CT image correction method and device, mobile CT equipment, computer storage medium and computer program product

Abstract

The invention relates to a CT image correction method and device, mobile CT equipment, a computer storage medium and a computer program product. The method comprises the steps that M circles of projection data for a target object and N circles of air projection data are collected, M and N are positive integers, and M is larger than N; cT image reconstruction is carried out according to the M circles of projection data, and a plurality of initial reconstruction images are obtained; determining a projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and performing CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstruction images in one-to-one correspondence with the initial reconstruction images; and performing correction processing on each initial reconstructed image by adopting each air reconstructed image to obtain a target reconstructed image. By adopting the method, the air correction efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the field of CT image reconstruction, and in particular to a CT image correction method, apparatus, mobile CT equipment, computer storage medium and computer program product. Background Art

[0002] In the process of CT (Computed Tomography) image reconstruction, in order to eliminate artifacts in the image, it is often necessary to obtain pre-generated air correction data according to the air correction protocol corresponding to the current scanning parameters to process the initially reconstructed CT image.

[0003] Since the air correction data is related to the usage scenario of the CT device, when the usage scenario of the CT device is changed, it is usually necessary to update the air correction data corresponding to each air correction protocol stored in the CT device. The specific update method is to scan the air once according to the scanning parameters corresponding to the air correction protocol, reconstruct the CT image based on the projection data obtained by the scan, and obtain the air correction data.

[0004] A mobile CT device is a CT device that can be moved to different locations such as wards and ambulances for use. Since the use environment of a mobile CT device changes frequently, if the air correction data of the mobile CT device is obtained according to the current air correction method, it will take a long time to update the air correction data after almost every movement of the mobile CT device, affecting the user experience of the mobile CT device. Summary of the invention

[0005] Based on this, it is necessary to provide a CT image correction method, apparatus, mobile CT equipment, computer storage medium and computer program product to address the above technical problems.

[0006] In a first aspect, the present application provides a CT image correction method. The method comprises:

[0007] Collect M circles of projection data for the target object and N circles of air projection data, where M and N are both positive integers, and M is greater than N;

[0008] Reconstructing a CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images;

[0009] Determine the projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and perform CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images;

[0010] Each of the air reconstructed images is used to perform correction processing on each of the initial reconstructed images to obtain a target reconstructed image.

[0011] In one embodiment, the performing CT image reconstruction on the projection data coverage range based on the N-circle air projection data to obtain an air reconstructed image corresponding to each of the initial reconstructed images comprises:

[0012] Reconstructing CT images for each circle of the air projection data to obtain a plurality of initial air reconstruction images corresponding to each circle of the air projection data;

[0013] Based on the initial air reconstruction images, air reconstruction images corresponding to the initial reconstruction images are generated.

[0014] In one embodiment, generating air reconstructed images corresponding to each of the initial reconstructed images based on each of the initial air reconstructed images comprises:

[0015] Respectively determining the imaging position corresponding to each of the initial reconstructed images, and determining the imaging position corresponding to each of the initial air reconstructed images;

[0016] Based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, respectively determining at least one initial air reconstructed image corresponding to each of the initial reconstructed images;

[0017] For any of the initial reconstructed images, an air reconstructed image corresponding to the initial reconstructed image is determined according to each of the initial air reconstructed images corresponding to the initial reconstructed image.

[0018] In one embodiment, the determining at least one initial air reconstruction image corresponding to each of the initial reconstructed images based on the imaging position corresponding to each of the initial reconstructed images and the imaging position corresponding to each of the initial air reconstruction images respectively includes:

[0019] For any of the initial reconstructed images, an initial air reconstructed image whose distance between the imaging position and the imaging position of the initial reconstructed image is less than a preset distance threshold is used as the initial air reconstructed image corresponding to the initial reconstructed image.

[0020] In one embodiment, for any of the initial reconstructed images, determining the air reconstructed image corresponding to the initial reconstructed image according to each of the initial air reconstructed images corresponding to the initial reconstructed image includes:

[0021] In the case where the initial reconstructed image corresponds to one initial air reconstructed image, using the initial air reconstructed image as the air reconstructed image corresponding to the initial reconstructed image; or,

[0022] In the case that the initial reconstructed image corresponds to more than one initial air reconstructed image, the air reconstructed image corresponding to the imaging position of the initial reconstructed image is interpolated according to the imaging position of each initial air reconstructed image.

