Calcification image generation method, electronic equipment and computer program product

Abstract

The invention is suitable for the technical field of medical treatment, and provides a calcification image generation method, electronic equipment and a computer program product. The calcification image generation method comprises the following steps: acquiring an energy spectrum CT image; performing first base material decomposition operation on the energy spectrum CT image to obtain a material density map; performing second base material decomposition operation on the energy spectrum CT image to obtain a virtual plain scanning image; extracting a calcium area mask according to the material density map; performing weighting operation on the energy spectrum CT image to obtain a mixed image; and generating a calcification image according to the calcium region mask, the virtual plain-scan image and the mixed image. The accuracy of calcification evaluation can be improved.

Description

Technical Field

[0001] The present application belongs to the field of medical technology, and in particular relates to a method for generating a calcification image, an electronic device, and a computer program product. Background Art

[0002] Vascular calcification and stenosis can affect multiple organs and are closely related to the occurrence of cardiovascular diseases. Computed tomography (CT) is often used clinically to assist in the examination of whether patients have diseases such as vascular calcification, stenosis or infarction.

[0003] In conventional CT angiography (CTA) examinations, the grayscale values ​​of calcification foci and contrast-enhanced blood vessels overlap, making it difficult to distinguish them when assessing the degree of vascular calcification. In order to accurately assess the degree of vascular calcification, the patient needs to undergo a contrast-free enhanced CT plain scan, but this means that the patient's radiation dose needs to be increased. Some related technologies use spectral CT to obtain virtual plain scan images (Virtual Non Calcium, VNCa) without contrast agents to achieve vascular calcification assessment, which can reduce one CT plain scan imaging and thus reduce the patient's radiation dose. However, its virtual plain scan image only contains information about part of the calcium area, and its use for calcification assessment often underestimates the calcification score. Summary of the invention

[0004] The embodiments of the present application provide a method for generating a calcification image, an electronic device, and a computer program product, which can improve the accuracy of calcification assessment.

[0005] A first aspect of an embodiment of the present application provides a method for generating a calcification image, comprising: acquiring an energy spectrum CT image; performing a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map; performing a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image; extracting a calcium region mask based on the material density map; performing a weighted operation on the energy spectrum CT image to obtain a mixed image; and generating a calcification image based on the calcium region mask, the virtual plain scan image, and the mixed image.

[0006] In some embodiments of the first aspect, generating a calcification image based on the calcium area mask, the virtual plain scan image and the mixed image includes: determining the calcium area in the mixed image and the non-calcium area in the virtual plain scan image based on the calcium area mask; generating the calcification image based on the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image.

[0007] In some embodiments of the first aspect, the calcification image is generated according to the image values ​​of the calcium areas in the mixed image and the image values ​​of the non-calcium areas in the virtual plain scan image, including: determining the boundary fusion area between the calcium areas and the non-calcium areas in the calcification image; for the non-boundary fusion area within the calcium area in the calcification image, using the image value in the mixed image as the image value of the calcification image; for the non-boundary fusion area within the non-calcium area in the calcification image, using the image value in the virtual plain scan image as the image value of the calcification image; for the boundary fusion area, performing a fusion operation on the image value in the mixed image and the image value in the virtual plain scan image to obtain the image value of the calcification image.

[0008] In some embodiments of the first aspect, performing a first basic substance decomposition operation on the energy spectrum CT image to obtain a substance density map includes: performing a basic substance decomposition operation of non-iodine substances and iodine substances on the energy spectrum CT image to obtain the substance density map, wherein the substance density map includes a non-iodine substance map; and extracting a calcium area mask based on the substance density map includes: performing image segmentation on the non-iodine substance map to obtain the calcium area mask.

[0009] In some embodiments of the first aspect, when the non-iodine substance image is a denoised image, performing image segmentation on the non-iodine substance image to obtain the calcium region mask comprises: performing threshold segmentation on the non-iodine substance image to obtain the calcium region mask; when the non-iodine substance image is an image to be denoised, performing image segmentation on the non-iodine substance image to obtain the calcium region mask comprises: performing image segmentation on the non-iodine substance image according to spatial features within the non-iodine substance image to obtain the calcium region mask.

