CN111768463A

CN111768463A - PET image attenuation correction method and device and computer equipment

Info

Publication number: CN111768463A
Application number: CN202010612545.3A
Authority: CN
Inventors: 刘士涛; 顾笑悦
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2020-10-13

Abstract

The application relates to a PET image attenuation correction method, a PET image attenuation correction device and computer equipment, wherein the PET image to be corrected and a plurality of first CT images are obtained, each first CT image comprises N pixel points, and N is a natural number which is more than or equal to 1; acquiring pixel values of N pixel points in each first CT image; respectively calculating the maximum value of the corresponding pixel value of each pixel point in a plurality of first CT images; assigning the N pixel points by using the maximum value, and taking the assigned N pixel points as second CT image pixel points; and performing attenuation correction on the PET image to be corrected according to the second CT image. According to the method, the attenuation correction is carried out on the PET image to be corrected by adopting the CT image formed by the maximum value of the pixel value, so that the accuracy of the attenuation correction of the PET image is improved, and the attenuation correction effect of the PET image is improved.

Description

PET image attenuation correction method and device and computer equipment

Technical Field

The application relates to the technical field of medical treatment, in particular to a PET image attenuation correction method, a PET image attenuation correction device and computer equipment.

Background

Positron Emission Tomography (PET) is a relatively advanced clinical examination imaging technique in the field of nuclear medicine. The principle is to take certain substances, which are generally necessary in the metabolism of biological life, such as: glucose, protein, nucleic acid, fatty acid, short-lived radionuclides (such as 18F, 11C) marked on the surface of the body, and after being injected into the human body, the radionuclides release positrons in the decay process, and a positron encounters an electron after traveling several tenths of millimeters to several millimeters and is annihilated, so that two gamma photons with equal energy and opposite directions are generated. Because the paths of two gamma photons in the body are different, the time for reaching the two PET detectors is also different, if a probe system positioned on a response line detects two photons which are 180 degrees away from each other in a specified time window, a coincidence event is formed, the processing device records the response data, and the recorded response data is processed by an image reconstruction technology to obtain a required PET image. However, since gamma photons are attenuated in the human body before the photons reach the PET detector, if such attenuation factor is not corrected, SUV (standard uptake value) of the reconstructed PET image is incorrect, and therefore attenuation correction needs to be performed on the PET image.

Conventionally, a plurality of CT images are obtained by performing a plurality of times of CT scanning, and the CT images obtained by averaging the plurality of CT images are used for PET attenuation correction.

Disclosure of Invention

The application provides a PET image attenuation correction method, a PET image attenuation correction device and computer equipment, which are used for at least solving the problem of inaccurate attenuation correction of PET images in the related art.

In a first aspect, an embodiment of the present application provides a PET image attenuation correction method, including:

acquiring a PET image to be corrected and a plurality of first CT images, wherein each first CT image comprises N pixel points, and N is a natural number more than or equal to 1;

acquiring pixel values of N pixel points in each first CT image;

respectively calculating the maximum value of the corresponding pixel value of each pixel point in a plurality of first CT images;

assigning values to the N pixel points by using the maximum value, and taking the assigned N pixel points as second CT image pixel points;

and performing attenuation correction on the PET image to be corrected according to the second CT image.

In some of these embodiments, the PET image is an image frame in parametric imaging, and the first CT images include CT images adjacent in phase to the PET image to be corrected.

In some embodiments, a scanning region corresponding to the PET image to be corrected is scanned by a 4D-CT scanning mode, so as to obtain a plurality of first CT images.

In some embodiments, after acquiring the plurality of first CT images, the method further comprises:

preprocessing a plurality of first CT images; the preprocessing mode comprises contrast enhancement processing of the first CT image.

In a second aspect, an embodiment of the present application provides a PET image attenuation correction method, including:

acquiring a PET image to be corrected and a plurality of third CT images, wherein each third CT image comprises N pixel points, and N is a natural number more than or equal to 1;

acquiring pixel values of N pixel points in each third CT image;

respectively calculating the maximum value of the corresponding pixel value of each pixel point in the plurality of third CT images and the average value of the corresponding pixel value of each pixel point in the plurality of third CT images;

calculating to obtain a comprehensive pixel value of each pixel point according to the maximum value and the average value;

assigning values to the N pixel points by using the comprehensive pixel value, and taking the assigned N pixel points as fourth CT image pixel points;

and performing attenuation correction on the PET image to be corrected according to the fourth CT image.

