Digital subtraction imaging method and device and computer equipment

Abstract

The invention relates to a digital subtraction imaging method and device and computer equipment. The method comprises the following steps: acquiring an energy spectrum image of a target object; the energy spectrum image comprises images of scanning signals of at least two energy levels; calculating base material data based on the energy spectrum image; and carrying out subtraction processing on the energy spectrum image based on the base material data to obtain an energy subtraction image, thereby solving the problem of poor quality of the subtraction image obtained during digital subtraction imaging, not only avoiding motion artifacts, but also simplifying the calculation difficulty of the subtraction image, improving the calculation reliability of the subtraction image, and improving the calculation efficiency of the energy spectrum image. And stable high-quality output is ensured.

Description

Technical Field

[0001] The present application relates to the field of image processing technology, and in particular to a digital subtraction imaging method, device and computer equipment. Background Art

[0002] Digital Subtraction Angiography (DSA) is a new medical imaging technology that emerged in the 1980s after CT. It is a new vascular examination method that combines conventional X-ray angiography machines with electronic computers. Its basic principle is to obtain an X-ray image before and after the injection of contrast agent into the human body. The image without contrast agent is called the mask, and the image with contrast agent is called the fill film. After the two images are input into the computer, they are subtracted in real time to eliminate parts such as muscles, bones, and soft tissues, leaving only the area of ​​interest containing blood vessels. DSA technology can well show the vascular area in the human body through subtraction and display the morphology and structure of blood vessels. At present, the DSA equipment used in clinical practice shoots videos of the contrast agent injection process. For a period of time at the beginning of the video, there is no contrast agent in the image, which can be processed as a mask. Subsequent frames containing contrast agent are subtracted from the same mask to obtain angiography images. This approach results in that if the patient moves or shifts during video recording, the subsequent full-length and mask images will not be spatially registered, and subtracting the two may produce motion-induced artifacts.

[0003] In order to overcome the artifacts caused by motion, some existing technologies process high- and low-energy X-ray images to obtain subtracted images. For example, the high-energy image and the low-energy image are multiplied by an independent weighting coefficient, and then the difference is taken to obtain the subtracted image. However, in different usage scenarios, different weighting coefficients need to be accurately adapted. The determination of the weighting coefficient is a difficult problem to solve, which leads to uneven quality of the output subtraction images and is difficult to be widely used. There is also a patent that proposes to train a deep neural network that converts high-energy shadow films into low-energy masks, and then use the low-energy shadow films to subtract from the mask given by the neural network to obtain a subtracted image. However, the method of generating low-energy masks based on neural networks will produce greater uncertainty due to probability problems, and it is difficult to guarantee the quality of the subtraction image.

[0004] Currently, no effective solution has been proposed to the problem of poor subtraction image quality in the related art. Summary of the invention

[0005] In this embodiment, a digital subtraction imaging method, apparatus and computer device are provided to solve the problem of poor imaging quality of subtraction images in the related art.

[0006] In a first aspect, a digital subtraction imaging method is provided in this embodiment, the method comprising:

[0007] Acquiring an energy spectrum image of a target object; the energy spectrum image includes images of scanning signals of at least two energy levels;

[0008] Calculate basic material data based on the energy spectrum image;

[0009] Based on the base material data, the energy spectrum image is subjected to subtraction processing to obtain an energy subtraction image.

[0010] In some of the embodiments, subtraction processing is performed on the energy spectrum image based on the base material data to obtain an energy subtraction image, including:

[0011] Extracting data corresponding to a preset material to be enhanced from the base material data to generate a first target material image;

[0012] Based on the first target material image, an energy subtraction image is obtained.

[0013] In some of the embodiments, obtaining an energy subtraction image based on the first target substance image includes:

[0014] Acquire a simulated perspective image of the target object;

[0015] Based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image.

[0016] In some of the embodiments, obtaining a simulated perspective image of a target object includes:

[0017] Extracting data corresponding to a preset substance to be suppressed from the base substance data to generate a second target substance image;

[0018] Based on the second target material image, the energy spectrum image is suppressed to obtain a simulated perspective image.