[0010] In some embodiments of the first aspect, the base substance decomposition operation of the non-iodine substance and the iodine substance is: a calcium-iodine base substance pair decomposition operation, a water-iodine base substance pair decomposition operation, or a water-calcium-iodine tri-base substance decomposition operation.

[0011] In some embodiments of the first aspect, performing a second base substance decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image includes: performing a water-iodine base substance pair decomposition operation on the energy spectrum CT image, and obtaining the virtual plain scan image according to a water map obtained by the decomposition.

[0012] In some embodiments of the first aspect, the weighting coefficient of the weighted operation is used to make the sample CT value equal to the CT value of the calcium substance in the CT scan image at a preset voltage, and the sample CT value is obtained by weighting the CT value of the calcium substance in each sample energy spectrum CT image according to the weighting coefficient.

[0013] A second aspect of an embodiment of the present application provides a device for generating a calcification image, comprising: an image acquisition unit, used to acquire an energy spectrum CT image; a first basis material decomposition unit, used to perform a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map; a second basis material decomposition unit, used to perform a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image; a mask extraction unit, used to extract a calcium area mask according to the material density map; a weighting unit, used to perform a weighted operation on the energy spectrum CT image to obtain a mixed image; and an image generation unit, used to generate a calcification image according to the calcium area mask, the virtual plain scan image and the mixed image.

[0014] A third aspect of an embodiment 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 when the processor executes the computer program, the steps of the method for generating a calcification image as described in any one of the first aspects are implemented.

[0015] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for generating a calcification image are implemented.

[0016] A fifth aspect of an embodiment of the present application provides a computer program product, including a computer program, and when the computer program is run, the method for generating a calcification image described in the first aspect is executed.

[0017] In an embodiment of the present application, a material-based decomposition operation is performed on the spectral CT image, and a calcium area mask is extracted based on the obtained material density map. When generating a calcification image, the calcium area indicated by the calcium area mask is referred to, which helps to remove the contrast agent in the calcification image and accurately retain the calcium area. On the other hand, since the mixed image is obtained by performing a weighted operation on the spectral CT image, a calcification image is generated based on the calcium area mask, the virtual plain scan image and the mixed image, which can make the CT value of the calcium area in the calcification image more accurate, thereby improving the accuracy of calcification assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 It is a schematic diagram of the implementation process of the method for generating a calcification image provided in an embodiment of the present application;

[0020] Figure 2 is a material density map provided in an embodiment of the present application;

[0021] Figure 3 It is a schematic diagram of a specific implementation process of generating a calcification image provided by an embodiment of the present application;

[0022] Figure 4 It is a structural schematic diagram of a calcification image generation device provided in an embodiment of the present application;

[0023] Figure 5 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are protected by the present application.

[0025] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0026] In the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and should not be understood as indicating or implying relative importance.

[0027] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0028] In conventional CTA examinations, the grayscale values ​​of calcification foci and contrast-enhanced blood vessels overlap, making it difficult to distinguish them when assessing the degree of vascular calcification. In order to accurately assess the degree of calcification, the patient needs to undergo an additional CT plain scan without contrast agents, but this means that the patient's radiation dose needs to be increased. Some related technologies use spectral CT to obtain virtual plain scan images without contrast agents to achieve calcification assessment, which can reduce one CT plain scan imaging and thus reduce the patient's radiation dose. However, in the process of generating virtual plain scan images by decomposing water-iodine-based substances, part of the human bone tissue and calcification foci are decomposed into the water map, and part are decomposed into the iodine map. Therefore, the virtual plain scan image generated based on the water map only contains information about part of the calcium area, resulting in calcification assessment often underestimating the calcification score.

[0029] In view of this, the present application proposes a method for generating a calcification image, which can remove contrast agent in the calcification image, accurately retain the calcium area, and make the CT value of the calcium area in the calcification image close to the CT value of the calcium material in the CT scan image at a preset voltage, thereby ensuring the accuracy of calcification assessment.

[0030] In order to illustrate the technical solution of the present application, a specific embodiment is provided below for illustration.