In some embodiments, the calculating a comprehensive pixel value of each pixel according to the maximum value and the average value includes:

and weighting the maximum value and the average value to obtain a comprehensive CT value of each pixel point.

In some embodiments, a scanning region corresponding to the PET image to be corrected is scanned by a cine CT scanning mode, so as to obtain at least one image of the third CT images.

In a third aspect, an embodiment of the present application provides a PET image attenuation correction apparatus, including:

the system comprises a first acquisition module, a second acquisition module and a correction module, wherein the first acquisition module is used for acquiring a PET image to be corrected and a plurality of first CT images, each first CT image comprises N pixel points, and N is a natural number which is more than or equal to 1;

the second acquisition module is used for acquiring the pixel values of N pixel points in each first CT image;

the first calculation module is used for calculating the maximum value of the corresponding pixel value of each pixel point in the plurality of first CT images;

the first assignment module is used for assigning the N pixel points by using the maximum value and taking the assigned N pixel points as second CT image pixel points;

and the first correction module is used for carrying out attenuation correction on the PET image to be corrected according to the second CT image.

In a fourth aspect, the present application provides a PET image attenuation correction apparatus, including:

the third acquisition module is used for acquiring a PET image to be corrected and a plurality of third CT images, wherein each third CT image comprises N pixel points, and N is a natural number which is more than or equal to 1;

the fourth acquisition module is used for acquiring the pixel values of N pixel points in each third CT image;

the second calculation module is used for calculating the maximum value of the corresponding pixel value of each pixel point in the plurality of third CT images and the average value of the pixel value of each pixel point in the plurality of third CT images;

the third calculation module is used for calculating to obtain a comprehensive pixel value of each pixel point according to the maximum value and the average value;

the second assignment module is used for assigning values to the N pixel points by using the comprehensive pixel value and taking the assigned N pixel points as fourth CT image pixel points;

and the second correction module is used for performing attenuation correction on the PET image to be corrected according to the fourth CT image.

In a fifth aspect, the present application provides a computer device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the computer program to implement the PET image attenuation correction method according to the first and second aspects.

Compared with the related art, the PET image attenuation correction method provided by the embodiment of the application comprises the following steps: acquiring a PET image to be corrected and a plurality of first CT images, wherein each first CT image comprises N pixel points, and N is a natural number more than or equal to 1; acquiring pixel values of N pixel points in each first CT image; respectively calculating the maximum value of the corresponding pixel value of each pixel point in a plurality of first CT images; assigning values to the N pixel points by using the maximum value, and taking the assigned N pixel points as second CT image pixel points; and attenuation correction is carried out on the PET image to be corrected according to the second CT image, so that the problem of inaccurate attenuation correction of the PET image in the prior art is solved.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the application.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a flowchart of a PET image attenuation correction method according to an embodiment;

FIG. 2 is a flowchart of a PET image attenuation correction method according to another embodiment;

FIG. 3 is a block diagram showing the structure of an attenuation correction apparatus for PET images according to an embodiment;

FIG. 4 is a block diagram of a PET image attenuation correction apparatus according to another embodiment;

FIG. 5 is a diagram illustrating an internal structure of a computer device according to an embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present application without any inventive step are within the scope of protection of the present application.

It is obvious that the drawings in the following description are only examples or embodiments of the present application, and that it is also possible for a person skilled in the art to apply the present application to other similar contexts on the basis of these drawings without inventive effort. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of ordinary skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms referred to herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar words throughout this application are not to be construed as limiting in number, and may refer to the singular or the plural. The present application is directed to the use of the terms "including," "comprising," "having," and any variations thereof, which are intended to cover non-exclusive inclusions; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to the listed steps or elements, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Reference to "connected," "coupled," and the like in this application is not intended to be limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as referred to herein means two or more. "and/or" describes an association relationship of associated objects, meaning that three relationships may exist, for example, "A and/or B" may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. Reference herein to the terms "first," "second," "third," and the like, are merely to distinguish similar objects and do not denote a particular ordering for the objects.

