CT image generation method and device, electronic equipment and storage medium

Abstract

The invention provides a CT image generation method and device, electronic equipment and a storage medium, and relates to the technical field of intelligent medical treatment. The first CT projection image subset is obtained by scanning based on low-level voltage segments in a plurality of periods, and soft tissue features in the first CT image are obvious; the second CT projection image subset is obtained by scanning based on high-level voltage segments in multiple periods, and bone tissue features in the second CT image are obvious. Further, the first CT projection image subset is expanded according to an interpolation method to obtain an expanded first projection image subset, and the second CT projection image subset is expanded according to the interpolation method to obtain an expanded second projection image subset; the reconstructed first CT image associated with the low-level voltage section is high in spatial resolution and few in artifacts, and the reconstructed second CT image associated with the high-level voltage section is high in spatial resolution and few in artifacts.

Description

Technical Field

[0001] This application relates to the field of intelligent medical technology, and in particular, to a method, apparatus, electronic device, and storage medium for generating CT images. Background Art

[0002] Computed Tomography (CT) imaging is obtained by reconstructing multiple projection images obtained by scanning a target body part of a human body at preset time intervals based on a preset periodic scanning voltage waveform during the rotation of a CT device around the human body. Since different human tissues have different absorption capabilities for X-rays excited by different voltages (for example, the bone tissue of the human body has a higher absorption capability for X-rays excited by high-level voltages and a lower absorption capability for X-rays excited by low-level voltages; the soft tissues of the human body (such as muscle, skin, and blood vessel tissues) have a higher absorption capability for X-rays excited by low-level voltages and a lower absorption capability for X-rays excited by high-level voltages). Thus, each period in the periodic scanning voltage waveform can include a high-level voltage segment and a low-level voltage segment. Furthermore, a first CT image can be reconstructed based on the projection images obtained by scanning with X-rays excited by the high-level voltage segments of multiple periods, and the bone tissue features in the first CT image are relatively obvious compared to the soft tissue features. Also, a second CT image can be reconstructed based on the projection images obtained by scanning with X-rays excited by the low-level voltage segments of multiple periods, and the soft tissue features in the second CT image are relatively obvious compared to the bone tissue features. Doctors can comprehensively refer to the first CT image and the second CT image to diagnose the patient's condition.

[0003] It can be understood that the above process of reconstructing the first CT image only refers to the projection images obtained by scanning with X-rays excited by the high-level voltage segments of multiple periods, and the process of reconstructing the second CT image only refers to the projection images obtained by scanning with X-rays excited by the low-level voltage segments of multiple periods. Thus, the spatial resolution of the reconstructed first CT image and the second CT image is low and there are many artifacts. Summary of the Invention

[0004] This application provides a method, apparatus, electronic device, and storage medium for generating CT images, which are used to solve the problems of low spatial resolution and many artifacts in the reconstructed CT images in the prior art.

[0005] In a first aspect, an embodiment of this application provides a method for generating CT images, including:

[0006] Receive a set of CT projection images obtained by scanning a target body part of a human body by a CT device, where the set of CT projection images is obtained by scanning the target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the process of the CT device rotating around the human body. Each period of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to the preset time length, a rising voltage segment corresponding to the preset time length for switching from the low-level voltage segment to the high-level voltage segment, a high-level voltage segment corresponding to the preset time length, and a falling voltage segment corresponding to the preset time length for switching back from the high-level voltage segment to the low-level voltage segment;

[0007] Extract a first sub-set of CT projection images and a second sub-set of CT projection images from the set of CT projection images, where the first sub-set of CT projection images is obtained by scanning based on the low-level voltage segments in multiple periods, and the second sub-set of CT projection images is obtained by scanning based on the high-level voltage segments in multiple periods;

[0008] Expand the first sub-set of CT projection images according to the interpolation method to obtain an expanded first sub-set of projection images, and expand the second sub-set of CT projection images according to the interpolation method to obtain an expanded second sub-set of projection images;

[0009] Reconstruct a first CT image associated with the low-level voltage segment according to the expanded first sub-set of projection images, and reconstruct a second CT image associated with the high-level voltage segment according to the expanded second sub-set of projection images.

[0010] In a second aspect, the present application also provides a CT image generation device, including:

[0011] A data receiving unit for receiving a set of CT projection images obtained by scanning a target body part of a human body by a CT device, where the set of CT projection images is obtained by scanning the target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the process of the CT device rotating around the human body. Each period of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to the preset time length, a rising voltage segment corresponding to the preset time length for switching from the low-level voltage segment to the high-level voltage segment, a high-level voltage segment corresponding to the preset time length, and a falling voltage segment corresponding to the preset time length for switching back from the high-level voltage segment to the low-level voltage segment;

[0012] A data extraction unit for extracting a first sub-set of CT projection images and a second sub-set of CT projection images from the set of CT projection images, where the first sub-set of CT projection images is obtained by scanning based on the low-level voltage segments in multiple periods, and the second sub-set of CT projection images is obtained by scanning based on the high-level voltage segments in multiple periods;

[0013] A data interpolation unit, configured to expand the first sub - set of CT projection images according to an interpolation method to obtain an expanded first sub - set of projection images, and expand the second sub - set of CT projection images according to the interpolation method to obtain an expanded second sub - set of projection images;

[0014] An image reconstruction unit, configured to reconstruct a first CT image associated with a low - level voltage segment according to the expanded first sub - set of projection images, and reconstruct a second CT image associated with a high - level voltage segment according to the expanded second sub - set of projection images.

