular boxes around the signal collecting electrode representing the non-collecting electrodes. In some embodiments, the shape of the non-collecting electrode may include a circle, a rectangle, a hexagon, an ellipse, etc., or any combination thereof. In some embodiments, the signal collecting electrode may be located at any reasonable position such as the center, the top, the bottom, etc. of the electrode strip, and is not limited herein. In some embodiments, the signal collecting electrodes and non-collecting electrodes of at least one set of electrode strips may be connected by interdigitation, such as shown in fig. 6A-6B. In some embodiments, the plurality of sets of electrode strips may include electrode strips in which the signal collecting electrodes are connected to the non-collecting electrodes in an interdigitated manner, and electrode strips in which the signal collecting electrodes are surrounded by a plurality of non-collecting electrodes.

At least one group of the electrode strips of the detector module is set to be of a special geometric structure formed by the signal collecting electrodes and the non-collecting electrodes, the area of the signal reading electrodes (namely the signal collecting electrodes) can be reduced, the read capacitance of the detector is reduced, the uniformity of the performance of the electrodes is improved, the influence of incomplete collection on a sensitive area of the detector is reduced, and the energy resolution and the counting rate of the detector are improved.

5A-5C are schematic diagrams of detector modules according to further embodiments of the present disclosure.

In some embodiments, each set of sub-electrodes or each set of electrode strips of the detector module may be comprised of a signal collecting electrode and a non-collecting electrode. In some embodiments, the signal collection electrodes may be surrounded by one or more non-collection electrodes, i.e. the electrode strips or sub-electrodes are of a drift-type structure. For example, as shown in fig. 5A, each set of sub-electrodes may be constituted by a structure in which a plurality of non-collecting electrodes surround the signal collecting electrode. All electrode strips of the detector are arranged in a structural form that the non-collecting electrodes surround the signal collecting electrodes, so that the areas of the signal collecting electrodes of the electrodes (namely sub-electrodes) with different depths are consistent, and the response consistency of different channels of the detector is improved.

In some embodiments, some of the sub-electrodes of the detector module may be comprised of signal collecting electrodes and non-collecting electrodes. In some embodiments, one of the at least two sets of sub-electrodes of each set of electrode strips near the edge of the detector module may include a signal collecting electrode and a non-collecting electrode, for example, as shown in fig. 5B or 5C. In some embodiments, the shorter length sub-electrodes of the at least two sets of sub-electrodes of each set of electrode strips may comprise signal collecting electrodes and non-collecting electrodes. For example, as shown in fig. 5B, of the sub-electrodes of the detector module 500 in which the length of each group of electrode strips increases exponentially along the incident direction of the radiation, the first sub-electrode 201 close to the incident direction of the radiation may be composed of a signal collecting electrode and a non-collecting electrode.

In some embodiments, one or more sub-electrodes far away from the incident direction of the radiation may include a signal collecting electrode and a non-collecting electrode, i.e., the sub-electrode with a longer length in the plurality of sub-electrodes of the detector module may be composed of the signal collecting electrode and the non-collecting electrode. For example, as shown in fig. 5C, the third sub-electrode 205 with the longest length in each set of electrode strips of the detector module 500 may be composed of a signal collecting electrode and a non-collecting electrode. As another example, the second sub-electrode 203 with the longer length and the third sub-electrode 205 with the longest length in each set of electrode strips of the detector module 500 may be both composed of signal collecting electrodes and non-collecting electrodes. For another example, the second sub-electrodes 203 with longer lengths in each set of electrode strips of the detector module 500 may be composed of signal collecting electrodes and non-collecting electrodes.

The non-collecting electrodes surrounding the signal collecting electrodes can generate depletion regions at two sides of the detector module (namely two sides corresponding to the incident direction of rays), under the action of an external electric field, the inside of the detector can be helped to reach a full depletion state, a drift electric field pointing to the signal collecting electrodes is formed, and electrons drift to the signal collecting electrodes under the action of the electric field. The electrons drift in the depletion region for a long time to reach the signal collecting electrode with small area, and the capacitance between the electrodes is small, so that the noise is small, and the energy resolution of the detector is favorably improved.

Figures 6A-6B are schematic diagrams of detector modules according to further embodiments of the present disclosure.

