Multi-energy CT descattering and noise reduction material decomposition method, device, equipment and medium

Abstract

The present application relates to a multi-energy CT descattering and denoising material decomposition method, device, equipment and medium. The method comprises: dimensionality reduction processing of N energy spectrum data information of different equivalent energies acquired from a multi-energy spectrum imaging system and ray transmission intensity information detected when scanning an object to be imaged, and generating decomposed and expanded projection data items based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, performing base material decomposition of the object to be imaged using the decomposed and expanded projection data items, and obtaining a multi-energy CT descattering and denoising material decomposition result, wherein N is an integer greater than or equal to 3, and solves the problem that the appearance of ray scattering signals during CT scanning will cause decomposition deviations in the original line integral model, i.e., dual-energy / multi-energy CT material, resulting in scattering artifacts in the image, affecting the quantitative performance of CT spectral imaging, and the like, and realizes optimization processing such as efficient data denoising while decomposing descattering correction materials.

Description

Technical Field

[0001] The present application relates to the field of radiation imaging technology, and in particular to a multi-energy CT (Computed Tomography) descattering and noise reduction material decomposition method, device, equipment and medium. Background Art

[0002] X-ray computed tomography (CT) is an important imaging technology that is widely used in medical diagnosis and treatment, industrial non-destructive testing, safety inspection and other fields. The basic principle of CT is to reconstruct the attenuated X-ray signal received on the detector based on the different absorption capabilities of different substances to X-rays, and obtain a tomographic or three-dimensional image of the scanned object.

[0003] In the past decade, dual-energy / multi-energy CT technology has developed rapidly. In 2006, the first generation of medical dual-energy CT system was applied in clinical practice. Compared with single-spectrum CT, dual-energy CT obtains CT projection data obtained under two different equivalent energy spectra, and then obtains multi-dimensional scanned information such as material composition and virtual single-energy images based on the material decomposition physical model. Dual-energy CT greatly improves the material identification ability, contrast-to-noise ratio, reduction of metal artifacts, suppression of beam hardening artifacts, etc. of CT imaging, and is an important research direction in the current CT imaging field.

[0004] At present, mature medical dual-energy CT technologies mainly include: dual-source dual-detector technology, fast kilovolt switching technology, and double-layer detector technology. These dual-energy imaging technologies all have extremely high requirements for CT hardware. In recent years, new dual-energy / multi-energy imaging technologies and methods with relatively low hardware requirements have also begun to appear. Energy spectrum modulation technology is one of them. By placing a filter material with a certain spatial distribution structure between the radiation source and the imaged object, the spatial distribution of the X-ray intensity and the energy spectrum of the radiation when it reaches the scanned object are changed, thereby achieving multi-energy imaging.

[0005] Ray scattering is a major physical problem in the field of CT imaging, and it also seriously restricts the imaging performance of dual-energy / multi-energy CT. The ideal CT imaging theory believes that X-rays will follow an exponential attenuation law when passing through an object. The exponential part is the line integral of the object's attenuation coefficient, and the influence of ray scattering is not considered. However, during actual CT scanning, scattered photons will also be collected when they reach the detector. The appearance of scattered signals will cause obvious deviations in the original line integral model, resulting in scattering artifacts in the image and reducing the quality of the reconstructed image. Ray scattering will cause deviations in the material decomposition of dual-energy / multi-energy CT and affect the quantitative performance of CT energy spectrum imaging.

[0006] Therefore, energy spectrum modulation technology is expected to establish a unified physical model and processing mechanism for material decomposition and scattering correction, but it requires collaborative innovation in data processing and imaging algorithms. Summary of the invention

[0007] The present application provides a multi-energy CT descattering and denoising material decomposition method, device, equipment and medium to solve the problem that the appearance of ray scattering signals during CT scanning will cause decomposition deviation of the original line integral model, i.e., dual-energy / multi-energy CT material, resulting in scattering artifacts in the image, reducing the quality of the reconstructed image and thus affecting the quantitative performance of CT energy spectrum imaging. While descattering and correcting the material decomposition, optimization processing such as efficient data denoising is achieved.