[0023] In one embodiment, generating air reconstructed images corresponding to each of the initial reconstructed images based on each of the initial air reconstructed images comprises:

[0024] According to the acquisition positions of the M circles of projection data, the initial air reconstruction images corresponding to the N circles of air projection data are copied to obtain air reconstruction images corresponding to the initial reconstruction images one by one.

[0025] In one embodiment, when the M circles of projection data overlap with each other, the initial air reconstruction images corresponding to the N circles of air projection data are copied according to the acquisition positions of the M circles of projection data to obtain air reconstruction images corresponding to the initial reconstruction images one by one, including:

[0026] Determine an overlapping reconstruction range and a non-overlapping reconstruction range in a coverage range of the projection data according to acquisition positions of two adjacent circles of the projection data in the M circles of projection data;

[0027] Determine 2 circles of target air projection data according to the N circles of air projection data, wherein the 2 circles of target air projection data have overlapping areas;

[0028] Interpolating the initial air reconstruction images of the overlapping area corresponding to the two circles of target air projection data to obtain the target air reconstruction image corresponding to the overlapping area;

[0029] The target air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain air reconstructed images corresponding one to one to each of the initial reconstructed images.

[0030] In one embodiment, the performing CT image reconstruction on the projection data coverage range based on the N-circle air projection data to obtain an air reconstructed image corresponding to each of the initial reconstructed images comprises:

[0031] Filling the projection data coverage range based on the N circles of air projection data to obtain target air projection data;

[0032] Perform CT image reconstruction on the target air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images.

[0033] In one embodiment, the filling process of the projection data coverage range based on the N-circle air projection data to obtain the target air projection data includes:

[0034] Determine at least one circle of filled air projection data from the N circles of air projection data;

[0035] The filled air projection data is copied to the acquisition position of the M-circle projection data to obtain the target air projection data.

[0036] In a second aspect, the present application also provides a CT image correction device. The device comprises:

[0037] A collection module, used for collecting M circles of projection data for the target object and N circles of air projection data, wherein M and N are both positive integers, and M is greater than N;

[0038] A first reconstruction module, used for reconstructing a CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images;

[0039] A second reconstruction module is used to determine the projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and to perform CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images;

[0040] The correction module is used to respectively use the air reconstructed images to perform correction processing on the initial reconstructed images to obtain a target reconstructed image.

[0041] In one embodiment, the second reconstruction module is further used for:

[0042] Reconstructing CT images for each circle of the air projection data to obtain a plurality of initial air reconstruction images corresponding to each circle of the air projection data;

[0043] Based on the initial air reconstruction images, air reconstruction images corresponding to the initial reconstruction images are generated.

[0044] In one embodiment, the second reconstruction module is further used for:

[0045] Respectively determining the imaging position corresponding to each of the initial reconstructed images, and determining the imaging position corresponding to each of the initial air reconstructed images;

[0046] Based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, respectively determining at least one initial air reconstructed image corresponding to each of the initial reconstructed images;

[0047] For any of the initial reconstructed images, an air reconstructed image corresponding to the initial reconstructed image is determined according to each of the initial air reconstructed images corresponding to the initial reconstructed image.

[0048] In one embodiment, the second reconstruction module is further used for:

[0049] For any of the initial reconstructed images, an initial air reconstructed image whose distance between the imaging position and the imaging position of the initial reconstructed image is less than a preset distance threshold is used as the initial air reconstructed image corresponding to the initial reconstructed image.

[0050] In one embodiment, the second reconstruction module is further used for:

[0051] In the case where the initial reconstructed image corresponds to one initial air reconstructed image, using the initial air reconstructed image as the air reconstructed image corresponding to the initial reconstructed image; or,

[0052] In the case that the initial reconstructed image corresponds to more than one initial air reconstructed image, the air reconstructed image corresponding to the imaging position of the initial reconstructed image is interpolated according to the imaging position of each initial air reconstructed image.

[0053] In one embodiment, the second reconstruction module is further used for:

[0054] According to the acquisition positions of the M circles of projection data, the initial air reconstruction images corresponding to the N circles of air projection data are copied to obtain air reconstruction images corresponding to the initial reconstruction images one by one.