[0015] In a third aspect, the present application further provides an electronic device, including:

[0016] A processor;

[0017] A memory for storing instructions executable by the processor;

[0018] Wherein, the processor is configured to execute instructions to implement the CT image generation method provided in the first aspect of the present application.

[0019] In a fourth aspect, the present application further provides a storage medium. When the instructions in the storage medium are executed by the processor of the electronic device, the electronic device can execute the CT image generation method provided in the first aspect of the present application.

[0020] The present application provides a CT image generation method, apparatus, electronic device and storage medium. The first sub - set of CT projection images is obtained by scanning during a low - level voltage segment in multiple cycles, so the soft - tissue features in the first CT image are obvious; the second sub - set of CT projection images is obtained by scanning during a high - level voltage segment in multiple cycles, and the bone tissue features in the second CT image are obvious. Furthermore, the first sub - set of CT projection images is expanded according to an interpolation method to obtain an expanded first sub - set of projection images, and the second sub - set of CT projection images is expanded according to the interpolation method to obtain an expanded second sub - set of projection images. It can be understood that the image content in the expanded first sub - set of CT projection images according to the interpolation method is more abundant and reliable, and the image content in the expanded second sub - set of CT projection images according to the interpolation method is also more abundant and reliable. Therefore, the first CT image reconstructed according to the expanded first sub - set of projection images associated with the low - level voltage segment has high spatial resolution and few artifacts, and the second CT image reconstructed according to the expanded second sub - set of projection images associated with the high - level voltage segment has high spatial resolution and few artifacts. In this way, doctors can more clearly observe the bone tissue and soft tissue of patients according to the first CT image and the second CT image respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Schematic diagram of the interaction between the server provided by the embodiment of the present application and the CT device and the medical terminal;

[0023] Figure 2 One of the flowcharts of the CT image generation method provided by the embodiment of the present application;

[0024] Figure 3 Schematic diagram of the structure of the CT device provided by the embodiment of the present application;

[0025] Figure 4 Preset periodic scanning voltage waveform diagram provided by the embodiment of the present application;

[0026] Figure 5 Another flowchart of the CT image generation method provided by the embodiment of the present application;

[0027] Figure 6 For Figure 5 Specific flowchart of S501 in

[0028] Figure 7 Functional module block diagram of the CT image generation device provided by the embodiment of the present application;

[0029] Figure 8 Circuit structure block diagram of the electronic device provided by the embodiment of the present application. Detailed implementation manners

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure.

[0031] Various structural schematic diagrams according to the embodiments of the present disclosure are shown in the drawings. These figures are not drawn to scale. For the purpose of clear expression, some details are enlarged, and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0032] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0033] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0034] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0035] Computed Tomography (CT) imaging is obtained by reconstructing multiple projection images obtained by scanning a target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the rotation of the CT device around the human body. Currently, the above process of reconstructing CT images only refers to the projection images obtained by X-ray scanning excited by the high-level voltage segments of multiple cycles, and the process of reconstructing CT images only refers to the projection images obtained by X-ray scanning excited by the low-level voltage segments of multiple cycles. Thus, the reconstructed CT images and the spatial resolution of the CT images are low and there are many artifacts.

[0036] In view of this, the present application provides a CT image generation method, apparatus, electronic device, and storage medium, which can expand a first subset of CT projection images obtained by scanning based on low-level voltage segments in multiple cycles, expand a second subset of CT projection images obtained by scanning based on high-level voltage segments in multiple cycles, and reconstruct a first CT image associated with the low-level voltage segment according to the expanded first subset of projection images, and reconstruct a second CT image associated with the high-level voltage segment according to the expanded second subset of projection images. Since the image content in the expanded first subset of CT projection images is richer and more reliable, and the image content in the expanded second subset of CT projection images is also richer and more reliable. Furthermore, the accuracy of the reconstructed first CT image and second CT image is also higher. In this way, doctors can more clearly observe the patient's bone tissue and soft tissue according to the first CT image and the second CT image respectively.

[0037] Next, specific embodiments will be used to describe in detail the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0038] An embodiment of the present application provides a CT image generation method, which is applied to a server 200. As Figure 1 shown, the server 200 is respectively communicatively connected to a CT device 100 and a doctor terminal 300. The CT device 100 scans a target body part of the human body at a certain thickness layer with X-rays. When the X-rays irradiate the human tissue, part of the X-rays are absorbed by the tissue, and part of the X-rays pass through the human body and are received by the X-ray detector, generating signals. Because the density of various human tissues is different and the penetration ability of X-rays is different, the rays received by the X-ray detector are different. After converting the received differential ray signals into digital information and processing them by a computer, a tomographic image of the target body part of the human body can be obtained. In addition, the doctor terminal can be, but is not limited to, a working computer located in the doctor's office.

[0039] Specifically, as Figure 2 shown, the method provided by the embodiment of the present application includes:

[0040] S201: Receive a set of CT projection images obtained by scanning a target body part of the human body by the CT device 100.

[0041] Among them, the set of CT projection images is: during the process of the CT device 100 rotating around the human body, the target body part of the human body is scanned at a preset time interval based on a preset periodic scanning voltage waveform.