[0019] In some embodiments, based on the second target substance image, suppressing the energy spectrum image to obtain a simulated perspective image includes:

[0020] Based on the second target substance image and the first target substance image, the substance to be suppressed and the substance to be enhanced in the energy spectrum image are jointly suppressed to obtain a simulated perspective image.

[0021] In some of the embodiments, based on the first target substance image, the simulated perspective image is enhanced to obtain an energy subtraction image, including:

[0022] Get enhancement coefficient and suppression coefficient;

[0023] Based on the enhancement coefficient and the first target substance image, the simulated perspective image is enhanced to obtain a primary processed image;

[0024] Based on the suppression coefficient and the second target substance image, the first-processed image is subjected to suppression processing to obtain a second-processed image, and the second-processed image is used as an energy subtraction image.

[0025] In some of the embodiments, subtraction processing is performed on the energy spectrum image based on the base material data to obtain an energy subtraction image, including:

[0026] Extracting data corresponding to a preset substance to be suppressed from the base substance data to generate a second target substance image;

[0027] The second target material image is subtracted from the energy spectrum image to obtain the energy subtraction image.

[0028] In some of the embodiments, the target object is an object to which a contrast enhancement medium is administered; the substance to be enhanced includes a substance in the contrast enhancement medium; and the substance to be suppressed includes an interfering substance in the target object.

[0029] In a second aspect, a digital subtraction imaging device is provided in this embodiment, and the device includes:

[0030] An acquisition module, used for acquiring an energy spectrum image of the target object at the same time; the energy spectrum image includes scanning signal images of at least two energy levels;

[0031] A base material decomposition module, used for calculating base material data based on the energy spectrum image;

[0032] A subtraction module is used to perform subtraction processing on the energy spectrum image based on the base material data to obtain an energy subtraction image.

[0033] In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the digital subtraction imaging method described in the first aspect is implemented.

[0034] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the digital subtraction imaging method described in the first aspect is implemented.

[0035] Compared with the related art, the digital subtraction imaging method, device and computer equipment provided in this embodiment collect an energy spectrum image of the target object; the energy spectrum image includes images of scanning signals of at least two energy levels; basic material data are calculated based on the energy spectrum image; based on the basic material data, the energy spectrum image is subtracted to obtain an energy subtraction image, which solves the problem of poor quality of the subtraction image obtained during digital subtraction imaging, not only avoids the occurrence of motion artifacts, but also simplifies the difficulty of subtraction image calculation, improves the reliability of subtraction image calculation, and ensures stable high-quality output.

[0036] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0038] Figure 1 A hardware structure block diagram of a terminal of a digital subtraction imaging method in one embodiment;

[0039] Figure 2 is a schematic flow chart of a digital subtraction imaging method in one embodiment;

[0040] Figure 3 It is a traditional time subtraction image obtained based on the existing technology;

[0041] Figure 4 is an energy spectrum subtraction image in one embodiment;

[0042] Figure 5 A simulated perspective image in one embodiment;

[0043] Figure 6 A schematic diagram of a digital subtraction imaging method in a preferred embodiment;

[0044] Figure 7 FIG. 4 is a structural block diagram of a digital subtraction imaging device in one embodiment. DETAILED DESCRIPTION

[0045] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0046] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the", "these" and the like in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. Usually, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0047] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 1 FIG. 1 is a hardware structure diagram of a terminal of the digital subtraction imaging method of this embodiment. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) processor 102 and memory 104 for storing data, wherein processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0048] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the digital subtraction imaging method in the present embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0049] The transmission device 106 is used to receive or send data via a network. The above network includes a wireless network provided by the communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0050] In this embodiment, a digital subtraction imaging method is provided, which can be applied in the field of biology, for example, to analyze the structure and development process of animals and plants, to perform digital subtraction imaging on animal or plant samples, or to provide important data support for studying diseases and pathological conditions in organisms through digital subtraction imaging, such as improving the imaging quality of angiography. The method can also be applied in the industrial field, for example, the subtraction image obtained for the detection material can be used to analyze the material distribution and material properties, or to perform subtraction imaging on complex parts for further use in non-destructive testing.