[0055] In one embodiment, when the M circles of projection data overlap each other, the second reconstruction module is further used to:

[0056] Determine an overlapping reconstruction range and a non-overlapping reconstruction range in a coverage range of the projection data according to acquisition positions of two adjacent circles of the projection data in the M circles of projection data;

[0057] Determine 2 circles of target air projection data according to the N circles of air projection data, wherein the 2 circles of target air projection data have overlapping areas;

[0058] Interpolating the initial air reconstruction images of the overlapping area corresponding to the two circles of target air projection data to obtain the target air reconstruction image corresponding to the overlapping area;

[0059] The target air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain air reconstructed images corresponding one to one to each of the initial reconstructed images.

[0060] In one embodiment, the second reconstruction module is further used for:

[0061] Filling the projection data coverage range based on the N circles of air projection data to obtain target air projection data;

[0062] Perform CT image reconstruction on the target air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images.

[0063] In one embodiment, the second reconstruction module is further used for:

[0064] Determine at least one circle of filled air projection data from the N circles of air projection data;

[0065] The filled air projection data is copied to the acquisition position of the M-circle projection data to obtain the target air projection data.

[0066] In a third aspect, the present application further provides a mobile CT device. The mobile CT device comprises a memory and a processor, the memory stores a computer program, and the processor implements any of the above methods when executing the computer program.

[0067] In a fourth aspect, the present application further provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, any of the above methods is implemented.

[0068] In a fifth aspect, the present application further provides a computer program product, wherein the computer program product comprises a computer program, and when the computer program is executed by a processor, any of the above methods is implemented.

[0069] The above-mentioned CT image correction method, apparatus, mobile CT device, computer storage medium and computer program product, when performing a CT scan on a target object, collects M circles of projection data and N circles of air projection data less than M at the same time, and reconstructs the CT image of the range covered by the M circles of projection data based on the N circles of air projection data, obtains air reconstruction images corresponding to each initial reconstructed image within the projection data coverage range, and uses the air reconstruction images to perform correction processing on the initial reconstructed image. The embodiment of the present application can collect air projection data for air correction while performing a CT scan on the target object, and the number of circles of air projection data collected is less than the number of circles of projection data, which can improve the collection efficiency of air projection data, and thus improve the efficiency of air correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 is a schematic flow chart of a CT image correction method in one embodiment;

[0071] Figure 2 A schematic diagram of collecting projection data and air projection data in one embodiment;

[0072] Figure 3 A schematic diagram of collecting projection data and air projection data in another embodiment;

[0073] Figure 4 is a schematic diagram of correcting an initial reconstructed image using an air reconstructed image in one embodiment;

[0074] Figure 5 is a flow chart of step 106 in one embodiment;

[0075] Figure 6 is a flow chart of step 504 in one embodiment;

[0076] Figure 7 A schematic diagram of generating an air reconstruction image for an overlapping scanning situation in one embodiment;

[0077] Figure 8 A schematic diagram of replicating an initial air reconstruction image in one embodiment;

[0078] Fig. 9 is a flow chart of step 106 in one embodiment;

[0079] Fig.10 is a flow chart of step 902 in one embodiment;

[0080] Fig.11 is a schematic flow chart of a CT image correction method in one embodiment;

[0081] Fig.12is a structural block diagram of a CT image correction device in one embodiment;

[0082] Fig.13 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0083] In order to make the purpose, technical solution 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 used to limit the present application.

[0084] In one embodiment, Figure 1 As shown, a CT image correction method is provided. This embodiment uses the method applied to a mobile CT device as an example, and includes the following steps:

[0085] Step 102 : collecting M circles of projection data for the target object and N circles of air projection data, wherein M and N are both positive integers, and M is greater than N.

[0086] In the embodiment of the present application, the target object is a scanning object of the mobile CT. When the mobile CT performs CT scanning on the target object, it is necessary to scan the target object M circles in total and collect M circles of projection data. The specific number of M can be determined according to the actual scanning requirements of the target object. Projection data of different circles can be collected at the same collection position (the collection position refers to the position where the imaging device of the mobile CT is located when collecting projection data), or at different collection positions.

[0087] Mobile CT also needs to collect N circles of air projection data. Air projection data is obtained by mobile CT scanning the air using the same parameters as when collecting projection data. The collection position of air projection data does not have to be the same as the collection position of projection data. In order to shorten the collection time of air projection data, N should be less than M.