[0031] Please refer to Figure 1 , Figure 1 A schematic diagram of the implementation process of a method for generating a calcification image provided in an embodiment of the present application is shown. The method can be applied to an electronic device, which may be a computer, a smart phone, a medical device specifically used for image processing, or other smart devices, and the present application does not impose any restrictions on this.

[0032] Specifically, the above-mentioned method for generating a calcification image may include the following steps S101 to S106.

[0033] Step S101, acquiring a spectral CT image.

[0034] The spectral CT image is a CT image generated by using the absorption characteristics of the object under different X-ray energies. The object under test refers to the object that needs calcification assessment, which can be blood vessels, soft tissues, lungs, etc., and this application does not limit this.

[0035] In some embodiments of the present application, the above-mentioned spectral CT image may be a dual-energy image, i.e., a high- and low-energy image. A dual-energy image is an image corresponding to two different energies, which may be obtained by scanning an object with X-rays of two different energies, or by scanning an object with X-rays of one energy and separating the information of the two energies by a detector, and the present application does not impose any limitation on this.

[0036] Step S102: performing a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map.

[0037] Step S103: performing a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image.

[0038] The base material decomposition operation is used to express the attenuation information of the object to be measured as a combination of two or more base materials with known attenuation characteristics, thereby separating an image that characterizes the distribution of a specific base material.

[0039] In an embodiment of the present application, by performing a first basis substance decomposition operation on the energy spectrum CT image, a material density map can be obtained, and by performing a second basis substance decomposition operation on the energy spectrum CT image, a virtual plain scan image can be obtained. The first basis substance decomposition operation and the second basis substance decomposition operation can be different basis substance decomposition operations, that is, the material density map and the virtual plain scan image can be obtained through two different basis substance decomposition operations. The first basis substance decomposition operation and the second basis substance decomposition operation can also be the same basis substance decomposition operation, that is, the material density map and the virtual plain scan image can be obtained through the same basis substance decomposition operation, and this application does not limit this. The obtained material density map can be used to indicate the distribution of calcium substances. The obtained virtual plain scan image is a CT image with contrast agent removed, which is an image similar to a true plain scan (true non-contrast, TNC) obtained by removing iodine during the material separation process.

[0040] The present application may implement the base material decomposition operation by using image domain base material decomposition, projection domain base material decomposition, direct inversion method or other existing methods, and the present application does not impose any limitation on this.

[0041] Step S104: extracting a calcium region mask according to the material density map.

[0042] In the embodiment of the present application, since the material density map can be used to indicate the distribution of calcium material, a calcium area mask can be extracted by representing the area containing calcium material and the area not containing calcium material with different image values. The calcium area mask is a mask image that can be used to indicate the calcium area in the material density map, that is, the area containing calcium material.

[0043] In some embodiments of the present application, within the calcium region mask, the image value of the calcium region may be 1, and the image value of other regions outside the calcium region may be 0. Of course, the present application does not exclude the possibility of representing the calcium region and other regions with other image values, as long as the calcium region and other regions can be distinguished.

[0044] Step S105: performing a weighted operation on the energy spectrum CT image to obtain a mixed image.

[0045] Specifically, the spectral CT image includes CT images corresponding to different X-ray energies. The image values ​​of the CT images corresponding to different X-ray energies at the same position are weighted to obtain the image value at the corresponding position of the mixed image. Taking the dual-energy image as an example, the image value at the image coordinate position (1,1) in the high-energy image and the image value at the image coordinate position (1,1) in the low-energy image are weighted to obtain the image value at the image coordinate position (1,1) in the mixed image.

[0046] In some embodiments of the present application, the weighting coefficient of the weighting operation is determined according to the CT value of the calcium substance in the CT scan image at a preset voltage. Since the weighting coefficient of the weighting operation is determined according to the CT value of the calcium substance in the CT scan image at a preset voltage, the image value of the calcium area in the mixed image can be close to or even equal to the CT value of the calcium substance in the CT scan image at the preset voltage.

[0047] It should be noted that the preset voltage can be determined according to actual needs. For example, the preset voltage can be set to 120kvp, so that the hybrid image can achieve the effect of a 120kvp CT image. Since the Agatston method is commonly used in clinical calcification scoring, which performs calcification score statistics based on 120kvp images, setting the preset voltage to 120kvp can ensure the accuracy of calcification images when used for calcification scoring.