Positron Emission Tomography (PET) is a relatively advanced clinical examination imaging technique in the field of nuclear medicine. The principle is to take certain substances, which are generally necessary in the metabolism of biological life, such as: glucose, protein, nucleic acid, fatty acid, short-lived radionuclides (such as 18F, 11C) marked on the surface of the body, and after being injected into the human body, the radionuclides release positrons in the decay process, and a positron encounters an electron after traveling several tenths of millimeters to several millimeters and is annihilated, so that two gamma photons with equal energy and opposite directions are generated. Because the paths of two gamma photons in the body are different, the time for reaching the two PET detectors is also different, if a probe system positioned on a response line detects two photons which are 180 degrees away from each other in a specified time window, a coincidence event is formed, the processing device records the response data, and the recorded response data is processed by an image reconstruction technology to obtain a required PET image.

A Computed Tomography (CT) apparatus typically includes a gantry, a couch, and a console for operation by a physician. One side of the frame is provided with a bulb tube, and the side opposite to the bulb tube is provided with a detector. The console is a computer device for controlling the bulb tube and the detector to scan, and the computer device is also used for receiving data collected by the detector, processing and reconstructing the data and finally forming a CT image. When CT is used for scanning, a patient lies on a scanning bed, the scanning bed sends the patient into the aperture of a stand, a bulb tube arranged on the stand emits X rays, the X rays penetrate through the patient and are received by a detector to form data, the data are transmitted to computer equipment, and the computer equipment carries out primary processing and image reconstruction on the data to obtain a CT image.

The PET-CT equipment is a relatively advanced clinical examination imaging equipment, and is an organic combination of the PET equipment and the CT equipment.

Fig. 1 is a flowchart of a PET image attenuation correction method according to an embodiment, and as shown in fig. 1, the PET image attenuation correction method includes steps 110 to 150, where:

step 110, a PET image to be corrected and a plurality of first CT images are obtained, each first CT image includes N pixel points, and N is a natural number greater than or equal to 1.

In order to perform attenuation correction on the PET image, it is necessary to acquire attenuation information of the region through which the data line passes during the PET reconstruction. Specifically, the CT image includes electron density information (attenuation coefficient of the radiation) by which attenuation information is provided. In addition, because the CT scanning speed is higher, an image of a certain time phase of respiratory motion is obtained; the PET scan time is long, the PET image is the average effect of the whole respiratory motion, and for better attenuation correction, a plurality of first CT images are needed to provide attenuation information.

Each first CT image includes N pixel points, which are basic units constituting the CT image and generally represent the resolution of the image in units of ppi (pixels per inch). For example, 300 × 300PPI resolution, which means that the number of pixels per inch of length in both the horizontal and vertical directions is 300, and can also be expressed as 9 ten thousand (300 × 300) pixels in one square inch. It can be understood that the larger the number of pixels used to represent the CT image, the closer the CT image is to the real image.

And step 120, acquiring pixel values of N pixel points in each first CT image.

The pixel value is a value given by a computer after the CT image is digitized, and is used to represent luminance information of the pixel point. The larger the pixel value is, the higher the brightness of the pixel point is, and the clearer the area where the pixel point is located is; correspondingly, the smaller the pixel value is, the lower the brightness of the pixel point is, and the more fuzzy the area where the pixel point is located.

Step 130, respectively calculating the maximum value of the corresponding pixel value of each pixel point in the plurality of first CT images.

The maximum value of the pixel values is the highest brightness of the same pixel points in all the first CT images, and the information contained in the first CT images can be presented more clearly by selecting the maximum value of each pixel point in all the first CT images. Specifically, pixel values corresponding to pixel points at the same position in the multiple first CT images are compared, and the maximum value is screened out, so that the maximum value of the pixel values corresponding to the N pixel points is obtained.

And 140, assigning the N pixel points by using the maximum value, and taking the assigned N pixel points as second CT image pixel points.

And generating a second CT image by using the maximum value of the pixel values corresponding to the N pixel points. It can be understood that the pixel points in the second CT image correspond to the pixel points in the first CT image one to one.

And 150, performing attenuation correction on the PET image to be corrected according to the second CT image.

The PET image attenuation correction method provided by the embodiment performs attenuation correction on a PET image to be corrected by using a CT image composed of the maximum values of pixel values, and because the position where the maximum value of the corresponding pixel value in a plurality of first CT images is located has the highest definition, information of the CT image at the position can be better represented, the CT image composed of the maximum values of the pixel values performs attenuation correction on the PET image to be corrected, and the clearest and refined attenuation information is used as attenuation correction data, so that the accuracy of attenuation correction of the PET image is improved, and the effect of attenuation correction of the PET image is improved.