[0088] The air projection data may be collected before the scanning process for the target object is started, or after the scanning process for the target object is completed. For example, the mobile CT may first collect N circles of air projection data before moving the target object into the scanning range, and then move the target object into the scanning range of the mobile CT, and start the scanning process for the target object, and collect M circles of projection data for the target object.

[0089] Alternatively, air projection data can also be collected during the execution of the scanning process for the target object. For example, when a mobile CT collects M-circle projection data, the imaging device can be moved out of the target object range (or the target object can be moved out of the scanning range) to collect air projection data after collecting a part of the projection data, and then the imaging device can be moved back to the target object range to collect projection data, and then the imaging device can be moved out of the target object range to collect air projection data after collecting a part of the projection data. Repeat the above process until the collected projection data reaches the preset M circles. Which solution to adopt can be determined according to actual needs, and the embodiments of the present application do not make specific limitations.

[0090] The embodiments of the present application do not limit how to determine the value represented by N. In one embodiment, N is negatively correlated with the preset scanning time. The preset scanning time is a pre-set time length, which represents the maximum time length that a target object occupies the mobile CT, which is equivalent to the time length for collecting projection data for the target object, and the sum of the time lengths of the air projection data corresponding to the collected projection data should not exceed the preset scanning time length. The time length required for the mobile CT to collect one circle of projection data or one circle of air projection data can be determined, and the total time length required for the mobile CT to collect M circles of projection data can be determined based on the time length, and then the available time length for collecting N circles of air projection data can be determined based on the difference between the preset scanning time length and the total time length required for the mobile CT to collect M circles of projection data, and then the reasonable value of N can be determined based on the available time length.

[0091] In another embodiment, the projection data coverage range can be determined according to the acquisition positions corresponding to the M circles of projection data, the value represented by N can be determined according to the projection data coverage range, and the acquisition positions corresponding to the N circles of air projection data can be determined. Each circle of projection data is the imaging result of an area at a certain acquisition position, and the area is the coverage range corresponding to the circle of projection data. The projection data coverage range refers to the union of the coverage ranges corresponding to all projection data, such as Figure 2 shown.

[0092] Since the acquisition position of the projection data has a certain influence on the acquisition quality of the projection data, and the reconstructed image is reconstructed based on the projection data within a certain range, when the acquisition position of the projection data used to reconstruct a certain reconstructed image and the air projection data used to reconstruct the air reconstruction image corresponding to the reconstructed image are closest, the quality of air correction of the reconstructed image using the air reconstruction image is the best. At the same time, in order to shorten the acquisition time of the air projection data as much as possible, the value represented by N should be as small as possible. Based on the above principles, the value represented by N can be determined according to the coverage range of the projection data, and the acquisition positions corresponding to the N circles of air projection data can be determined.

[0093] Exemplarily, multiple preset coverage range intervals may be determined based on the length of a circle of projection data. For example, the first preset coverage range interval may be set to be 1 times the length of a circle of projection data to 3 times the length of a circle of projection data, the second preset coverage range interval may be set to be 3 times the length of a circle of projection data to 5 times the length of a circle of projection data, and so on. Furthermore, the value of N and the air projection data collection position may be determined for each preset coverage range interval. For example, for the first preset coverage range interval, N may be set to be equal to 1, and the air projection data collection position may be set to be located at the average position of the collection positions of each circle of projection data (e.g., Figure 2 ). For the second preset coverage range interval, N can be set to 2, and the collection position of the air projection data can be located at the collection position of the first circle of projection data and the collection position of the last circle of projection data. In the application, after determining the projection data coverage range, the preset coverage range interval to which the projection data coverage range belongs can be determined, and the collection position of the air projection data and the value of N can be determined according to the preset coverage range interval, and the air projection data can be collected according to the value of N and the collection position.

[0094] In another embodiment, considering that calculating the projection data coverage range and then collecting air projection data according to the projection data coverage range will increase the amount of calculation of the mobile CT in the data collection stage, thereby increasing the time it takes for the mobile CT to complete a CT scan. Therefore, in order to further save the time for determining the air projection data collection position, the mobile CT can record the collection positions of M circles of projection data when collecting M circles of projection data, and then determine N air projection data collection positions from the collection positions corresponding to the M circles of projection data, and then collect 1 circle of air projection data at each air projection data collection position to obtain N circles of air projection data. In the above manner, the mobile CT does not need to calculate the position for collecting air projection data, thereby improving the efficiency of the mobile CT in completing a CT scan.