[0008] The first aspect of the present application provides a multi-energy CT descattering noise reduction material decomposition method, comprising the following steps:

[0009] Acquire N energy spectrum data information of different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged, and perform dimensionality reduction processing on the N energy spectrum data information of different equivalent energies and the ray transmission intensity information respectively to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, wherein N is an integer greater than or equal to 3;

[0010] Generate decomposed and expanded projection data items based on the descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies; and

[0011] The decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged, so as to obtain a multi-energy CT descattering and noise reduction material decomposition result.

[0012] According to an embodiment of the present application, generating decomposed and expanded projection data items based on the descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies includes:

[0013] Converting the transmission intensity in the descattered ray transmission intensity information into projection data;

[0014] The projection data is decomposed, and Taylor expansion is performed on some of the decomposed items to obtain the decomposed and expanded projection data items.

[0015] According to an embodiment of the present application, the method of performing base material decomposition on the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result includes:

[0016] The sum of the Taylor expansion items of the decomposed and expanded projection data items is filtered as a whole, or the noise of each item of the Taylor expansion item is individually reduced by using a preset filtering method and denoising method.

[0017] According to an embodiment of the present application, the method of performing base material decomposition of the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result further includes:

[0018] The portion of the decomposed and expanded projection data item that has not been Taylor expanded is subjected to denoising, and material decomposition is performed based on the optimized processing result after the denoising and filtering processing to obtain the decomposition result.

[0019] According to the multi-energy CT descattering and denoising material decomposition method of the embodiment of the present application, the energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the dimensionality reduction processing is performed on them respectively, and based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, the decomposed and expanded projection data items are generated, and the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain the multi-energy CT descattering and denoising material decomposition result. In this way, the problem that the appearance of ray scattering signals during CT scanning will cause the decomposition deviation of the original line integral model, i.e., the dual-energy / multi-energy CT material, will cause scattering artifacts in the image, reduce the quality of the reconstructed image, and affect the quantitative performance of CT energy spectrum imaging is solved. While decomposing the descattering correction material, the optimization processing such as efficient denoising of the data is achieved.

[0020] A second aspect of the present application provides a multi-energy CT descattering and noise reduction material decomposition device, comprising:

[0021] An acquisition module, used to acquire N energy spectrum data information of different equivalent energies of the multi-spectral imaging system and the ray transmission intensity information detected when scanning the object to be imaged, and perform dimensionality reduction processing on the N energy spectrum data information of different equivalent energies and the ray transmission intensity information, respectively, to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, wherein N is an integer greater than or equal to 3;

[0022] A generating module, configured to generate decomposed and expanded projection data items based on the descattered ray transmission intensity information and corresponding energy spectrum data information of a plurality of different equivalent energies; and

[0023] The decomposition module is used to perform base material decomposition on the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result.

[0024] According to one embodiment of the present application, the generating module is specifically used for:

[0025] Converting the transmission intensity in the descattered ray transmission intensity information into projection data;

[0026] The projection data is decomposed, and Taylor expansion is performed on some of the decomposed items to obtain the decomposed and expanded projection data items.

[0027] According to one embodiment of the present application, the decomposition module is specifically used to:

[0028] The sum of the Taylor expansion items of the decomposed and expanded projection data items is filtered as a whole, or the noise of each item of the Taylor expansion item is individually reduced by using a preset filtering method and denoising method.

[0029] According to one embodiment of the present application, the decomposition module is further used to:

[0030] The portion of the decomposed and expanded projection data item that has not been Taylor expanded is subjected to denoising, and material decomposition is performed based on the optimized processing result after the denoising and filtering processing to obtain the decomposition result.

[0031] According to the multi-energy CT descattering and denoising material decomposition device of the embodiment of the present application, the energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the dimensionality reduction processing is performed on them respectively, and based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, the decomposed and expanded projection data items are generated, and the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain the multi-energy CT descattering and denoising material decomposition result. In this way, the problem that the appearance of ray scattering signals during CT scanning will cause the decomposition deviation of the original line integral model, i.e., the dual-energy / multi-energy CT material, will cause scattering artifacts in the image, reduce the quality of the reconstructed image, and affect the quantitative performance of CT spectral imaging is solved. While decomposing the descattering correction material, the optimization processing such as efficient denoising of the data is achieved.