As shown in fig. 6A or 6B, in some embodiments, all or part of the electrode strips or strip-shaped sub-electrodes of the detector module may be coplanar gate electrodes, i.e. the signal collecting electrodes and the non-collecting electrodes are connected by interdigitated means. For example, any 3 groups, or 6 groups, or 8 groups, etc. of the electrode strips may be selected to be disposed as coplanar gate electrodes, or any 1 group (such as the first sub-electrode 201, or the third sub-electrode 205), or 2 groups, or 3 groups of the strip-shaped sub-electrodes may be selected, and the signal collecting electrodes and the non-collecting electrodes thereof may be disposed to be connected by means of fingers. In some embodiments, the interdigitated signal collection and non-collection electrodes may be connected together on the side opposite the insertion side, such as shown in the dashed box of fig. 6A, with the interdigitated signal collection and non-collection electrodes connected, and with the respective other sides of the interdigitated signal collection and non-collection electrodes opposite the insertion side connected by a wire or other conductive structure. In some embodiments, the number of branches of the signal collecting electrode and the number of branches of the non-collecting electrode may be any reasonable value and be the same as each other.

The electrode strips or strip-shaped sub-electrodes of the detector are designed into a coplanar grid structure with signal collecting electrodes and non-collecting electrodes connected in an inserting finger mode, the output signals of the photosensitive substrate are the difference values of the signals of the signal collecting electrodes and the signals of the non-collecting electrodes, and the influence of incomplete collection can be almost eliminated on one hand by adjusting the weight factors of the signal collecting electrodes and the non-collecting electrodes, on the other hand, the influence of nonuniformity of weight potential on electron collection in a non-sensitive area is reduced, and the energy resolution of the detector is further improved.

It should be noted that the above description of the detector modules 500 and 600 is for illustration and description only and is not intended to limit the scope of the present disclosure. Various modifications and changes to the structure of the detector modules 500 and 600 will be apparent to those skilled in the art in light of this description. For example, the plurality of sets of electrode stripes may comprise only one set of coplanar gate structure electrodes or drift type structure electrodes. For another example, the drift-type structure electrode, the coplanar gate structure electrode, and the stripe-shaped electrode may be provided at intervals. For another example, the signal collecting electrodes and the non-collecting electrodes of the sub-electrodes with shorter or longer length in at least two groups of sub-electrodes of each group of electrode strips may be connected in a finger-inserting manner. However, such modifications and variations are intended to be within the scope of the present description.

FIG. 7 is an exemplary schematic diagram of a semiconductor detector shown in accordance with some embodiments herein.

As shown in fig. 7, in some embodiments, the semiconductor detector 700 may include a plurality of detector modules (e.g., detector modules 200, 400, 500, or 600), e.g., 500, 1000, 3000, etc. In some embodiments, multiple detector modules of semiconductor detector 700 may be combined in any reasonable manner. For example, the plurality of detector modules may be divided into two groups that are interdigitated or stacked together to form the semiconductor detector 700. In some embodiments, the semiconductor detector may be composed of silicon, cadmium telluride, cadmium zinc telluride, or the like. In some embodiments, when the semiconductor detector is made of silicon, the thickness in the depth direction (Z direction) may be set to be greater than 30mm in order to achieve 80% quantum efficiency due to the low blocking capability of silicon for X photons.

In some embodiments, to reduce cross talk between each detector module of the semiconductor detector and improve the quantum efficiency of the semiconductor detector, a layer of reflective material, such as tungsten, may be coated on the back electrode side of each detector module. In some embodiments, the reflective material may have a thickness in the range of 0.2 microns to 0.5 microns.

It should be noted that the above description of the semiconductor detector 700 is for illustration and explanation only, and does not limit the scope of applicability of the present description. Various modifications and changes to the structure of the semiconductor detector 700 will be apparent to those skilled in the art in light of the present description. However, such modifications and variations are intended to be within the scope of the present description.

In some embodiments, the imaging device may include a radiation source, a semiconductor detector 700, and an image processing apparatus. Therein, the radiation source may be configured to emit radiation having a plurality of energy intervals, e.g. X-rays having a range of energies, towards the target object. Semiconductor detectors may be used to convert radiation passing through a target object into digitized data. The image processing device may be adapted to generate a medical image of the target object based on the digitized data of the target object.

Fig. 8 is an exemplary flow chart of a medical imaging method, shown in accordance with some embodiments of the present description.

The medical imaging method 800 may be performed by the medical imaging device 110. For example, the medical imaging method 800 may be stored in a storage device (e.g., storage device 140) in the form of a program or instructions that, when executed by the imaging device 110, may implement the medical imaging method 800. In some embodiments, the medical imaging method 800 may be performed by the medical imaging system 900.