[0048] Step S106, generating a calcification image according to the calcium region mask, the virtual plain scan image and the mixed image.

[0049] The calcification image is an image used to display the calcium content at various locations within the object to be tested, and can be used to evaluate the degree of calcification of the object to be tested.

[0050] In the implementation of the present application, since the calcium region mask can indicate the calcium region, and the image value of the calcium region in the mixed image can be close to or even equal to the CT value of the calcium substance in the CT scan image at a preset voltage, for the calcium region, when generating a calcification image based on the calcium region mask, the virtual plain scan image, and the mixed image, the image value of the calcium region in the calcification image is more in line with the actual distribution of calcium substances in the object to be tested; for the area outside the calcium region, the contrast agent can be better removed based on the virtual plain scan image. Therefore, the calcification image is used to evaluate the degree of calcification, and the overall calcification evaluation result will be closer to the actual situation of the object to be tested.

[0051] In the implementation manner of the present application, on the one hand, by performing a material-based decomposition operation on the spectral CT image, a calcium region mask is extracted according to the obtained material density map, and the calcium region of the calcification image indicated by the calcium region mask is referred to, which helps to remove the contrast agent in the calcification image and accurately retain the calcium region; on the other hand, since the mixed image is obtained by performing a weighted operation on the spectral CT image, a calcification image is generated according to the calcium region mask, the virtual plain scan image and the mixed image, which can make the CT value of the calcium region in the calcification image more accurate, thereby improving the accuracy of calcification assessment.

[0052] In some embodiments of the present application, performing a first base substance decomposition operation on the spectral CT image to obtain a substance density map may include: performing a base substance decomposition operation of non-iodine substances and iodine substances on the spectral CT image to obtain a substance density map, wherein the substance density map includes a non-iodine substance map.

[0053] Correspondingly, extracting the calcium region mask according to the material density map may include: performing image segmentation on the non-iodine material map to obtain the calcium region mask.

[0054] Wherein, the base substance decomposition operation of non-iodine substance and iodine substance can be used to separate iodine and non-iodine substance. In some embodiments of the present application, the base substance decomposition operation of non-iodine substance and iodine substance can be: calcium-iodine base substance pair decomposition operation, water-iodine base substance pair decomposition operation, or water-calcium-iodine three base substance decomposition operation. Of course, the present application does not exclude other non-iodine substances other than calcium and water, and actual application can also be combined with iodine substance and more different base substances for decomposition.

[0055] The above-mentioned image segmentation can adopt threshold segmentation, deep learning-based image segmentation or other existing image segmentation methods, which is not limited in this application.

[0056] In some embodiments of the present application, when the non-iodine substance image is a noise-reduced image, performing image segmentation on the non-iodine substance image to obtain a calcium region mask may include: performing threshold segmentation on the non-iodine substance image to obtain a calcium region mask.

[0057] Taking the decomposition operation of calcium-iodine based material pairs as an example, the decomposition operation of calcium-iodine based material pairs is performed on the spectral CT image, and the obtained material density map may include a calcium map (non-iodine material map) and an iodine map. Figure 2 As shown in the figure, 2A represents the calcium map obtained by performing the calcium-iodine based substance pair decomposition operation, and 2B represents the iodine map obtained by performing the calcium-iodine based substance pair decomposition operation. Although calcium and iodine have similar CT values ​​in the spectral CT image, the distribution of calcium and iodine substances can be displayed in the calcium map and iodine map respectively by performing the calcium-iodine based substance pair decomposition operation. At this time, the calcium map is threshold segmented by setting a threshold value to obtain a calcium area mask.

[0058] Similarly, if the base substance decomposition operation of non-iodine substances and iodine substances is a water-iodine base substance pair decomposition operation, the distribution of calcium substances and iodine substances will be displayed in the water map (non-iodine substance map) and the iodine map, respectively. At this time, the water map is threshold segmented by setting a threshold value to obtain a calcium region mask. If the base substance decomposition operation of non-iodine substances and iodine substances is a water-calcium-iodine three-base substance decomposition operation, the distribution of calcium substances and iodine substances will be displayed in the calcium map (non-iodine substance map) and the iodine map, respectively. At this time, the calcium map is threshold segmented by setting a threshold value to obtain a calcium region mask.