[0032] A third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the multi-energy CT descattering and denoising material decomposition method as described in the above embodiment.

[0033] A fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the multi-energy CT descattering and denoising material decomposition method as described in the above embodiments.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0036] Figure 1 It is a flow chart of a multi-energy CT descattering and noise reduction material decomposition method provided according to an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the focus of an X-ray source during CT imaging according to an embodiment of the present application;

[0038] Figure 3 A schematic diagram of decomposition of water before filtering, water after filtering, iodine before filtering, and iodine after filtering provided according to an embodiment of the present application;

[0039] Figure 4 It is a flow chart of a multi-energy CT descattering and noise reduction material decomposition method according to a specific embodiment of the present application;

[0040] Figure 5 This is an exemplary diagram of an energy CT descattering noise reduction material decomposition device according to an embodiment of the present application;

[0041] Figure 6 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0043] The following describes the multi-energy CT descattering and denoising material decomposition method, device, equipment and medium of the embodiment of the present application with reference to the accompanying drawings. In view of the problem mentioned in the background technology center that the appearance of ray scattering signals during CT scanning will cause the original line integral model, i.e., dual-energy / multi-energy CT material, to have decomposition deviation, resulting in scattering artifacts in the image, reducing the quality of the reconstructed image and thus affecting the quantitative performance of CT energy spectrum imaging, the present application provides a multi-energy CT descattering and denoising material decomposition method, in which the energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the dimensionality reduction processing is performed on them respectively, and based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, the decomposed and expanded projection data items are generated, and the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain the multi-energy CT descattering and denoising material decomposition results. As a result, the problem that the appearance of ray scattering signals during CT scanning would cause decomposition deviations in the original line integral model, i.e., dual-energy / multi-energy CT material, resulting in scattering artifacts in the image, reduced reconstructed image quality, and affected the quantitative performance of CT spectral imaging was solved. While de-scattering and correcting the material decomposition, optimization processing such as efficient data denoising was achieved.

[0044] Specifically, Figure 1 A schematic flow chart of a multi-energy CT descattering and noise reduction material decomposition method provided in an embodiment of the present application.

[0045] like Figure 1 As shown, the multi-energy CT descattering noise reduction material decomposition method includes the following steps:

[0046] In step S101, energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the energy spectrum data information of the N different equivalent energies and the ray transmission intensity information are respectively subjected to dimensionality reduction processing to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, wherein N is an integer greater than or equal to 3, that is, the embodiment of the present application obtains energy spectrum information of three energies or more and the ray transmission intensity information detected when scanning the object to be imaged, and respectively performs dimensionality reduction processing on the energy spectrum information of three energies or more and the ray transmission intensity information to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, and the corresponding energy spectrum data information of multiple different equivalent energies is energy spectrum information of dual energy or more.

[0047] Specifically, Figure 2 As shown, according to CT imaging theory, the energy spectrum {S i (E), i = 1, 2, 3} and the intensity of the ray that passes through the scanned object and reaches the detector {Ii , i=1,2,3}, expressed as:

[0048]

[0049] Among them, μ1(E) and μ2(E) are the attenuation values ​​corresponding to the two base materials, L1 and L2 are the equivalent path integrals of the two base materials (i.e., the projection values ​​of the weighted coefficients), I si is the energy spectrum S of the light source i (E) Scattering intensity under.

[0050] Furthermore, in the embodiment of the present application, dimensionality reduction processing is performed on N energy spectrum data information of different equivalent energies to obtain corresponding energy spectrum data information of multiple different equivalent energies;

[0051] Specifically, the form of the dimensionality reduction function can be expressed as:

[0052] S ij (E) = g ij (S i (E)-S j (E)) or S ij (E)=S i (E)-S j (E); (2)

[0053] Among them, S ij (E) is the new energy spectrum data information after dimensionality reduction processing, S i (E) and S j (E) are the energy spectrum data information of two different equivalent energies among the original N energy spectrum data information of different equivalent energies (i.e., S i (E) is an energy spectrum in the multi-energy spectrum information before dimensionality reduction; S j (E) is another energy spectrum in the multi-energy spectrum information before dimensionality reduction), g ij It means to optimize the energy spectrum data information of different equivalent energies. In other words, the S representing different equivalent energies i (E), represents S with different equivalent energies j (E) Dimension reduction processing is performed respectively, and finally multiple new energy spectrum data information S with different equivalent energies can be obtained ij (E).