[0095] For example, starting from the first acquisition position of the M-circle projection data, an air projection data acquisition position can be determined every preset number of acquisition positions. The preset number can be determined according to the demand for CT scanning efficiency in actual applications. The higher the demand for CT scanning efficiency, the lower the preset number should be. To illustrate with a practical example, for example, when M is 3 and the preset number is 1, the first acquisition position can be used as the air projection data acquisition position, and then the third acquisition position can be used as the air projection data acquisition position after an interval of one acquisition position, such as Figure 3 shown.

[0096] When the method is used to determine the air projection data acquisition position, in actual applications, the mobile CT can record the air projection data acquisition position while acquiring M-circle projection data. The mobile CT can determine which acquisition position the current acquisition position is in the entire scanning process when acquiring M-circle projection data. When the current acquisition position is a preset number of acquisition positions away from the previous air projection data acquisition position, the current acquisition position is recorded as the air projection data acquisition position until the acquisition of the M-circle projection data is completed. The mobile CT can save the recorded air projection data acquisition positions as a list. After the acquisition of the M-circle projection data is completed, the mobile CT can immediately complete the acquisition of the air projection data according to the air projection data acquisition positions recorded in the list. No additional calculations are required during the entire process, which can improve the efficiency of air projection data acquisition.

[0097] Step 104 , reconstructing the CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images.

[0098] In the embodiment of the present application, the mobile CT can reconstruct multiple initial reconstructed images based on the M-circle projection data. The CT image reconstruction is three-dimensional reconstruction. Each slice position in the obtained three-dimensional image is the imaging position. The slice image corresponding to each imaging position is the reconstructed image of the position. The initial reconstructed image is a reconstructed image with artifacts. Each initial reconstructed image is reconstructed based on the projection data within a certain range and corresponds to an imaging position on the target object. An example of an initial reconstructed image can be seen in Figure 4 As shown on the left, by using one circle of projection data to reconstruct CT images, multiple initial reconstructed images can be obtained. Then, by using multiple circles of head shadow data to reconstruct CT images, more initial reconstructed images can be obtained.

[0099] Step 106 , determining the projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and reconstructing the projection data coverage range by CT images based on the N circles of air projection data to obtain air reconstructed images corresponding to each initial reconstructed image.

[0100] In the embodiment of the present application, CT image reconstruction is performed on the air head shadow data to obtain a three-dimensional image corresponding to the air. The tomographic image at each position of the three-dimensional image is the air reconstruction image at the corresponding position. Mobile CT needs to generate the most suitable air reconstruction image for correcting the initial reconstruction image for each initial reconstruction image in the projection data coverage range based on N circles of air projection data. An example of an air reconstruction image can be found in Figure 4 Shown on the right.

[0101] The air projection data coverage range can be determined according to the acquisition position of N circles of air projection data, and the air projection data missing range can be determined according to the air projection data coverage range and the projection data coverage range, that is, the area covered by the projection data without corresponding air projection data. Then, simulated air projection data corresponding to the air projection data missing range can be generated through the air projection data, and then the simulated air projection data and the actually acquired air projection data are reconstructed by the reconstruction algorithm used when reconstructing M layers of projection data. Since the reconstruction algorithm used is the same and the coverage range of the projection data used is also the same, the imaging positions of each reconstructed air reconstruction image and the imaging positions of each initial reconstruction image correspond one-to-one, and an air reconstruction image corresponding one-to-one to each initial reconstruction image can be obtained.

[0102] Alternatively, the air projection data may be first reconstructed by CT image reconstruction to obtain multiple initial air reconstruction images within the coverage range of the air projection data, and then a simulated air reconstruction image corresponding to the missing range of the air projection data may be generated based on the initial air reconstruction image. The imaging positions of the initial air reconstruction image and the simulated air reconstruction image generated by this method do not necessarily correspond to the initial reconstructed image. At this time, each initial air reconstruction image and the simulated air reconstruction image may be used to further generate an air reconstruction image whose imaging position corresponds to the initial reconstructed image, or an air reconstruction image may be selected from the initial air reconstruction image and the simulated air reconstruction image for each initial reconstructed image, which is not specifically limited in the embodiments of the present application.