[0051] Figure 2 is a flow chart of the digital subtraction imaging method of this embodiment, such as Figure 2 As shown, the process includes the following steps:

[0052] Step S210, acquiring an energy spectrum image of the target object; the energy spectrum image includes images of scanning signals of at least two energy levels.

[0053] Specifically, according to different application scenarios, the target object is a different scanned object. Exemplarily, the method is applied to angiography to collect energy spectrum images of target parts of the human body. The target parts can be the head, limbs, chest, abdomen and other parts. Among them, the blood vessels in the chest and abdomen, etc., will have obvious changes in position and shape with breathing and organ movement, resulting in the use of conventional digital angiography methods. Because it is necessary to obtain the overlay and mask at different times of a video, the blood vessels in the overlay and mask are misaligned in space. The image after the overlay and mask are subtracted will produce serious artifacts and cannot be used directly. Traditional solutions are mostly based on image registration technology to eliminate the possible spatial misalignment of the two, which has high requirements for the registration algorithm, and the real-time and quality of vascular imaging are difficult to guarantee. In general, the subtraction image quality caused by the above method is poor. The fundamental reason is that the interval between the shooting time of the overlay and mask is large. Therefore, in this embodiment, the energy spectrum image is collected, and the scanning signals of different energy levels are usually at the same time or adjacent times. For example, images of scanning signals of different energy levels can be acquired at the same time point or approximately at the same time point by using a double-layer detector or a photon counting detector. Two high-energy images and low-energy images with very small time difference can also be obtained by quickly switching the kv (voltage value) of the tube. Other types of color or multi-energy level detectors can be used to fundamentally and thoroughly solve the problem of poor imaging quality caused by motion artifacts.

[0054] The scanning signal includes one of signals such as x-rays, ultrasonic signals, magnetic resonance signals, and radioactive signals.

[0055] Step S220, calculating base material data based on the energy spectrum image.

[0056] Specifically, each pixel on the energy spectrum image can be considered to be composed of data of various substances. On the energy spectrum image, the same position and the same substance have different signal responses on low-energy images and high-energy images, thereby separating the contribution values ​​of various preset material components (such as water, calcium and iodine) in each pixel. Thus, the image corresponding to each substance is obtained. Among them, in order to enhance the effect of subtraction, the substance to be enhanced and the substance to be suppressed are separated. For example, in angiography applications, the calcium corresponding to the bones will affect the judgment of the vascular morphology, and the iodine in the contrast agent is the key substance to display the vascular morphology. Therefore, the calcium map corresponding to the calcium and the iodine map corresponding to the iodine are specifically extracted to distinguish and process substances with different functions and effects, thereby improving the subtraction processing effect.

[0057] Step S230: performing subtraction processing on the energy spectrum image based on the base material data to obtain an energy subtraction image.

[0058] Specifically, one or more substances are set as target substances as needed. Based on the base substance decomposition technology, the base substance data corresponding to each target substance can be extracted from the energy spectrum image, and each target substance image can be generated based on each base substance data. Among them, the target substance can be a substance to be enhanced or a substance to be suppressed. In the case of generating a first target substance image based on the base substance data of the substance to be enhanced, the first target substance image can be directly used as an energy subtraction image, or the first target substance image can be used to enhance the image of any energy level in the energy spectrum image to obtain an energy subtraction image, thereby achieving the effect of removing or weakening substances other than the substance to be enhanced in the energy spectrum image. In the case of generating a second target substance image based on the base substance data of the substance to be suppressed, the second target substance image is used to suppress the image of any energy level in the energy spectrum image, for example, the second target substance image is subtracted from the energy spectrum image to obtain an energy subtraction image, and the intensity of the substance to be suppressed in the energy spectrum image is weakened, thereby achieving the effect of highlighting substances other than the substance to be suppressed.