[0042] Specifically, as Figure 3 shown, the CT device 100 includes a CT gantry 102, an X-ray emitter 101 disposed at the top of the CT gantry 102, an X-ray detector 104 disposed at the bottom of the CT gantry 102 and opposite to the X-ray emitter 101, and an examination table 103 disposed between the X-ray emitter 101 and the X-ray detector 104. A patient can lie on the examination table 103, and the rotation of the CT gantry 102 can drive the X-ray emitter 101 and the X-ray detector 104 to rotate. During the rotation, the X-rays emitted by the X-ray emitter 101 can pass through the target body part (such as the chest and abdomen) of the human body from different angles and be absorbed by the target body part of the human body and then detected by the X-ray detector 104, so as to obtain a set of CT projection images.

[0043] Further, as Figure 4 shown, each period of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to a preset duration (that is, the low-level voltage segment maintains the preset duration), a rising voltage segment corresponding to a preset duration for switching from the low-level voltage segment to the high-level voltage segment (that is, the rising voltage segment maintains the preset duration), a high-level voltage segment corresponding to a preset duration (that is, the high-level voltage segment maintains the preset duration), and a falling voltage segment corresponding to a preset duration for switching back from the high-level voltage segment to the low-level voltage segment (that is, the falling voltage segment maintains the preset duration).

[0044] It can be understood that the low-level voltage segment, the rising voltage segment, the high-level voltage segment, and the falling voltage segment excite the X-ray emitter 101 to emit X-rays with different energies. The energy spectrum of the X-rays emitted by the X-ray emitter 101 excited by the rising voltage segment, the high-level voltage segment, and the falling voltage segment can be detected by the aluminum sheet experiment method.

[0045] It can be understood that since aluminum sheets have different absorptions of X-rays with different energies, relatively thin aluminum sheets have a stronger absorption of low-energy X-rays, and relatively thick aluminum sheets gradually have an enhanced absorption of high-energy X-rays. By adjusting the thickness of multiple aluminum sheets, a series of light intensities of X-rays corresponding to aluminum sheets with different thicknesses can be obtained. Since the absorption degrees of X-rays by aluminum sheets with different thicknesses are known quantities, solving the equation of light intensity and energy can obtain the energy spectrum and can detect whether the energy spectrum is correct.

[0046] S202: Extract a first sub-set of CT projection images and a second sub-set of CT projection images from the set of CT projection images.

[0047] Among them, the first sub-set of CT projection images is obtained by scanning based on the low-level voltage segments in multiple periods, and the second sub-set of CT projection images is obtained by scanning based on the high-level voltage segments in multiple periods.

[0048] Exemplarily, assume that during the rotation of the CT device 100 around the human body, based on the periodic scanning voltage waveform as shown below, 2000 CT projection images are obtained by scanning the target body part of the human body every preset time duration. Then, the first CT projection image subset includes 500 first CT projection images, and the second CT projection image subset also includes 500 second CT projection images. Figure 4 In addition, since the 500 CT projection images obtained during the rising voltage segment and the 500 CT projection images obtained during the falling voltage segment are relatively blurred due to voltage stabilization, they are discarded.

[0049] In addition, since the 500 CT projection images obtained during the rising voltage segment and the 500 CT projection images obtained during the falling voltage segment are relatively blurred due to voltage stabilization, they are discarded.

[0050] S203: Expand the first CT projection image subset according to the interpolation method to obtain the expanded first projection image subset, and expand the second CT projection image subset according to the interpolation method to obtain the expanded second projection image subset.

[0051] Exemplarily, the above interpolation method can be, but is not limited to, linear interpolation, spline interpolation, Lagrange interpolation, or Newton interpolation. Among them, linear interpolation refers to an interpolation method in which the interpolation function is a first-degree polynomial. Linear interpolation can be used to approximately replace the original function with high reliability. Spline interpolation is a mathematical method that uses variable splines to create a smooth curve passing through a series of points; the interpolation spline is composed of some polynomials, and each polynomial is determined by two adjacent data points, so that any two adjacent polynomials and their derivatives are continuous at the connection points, with high reliability. The principle of Lagrange interpolation is that there must be a polynomial that can satisfy the conditions passing through N points, and the highest degree of the polynomial is N - 1. Let the x of each term of the polynomial be (x0, x1... xN), then substituting each point can obtain the polynomial, and no data will be lost, with high reliability. Newton interpolation has the advantage of inheritance compared with Lagrange interpolation, that is, when adding additional interpolation points, the previous calculation results can be used to reduce the amount of calculation.

[0052] Next, taking the linear interpolation method as an example, it is explained how to expand the first CT projection image subset.

[0053] Assume that the pixel values of two first CT projection images obtained by scanning the low-level voltage segments in two adjacent periods are S1.1 and S1.2 respectively. Then, according to the formula S3 ' _1 = (S1_1 + S1_2) / 2, the pixel value S3 ' _1 of the simulated first projection image corresponding to the high-level voltage segment between the low-level voltage segments in two adjacent periods can be determined. According to the formula S2 ' _1 = (S1_1 + S3' _1) / 2 to determine the pixel value S2 of the rising voltage segment corresponding to the analog first projection image between the low-level voltage segments within two adjacent cycles ' _1, according to the formula S4 ' _1 = (S3 ' _1 + S1_2) / 2) to determine the pixel value S4 of the falling voltage segment corresponding to the analog first projection image between the low-level voltage segments within two adjacent cycles ' _1. Similarly, the method for expanding the second CT projection image subset is the same as the method for expanding the first CT projection image subset described above, and will not be elaborated here.