At step 810, digitized data relating to photons traversing the target object is acquired using the semiconductor detector. In some embodiments, step 810 may be performed by probing module 910.

In some embodiments, the digitized data may include projection data of the target object. In some embodiments, the digitized data may include photon counts for different energy intervals. In some embodiments, the digitized data may include energy integrals for different energy intervals. In some embodiments, digitized data relating to photons passing through the target object may be acquired from the semiconductor detector. In some embodiments, digitized data relating to photons passing through the target object may be retrieved from a storage device.

In some embodiments, the imaging device emits radiation through the radiation source toward the target object, which is converted to electron-hole pairs after passing through the target object into the semiconductor detector. The electron-hole pairs drift to the corresponding electrode under the action of the external electric field and generate induced charges. The readout circuit of the semiconductor detector can calculate photon counts or energy integrals of different energy intervals based on the readout induced charges, so as to obtain projection data, namely digitalized data, of rays with different energy intervals after passing through the target object.

Based on the digitized data, a medical image of the target object is generated, step 820. In some embodiments, step 820 may be performed by medical image generation module 920.

In some embodiments, the processor may perform image processing based on the digitized data of the target object to generate a medical image of the target object. For example, image processing may include image normalization, image reconstruction, image smoothing, image compression, image enhancement, image matching, image registration, image geometry correction, image fusion, image inpainting, or removing image distortion, noise, or the like, or any combination thereof.

In some embodiments, the processing device may post-process the medical image generated by the imaging device to obtain the target medical image. For example, the medical image generation module 920 may perform image quality evaluation on the medical image reconstructed by the imaging device 110 to obtain a better quality medical image, help medical staff to clearly understand the lesion information of the user, and the like.

It should be noted that the above description of method 800 is for purposes of example and illustration only and is not intended to limit the scope of applicability of the present description. Various modifications and alterations to method 800 will be apparent to those skilled in the art in light of this description. However, such modifications and variations are intended to be within the scope of the present description.

FIG. 9 is an exemplary block diagram of a medical imaging system shown in accordance with some embodiments of the present description.

As shown in fig. 9, the medical imaging system 900 may include a detection module 910, a medical image generation module 920, and an output module 930. In some embodiments, the medical imaging system 900 may be implemented by the imaging device 110 shown in fig. 1.

The detection module 910 may be used to convert photons that pass through a target object into digitized data.

The medical image generation module 920 may be used to generate a medical image of the target object based on the digitized data. In some embodiments, the medical image generation module 920 may further include a data processing unit 923 and an image generation unit 925. In some embodiments, the data processing unit 923 may be configured to process the digitized data of the target object. In some embodiments, the image generation unit 925 may be used to generate a medical image of the target object based on the projection data. In some embodiments, the image generation unit 925 may be configured to perform image processing on the reconstructed image. In some embodiments, the image generation unit 925 may be used to post-process the medical image to obtain the target medical image.

The output module 930 may be used to output medical images. In some embodiments, the output module 930 may output the medical image to a user. For example, the output module 930 may output the generated medical image to the display device 130 for presentation to the user.

It should be noted that the above description of the system 900 and its modules is merely for convenience of description and should not be construed as limiting the present disclosure to the illustrated embodiments. It will be appreciated by those skilled in the art that, given the teachings of the present system, any combination of modules or sub-system configurations may be used to connect to other modules without departing from such teachings. In some embodiments, the detection module 910, the medical image generation module 920 and the output module 930 may be different modules in a system, or may be a module that implements the functions of two or more modules described above. In some embodiments, the detection module 910, the medical image generation module 920 and the output module 930 may share one storage module, and each module may also have its own storage module. Such variations are within the scope of the present disclosure.