[0059] In one embodiment, energy spectrum images are continuously collected over a period of time, and base material decomposition and subtraction processing are performed in real time to obtain continuous energy subtraction images. The continuous energy subtraction images form video data, thereby dynamically displaying the detection results of the target object.

[0060] In this embodiment, an energy spectrum image of the target object is acquired; the energy spectrum image includes images of scanning signals of at least two energy levels; basic material data is calculated based on the energy spectrum image; based on the basic material data, the energy spectrum image is subtracted to obtain an energy subtraction image, which solves the problem of poor quality of subtraction images obtained during digital subtraction imaging, avoids the occurrence of motion artifacts, simplifies the difficulty of subtraction image calculation, improves the reliability of subtraction image calculation, and ensures stable high-quality output.

[0061] In one embodiment, based on the above step S220, the energy spectrum image is subjected to basic substance decomposition processing to obtain basic substance data, including:

[0062] Step S221, based on the energy spectrum image, calculate the contribution value of various material components in the target object to each pixel point.

[0063] Step S222: obtaining base substance data based on the contribution value.

[0064] In one embodiment, based on the above step S230, based on the base material data, subtraction processing is performed on the energy spectrum image to obtain an energy subtraction image, including:

[0065] Step S231: extracting data corresponding to a preset material to be enhanced from the base material data to generate a first target material image.

[0066] Specifically, the area where the substance to be enhanced is located is the area of ​​interest, and the first target substance image can be directly output as an energy subtraction image to clearly display the area where the substance to be enhanced is located; in other embodiments, the first target substance image is superimposed on the energy spectrum image or other background image to obtain an energy subtraction image, so as to highlight the area where the substance to be enhanced is located.

[0067] Step S232: obtaining an energy subtraction image based on the first target material image.

[0068] Taking angiography as an example, Figure 3 is a traditional time subtraction image obtained based on the existing technology, Figure 4 This is the energy spectrum subtraction image obtained in this embodiment. It can be seen that Figure 4 The impact of motion artifacts is greatly reduced and image quality is improved.

[0069] In one embodiment, the above step S232, based on the first target material image, obtains an energy subtraction image, including:

[0070] Step S232-a, obtaining a simulated perspective image of the target object.

[0071] Step S232-b: Based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image.

[0072] Specifically, Figure 5 As shown, the simulated perspective image is a background image representing the overall perspective structure of the target object. The simulated perspective image can be obtained by weakening the target material area in the target material image based on the energy spectrum image. Alternatively, a unified template image is used, which is adaptively modified based on different features such as the scanning position to match the target object; or the energy spectrum image can be used as input, and the target area is weakened through a trained neural network model to output a simulated perspective image.

[0073] The target substance image may be for a certain target substance or may be multiple images for multiple target substances. For example, in angiography scenario, the target substances are iodine and calcium, and the target substance images obtained include iodine images and calcium images. The area where the iodine is located is the region of interest, and the area where the calcium is located is the interference region; therefore, the above step S232-b can be based on the simulated perspective image, and the iodine image is enhanced to obtain an energy subtraction image; or the iodine image is enhanced and the calcium image is suppressed to obtain a simulated perspective image. The energy subtraction image is an angiography image that can clearly display the region of interest.

[0074] In one embodiment, the above step S232-a, obtaining a simulated perspective image of the target object, includes:

[0075] Step S310: extracting data corresponding to the preset substance to be suppressed from the base substance data to generate a second target substance image.

[0076] In one embodiment, the preset substance to be inhibited is a certain substance, such as calcium, and the distribution data of the calcium element is extracted from the base substance data, and the second target substance image is obtained based on the distribution data of the calcium element; multiple second target substance images can be obtained based on multiple substances to be inhibited. In other embodiments, the preset substances to be inhibited are multiple, such as calcium and carbon, and based on the base substance data corresponding to the multiple substances to be inhibited, a second target substance image containing multiple substances is generated.