[0059] In other embodiments of the present application, when a non-iodine substance image is an image to be denoised, performing image segmentation on the non-iodine substance image to obtain a calcium region mask may include: performing image segmentation on the non-iodine substance image according to spatial features within the non-iodine substance image to obtain a calcium region mask.

[0060] Specifically, in some embodiments, whether the non-iodine substance map is an image to be denoised can be determined by performing image clarity analysis or noise analysis on the non-iodine substance map. In other embodiments, since the source of the non-iodine substance map is known, that is, the algorithm used by the base substance decomposition operation is known, whether the non-iodine substance map is an image to be denoised is a priori information. If the non-iodine substance map is an image after denoising, the calcium map can be threshold segmented by setting a threshold value to obtain a calcium region mask. If the non-iodine substance map is an image to be denoised, the non-iodine substance map can be segmented according to the spatial features in the non-iodine substance map to obtain a calcium region mask, to achieve the effect of denoising.

[0061] Specifically, according to the spatial features in the non-iodine substance map, the image segmentation of the non-iodine substance map can be performed by using a region-based image segmentation method, such as a region growing method, or other methods such as superpixel image segmentation and Markov random field classification based on a Gaussian mixture model. The non-iodine substance map itself has a good distinction between calcium areas and non-calcium areas. Considering the spatial features during segmentation can reduce the sensitivity to noise and obtain an ideal segmentation result.

[0062] In some embodiments of the present application, performing a second base substance decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image may include: performing a water-iodine base substance pair decomposition operation on the energy spectrum CT image, and obtaining a virtual plain scan image according to a water map obtained by the decomposition.

[0063] Specifically, through the water-iodine-based substance pair decomposition operation, since the water map does not contain iodine contrast agent, a virtual plain scan image without contrast agent can be obtained. It can be understood that if the material density map is obtained through the water-iodine-based substance pair decomposition operation or the water-calcium-iodine tri-based substance decomposition operation, then one water-iodine-based substance pair decomposition operation or one water-calcium-iodine tri-based substance decomposition operation can simultaneously obtain the material density map and the virtual plain scan image.

[0064] In some embodiments of the present application, the weighting coefficient can be used to make the sample CT value equal to the CT value of the calcium substance in the CT scan image at a preset voltage. The sample CT value is obtained by weighting the CT value of the calcium substance in each sample energy spectrum CT image according to the weighting coefficient.

[0065] Specifically, the sample spectral CT image is a spectral CT image obtained by scanning a sample object containing calcium substances. It should be noted that the sample object can be the aforementioned object to be tested. In this case, the sample spectral CT image can be a historical spectral CT image of the object to be tested, or a real-time spectral CT image of the object to be tested. The sample object can also be other objects other than the object to be tested, such as other patients, bone phantoms, etc. When using historical spectral CT images or other objects, the object to be tested does not need to be scanned multiple times this time, which helps to reduce the amount of radiation in the patient's body.

[0066] For the position containing calcium, the image values ​​of the CT images corresponding to different X-ray energies are weighted according to the weighting coefficient to obtain a sample CT value. If the sample CT value is not equal to the CT value of the calcium in the CT scan image at a preset voltage, the weighting coefficient needs to be adjusted until the weighted sample CT value is equal to the CT value of the calcium in the CT scan image at the preset voltage. The weighting coefficient can then be applied to the weighted spectral CT image. In this way, the CT value of the calcium in the obtained mixed image is equal to the CT value of the calcium in the CT scan image at the preset voltage.

[0067] Considering that the Agatston method is often used for scoring in clinical calcification assessment, which is based on 120kvp images for calcification score statistics, the above-mentioned preset voltage can be 120kvp. In this way, in the weighted mixed image, the CT value of the calcium substance will be equal to the CT value of the calcium substance on the 120kvp image, so that when evaluating the degree of calcification, the calcification score statistical result is more accurate.