[0054] The ray transmission intensity information is subjected to dimensionality reduction processing to obtain the de-scattered ray transmission intensity information, which can be expressed as:

[0055] I ij =f ij (I i -I j ) or I ij =I i-I j ; (3)

[0056] Among them, I ij is the new ray transmission intensity information, I i and I j is the ray transmission intensity information corresponding to different original energy spectra, f ij Indicates that the ray transmission intensity information is optimized.

[0057] In step S102, decomposed and expanded projection data items are generated based on the descattered ray transmission intensity information and corresponding energy spectrum data information of a plurality of different equivalent energies.

[0058] Furthermore, in some embodiments, based on the descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, decomposed and expanded projection data items are generated, including: converting the transmission intensity in the descattered ray transmission intensity information into projection data; decomposing the projection data, and performing Taylor expansion on some of the decomposition items to obtain decomposed and expanded projection data items, wherein the decomposed and expanded projection data items are decomposition items containing Taylor expansion items.

[0059] In step S103, the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged, and a multi-energy CT descattering and noise reduction material decomposition result is obtained.

[0060] Furthermore, in some embodiments, the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain a multi-energy CT descattering and denoising material decomposition result, including: filtering the sum of Taylor expansion items of the decomposed and expanded projection data items as a whole, or using preset filtering methods and denoising methods to individually reduce the noise of each item of the Taylor expansion item.

[0061] Furthermore, in some embodiments, the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain a multi-energy CT descattering and denoising material decomposition result, which also includes: denoising the part of the decomposed and expanded projection data items that has not been Taylor expanded, and performing material decomposition based on the optimized processing results after denoising and filtering to obtain a decomposition result.

[0062] Specifically, the base material decomposition of the object to be imaged is performed according to the descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies. Based on this step, the scattering distribution under different energy spectra in a specific imaging mode has a high correlation, so it can be approximately considered that: s1 ≈I s2 ≈I s3 ≈I sAfter the scattering term is eliminated through dimensionality reduction, the new transmission intensity result corresponding to formula (1) is:

[0063] I ij =I i -f ij (I j )=∫[S i (E)-g ij (S j (E))]exp(-μ1(E)L1-μ2(E)L2)dE; (4)

[0064] Among them, f ij (I j ) is to interpolate x according to the detector pixel position, or other j The result of the optimization process. ij (S j (E)) is the corresponding optimization process of the energy spectrum. i , S i (E) is optimized, and the effect obtained is similar to that of I j , S j (E) has the same processing effect. Among them, f ij (I j ), g ij (S j A special case of (E)) (j=1, 2, 3) is: (ie, no optimization processing is required).

[0065] f ij (I j )=I j ; (5)

[0066] g ij (S j (E))=S j (E); (6)

[0067] Among them, in the equation, I1, I2, I3, S1(E), S2(E), S3(E), μ1(E), μ2(E) are all known, and L1 and L2 need to be solved. In the embodiment of the present application, two unknown quantities are solved by two equations. A variety of methods such as iterative solution, lookup table method, polynomial fitting method, etc. can be used to directly perform base material decomposition or image reconstruction. L1 and L2 can also be obtained by only using part of the multi-energy data. Using the obtained L1 and L2, according to the formula

[0068]

[0069] Recalculate the scattering and use the similarity of the scattering distribution in the neighborhood to get the overall scattering estimate, and then combine part of the dual-energy data or monoenergetic data to perform material decomposition or sparse data reconstruction with scattering correction.

[0070] Furthermore, when the embodiment of the present application performs material decomposition on the data after dimensionality reduction processing, since the dimensionality reduction operation (such as subtraction) will cause the noise to become larger, and the material decomposition itself is more sensitive to noise, therefore, the material decomposition after dimensionality reduction processing needs to be denoised in a timely manner.

[0071] Specifically, when decomposing a material, the transmission intensity is usually first converted into projection data, and its expression can be expressed as:

[0072]

[0073] Where I is the transmission intensity through the object, and I0 is the X-ray intensity when it does not pass through the object.