[0077] Specifically, the main principle of the base material decomposition technology is that the target object will show different attenuation characteristics under the irradiation of the scanning signal source. These attenuation characteristics are not only related to the structure of the target object, but also closely related to its chemical composition. Therefore, by analyzing the attenuation of the scanning signal at different energies, the chemical composition of the tissue can be inferred. The degree of attenuation of the photon beam in the scanning signal depends on the energy of the incident beam and the density and atomic number (Z) of the material (absorbent) that interacts with the scanning signal photons. For example, the atomic number of the material elements (including hydrogen, oxygen, carbon and nitrogen) that make up the soft tissue in the human body is lower than that of calcium, trace elements (such as iron, copper, zinc, iodine and manganese) and exogenous administration substances (such as barium, iodine contrast agents and gadolinium). When the energy level of the scanning signal of different materials is just greater than the binding energy (k edge), the attenuation will suddenly increase. The K edge varies from material to material and usually increases with the increase of atomic number. Spectral analysis provides an opportunity to distinguish different substances in the target object based on the unique k edge characteristics and the difference in attenuation at different energy levels. Among them, the base material decomposition process is not limited to the use of dual-substance decomposition technology and multi-substance decomposition technology.

[0078] Step S320: based on the second target material image, suppress the energy spectrum image to obtain a simulated perspective image.

[0079] Specifically, the energy spectrum image is subtracted from the second target substance image to weaken or eliminate the substance to be suppressed in the energy spectrum image to obtain a simulated perspective image; or the energy spectrum image is suppressed by setting a mask or filtering.

[0080] In this embodiment, the energy spectrum image of the target object is suppressed by the second target substance image, and the background image is more closely matched with the target object, thereby improving the quality of subtraction imaging.

[0081] In one embodiment, step S320, based on the second target material image, suppressing the energy spectrum image to obtain a simulated perspective image, includes:

[0082] Step S321 : based on the second target substance image and the first target substance image, jointly suppress the substance to be suppressed and the substance to be enhanced in the energy spectrum image to obtain a simulated perspective image.

[0083] Specifically, the second target substance image and the first target substance image are sequentially subtracted from the energy spectrum image to weaken or eliminate the substance to be suppressed and the substance to be enhanced in the energy spectrum image, thereby obtaining a simulated perspective image. In addition, a mask image may be produced based on the second target substance image and the first target substance image, and a simulated perspective image may be obtained based on the product of the mask image and the energy spectrum image.

[0084] In this embodiment, the substance to be enhanced and the substance to be suppressed are double suppressed to further remove the interference signal in the simulated perspective image.

[0085] In one embodiment, based on the above step S232-b, based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image, including:

[0086] Step S410, obtaining enhancement coefficient and suppression coefficient.

[0087] Step S420: Based on the enhancement coefficient and the first target material image, the simulated perspective image is enhanced to obtain a primary processed image.

[0088] Step S430: Based on the suppression coefficient and the second target substance image, the first-processed image is subjected to suppression processing to obtain a second-processed image, and the second-processed image is used as an energy subtraction image.

[0089] Specifically, the effects of enhancement and suppression can be adjusted by adjusting the size of the enhancement coefficient and the suppression coefficient, so that enhancement and suppression can be performed based on the original intensities of the images of the materials to be enhanced and the materials to be suppressed. The degree of enhancement and suppression can also be strengthened or weakened as needed, making the subtraction process more flexible.

[0090] In other non-limiting embodiments, after obtaining the enhancement coefficient and the suppression coefficient, the simulated perspective image is suppressed based on the suppression coefficient and the second target substance image to obtain a primary processed image; the primary processed image is enhanced based on the enhancement coefficient and the first target substance image to obtain a secondary processed image; the secondary processed image is used as an energy subtraction image. The order of suppression and enhancement of the simulated perspective image can be set in combination with actual image processing needs.

[0091] In other non-limiting embodiments, the second target substance image may not be involved in the processing, for example, the suppression coefficient is set to zero. In this case, the above step S232-b can be simplified as follows: based on the enhancement coefficient and the first target substance image, the simulated perspective image is enhanced to obtain a processed image, and the processed image is used as an energy subtraction image.