[0054] S204: Reconstruct the first CT image associated with the low-level voltage segment according to the expanded first projection image subset, and reconstruct the second CT image associated with the high-level voltage segment according to the expanded second projection image subset.

[0055] Exemplarily, the algorithms for reconstructing the first CT image associated with the low-level voltage segment and the second CT image associated with the high-level voltage segment may be, but are not limited to, the filtered back projection (FBP) method, the compressed sensing algorithm with prior image constraint, or the iterative reconstruction algorithm.

[0056] Specifically, in the filtered back projection method, after the projection data undergoes the Radon transform, filtering and back projection operations are performed to restore the pixel values of the object. Among them, the filtering operation uses a filtering function to perform weighted filtering on the projection data to eliminate artifacts and noise; the back projection operation projects the filtered projection data back to the original position to restore the pixel values of the object, and through multiple back projections, the final image is reconstructed. The iterative reconstruction method can perform CT scans at a lower radiation dose and reduce CT image noise at the same time. Therefore, compared with the filtered back projection method under the same conditions, higher-quality CT images can be obtained.

[0057] It can be understood that based on the above, the first CT image and the second CT image are obtained by scanning a target body part of the human body with X-rays at a certain thickness layer, and using the different absorption capabilities of different human tissues for X-rays to reconstruct the tomographic images of the human tissues, which can clearly express the internal characteristics of the patient's body.

[0058] Furthermore, the server 200 can upload the first CT image and the second CT image to the doctor terminal 300 (such as a computer) for the doctor to observe.

[0059] In summary, the embodiment of the present application provides a method for generating a CT image. The first CT projection image subset is obtained by scanning in the low-level voltage segments of multiple cycles, so the soft tissue features in the first CT image are obvious; the second CT projection image subset is obtained by scanning in the high-level voltage segments of multiple cycles, and the bone tissue features in the second CT image are obvious. Furthermore, the first CT projection image subset is expanded according to the interpolation method to obtain an expanded first projection image subset, and the second CT projection image subset is expanded according to the interpolation method to obtain an expanded second projection image subset. It can be understood that the image content in the first CT projection image subset expanded according to the interpolation method is richer and more reliable, and the image content in the second CT projection image subset expanded according to the interpolation method is also richer and more reliable. Therefore, the first CT image reconstructed according to the expanded first projection image subset associated with the low-level voltage segment has a high spatial resolution and few artifacts, and the second CT image reconstructed according to the expanded second projection image subset associated with the high-level voltage segment has a high spatial resolution and few artifacts. In this way, doctors can more clearly observe the bone tissue and soft tissue of patients based on the first CT image and the second CT image.

[0060] In addition, based on the above Figure 2 corresponding embodiment, after S203, as Figure 5 shown, the method provided by the embodiment of the present application may further include:

[0061] S501: Calibrate the expanded first projection image subset and the expanded second projection image subset. In this way, the accuracy of the expanded first projection image subset and the second projection image subset can be made higher and more referenceable.

[0062] Specifically, the simulated first projection images corresponding to the rising voltage segments in each cycle, the simulated first projection images corresponding to the high-level voltage segments, and the simulated first projection images corresponding to the falling voltage segments; the expanded second projection image subset further includes: the simulated second projection images corresponding to the low-level voltage segments, the simulated second projection images corresponding to the rising voltage segments in each cycle, and the simulated second projection images corresponding to the falling voltage segments. Furthermore, as Figure 6 shown, S501 can be specifically implemented as:

[0063] S601: Scan the first CT image and the second CT image based on a preset periodic scanning voltage waveform to obtain a second CT projection image set and a third CT projection image set respectively.

[0064] S602: For each period, determine the first difference between the pixel values of the second CT projection images associated with the low-voltage segments in the second CT projection image set and the pixel values of the first CT projection images associated with the low-voltage segments in the corresponding period of the first CT projection image subset, and determine the second difference between the pixel values of the third CT projection images associated with the high-voltage segments in the second CT projection image set and the pixel values of the fourth CT projection images associated with the high-voltage segments in the corresponding period of the first CT projection image subset.

[0065] Understandably, the pixel values of the first CT projection images associated with the low-voltage segments in the corresponding period of the first CT projection image subset are obtained by actually scanning the target body part of the human body, while the pixel values of the second CT projection images associated with the low-voltage segments in the second CT projection image set are obtained from the first CT image reconstructed based on the expanded first projection image subset. Thus, the above first difference characterizes the gap between the expanded first projection image subset and the actual situation. Thus, the first difference can be used to correct each simulated first projection image in the expanded first projection image subset, with high reliability. Similarly, the second difference can be used to correct each simulated second projection image in the expanded second projection image subset, with high reliability.

[0066] S603: According to the first difference and the second difference, correct the simulated first projection images corresponding to the rising voltage segments, the high-voltage segments, and the falling voltage segments in the corresponding period of the expanded first projection image subset; and according to the first difference and the second difference, correct the simulated second projection images corresponding to the low-voltage segments, the rising voltage segments, and the falling voltage segments in the corresponding period of the expanded second projection image subset.

[0067] Understandably, through the above S601 - S603, the expanded first projection image subset can be accurately corrected and the expanded second projection image subset can be accurately corrected.