[0074] Therefore, after dimensionality reduction, first of all, we do not consider the optimization function f ij (·), g ij (·), taking direct subtraction as an example, the projected data after dimensionality reduction obtained by simplified representation can be expressed as:

[0075]

[0076] It should be noted that the subscripts or superscripts L, M, and H represent different energy spectra. L ′P H ′ represents the projection data after dimensionality reduction.

[0077] Secondly, if no dimensionality reduction is performed, the original projection data used for material decomposition is:

[0078]

[0079] Furthermore, by decomposing equation (10) and performing Taylor expansion, we can obtain:

[0080]

[0081]

[0082] As shown in the above formula, after Taylor expansion, the projection data after dimensionality reduction can be written as the sum of the original projection data used for material decomposition and the subsequent terms. It should be noted that I0 is the transmission intensity when it does not pass through the object, which usually does not change with the change of scanning angle and has very little noise, so it can be is regarded as a noise-free term. Compared with directly using P L , P MMaterial decomposition, for the dimensionality reduction operation for scatter correction, the additional noise mainly comes from for The sum can be filtered as a whole, or the individual The noise in the picture.

[0083] In addition, the embodiment of the present application can also perform denoising on the first two terms (without Taylor expansion) of the decomposition of equations (11)-(12). The embodiment of the present application can also adjust the degree of denoising, such as denoising the first two terms at a lighter level, so that the result can better suppress noise while maintaining the original characteristics.

[0084] For example, you can use I L with I H The structural similarity of L is the reference image, H Filtering is performed. (Here, it is considered that I L Indicates the data corresponding to low-energy X-rays, with low noise; I H Indicates that high-energy data has large noise), or directly Use a denoising algorithm. For example, based on 3D block matching filtering (BM3D), low-pass filtering, etc. In the embodiment of the present application, collaborative bilateral filtering is taken as an example, that is, filtering is performed in the projection domain and the image domain respectively. When filtering is performed in the projection domain, material decomposition is performed before and after filtering, and the decomposed images before and after the water and iodine decomposition filtering are observed. Figure 3 As shown in (a), 3(b), 3(c) and 3(d), it can be seen from the figure that the image noise level is significantly reduced after filtering, and the image maintains a good decomposition effect. Figure 3 In (a), area ① in the box is the background area, and areas ②, ③, and ④ are selected as the region of interest (ROI, Return On Investment). The evaluation index is contrast-to-noise ratio Among them, μ i is the mean value of region i, μ b is the background area mean, is the variance of region i, is the background area variance. The evaluation results are shown in Table 1:

[0085] Table 1

[0086] CNR\Region 1 2 3 Raw water decomposition image 3.447 3.171 2.817 Filtered water decomposition image 9.787 9.323 8.275

[0087] From the table, we can see that the noise level of the image has been significantly improved after filtering, and the contrast-to-noise ratio has been greatly improved. Filtering can also be performed in the image domain. or After or without the aforementioned projection domain processing, the whole is reconstructed into an image, and then the image is filtered; or Some constraints are added during reconstruction, such as similarity constraints, TV constraints, etc., so that the image can better retain its original features, and then forward projected to obtain the processed or

[0088] Optionally, in addition to Filtering can also be performed on the previous item of the expansion Filtering makes the result better. As an approximate constant term, it can also be incorporated into The sum of the data is filtered together, so that the value of the background area of ​​the image tends to 0. After the optimization process, material decomposition is performed based on the new data to achieve material decomposition with scattering correction.

[0089] It should be noted that after image domain processing, the image can be forward projected to obtain the processed projection data for material decomposition; or it can be left at the filtered image without forward projection, and then directly add the reconstructed images of other terms of equations (11) and (12) to directly obtain the processed dual-energy image for image domain material decomposition. In both the projection domain and image domain methods, only the first k terms of the Taylor expansion can be taken to make it smoother, and the two methods can be superimposed and used together.

[0090] At the same time, if Figure 3 As shown, in the embodiment of the present application, the selection of the number of Taylor expansion terms k can be adjusted accordingly according to the X-ray energy spectrum during scanning and the scanned object. It is not necessary to select a very large k to ensure that the result is almost completely consistent with that before expansion. When k is selected to be small, It is smoother and suppresses noise to a certain extent. However, when the k value is small, there will be obvious numerical deviation, which needs to be balanced.