[0092] In this embodiment, by weakening the display intensity of the substance to be suppressed in the same simulated perspective image and enhancing the display intensity of the substance to be enhanced in the image, the contrast of the substance to be enhanced is improved, and the clarity of the energy subtraction image is improved. The simulated perspective image is used as a background image to show the overall perspective structure of the target object and the positional relationship and contrast relationship of the substance to be enhanced, so that the entire energy subtraction image contains more analyzable information.

[0093] In one embodiment, the above step S230, based on the base material data, performs subtraction processing on the energy spectrum image to obtain the energy subtraction image, further includes:

[0094] Data corresponding to the preset substance to be suppressed is extracted from the base substance data to generate a second target substance image; the second target substance image is subtracted from the energy spectrum image to obtain an energy subtraction image.

[0095] Specifically, the substance to be suppressed is an interfering substance that interferes with the image quality or affects the contrast of the region of interest, so these interfering substances can be suppressed in the energy spectrum image. The suppression method can be achieved by making a difference between the energy spectrum image and the second target substance image to improve the processing speed of subtraction.

[0096] In one embodiment, the target object is a subject to which a contrast enhancement medium is administered; the substance to be enhanced includes a substance in the contrast enhancement medium; and the substance to be suppressed includes an interfering substance in the body of the target object.

[0097] Specifically, in medical imaging, contrast enhancement media can be exogenous administrated substances injected into the human body to enhance the contrast between tissues, such as barium, iodine contrast agents and gadolinium. Since the shape of the identified contrast enhancement medium in medical imaging reflects the state of a specific organ or tissue, it is necessary to highlight the contrast enhancement medium in the energy subtraction image, and some structures in the target object will overlap with the contrast enhancement medium in terms of perspective. When the material of the overlapping structure is similar to the density of the contrast enhancement medium, there will be interference during imaging. At this time, this part of the overlapping material can be used as a substance to be suppressed, thereby more effectively strengthening the area where the contrast enhancement medium is located. Since the present embodiment can flexibly adjust the degree of subtraction through the substance to be enhanced and the substance to be suppressed, when applying the contrast enhancement medium, the concentration of the application can also be adaptively diluted to save materials and reduce the burden of human body discharge. Among them, the substance to be enhanced includes but is not limited to the substance in the contrast enhancement medium, and can also include other substances of interest outside the contrast enhancement medium.

[0098] In other possible implementations, the contrast enhancement medium itself contains multiple components, and some substances in the contrast enhancement medium can be set as substances to be enhanced, and another part of the substances can be set as substances to be suppressed.

[0099] In one embodiment, based on the above step S210, acquiring the energy spectrum image of the target object specifically includes the following steps:

[0100] Step S510 : collecting a scanning signal passing through the target object based on a photon counting detector, and recording the energy of the scanning signal.

[0101] Step S520: outputting the collected scanning signals as energy spectrum images with different energy levels based on the different energies of the scanning signals.

[0102] Specifically, photon counting detectors can accurately measure the energy and position of each photon, thus providing higher spatial resolution. Although the number of photons is limited in a narrow energy range, photon counting detectors can reduce the impact of noise on image quality to a certain extent through accurate counting and energy level measurement.

[0103] In one embodiment, based on the above step S210, acquiring the energy spectrum image of the target object specifically includes the following steps:

[0104] Step S610, based on the double-layer detector, a scanning signal passing through the target object is collected to obtain an energy spectrum image; wherein the double-layer detector includes a first detector, a second detector and a filter located between the first detector and the second detector; the filter is used to block the scanning signal of the first energy level and pass the scanning signal of the second energy level; the first detector is used to collect the scanning signal of the first energy level to obtain an energy spectrum image of the first energy level; the second detector is used to collect the scanning signal of the second energy level to obtain an energy spectrum image of the second energy level.

[0105] Specifically, a copper filter is usually set between the two layers of the double-layer detector. The first layer of the detector receives the direct X-rays, and the high-energy X-rays can penetrate the copper filter and irradiate the second layer of the detector. The high- and low-energy images are output according to the image signals collected by the two layers of the detector. This embodiment uses a "sandwich" detector design to efficiently collect dual-energy level images and more accurately identify the composition and distribution of different substances.