[0068] In some embodiments, the simulated first projection images corresponding to the rising voltage segments in the corresponding period of the expanded first projection image subset can be corrected according to the formula S2 ' cal ibration = S2 ' + k1 * ΔS2 + k2 * ΔS4, and according to the formula S3 ' calibration = S3' + k1 * ΔS2 + k2 * ΔS4, correcting the analog first projection image corresponding to the high-level voltage segment in the corresponding period of the first projection image subset after correction and expansion; and according to the formula S4 ' cal ibration = S4' + k1 * ΔS2 + k2 * ΔS4, correcting the analog first projection image corresponding to the falling voltage segment in the corresponding period of the first projection image subset after correction and expansion.

[0069] In this way, the accuracy of the analog first projection image corresponding to the rising voltage segment, the analog first projection image corresponding to the high-level voltage segment, and the analog first projection image corresponding to the falling voltage segment obtained by correction is high.

[0070] Among them, k1 is a preset first weight, k1 is a preset second weight, ΔS2 is the first difference, ΔS4 is the second difference, S2 ' is the analog first projection image corresponding to the rising voltage segment before correction, S3 ' is the analog first projection image corresponding to the high-level voltage segment before correction, S4 ' is the analog first projection image corresponding to the falling voltage segment before correction, S2 ' cal ibration is the analog first projection image corresponding to the rising voltage segment after correction, S3 ' cal ibration is the analog first projection image corresponding to the high-level voltage segment after correction, S4 ' cal ibration is the analog first projection image corresponding to the falling voltage segment after correction.

[0071] In some embodiments, according to the formula S1″ calibration = S1' + k3 * ΔS2 + k4 * ΔS4, correcting the analog second projection image corresponding to the low-level voltage segment in the corresponding period of the second projection image subset after correction and expansion; according to the formula S2″ calibration = S2' + k3 * ΔS2 + k4 * ΔS4, correcting the analog second projection image corresponding to the rising voltage segment in the corresponding period of the second projection image subset after correction and expansion; according to the formula S4″ calibration = S4' + k3 * ΔS2 + k4 * ΔS4, correcting the analog second projection image corresponding to the falling voltage segment in the corresponding period of the second projection image subset after correction and expansion. In this way, the accuracy of the analog second projection image corresponding to the rising voltage segment, the analog second projection image corresponding to the high-level voltage segment, and the analog second projection image corresponding to the falling voltage segment obtained by correction is high.

[0072] Among them, k3 is a preset third weight, k4 is a preset fourth weight, ΔS2 is the first difference, ΔS4 is the second difference, S1' is the analog second projection image corresponding to the low-level voltage segment before calibration, S2' is the analog second projection image corresponding to the rising voltage segment before calibration, S4' is the analog first projection image corresponding to the falling voltage segment before calibration, and S1″ calibration is the analog second projection image corresponding to the low-level voltage segment after calibration, and S2″ calibration is the analog second projection image corresponding to the rising voltage segment after calibration, and S4″ calibration is the analog first projection image corresponding to the falling voltage segment after calibration.

[0073] Please refer to Figure 7 , the embodiment of the present application further provides a CT image generation device 700. It should be noted that the basic principle and the technical effects generated by the CT image generation device 700 provided in the embodiment of the present application are the same as those in the above embodiment. For a brief description, for the parts not mentioned in the embodiment of the present application, reference can be made to the corresponding content in the above embodiment. Specifically, the CT image generation device 700 provided in the embodiment of the present application includes a data receiving unit 701, a data extraction unit 702, a data interpolation unit 703, and an image reconstruction unit 704.

[0074] Among them,

[0075] The data receiving unit 701 is configured to receive a set of CT projection images obtained by scanning a target body part of a human body by a CT device 100.

[0076] The set of CT projection images is obtained by scanning the target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the rotation of the CT device 100 around the human body. Each period of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to a preset time length, a rising voltage segment corresponding to a preset time length for switching from the low-level voltage segment to the high-level voltage segment, a high-level voltage segment corresponding to a preset time length, and a falling voltage segment corresponding to a preset time length for switching back from the high-level voltage segment to the low-level voltage segment.

[0077] The data extraction unit 702 is configured to extract a first set of CT projection image subsets and a second set of CT projection image subsets from the set of CT projection images. The first set of CT projection image subsets is obtained by scanning based on the low-level voltage segments in multiple periods, and the second set of CT projection image subsets is obtained by scanning based on the high-level voltage segments in multiple periods.

[0078] A data interpolation unit 703 is configured to expand the first CT projection image subset according to an interpolation method to obtain an expanded first projection image subset, and expand the second CT projection image subset according to the interpolation method to obtain an expanded second projection image subset.

[0079] In some embodiments, the interpolation method may be, but is not limited to, linear interpolation, spline interpolation, Lagrange interpolation, or Newton interpolation.

[0080] An image reconstruction unit 704 is configured to reconstruct a first CT image associated with a low-level voltage segment according to the expanded first projection image subset, and reconstruct a second CT image associated with a high-level voltage segment according to the expanded second projection image subset.

[0081] In some embodiments, the algorithms for reconstructing the first CT image associated with the low-level voltage segment and the second CT image associated with the high-level voltage segment are: filtered backprojection method, compressed sensing algorithm with prior image constraint, or iterative reconstruction algorithm.

[0082] In some embodiments, the apparatus 700 provided by the embodiments of the present application may further include a data correction unit, configured to correct the expanded first projection image subset and the expanded second projection image subset.