[0068] In some embodiments of the present application, generating a calcification image based on a calcium area mask, a virtual plain scan image, and a mixed image may include: determining the calcium area in the mixed image and the non-calcium area in the virtual plain scan image based on the calcium area mask; generating a calcification image based on the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image.

[0069] Specifically, the image value of 1 in the calcium area mask represents the calcium area, and the image value of 0 represents the non-calcium area. When generating a calcification image, the calcium area can retain the image value of the calcium area in the mixed image, and the non-calcium area can retain the image value of the non-calcium area in the virtual plain scan image. At this time, the fused calcification image can not only leave only the signal of the calcium substance in the object to be tested without being interfered by the contrast agent, but also ensure that the CT value of the calcium area is the same as the CT value of the calcium substance in the scan image of the preset voltage, thereby ensuring the accuracy of the assessment of the degree of calcification.

[0070] In some embodiments of the present application, Figure 3 As shown, generating a calcification image according to the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image may also include: step S301 to step S304.

[0071] Step S301, determining a boundary fusion region between a calcium region and a non-calcium region in a calcification image.

[0072] Specifically, the boundary fusion area refers to the area where the calcium area and the non-calcium area meet. The boundary line between the calcium area and the non-calcium area can be determined, and the image area surrounded by a number of pixels adjacent to the boundary line can be used as the boundary fusion area.

[0073] Step S302: for the non-boundary fusion area in the calcium area in the calcification image, the image value in the mixed image is used as the image value of the calcification image.

[0074] The non-boundary fusion area in the calcium region is the area outside the boundary fusion area in the calcium region. This area is far away from the boundary line between the calcium region and the non-calcium region. Therefore, for this area, the image value in the mixed image can be used as the image value of the calcification image, so that the image value of the non-boundary fusion area in the calcium region in the calcification image is the same as the CT value of the calcium material in the scan image of the preset voltage, so as to accurately represent the calcium region.

[0075] Step S303 : for the non-boundary fusion area in the non-calcium area in the calcification image, the image value in the virtual plain scan image is used as the image value of the calcification image.

[0076] The non-boundary fusion area in the non-calcium area is an area outside the boundary fusion area in the non-calcium area. This area is far away from the boundary line between the calcium area and the non-calcium area. Therefore, for this area, the image value in the virtual plain scan image can be used as the image value of the calcification image, so that the image value of the non-boundary fusion area in the non-calcium area is the same as the image value in the virtual plain scan image, so as to accurately represent the non-calcium area.

[0077] Step S304: performing a fusion operation on the image values ​​in the mixed image and the image values ​​in the virtual plain scan image in the boundary fusion area to obtain image values ​​of the calcification image.

[0078] For the boundary fusion area, the image values ​​in the mixed image and the image values ​​in the virtual plain scan image are fused to obtain the image values ​​of the calcification image, which can achieve a smooth boundary transition effect.

[0079] The present application does not limit the algorithm used in the fusion operation. For example, a weighted averaging method, a filtering blur method (weighted averaging of images before and after filtering to obtain a calcification image), and a Laplacian pyramid image fusion method (constructing a Laplacian pyramid for the mixed image and the virtual plain scan image, constructing a Gaussian pyramid in the boundary fusion area, and weighted fusion of each layer to reconstruct a calcification image) may be used.

[0080] In the embodiment of the present application, the calcium area is determined based on the spectral CT image, and the calcium area is protected when the contrast agent is removed, so that a calcification image with the contrast agent removed and the calcium material information retained can be generated. Calcification assessment based on the calcification image can not only reduce one plain scan, thereby reducing the patient's radiation dose, but also obtain an accurate calcification score, and it is not easy to underestimate the degree of calcification.

[0081] It should be noted that, for the sake of simplicity of description, the aforementioned method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the described order of actions, because according to the present application, certain steps can be performed in other orders.

[0082] like Figure 4 FIG. 4 is a schematic diagram of the structure of a calcification image generating device 400 provided in an embodiment of the present application. The calcification image generating device 400 is configured on an electronic device.