[0106] The present embodiment is described and illustrated below through a preferred embodiment. Figure 6 This is a flow chart of the preferred embodiment. Figure 6 As shown, the process includes the following steps:

[0107] S1. Collecting energy spectrum X-ray images of the human body. The collection method includes: 1) The photon counting detector collects X-rays, and according to the energy of the recorded X-rays, the ray signals are divided into high-energy X-rays and low-energy X-rays, and high-energy images and low-energy images are output respectively. 2) A double-layer detector, a copper filter is usually set between the two layers of detectors, the first layer of the detector receives the directly irradiated X-rays, and the high-energy X-rays can penetrate the copper filter to irradiate the second layer of the detector, and the high-energy image and low-energy image are output according to the image signals collected by the two layers of detectors. 3) The X-ray tube performs rapid KV (voltage value) switching, and emits high and low energy X-rays successively in a very short time. The detector collects the images generated by high-energy and low-energy X-rays twice successively. 4) Dual-energy X-ray images or multi-energy-level X-ray images collected by other types of color or multi-energy-level X-ray detectors and other technical means.

[0108] S2. Based on the material decomposition technology, the energy spectrum X-ray image is decomposed into materials to obtain iodine map, calcium map and simulated perspective map, among which the iodine map is used to represent the morphology of the contrast agent; the calcium map is used to represent the morphology of the bones; the simulated perspective map is used to represent the perspective structure of the human body; among which, the materials used in the basic material decomposition include water, calcium and iodine.

[0109] S3. On the basis of simulating conventional perspective images, the calcium image is suppressed and the iodine image is enhanced to obtain an energy subtraction image.

[0110] In this preferred embodiment, the energy spectrum X-ray image is decomposed by material decomposition through the basic material decomposition technology, and calcium is suppressed and iodine is enhanced on the simulated perspective image, so as to obtain a high-quality energy subtraction image, which not only avoids the occurrence of motion artifacts, but also simplifies the difficulty of subtraction image calculation, improves the reliability of subtraction image calculation, and ensures stable high-quality output.

[0111] It should be noted that the steps shown in the above process or the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0112] In this embodiment, a digital subtraction imaging device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. The terms "module", "unit", "subunit", etc. used below can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0113] Figure 7 is a structural block diagram of the digital subtraction imaging device of this embodiment, such as Figure 7 As shown, the device includes: a collection module 61, a base material decomposition module 62 and a subtraction module 63.

[0114] The acquisition module 61 is used to acquire the energy spectrum image of the target object at the same time; the energy spectrum image includes scanning signal images of at least two energy levels.

[0115] The base material decomposition module 62 is used to calculate base material data based on the energy spectrum image.

[0116] The subtraction module 63 is used to perform subtraction processing on the energy spectrum image based on the base material data to obtain an energy subtraction image.

[0117] In some of the embodiments, the base material decomposition module 62 is further used to calculate the contribution value of various material components in the target object to each pixel point based on the energy spectrum image; and obtain the base material data based on the contribution value.

[0118] In some of the embodiments, the subtraction module 63 is further used to extract data corresponding to the preset material to be enhanced from the base material data to generate a first target material image; and obtain an energy subtraction image based on the first target material image.

[0119] In some of the embodiments, the subtraction module 63 is further used to extract data corresponding to a preset substance to be suppressed from the base material data to generate a second target material image; and to subtract the second target material image from the energy spectrum image to obtain an energy subtraction image.

[0120] In some of the embodiments, the subtraction module 63 is further used to obtain a simulated perspective image of the target object; based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image.

[0121] In some of the embodiments, the subtraction module 63 is further used to extract data corresponding to a preset substance to be suppressed from the base material data to generate a second target material image; based on the second target material image, the energy spectrum image is suppressed to obtain a simulated perspective image.

[0122] In some of the embodiments, the subtraction module 63 is further used to jointly suppress the substance to be suppressed and the substance to be enhanced in the energy spectrum image based on the second target substance image and the first target substance image to obtain a simulated perspective image.