[0083] In some embodiments, the expanded first projection image subset further includes: an analog first projection image corresponding to the rising voltage segment in each period, an analog first projection image corresponding to the high-level voltage segment, and an analog first projection image corresponding to the falling voltage segment; the expanded second projection image subset further includes: an analog second projection image corresponding to the low-level voltage segment, an analog second projection image corresponding to the rising voltage segment in each period, and an analog second projection image corresponding to the falling voltage segment.

[0084] The data correction unit is specifically configured to scan the first CT image and the second CT image based on a preset periodic scanning voltage waveform, and respectively obtain a second CT projection image set and a third CT projection image set; for each period, determine the first difference between the pixel values of the second CT projection images associated with the low-level voltage segments in the second CT projection image set and the pixel values of the first CT projection images associated with the low-level voltage segments in the corresponding period of the first CT projection image subset, and determine the second difference between the pixel values of the third CT projection images associated with the high-level voltage segments in the second CT projection image set and the pixel values of the fourth CT projection images associated with the high-level voltage segments in the corresponding period of the first CT projection image subset; according to the first difference and the second difference, correct the analog first projection images corresponding to the rising voltage segments, the analog first projection images corresponding to the high-level voltage segments, and the analog first projection images corresponding to the falling voltage segments in the corresponding period of the expanded first projection image subset; and according to the first difference and the second difference, correct the analog second projection images corresponding to the low-level voltage segments, the analog second projection images corresponding to the rising voltage segments, and the analog second projection images corresponding to the falling voltage segments in the corresponding period of the expanded second projection image subset.

[0085] Further, the data correction unit is specifically configured to, according to the formula S2 ' cal ibration = S2 ' + k1 * ΔS2 + k2 * ΔS4, correct the analog first projection images corresponding to the rising voltage segments in the corresponding period of the expanded first projection image subset; according to the formula S3 ' cal ibration = S3' + k1 * ΔS2 + k2 * ΔS4, correct the analog first projection images corresponding to the high-level voltage segments in the corresponding period of the expanded first projection image subset; and according to the formula S4 ' cal ibration = S4' + k1 * ΔS2 + k2 * ΔS4, correct the analog first projection images corresponding to the falling voltage segments in the corresponding period of the expanded first projection image subset.

[0086] Wherein, k1 is a preset first weight, k1 is a preset second weight, ΔS2 is the first difference, ΔS4 is the second difference, S2 ' is the analog first projection image corresponding to the rising voltage segment before correction, S3 ' is the analog first projection image corresponding to the high-level voltage segment before correction, S4 ' is the analog first projection image corresponding to the falling voltage segment before correction, S2 ' calibration is the analog first projection image corresponding to the rising voltage segment after calibration, S3 ' cal ibration is the analog first projection image corresponding to the high-level voltage segment after calibration, S4 ' cal ibration is the analog first projection image corresponding to the falling voltage segment after calibration.

[0087] Further, the data correction unit is specifically configured to correct the analog second projection image corresponding to the low-level voltage segment in the corresponding period of the expanded second projection image subset according to the formula S1'c'al ibration = S1' + k3 * ΔS2 + k4 * ΔS4; according to the formula S2 ' c ' al ibration = S2' + k3 * ΔS2 + k4 * ΔS4, correct the analog second projection image corresponding to the rising voltage segment in the corresponding period of the expanded second projection image subset; according to the formula S4 ' c ' al ibration = S4' + k3 * ΔS2 + k4 * ΔS4, correct the analog second projection image corresponding to the falling voltage segment in the corresponding period of the expanded second projection image subset.

[0088] Wherein, k3 is a preset third weight, k4 is a preset fourth weight, ΔS2 is the first difference, ΔS4 is the second difference, S1 ' is the analog second projection image corresponding to the low-level voltage segment before calibration, S2 ' is the analog second projection image corresponding to the rising voltage segment before calibration, S4 ' is the analog first projection image corresponding to the falling voltage segment before calibration, S1 ' c ' al ibration is the analog second projection image corresponding to the low-level voltage segment after calibration, S2 ' c ' al ibration is the analog second projection image corresponding to the rising voltage segment after calibration, S4 ' c ' al ibration is the analog first projection image corresponding to the falling voltage segment after calibration.

[0089] Similarly, an embodiment of the present application provides a CT image generation device. Since the first subset of CT projection images is obtained by scanning based on the low-level voltage segments in multiple cycles, the soft tissue features in the first CT image are obvious; the second subset of CT projection images is obtained by scanning based on the high-level voltage segments in multiple cycles, and the bone tissue features in the first CT image are obvious. Furthermore, the first subset of CT projection images is expanded according to the interpolation method to obtain an expanded first subset of projection images, and the second subset of CT projection images is expanded according to the interpolation method to obtain an expanded second subset of projection images. It can be understood that the image content in the expanded first subset of CT projection images according to the interpolation method is more abundant and reliable, and the image content in the expanded second subset of CT projection images according to the interpolation method is also more abundant and reliable. Therefore, the first CT image reconstructed according to the expanded first subset of projection images associated with the low-level voltage segments has high spatial resolution and few artifacts, and the second CT image reconstructed according to the expanded second subset of projection images associated with the high-level voltage segments has high spatial resolution and few artifacts. In this way, doctors can more clearly observe the bone tissue and soft tissue of patients based on the first CT image and the second CT image respectively.