[0091] In summary, if Figure 4 As shown, in order to facilitate those skilled in the art to further understand the multi-energy CT descattering noise reduction material decomposition method of the embodiment of the present application, the following is further described according to its specific steps:

[0092] S401, acquiring energy spectrum data information of N different equivalent energies of a multi-energy spectrum imaging system and information on the ray transmission intensity detected when scanning an object to be imaged.

[0093] S402, performing dimensionality reduction processing on N energy spectrum data information and ray transmission intensity information of different equivalent energies to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, and generating descattered dual-energy or triple-energy or higher projection data.

[0094] S403, decomposing the descattered projection data, and performing Taylor expansion on some of the decomposition items.

[0095] S404, filtering the Taylor expansion sum of the decomposition items as a whole, or using a preset filtering method and denoising method to reduce the noise of each expansion item of the Taylor expansion separately, and also performing denoising on the part of the decomposition items that has not been Taylor expanded.

[0096] S405, performing material decomposition using the noise-reduced dual-energy or triple-energy or higher projection data to obtain a multi-energy CT descattering and noise-reducing material decomposition result.

[0097] According to the multi-energy CT descattering and denoising material decomposition method of the embodiment of the present application, the energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the dimensionality reduction processing is performed on them respectively, and based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, the decomposed and expanded projection data items are generated, and the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain the multi-energy CT descattering and denoising material decomposition result. In this way, the problem that the appearance of ray scattering signals during CT scanning will cause the decomposition deviation of the original line integral model, i.e., the dual-energy / multi-energy CT material, will cause scattering artifacts in the image, reduce the quality of the reconstructed image, and affect the quantitative performance of CT energy spectrum imaging is solved. While decomposing the descattering correction material, the optimization processing such as efficient denoising of the data is achieved.

[0098] Next, the multi-energy CT descattering and noise reduction material decomposition device proposed according to the embodiment of the present application is described with reference to the accompanying drawings.

[0099] Figure 5 It is a block diagram of a multi-energy CT descattering and noise reduction material decomposition device according to an embodiment of the present application.

[0100] like Figure 5 As shown, the multi-energy CT descattering and noise reduction material decomposition device 10 includes: an acquisition module 100 , a generation module 200 and a decomposition module 300 .

[0101] The acquisition module 100 is used to acquire N energy spectrum data information of different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged, and respectively perform dimensionality reduction processing on the energy spectrum data information of multiple different equivalent energies and the ray transmission intensity information to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies;

[0102] The generating module 200 is used to generate decomposed and expanded projection data items based on the descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies; and

[0103] The decomposition module 300 is used to perform base material decomposition on the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result.

[0104] Furthermore, in some embodiments, the generating module 200 is specifically configured to:

[0105] The transmission intensity in the descattered ray transmission intensity information is converted into projection data.

[0106] The projection data is decomposed, and Taylor expansion is performed on some of the decomposition items to obtain decomposition items containing Taylor expansion items.

[0107] Furthermore, in some embodiments, the decomposition module 300 is specifically configured to:

[0108] The sum of Taylor expansion items of the decomposed and expanded projection data items is filtered as a whole, or the noise of each item of the Taylor expansion item is individually reduced by using a preset filtering method and denoising method.

[0109] Furthermore, in some embodiments, the decomposition module 300 is further configured to:

[0110] The part of the decomposed and expanded projection data item that has not been Taylor expanded is denoised, and material decomposition is performed based on the optimized processing result after the denoising and filtering processing to obtain a decomposition result.

[0111] According to the multi-energy CT descattering and denoising material decomposition device of the embodiment of the present application, the energy spectrum data information of N different equivalent energies of the multi-energy spectrum imaging system and the ray transmission intensity information detected when scanning the object to be imaged are obtained, and the dimensionality reduction processing is performed on them respectively, and based on the obtained descattered ray transmission intensity information and the corresponding energy spectrum data information of multiple different equivalent energies, the decomposed and expanded projection data items are generated, and the decomposed and expanded projection data items are used to perform base material decomposition on the object to be imaged to obtain the multi-energy CT descattering and denoising material decomposition result. In this way, the problem that the appearance of ray scattering signals during CT scanning will cause the decomposition deviation of the original line integral model, i.e., the dual-energy / multi-energy CT material, will cause scattering artifacts in the image, reduce the quality of the reconstructed image, and affect the quantitative performance of CT spectral imaging is solved. While decomposing the descattering correction material, the optimization processing such as efficient denoising of the data is achieved.