[0123] In some of the embodiments, the subtraction module 63 is further used to obtain an enhancement coefficient and a suppression coefficient;

[0124] Based on the enhancement coefficient and the first target substance image, the simulated perspective image is enhanced to obtain a primary processed image; based on the suppression coefficient and the second target substance image, the primary processed image is suppressed to obtain a secondary processed image, and the secondary processed image is used as an energy subtraction image.

[0125] In some of the embodiments, the target object is an object to which a contrast enhancement medium is applied; the substance to be enhanced includes a substance in the contrast enhancement medium; and the substance to be suppressed includes an interfering substance in the target object.

[0126] It should be noted that the above modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0127] In this embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0128] Optionally, the computer device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0129] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0130] In addition, in combination with the digital subtraction imaging method provided in the above embodiments, a storage medium may be provided in this embodiment to implement the method. The storage medium stores a computer program; when the computer program is executed by a processor, any one of the digital subtraction imaging methods in the above embodiments is implemented.

[0131] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0132] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0133] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0134] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A digital subtraction imaging method, characterized in that: The method comprises: Acquiring an energy spectrum image of a target object; the energy spectrum image includes images of scanning signals of at least two energy levels; Calculate basic material data based on the energy spectrum image; Based on the base material data, the energy spectrum image is subjected to subtraction processing to obtain an energy subtraction image.

2. The digital subtraction imaging method according to claim 1, characterized in that: Based on the base material data, the energy spectrum image is subjected to subtraction processing to obtain an energy subtraction image, including: Extracting data corresponding to a preset material to be enhanced from the base material data to generate a first target material image; Based on the first target material image, an energy subtraction image is obtained.

3. The digital subtraction imaging method according to claim 2, characterized in that: Based on the first target material image, an energy subtraction image is obtained, including: Acquire a simulated perspective image of the target object; Based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image.

4. The digital subtraction imaging method according to claim 3, characterized in that: Acquire a simulated perspective image of the target object, including: Extracting data corresponding to a preset substance to be suppressed from the base substance data to generate a second target substance image; Based on the second target material image, the energy spectrum image is suppressed to obtain a simulated perspective image.

5. The digital subtraction imaging method according to claim 4, characterized in that: Based on the second target material image, the energy spectrum image is suppressed to obtain a simulated perspective image, including: Based on the second target substance image and the first target substance image, the substance to be suppressed and the substance to be enhanced in the energy spectrum image are jointly suppressed to obtain a simulated perspective image.

6. The digital subtraction imaging method according to claim 5, characterized in that: Based on the first target material image, the simulated perspective image is enhanced to obtain an energy subtraction image, including: Get enhancement coefficient and suppression coefficient; Based on the enhancement coefficient and the first target substance image, the simulated perspective image is enhanced to obtain a primary processed image; Based on the suppression coefficient and the second target substance image, the first-processed image is subjected to suppression processing to obtain a second-processed image, and the second-processed image is used as an energy subtraction image.

7. The digital subtraction imaging method according to claim 1, characterized in that: Based on the base material data, the energy spectrum image is subjected to subtraction processing to obtain an energy subtraction image, including: Extracting data corresponding to a preset substance to be suppressed from the base substance data to generate a second target substance image; The second target material image is subtracted from the energy spectrum image to obtain the energy subtraction image.

8. The digital subtraction imaging method according to any one of claims 6 or 7, characterized in that: The target object is an object to which a contrast enhancement medium is applied; the substance to be enhanced includes the substance in the contrast enhancement medium; and the substance to be suppressed includes the interfering substance in the target object.

9. A digital subtraction imaging device, characterized in that: The device comprises: An acquisition module, used for acquiring an energy spectrum image of the target object at the same time; the energy spectrum image includes scanning signal images of at least two energy levels; A base material decomposition module, used for calculating base material data based on the energy spectrum image; A subtraction module is used to perform subtraction processing on the energy spectrum image based on the base material data to obtain an energy subtraction image.

10. A computer device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to perform the steps of the digital subtraction imaging method according to any one of claims 1 to 8.

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