The beneficial effects that may be brought by the embodiments of the present description include, but are not limited to: (1) by dividing the electrode strips into a plurality of groups of sub-electrodes, the collection efficiency of photon charges in three energy intervals of high, medium and low energy can be improved, and the imaging efficiency is further improved; (2) by designing the electrode strips into drift type electrodes or coplanar gate electrodes, the area of the signal collecting electrodes can be reduced, noise is reduced, and resolution is improved; (3) the sub-electrodes of the detector module, which are close to the incident direction of the rays and mainly absorb low-energy rays, are arranged in a structural form that a plurality of non-collecting electrodes surround the signal collecting electrodes, so that the counting rate and the energy resolution of the layer where the sub-electrodes are located are improved, and the performance of the detector is further improved; (4) the sub-electrode with the longer length of the semiconductor detector is arranged in a structural form that a plurality of non-collecting electrodes surround the signal collecting electrode, so that the area increase caused by longer electrode strips is avoided, the performance of a deep electrode is improved, and the uniformity of electrodes with different depths of the detector is facilitated; (5) the number of the reading circuits is the same as the number of the sub-electrodes contained in each group of electrode strips, so that the interference among the reading circuits can be reduced, the reading efficiency is improved, and the detection efficiency of the detector is improved. It is to be noted that different embodiments may produce different advantages, and in different embodiments, any one or combination of the above advantages may be produced, or any other advantages may be obtained.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be regarded as illustrative only and not as limiting the present specification. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present specification and thus fall within the spirit and scope of the exemplary embodiments of the present specification.

Also, the description uses specific words to describe embodiments of the description. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification is included. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the specification may be combined as appropriate.

Additionally, the order in which the elements and sequences of the process are recited in the specification, the use of alphanumeric characters, or other designations, is not intended to limit the order in which the processes and methods of the specification occur, unless otherwise specified in the claims. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

For each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this specification, the entire contents of each are hereby incorporated by reference into this specification. Except where the application history document does not conform to or conflict with the contents of the present specification, it is to be understood that the application history document, as used herein in the present specification or appended claims, is intended to define the broadest scope of the present specification (whether presently or later in the specification) rather than the broadest scope of the present specification. It is to be understood that the descriptions, definitions and/or uses of terms in the accompanying materials of this specification shall control if they are inconsistent or contrary to the descriptions and/or uses of terms in this specification.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present disclosure. Other variations are also possible within the scope of the present description. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the specification can be considered consistent with the teachings of the specification. Accordingly, the embodiments of the present description are not limited to only those embodiments explicitly described and depicted herein.

Claims (10)

1. A semiconductor detector comprising at least one set of detector modules, wherein the detector modules comprise:

the electrode strip-type touch screen comprises a photosensitive substrate, a back bottom electrode positioned on the first main surface of the photosensitive substrate, and a plurality of groups of electrode strips positioned on the second main surface of the photosensitive substrate, wherein at least one group of electrode strips in the plurality of groups of electrode strips comprises a signal collecting electrode and a non-collecting electrode; and

and the reading circuit is used for reading the electric signals output by the plurality of groups of electrode strips and converting the electric signals into digital data, wherein the electric signals comprise the electric signals collected by the signal collecting electrodes or the electric signals collected by the signal collecting electrodes and the non-collecting electrodes.

2. The semiconductor detector of claim 1, wherein each of the electrode strips comprises at least two sets of sub-electrodes arranged longitudinally, and the difference between photon counting rates output by each of the at least two sets of sub-electrodes is within a preset range.

3. The semiconductor detector of claim 2, wherein the length of each of the at least two sets of sub-electrodes increases or decreases exponentially along the longitudinal direction.

4. The semiconductor detector of claim 2, wherein one of the at least two sets of sub-electrodes near the edge of the detector module comprises a signal collecting electrode and a non-collecting electrode.

5. The semiconductor detector of claim 3, wherein the longer of the at least two sets of sub-electrodes comprises a signal collecting electrode and a non-collecting electrode.

6. A semiconductor detector according to any of claims 1-5, characterized in that the signal collecting electrodes of the at least one set of electrode strips are surrounded by the non-collecting electrodes and/or that the signal collecting electrodes are finger-inserted in connection with the non-collecting electrodes.

7. The semiconductor detector of claim 1,

the semiconductor detector is an energy integration type detector;

the readout circuits at least comprise charge integrators, and the number of readout circuits is the same as the number of sub-electrodes included in each group of the electrode strips.

8. An image forming apparatus, characterized by comprising:

a radiation source for emitting X-rays toward a target object;

a semiconductor detector according to any one of claims 1-7, for converting X-rays passing through the target object into digitized data; and

image processing means for generating a medical image of the target object based on the digitized data.

9. The imaging apparatus of claim 8, wherein the X-rays are incident along a sub-electrode arrangement direction of one set of electrode strips of the semiconductor detector.

10. The imaging apparatus according to claim 9, wherein the sub-electrodes close to the X-ray incidence direction include signal collecting electrodes and non-collecting electrodes, or at least one group of sub-electrodes far from the X-ray incidence direction includes signal collecting electrodes and non-collecting electrodes.

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