[0083] Specifically, the calcification image generating device 400 may include:

[0084] An image acquisition unit 401 is used to acquire a spectral CT image;

[0085] A first basis material decomposition unit 402, configured to perform a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map;

[0086] A second basis material decomposition unit 403 is used to perform a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image;

[0087] A mask extraction unit 404, configured to extract a calcium region mask according to the material density map;

[0088] A weighting unit 405, configured to perform a weighting operation on the energy spectrum CT image to obtain a mixed image;

[0089] The image generating unit 406 is configured to generate a calcification image according to the calcium region mask, the virtual plain scan image and the mixed image.

[0090] In some embodiments of the present application, the image generation unit 406 is specifically used to: determine the calcium area and the non-calcium area according to the calcium area mask; generate the calcification image according to the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image.

[0091] In some embodiments of the present application, the image generation unit 406 is specifically used to: determine the boundary fusion area between the calcium area and the non-calcium area in the calcification image; for the non-boundary fusion area within the calcium area in the calcification image, use the image value in the mixed image as the image value of the calcification image; for the non-boundary fusion area within the non-calcium area in the calcification image, use the image value in the virtual plain scan image as the image value of the calcification image; for the boundary fusion area, perform a fusion operation on the image value in the mixed image and the image value in the virtual plain scan image to obtain the image value of the calcification image.

[0092] In some embodiments of the present application, the first base material decomposition unit 402 is specifically used to: perform base material decomposition operations of non-iodine materials and iodine materials on the energy spectrum CT image to obtain the material density map, and the material density map includes a non-iodine material map; the mask extraction unit 404 is specifically used to: perform image segmentation on the non-iodine material map to obtain the calcium area mask.

[0093] In some embodiments of the present application, the first base material decomposition unit 402 is specifically used for: when the non-iodine material image is a denoised image, performing threshold segmentation on the non-iodine material image to obtain the calcium area mask; when the non-iodine material image is an image to be denoised, performing image segmentation on the non-iodine material image according to the spatial features within the non-iodine material image to obtain the calcium area mask.

[0094] In some embodiments of the present application, the base substance decomposition operation of the non-iodine substance and the iodine substance is: a calcium-iodine base substance pair decomposition operation, a water-iodine base substance pair decomposition operation, or a water-calcium-iodine tri-base substance decomposition operation.

[0095] In some embodiments of the present application, the second base substance decomposition unit 403 is specifically used to: perform a water-iodine base substance pair decomposition operation on the energy spectrum CT image, and obtain the virtual plain scan image according to the water map obtained by the decomposition.

[0096] In some embodiments of the present application, the weighting coefficient is used to make the sample CT value equal to the CT value of the calcium substance in the CT scan image at a preset voltage, and the sample CT value is obtained by weighting the CT value of the calcium substance in each sample energy spectrum CT image according to the weighting coefficient.

[0097] It should be noted that, for the convenience and simplicity of description, the specific working process of the calcification image generating device 400 can be referred to Figures 1 to 3 The corresponding process of the method will not be repeated here.

[0098] like Figure 5 FIG. 5 is a schematic diagram of an electronic device 5 provided in an embodiment of the present application. Specifically, the electronic device 5 may include: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50, such as a calcification image generation program. When the processor 50 executes the computer program 52, the steps in the above-mentioned calcification image generation method embodiments are implemented, such as Figure 1 Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 4 The functions of the image acquisition unit 401, the first basis material decomposition unit 402, the second basis material decomposition unit 403, the mask extraction unit 404, the weighting unit 405 and the image generation unit 406 are shown.

[0099] The computer program may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to complete the present application. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the electronic device 5.

[0100] For example, the computer program can be divided into: an image acquisition unit, a first basis material decomposition unit, a second basis material decomposition unit, a mask extraction unit, a weighting unit and an image generation unit. The specific functions of each unit are as follows: an image acquisition unit, used to acquire a spectral CT image; a first basis material decomposition unit, used to perform a first basis material decomposition operation on the spectral CT image to obtain a material density map; a second basis material decomposition unit, used to perform a second basis material decomposition operation on the spectral CT image to obtain a virtual plain scan image; a mask extraction unit, used to extract a calcium region mask according to the material density map; a weighting unit, used to perform a weighting operation on the spectral CT image to obtain a mixed image; an image generation unit, used to generate a calcification image according to the calcium region mask, the virtual plain scan image and the mixed image.