[0103] Step 108 : Correct each initial reconstructed image using each air reconstructed image to obtain a target reconstructed image.

[0104] In the embodiment of the present application, the initial reconstructed image is further processed based on the air reconstructed image to obtain a target reconstructed image without artifacts. The embodiment of the present application does not specifically limit how to process the initial reconstructed image through the air reconstructed image, and any processing algorithm is applicable to the embodiment of the present application. The target reconstructed image obtained after processing can be found in Figure 4 Shown below.

[0105] The CT image correction method provided in the embodiment of the present application, when performing a CT scan on a target object, collects M circles of projection data and N circles of air projection data less than M at the same time, and reconstructs the CT image of the range covered by the M circles of projection data based on the N circles of air projection data, obtains air reconstruction images corresponding to each initial reconstructed image within the projection data coverage range, and uses the air reconstruction images to perform correction processing on the initial reconstructed image. The embodiment of the present application can collect air projection data for air correction while performing a CT scan on the target object, and the number of circles of air projection data collected is less than the number of circles of projection data, which can improve the collection efficiency of air projection data, and thus improve the efficiency of air correction.

[0106] In one embodiment, Figure 5 As shown, in step 106, CT image reconstruction is performed on the projection data coverage range based on N circles of air projection data to obtain air reconstructed images corresponding to each initial reconstructed image, including:

[0107] Step 502, performing CT image reconstruction on each circle of air projection data to obtain a plurality of initial air reconstruction images corresponding to each circle of air projection data;

[0108] Step 504 : Based on each initial air reconstruction image, generate an air reconstruction image corresponding to each initial reconstructed image one by one.

[0109] In the embodiment of the present application, CT image reconstruction is first performed on N circles of air projection data, and then based on the generated initial reconstructed images, air reconstructed images corresponding to the initial reconstructed images are further generated.

[0110] Based on a circle of air projection data, multiple initial air reconstruction images can be reconstructed. Each initial air reconstruction image is reconstructed based on air projection data within a certain range and corresponds to an imaging position.

[0111] Based on the imaging position of each initial air reconstruction image, an air reconstruction image corresponding to the imaging position of each initial reconstructed image can be further generated. For example, considering that the process of mobile CT collecting air projection data is similar to scanning at different positions on the axis of an air cylinder, the initial air reconstruction images obtained by imaging, that is, slices at different positions on the axis of the cylinder, have a certain correlation with each other. Therefore, interpolation can be performed based on the pixel values ​​of each pixel of each initial air reconstruction image to obtain a functional relationship between the pixel value of the pixel and the imaging position for each pixel. Then, based on the imaging position of the initial reconstructed image, the pixel value of each pixel corresponding to the imaging position can be calculated to obtain the air reconstruction image corresponding to the initial reconstructed image.

[0112] Alternatively, considering that each initial air reconstruction image can essentially be regarded as a time series, a neural network model suitable for processing time series data (such as LSTM (Long Short-Term Memory, long short-term memory network model, etc.)) can be trained, and then each initial air reconstruction image can be input into the neural network model to obtain an air reconstruction image corresponding to the imaging position of each initial reconstructed image. The embodiment of the present application does not make specific limitations on this.

[0113] The CT image correction method provided in the embodiment of the present application first reconstructs N circles of air projection data to obtain multiple initial air reconstruction images, and then generates an air reconstruction image based on each initial air reconstruction image. This can save the amount of data that needs to be processed in the image reconstruction step, improve the efficiency of generating air reconstruction images, and thus improve the air correction efficiency.

[0114] In one embodiment, Figure 6 As shown, in step 504, based on each initial air reconstruction image, an air reconstruction image corresponding to each initial reconstructed image is generated, including:

[0115] Step 602, respectively determining the imaging positions corresponding to each initial reconstructed image, and determining the imaging positions corresponding to each initial air reconstructed image;

[0116] Step 604, based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, respectively determine at least one initial air reconstructed image corresponding to each initial reconstructed image;

[0117] Step 606 : for any initial reconstructed image, determine the air reconstructed image corresponding to the initial reconstructed image according to each initial air reconstructed image corresponding to the initial reconstructed image.