The PET scan time is long and the PET image is the average effect of the whole respiratory motion. In the PET scanning process, a plurality of projection data with different phases are acquired, and the projection data with the plurality of phases are reconstructed to obtain an image frame with a certain phase. In this embodiment, a plurality of CT images adjacent to the PET image to be corrected in phase are acquired as the first CT image, and are used to perform attenuation correction on the PET image to be corrected. The phase of the PET image to be corrected is referred to herein as the reference phase.

It is understood that the adjacent CT images may include a CT image of a plurality of phases before the reference phase and a CT image of a plurality of phases after the reference phase, and the present embodiment is described by taking the example that the adjacent CT images include a CT image of a plurality of phases before the reference phase and a CT image of a plurality of phases after the reference phase. Because a plurality of CT images correspond to one state of the scanning area in the motion cycle, the attenuation information of the scanning area in the whole scanning process can be better represented by the CT images of a plurality of phases adjacent to the phase of the PET image to be corrected, so that the attenuation information can be better matched with the PET image, and the accuracy of PET image attenuation correction is further improved.

The four-Dimensional CT (4-Dimensional CT,4D-CT) scanning mode can perform CT scanning under different phases of respiratory motion of a patient, so that an image sequence capable of reflecting the motion rules of target tissues and surrounding tissues of the patient is obtained, and the method plays an important role in radiotherapy. The image sequence provides information related to respiratory motion, so that the acquired 4D-CT data can provide a comprehensive high-precision radiotherapy respiratory motion characterization, the tumor motion can be tracked, accurate radiotherapy is implemented, and damage to normal tissues is reduced. Specifically, the image sequence acquired by the 4D-CT scanning mode is composed of a plurality of 3D-CT images with different phases, and the plurality of 3D-CT images with different phases are taken as the first CT images in the present embodiment. Attenuation correction is carried out on the PET image by utilizing a plurality of first CT images obtained in the 4D-CT scanning mode, and the damage to normal tissues of a patient can be reduced on the premise of ensuring the attenuation correction effect of the PET image.

In some embodiments, after acquiring the plurality of first CT images, the PET image attenuation correction method further includes: preprocessing a plurality of first CT images; the preprocessing mode comprises contrast enhancement processing of the first CT image.

The CT is a projection imaging of a human body with a three-dimensional structure in a two-dimensional space, and is an image obtained by overlapping inner structures of the human body. Methods for contrast enhancement processing of CT can be divided into two categories: one is a direct contrast enhancement method and the other is an indirect contrast enhancement method. Histogram stretching and histogram equalization are two of the more common indirect contrast enhancement methods. The histogram stretching is to adjust the histogram through contrast stretching, so as to enlarge the difference between the foreground gray scale and the background gray scale, and achieve the purpose of enhancing the contrast, and the method can be realized by a linear or nonlinear method. Histogram equalization adjusts the gray scale value using an accumulation function to achieve contrast enhancement.

The method and the device adopt histogram equalization to carry out contrast enhancement processing on the first CT image. This method is commonly used to increase the local contrast of an image, especially when the pixel values of valid data in the image are relatively close. By the method, the brightness of the CT image can be better distributed on the histogram, so that the local contrast of the CT image can be enhanced without influencing the overall contrast, and in addition, the detail information in the CT image can be better displayed. By carrying out contrast enhancement processing on the first CT image, the maximum value of the corresponding pixel value of each pixel point in a plurality of first CT images can be screened out more quickly and accurately, and the efficiency of the PET image attenuation correction method is further improved.

The present application further provides a PET image attenuation correction method, as shown in fig. 2, the PET image attenuation correction method includes steps 210 to 260, where:

step 210, a PET image to be corrected and a plurality of third CT images are obtained, each third CT image includes N pixel points, and N is a natural number greater than or equal to 1.

Step 210 is similar to step 110, and is not described in detail in this embodiment.

And step 220, acquiring the pixel values of N pixel points in each third CT image.

Step 220 is similar to step 120, and is not described in detail in this embodiment.

Step 230, respectively calculating a maximum value of corresponding pixel values of each pixel point in the plurality of third CT images, and an average value of corresponding pixel values of each pixel point in the plurality of third CT images.