[0101] The electronic device 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the electronic device 5 and does not constitute a limitation of the electronic device 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 5 may also include input and output devices, network access devices, buses, etc.

[0102] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0103] The memory 51 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 51 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 5. Further, the memory 51 may also include both an internal storage unit of the electronic device 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the electronic device 5. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0104] It should be noted that, for the convenience and brevity of description, the structure of the electronic device 5 can also refer to the specific description of the structure in the method embodiment, which will not be repeated here.

[0105] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0106] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0107] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0108] In the embodiments provided in the present application, it should be understood that the disclosed devices / equipment and methods can be implemented in other ways. For example, the device / equipment embodiments described above are merely schematic, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0109] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0110] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0112] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for generating a calcification image, characterized in that: include: Acquire spectral CT images; Performing a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map; Performing a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image; extracting a calcium region mask according to the material density map; Performing a weighted operation on the energy spectrum CT image to obtain a mixed image; A calcification image is generated according to the calcium region mask, the virtual plain scan image and the mixed image.

2. The method for generating a calcification image according to claim 1, wherein: The step of generating a calcification image according to the calcium region mask, the virtual plain scan image and the mixed image comprises: Determining the calcium region in the mixed image and the non-calcium region in the virtual plain scan image according to the calcium region mask; The calcification image is generated according to the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image.

3. The method for generating a calcification image according to claim 2, wherein: The step of generating the calcification image according to the image value of the calcium area in the mixed image and the image value of the non-calcium area in the virtual plain scan image comprises: Determine a boundary fusion region between a calcium region and a non-calcium region in the calcification image; For a non-boundary fusion area within the calcium area in the calcification image, using an image value in the mixed image as an image value of the calcification image; For a non-boundary fusion area in a non-calcium area in the calcification image, using an image value in the virtual plain scan image as an image value of the calcification image; For the boundary fusion area, a fusion operation is performed on the image values ​​in the mixed image and the image values ​​in the virtual plain scan image to obtain the image values ​​of the calcification image.

4. The method for generating a calcification image according to claim 1, wherein: Performing a first basis material decomposition operation on the energy spectrum CT image to obtain a material density map includes: Performing a base substance decomposition operation of non-iodine substances and iodine substances on the energy spectrum CT image to obtain the substance density map, wherein the substance density map includes a non-iodine substance map; The step of extracting a calcium region mask according to the material density map comprises: Perform image segmentation on the non-iodine substance image to obtain the calcium region mask.

5. The method for generating a calcification image according to claim 4, characterized in that: When the non-iodine substance image is a denoised image, performing image segmentation on the non-iodine substance image to obtain the calcium region mask includes: performing threshold segmentation on the non-iodine substance image to obtain the calcium region mask; When the non-iodine substance image is the image to be denoised, performing image segmentation on the non-iodine substance image to obtain the calcium region mask includes: performing image segmentation on the non-iodine substance image according to spatial features in the non-iodine substance image to obtain the calcium region mask.

6. The method for generating a calcification image according to claim 4, characterized in that: The base substance decomposition operation of the non-iodine substance and the iodine substance is: a calcium-iodine base substance pair decomposition operation, a water-iodine base substance pair decomposition operation, or a water-calcium-iodine tri-base substance decomposition operation.

7. The method for generating a calcification image according to claim 1, wherein: Performing a second basis material decomposition operation on the energy spectrum CT image to obtain a virtual plain scan image includes: A water-iodine-based substance pair decomposition operation is performed on the energy spectrum CT image, and the virtual plain scan image is obtained according to the water map obtained by the decomposition.

8. The method for generating a calcification image according to any one of claims 1 to 7, characterized in that: The weighting coefficient of the weighting operation is used to make the sample CT value equal to the CT value of the calcium substance in the CT scan image at a preset voltage. The sample CT value is obtained by weighting the CT value of the calcium substance in each sample energy spectrum CT image according to the weighting coefficient.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for generating a calcification image according to any one of claims 1 to 8 are implemented.

10. A computer program product, characterized in that The invention comprises a computer program, which, when being executed, enables the method for generating a calcification image according to any one of claims 1 to 8 to be executed.

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