[0090] Figure 8 is a schematic structural diagram of the electronic device provided by the embodiment of the present application. Please refer to Figure 8 , at the hardware level, the electronic device includes a processor, and optionally also includes an internal bus, a network interface, and a memory. Among them, the memory may include internal memory, such as high-speed random access memory (Random-Access Memory, RAM), and may also include non-volatile memory, such as at least one disk memory, etc. Of course, the electronic device may also include other hardware required for other services. For example, the electronic device may be a server.

[0091] The processor, network interface, and memory can be interconnected through an internal bus, and the internal bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 8 only a bidirectional arrow is used in

[0092] A memory for storing programs. Specifically, the program may include program codes, and the program codes include computer operation instructions. The memory may include a memory and a non-volatile memory, and provide instructions and data to the processor.

[0093] The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it, forming a CT image generation device at the logical level. The processor executes the program stored in the memory and is specifically used to execute the CT image generation method provided in the above-mentioned embodiments.

[0094] As described in this application Figure 2 The method executed by the CT image generation device disclosed in the embodiments shown in this application can be applied to or implemented by the processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor or the instructions in software form. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in this application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with this application can be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by the combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0095] The electronic device can also execute Figure 2 the method and implement the functions of the CT image generation device in the Figure 2 embodiments shown. Details are not described herein again in this application.

[0096] Of course, in addition to the software implementation, the electronic device of the present application does not exclude other implementation manners, such as a logic device or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, and may also be hardware or a logic device.

[0097] The present application also provides a computer-readable storage medium storing one or more programs, where the one or more programs include instructions that, when executed by a portable electronic device including a plurality of application programs, can cause the portable electronic device to execute Figure 2 the method of the illustrated embodiment.

[0098] Computer-readable media includes both permanent and non-permanent, removable and non-removable media and can be implemented by any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technologies, compact disc read only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0099] In addition, an embodiment of the present application further provides a computer program product including a computer program that, when executed by a processor, implements the CT image generation method as in the embodiment of the present application Figure 2 as illustrated.

[0100] In the above description, technical details such as the composition of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. In addition, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination.

[0101] Although the preferred embodiments of the present application have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic creative concept. Therefore, the appended claims are intended to be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present application.

[0102] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and variations.

Claims

1. A CT image generation method, characterized in that, The method includes: Receiving a set of CT projection images obtained by scanning a target body part of a human body by a CT device, where the set of CT projection images is obtained by scanning the target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the rotation of the CT device around the human body, and each cycle of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to the preset time interval, a rising voltage segment corresponding to the preset time interval for switching from the low-level voltage segment to a high-level voltage segment, the high-level voltage segment corresponding to the preset time interval, and a falling voltage segment corresponding to the preset time interval for switching back from the high-level voltage segment to the low-level voltage segment; Extracting a first subset of CT projection images and a second subset of CT projection images from the set of CT projection images, where the first subset of CT projection images is obtained by scanning based on the low-level voltage segments in multiple cycles, and the second subset of CT projection images is obtained by scanning based on the high-level voltage segments in multiple cycles; Expanding the first subset of CT projection images according to the interpolation method to obtain an expanded first subset of projection images, and expanding the second subset of CT projection images according to the interpolation method to obtain an expanded second subset of projection images; Reconstructing a first CT image associated with the low-level voltage segment according to the expanded first subset of projection images, and reconstructing a second CT image associated with the high-level voltage segment according to the expanded second subset of projection images.

2. The method according to claim 1, wherein After obtaining the expanded first subset of projection images and the expanded first subset of projection images, the method further includes: Correcting the expanded first subset of projection images and correcting the expanded second subset of projection images.

3. The method according to claim 2, wherein The expanded first subset of projection images further includes: simulated first projection images corresponding to the rising voltage segments in each cycle, simulated first projection images corresponding to the high-level voltage segments, and simulated first projection images corresponding to the falling voltage segments. The expanded second subset of projection images further includes: simulated second projection images corresponding to the low-level voltage segment, simulated second projection images corresponding to the rising voltage segments in each cycle, and simulated second projection images corresponding to the falling voltage segments. Correcting the first CT image associated with the low-level voltage segment and correcting the second CT image associated with the high-level voltage segment includes: Scanning the first CT image and the second CT image based on the preset periodic scanning voltage waveform to obtain a second set of CT projection images and a third set of CT projection images respectively; For each period, determine a first difference between the pixel values of the second CT projection images associated with the low-level voltage segments in the second CT projection image set and the pixel values of the first CT projection images associated with the low-level voltage segments in the corresponding period of the first CT projection image subset, and determine a second difference between the pixel values of the third CT projection images associated with the high-level voltage segments in the second CT projection image set and the pixel values of the fourth CT projection images associated with the high-level voltage segments in the corresponding period of the first CT projection image subset; According to the first difference and the second difference, correct the simulated first projection images corresponding to the rising voltage segments, the simulated first projection images corresponding to the high-level voltage segments, and the simulated first projection images corresponding to the falling voltage segments in the corresponding period of the expanded first projection image subset; And according to the first difference and the second difference, correct the simulated second projection images corresponding to the low-level voltage segments, the simulated second projection images corresponding to the rising voltage segments, and the simulated second projection images corresponding to the falling voltage segments in the corresponding period of the expanded second projection image subset.