Calculating the maximum value of the corresponding pixel value of each pixel point in the plurality of third CT images is similar to the step 130, and details are not repeated in this embodiment. In this embodiment, the average value of the corresponding pixel values of each pixel point in the plurality of third CT images is also calculated. Specifically, after the pixel values of N pixel points in each third CT image are obtained, the average value of the pixel values corresponding to the pixel points in the plurality of third CT images is calculated for each pixel point, and the average value of the N pixel values corresponding to the N pixel points is obtained.

And 240, calculating to obtain a comprehensive pixel value of each pixel point according to the maximum value and the average value.

The integrated pixel value may be obtained by adding, multiplying or otherwise processing the maximum value and the average value, and the embodiment is not limited in this respect.

And step 250, assigning the N pixel points by using the comprehensive pixel value, and taking the assigned N pixel points as fourth CT image pixel points.

Step 250 is similar to step 140 described above and will not be described further herein. The difference is that the embodiment assigns values to N pixels by using the synthesized pixel values.

And 260, performing attenuation correction on the PET image to be corrected according to the fourth CT image.

In the embodiment, attenuation correction is performed on the PET image to be corrected by utilizing the CT image generated by the comprehensive pixel value obtained by the maximum value and the average value of the corresponding pixel value of each pixel point in the plurality of first CT images, and the CT image generated by the comprehensive pixel value not only comprises the information of the pixel point with the highest definition, but also comprises the information of other pixel points, so that the information contained in the CT image generated by the comprehensive pixel value is more comprehensive, and the generated fourth CT image contains more accurate attenuation information. Therefore, the fourth CT image generated by the comprehensive pixel values is used for carrying out attenuation correction on the PET image to be corrected, and the effect of attenuation correction of the PET image can be further improved.

In some embodiments, the calculating a comprehensive pixel value of each pixel according to the maximum value and the average value includes: and carrying out weighting processing on the maximum value and the average value to obtain a comprehensive pixel value of each pixel point.

Specifically, a first weight corresponding to the maximum value and a second weight corresponding to the average value may be set first. And according to the first weight and the second weight, carrying out weighted summation on the maximum value average value to obtain a comprehensive pixel value.

It should be noted that the maximum value generally has a larger influence on the attenuation information, and therefore, the first weight may be set to be larger than the second weight, for example, the first weight is 0.8, and the second weight is 0.2. It is to be understood that the specific values of the first weight and the second weight are only for illustration and not for limitation, and can be set according to practical situations. The maximum value and the average value are weighted by setting proper first weight and second weight to obtain the comprehensive pixel value of each pixel point, and the attenuation information contained in the maximum value and the average value can be fully and reasonably utilized by performing attenuation correction on the PET image to be corrected by utilizing the CT image generated by the comprehensive pixel value, so that the accuracy of the attenuation correction can be improved.

The cine CT scanning mode is to scan the scanning area in time sequence to obtain a plurality of CT images, and to perform averaging processing on the plurality of CT images to obtain a cine CT scanned image (a third CT image). And scanning the scanning area corresponding to the PET image to be corrected by a movie CT scanning mode, so that the influence of respiratory motion artifacts on the CT scanning image of the moving organ can be eliminated, and the attenuation correction effect is improved.

It should be noted that the steps illustrated in the above-described flow diagrams or in the flow diagrams of the figures may be performed in a computer system, such as a set of computer-executable instructions, and that, although a logical order is illustrated in the flow diagrams, in some cases, the steps illustrated or described may be performed in an order different than here.

In one embodiment, as shown in fig. 3, there is provided a PET image attenuation correction apparatus including: a first obtaining module 310, a second obtaining module 320, a first calculating module 330, a first assigning module 340, and a first correcting module 350, wherein:

a first obtaining module 310, configured to obtain a PET image to be corrected and a plurality of first CT images, where each first CT image includes N pixel points, and N is a natural number greater than or equal to 1;

a second obtaining module 320, configured to obtain pixel values of N pixel points in each first CT image;

the first calculating module 330 is configured to calculate a maximum value of corresponding pixel values of each pixel point in the plurality of first CT images;

the first assignment module 340 is configured to assign values to the N pixel points by using the maximum value, and use the assigned N pixel points as second CT image pixel points;

a first correction module 350, configured to perform attenuation correction on the PET image to be corrected according to the second CT image.