[0112] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0113] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0114] When the processor 602 executes the program, the multi-energy CT descattering and noise reduction material decomposition method provided in the above embodiment is implemented.

[0115] Furthermore, the electronic device further comprises:

[0116] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0117] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0118] The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0119] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0120] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0121] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0122] This embodiment further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the multi-energy CT descattering and noise reduction material decomposition method as described above is implemented.

[0123] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0124] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0125] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0126] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or otherwise processing in a suitable manner if necessary, and then stored in a computer memory.

[0127] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0128] A person skilled in the art may understand that all or part of the steps in the above-mentioned embodiment method may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0129] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0130] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A multi-energy CT descattering and noise reduction material decomposition method, characterized in that: The following steps are involved: Acquire energy spectrum data information of N different equivalent energies of the multi-spectral imaging system and the ray transmission intensity information detected when scanning the object to be imaged, and perform dimensionality reduction processing on the energy spectrum data information of N different equivalent energies and the ray transmission intensity information respectively to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, wherein N is an integer greater than or equal to 3; Generate decomposed and expanded projection data items based on the descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies; and Decomposing the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result; The generating of decomposed and expanded projection data items based on the descattered ray transmission intensity information and the corresponding energy spectrum data information of a plurality of different equivalent energies comprises: Converting the transmission intensity in the descattered ray transmission intensity information into projection data; Decomposing the projection data, and performing Taylor expansion on some decomposition items to obtain the decomposed and expanded projection data items; The method of performing base material decomposition of the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result includes: The sum of the Taylor expansion items of the decomposed and expanded projection data items is filtered as a whole, or the noise of each item of the Taylor expansion item is individually reduced by using a preset filtering method and denoising method.

2. The method according to claim 1, characterized in that The method of performing base material decomposition of the object to be imaged by using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result also includes: The portion of the decomposed and expanded projection data item that has not been Taylor expanded is subjected to denoising, and material decomposition is performed based on the optimized processing result after the denoising and filtering processing to obtain the decomposition result.

3. A multi-energy CT descattering noise reduction material decomposition device, characterized in that: include: An acquisition module, used to acquire N energy spectrum data information of different equivalent energies of the multi-spectral imaging system and the ray transmission intensity information detected when scanning the object to be imaged, and perform dimensionality reduction processing on the N energy spectrum data information of different equivalent energies and the ray transmission intensity information, respectively, to obtain descattered ray transmission intensity information and corresponding energy spectrum data information of multiple different equivalent energies, wherein N is an integer greater than or equal to 3; A generating module, configured to generate decomposed and expanded projection data items based on the descattered ray transmission intensity information and corresponding energy spectrum data information of a plurality of different equivalent energies; and A decomposition module, used to perform base material decomposition on the object to be imaged using the decomposed and expanded projection data items to obtain a multi-energy CT descattering and noise reduction material decomposition result; The generation module is specifically used for: Converting the transmission intensity in the descattered ray transmission intensity information into projection data; Decomposing the projection data, and performing Taylor expansion on some decomposition items to obtain the decomposed and expanded projection data items; The decomposition module is specifically used for: The sum of the Taylor expansion items of the decomposed and expanded projection data items is filtered as a whole, or the noise of each item of the Taylor expansion item is individually reduced by using a preset filtering method and denoising method.

4. The device according to claim 3, characterized in that The decomposition module is further used for: The portion of the decomposed and expanded projection data item that has not been Taylor expanded is subjected to denoising, and material decomposition is performed based on the optimized processing result after the denoising and filtering processing to obtain the decomposition result.

5. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the multi-energy CT descattering and noise reduction material decomposition method according to any one of claims 1 to 2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the multi-energy CT descattering and noise reduction material decomposition method as described in any one of claims 1 to 2.

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