4. The method according to claim 3, characterized in that, The step of correcting the simulated first projection images corresponding to the rising voltage segments, the simulated first projection images corresponding to the high-level voltage segments, and the simulated first projection images corresponding to the falling voltage segments in the corresponding period of the expanded first projection image subset according to the first difference and the second difference includes: According to the arithmetic formula S2' cal ibration = S2 ' + k1 * ΔS2 + k2 * ΔS4, to correct the analog first projection image corresponding to the rising voltage segment in the corresponding period of the expanded first projection image subset; According to the arithmetic formula S3 ' cal ibration = S3'+k1*ΔS2+k2*ΔS4 to calibrate the analog first projection image corresponding to the high-level voltage segment of the expanded first projection image subset within the corresponding period. and according to the arithmetic formula S4' calibration = S4'+ k1*ΔS2 + k2*ΔS4, to correct the analog first projection image corresponding to the falling voltage segment of the expanded first projection image subset within the corresponding period; Among them, k1 is a preset first weight, k2 is a preset second weight, ΔS2 is the first difference, ΔS4 is the second difference, S2' is the simulated first projection image corresponding to the rising voltage segment before correction, S3' is the simulated first projection image corresponding to the high-level voltage segment before correction, S4' is the simulated first projection image corresponding to the falling voltage segment before correction, and S2' calibration is the simulated first projection image corresponding to the rising voltage segment after correction, S3' calibration is the simulated first projection image corresponding to the high-level voltage segment after correction, and S4' calibration is the simulated first projection image corresponding to the falling voltage segment after correction.

5. The method according to claim 3, characterized in that, The step of correcting the simulated second projection images corresponding to the low-level voltage segments, the simulated second projection images corresponding to the rising voltage segments in each period, and the simulated second projection images corresponding to the falling voltage segments in the corresponding period of the expanded second projection image subset according to the first difference and the second difference includes: According to the arithmetic formula S1” calibration = S1'+ k3*ΔS2 + k4*ΔS4, correct the analog second projection image corresponding to the low-level voltage segment in the corresponding period of the expanded second projection image subset. According to the arithmetic formula S2” calibration = S2'+ k3*ΔS2 + k4*ΔS4, correct the analog second projection image corresponding to the rising voltage segment in the corresponding period of the expanded second projection image subset of the second projection image; According to the arithmetic formula S4” calibration = S4'+ k3*ΔS2 + k4*ΔS4, correct the analog second projection image corresponding to the falling voltage segment in the corresponding period of the expanded second projection image subset; Among them, k3 is a preset third weight, k4 is a preset fourth weight, ΔS2 is the first difference, ΔS4 is the second difference, S1' is the analog second projection image corresponding to the low-level voltage segment before calibration, S2' is the analog second projection image corresponding to the rising voltage segment before calibration, S4' is the analog first projection image corresponding to the falling voltage segment before calibration, and S1” calibration is the analog second projection image corresponding to the low-level voltage segment after calibration, S2 ' c ’ al ibration is the analog second projection image corresponding to the rising voltage segment after calibration, S4 ' c ' al ibration is the analog first projection image corresponding to the falling voltage segment after calibration.

6. The method according to any one of claims 1-5, characterized in that, The interpolation method is linear interpolation, spline interpolation, or Lagrange interpolation.

7. According to the method described in any one of claims 1-5, characterized in that, The algorithms for reconstructing the first CT image associated with the low-level voltage segment and the second CT image associated with the high-level voltage segment are: Filtered backprojection method or iterative reconstruction algorithm.

8. A CT image generation device, characterized in that, The device includes: A data receiving unit for receiving a set of CT projection images obtained by scanning a target body part of a human body by a CT device, wherein the set of CT projection images is obtained by scanning the target body part of the human body at preset time intervals based on a preset periodic scanning voltage waveform during the rotation of the CT device around the human body, and each period of the periodic scanning voltage waveform sequentially includes a low-level voltage segment corresponding to the preset time interval, a rising voltage segment corresponding to the preset time interval for switching from the low-level voltage segment to the high-level voltage segment, a high-level voltage segment corresponding to the preset time interval, and a falling voltage segment corresponding to the preset time interval for switching back from the high-level voltage segment to the low-level voltage segment; A data extraction unit, configured to extract a first sub-set of CT projection images and a second sub-set of CT projection images from the set of CT projection images, wherein the first sub-set of CT projection images is obtained by scanning based on the low-level voltage segments in a plurality of cycles, and the second sub-set of CT projection images is obtained by scanning based on the high-level voltage segments in a plurality of cycles; A data interpolation unit, configured to expand the first sub-set of CT projection images according to an interpolation method to obtain an expanded first sub-set of projection images, and expand the second sub-set of CT projection images according to the interpolation method to obtain an expanded second sub-set of projection images; An image reconstruction unit, configured to reconstruct a first CT image associated with the low-level voltage segment according to the expanded first sub-set of projection images, and reconstruct a second CT image associated with the high-level voltage segment according to the expanded second sub-set of projection images.

9. An electronic device, characterized in that, Comprising: A processor; A memory for storing instructions executable by the processor; Wherein the processor is configured to execute the instructions to implement the CT image generation method according to any one of claims 1 to 7.

10. A storage medium, when the instructions in the storage medium are executed by a processor of an electronic device, enabling the electronic device to execute the CT image generation method according to any one of claims 1 to 7.

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