In the attenuation correction device for a PET image provided by this embodiment, a first obtaining module 310 obtains a PET image to be corrected and a plurality of first CT images, where each first CT image includes N pixel points, and N is a natural number greater than or equal to 1; the second obtaining module 320 obtains pixel values of N pixel points in each first CT image; the first calculating module 330 calculates the maximum value of the corresponding pixel value of each pixel point in the plurality of first CT images; the first assignment module 340 assigns the N pixel points with the maximum value, and uses the assigned N pixel points as second CT image pixel points; the first correction module 350 performs attenuation correction on the PET image to be corrected according to the second CT image. The device performs attenuation correction on the PET image to be corrected by the CT image formed by the maximum value of the pixel values, and uses the clearest and fine attenuation information as attenuation correction data, so that the accuracy of the attenuation correction of the PET image is improved.

In some embodiments, after acquiring the plurality of first CT images, the PET image attenuation correction further includes a preprocessing module for preprocessing the plurality of first CT images; the preprocessing mode comprises contrast enhancement processing of the first CT image.

In one embodiment, as shown in fig. 4, there is provided another PET image attenuation correction apparatus including: a third obtaining module 410, a fourth obtaining module 420, a second calculating module 430, a third calculating module 440, a second assigning module 450, and a second correcting module 460, wherein:

a third obtaining module 410, configured to obtain a PET image to be corrected and a plurality of third CT images, where each third CT image includes N pixel points, and N is a natural number greater than or equal to 1;

a fourth obtaining module 420, configured to obtain pixel values of N pixel points in each third CT image;

the second calculating module 430 is configured to calculate a maximum value of corresponding pixel values of each pixel point in the plurality of third CT images and an average value of the pixel values of each pixel point in the plurality of third CT images, respectively;

a third calculating module 440, configured to calculate a comprehensive pixel value of each pixel point according to the maximum value and the average value;

the second assignment module 450 is configured to assign values to the N pixel points by using the integrated pixel values, and use the N assigned pixel points as fourth CT image pixel points;

a second correction module 460, configured to perform attenuation correction on the PET image to be corrected according to the fourth CT image.

In the attenuation correction device for a PET image provided by this embodiment, a third obtaining module 410 obtains a PET image to be corrected and a plurality of third CT images, where each third CT image includes N pixel points, and N is a natural number greater than or equal to 1; the fourth obtaining module 420 obtains pixel values of N pixel points in each third CT image; the second calculating module 430 is configured to calculate a maximum value of corresponding pixel values of each pixel point in the plurality of third CT images and an average value of the pixel values of each pixel point in the plurality of third CT images, respectively; the third calculating module 440 calculates a comprehensive pixel value of each pixel point according to the maximum value and the average value; the second assignment module 450 assigns the N pixel points with the integrated pixel value, and uses the assigned N pixel points as fourth CT image pixel points; the second correction module 460 performs attenuation correction on the PET image to be corrected according to the fourth CT image. The device obtains the comprehensive pixel value through the maximum value and the average value, so that the CT image generated by the comprehensive pixel value contains more comprehensive information, and the generated fourth CT image contains more accurate attenuation information. Therefore, the fourth CT image generated by the comprehensive pixel values is used for carrying out attenuation correction on the PET image to be corrected, and the effect of attenuation correction of the PET image can be further improved.

In some embodiments, the third calculating module 440 is further configured to perform weighting processing on the maximum value and the average value to obtain a comprehensive CT value of each pixel point.

For specific definition of the PET image attenuation correction device, reference may be made to the above definition of the PET image attenuation correction method, which is not described herein again. The modules in the PET image attenuation correction device can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In addition, the PET image attenuation correction method described in conjunction with fig. 1 and 2 in the embodiment of the present application may be implemented by a computer device. Fig. 5 is a hardware structure diagram of a computer device according to an embodiment of the present application.

The computer device may comprise a processor 51 and a memory 52 in which computer program instructions are stored.

Specifically, the processor 51 may include a Central Processing Unit (CPU), or A Specific Integrated Circuit (ASIC), or may be configured to implement one or more Integrated circuits of the embodiments of the present Application.

Memory 52 may include, among other things, mass storage for data or instructions. By way of example, and not limitation, memory 52 may include a Hard Disk Drive (Hard Disk Drive, abbreviated HDD), a floppy Disk Drive, a Solid State Drive (SSD), flash memory, an optical Disk, a magneto-optical Disk, tape, or a Universal Serial Bus (USB) Drive or a combination of two or more of these. Memory 52 may include removable or non-removable (or fixed) media, where appropriate. The memory 52 may be internal or external to the data processing apparatus, where appropriate. In a particular embodiment, the memory 52 is a Non-Volatile (Non-Volatile) memory. In particular embodiments, Memory 52 includes Read-Only Memory (ROM) and Random Access Memory (RAM). The ROM may be mask-programmed ROM, Programmable ROM (PROM), Erasable PROM (EPROM), Electrically Erasable PROM (EEPROM), Electrically rewritable ROM (earrom) or FLASH Memory (FLASH), or a combination of two or more of these, where appropriate. The RAM may be a Static Random-Access Memory (SRAM) or a Dynamic Random-Access Memory (DRAM), where the DRAM may be a Fast Page Mode Dynamic Random-Access Memory (FPMDRAM), an Extended Data Output Dynamic Random Access Memory (EDODRAM), a Synchronous Dynamic Random Access Memory (SDRAM), and the like.

The memory 52 may be used to store or cache various data files for processing and/or communication use, as well as possibly computer program instructions for execution by the processor 52.

The processor 51 may implement any of the PET image attenuation correction methods described in the above embodiments by reading and executing computer program instructions stored in the memory 52.

In some of these embodiments, the computer device may also include a communication interface 53 and a bus 50. As shown in fig. 5, the processor 51, the memory 52, and the communication interface 53 are connected via the bus 50 to complete mutual communication.

The communication interface 53 is used for implementing communication between modules, apparatuses, units and/or devices in the embodiments of the present application. The communication port 53 may also be implemented with other components such as: the data communication is carried out among external equipment, image/data acquisition equipment, a database, external storage, an image/data processing workstation and the like.

Bus 50 comprises hardware, software, or both coupling the components of the computer device to each other. Bus 50 includes, but is not limited to, at least one of the following: data Bus (Data Bus), Address Bus (Address Bus), Control Bus (Control Bus), Expansion Bus (Expansion Bus), and Local Bus (Local Bus). By way of example, and not limitation, Bus 50 may include an Accelerated Graphics Port (AGP) or other Graphics Bus, an Enhanced Industry Standard Architecture (EISA) Bus, a Front-Side Bus (FSB), a HyperTransport (HT) interconnect, an ISA (ISA) Bus, an InfiniBand (InfiniBand) interconnect, a Low Pin Count (LPC) Bus, a memory Bus, a Micro Channel Architecture (MCA) Bus, a Peripheral Component Interconnect (PCI) Bus, a PCI-Express (PCI-X) Bus, a Serial Advanced Technology Attachment (SATA) Bus, a Video electronics standards Association Local Bus (VLB) Bus, or other suitable Bus or a combination of two or more of these. Bus 50 may include one or more buses, where appropriate. Although specific buses are described and shown in the embodiments of the application, any suitable buses or interconnects are contemplated by the application.

The computer device may execute the PET image attenuation correction method in the embodiment of the present application based on the acquired program instructions, thereby implementing the PET image attenuation correction method described in conjunction with fig. 1.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A PET image attenuation correction method, the method comprising:

acquiring pixel values of N pixel points in each first CT image;

2. The method according to claim 1, wherein the PET image is an image frame in parametric imaging, and the first CT images include CT images adjacent in phase to the PET image to be corrected.

3. The method according to claim 1, wherein a scanning region corresponding to the PET image to be corrected is scanned by a 4D-CT scanning mode to obtain a plurality of first CT images.

4. The method of claim 1, wherein after acquiring the plurality of first CT images, the method further comprises:

5. A PET image attenuation correction method, the method comprising:

acquiring pixel values of N pixel points in each third CT image;

6. The method of claim 5, wherein calculating a composite pixel value for each pixel point according to the maximum value and the average value comprises:

7. The method according to claim 6, wherein the scanning region corresponding to the PET image to be corrected is scanned by a cine CT scanning mode to obtain at least one of the third CT images.

8. A PET image attenuation correction apparatus, characterized in that the apparatus comprises:

9. A PET image attenuation correction apparatus, characterized in that the apparatus comprises:

10. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.