[0118] In an embodiment of the present application, at least one initial air reconstruction image corresponding to the initial reconstructed image can be determined based on the imaging position corresponding to the initial reconstructed image and the imaging positions corresponding to each initial air reconstruction image, and then an air reconstruction image corresponding to the initial reconstructed image can be generated based on the initial air reconstruction image corresponding to each initial reconstructed image.

[0119] The embodiment of the present application does not specifically limit how to determine the corresponding initial air reconstruction image according to the imaging position. In one embodiment, a preset number of initial air reconstruction images whose imaging positions are closest to the initial reconstruction image can be used as the initial air reconstruction images corresponding to the initial reconstruction image.

[0120] In another embodiment, in overlapping scanning (that is, the projection data of two adjacent circles collected overlap, for example Figure 2) scenario, considering that the amount of data used in reconstruction has an impact on the quality of the reconstructed image, and the amount of data used in the reconstruction of the overlapping area is different from that of the non-overlapping area, in order to improve the air correction effect, it is best to make the amount of data used in the reconstruction of the air reconstruction image corresponding to the initial reconstructed image the same as or at least close to that of the initial reconstructed image. Figure 7 As shown, the number of projection data circles used in the reconstruction of each initial reconstructed image and the number of air projection data circles used in the reconstruction of each initial air reconstructed image can be recorded. For a certain initial reconstructed image, a preset number of initial air reconstructed images whose imaging position is closest to the initial reconstructed image and whose difference between the number of air projection data circles and the number of projection data circles of the initial reconstructed image is within a preset range can be used as the initial air reconstructed images corresponding to the initial reconstructed image.

[0121] After determining the initial air reconstruction images corresponding to the initial reconstructed image, the air reconstruction image corresponding to the initial reconstructed image can be determined by taking an average of the initial air reconstruction images or by interpolating according to the imaging positions of the initial air reconstruction images, which is not specifically limited in the embodiments of the present application.

[0122] In one embodiment, in step 604, based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, at least one initial air reconstructed image corresponding to each initial reconstructed image is determined, including:

[0123] For any initial reconstructed image, an initial air reconstructed image whose imaging position has a distance with the imaging position of the initial reconstructed image less than a preset distance threshold is used as the initial air reconstructed image corresponding to the initial reconstructed image.

[0124] In the embodiment of the present application, a preset distance threshold may be preset. For any initial reconstructed image, the distance between the imaging position of each initial air reconstructed image and the imaging position of the initial reconstructed image may be determined, and all initial air reconstructed images whose distance is less than the preset distance threshold may be used as the initial air reconstructed image corresponding to the initial reconstructed image. If there is no initial air reconstructed image whose distance is less than the preset distance threshold, the initial air reconstructed image with the closest distance may be used as the initial air reconstructed image corresponding to the initial reconstructed image.

[0125] By means of the above method, when generating an air reconstructed image corresponding to an initial reconstructed image, an initial air reconstructed image that is closer to the initial reconstructed image can be referred to, thereby improving the accuracy of the generated air reconstructed image.

[0126] In one embodiment, in step 606, for any initial reconstructed image, determining the air reconstructed image corresponding to the initial reconstructed image according to each initial air reconstructed image corresponding to the initial reconstructed image includes:

[0127] In the case where the initial reconstructed image corresponds to one initial air reconstructed image, the initial air reconstructed image is used as the air reconstructed image corresponding to the initial reconstructed image; or,

[0128] In the case that the initial reconstructed image corresponds to more than one initial air reconstructed image, the air reconstructed image corresponding to the imaging position of the initial reconstructed image is interpolated according to the imaging positions of the initial air reconstructed images.

[0129] In the embodiment of the present application, after the initial air reconstruction image corresponding to each initial reconstructed image is determined by the method of the aforementioned embodiment, if a certain initial reconstructed image corresponds to only one initial air reconstruction image, the initial air reconstruction image can be used as the air reconstruction image corresponding to the initial reconstructed image. If a certain initial reconstructed image corresponds to multiple initial air reconstruction images, the air reconstruction image corresponding to the imaging position of the initial reconstructed image can be interpolated based on the imaging positions of each initial air reconstruction image. The specific interpolation method can be referred to the aforementioned embodiment, and the embodiment of the present application does not specifically limit this.

[0130] In one embodiment, in step 504, based on each initial air reconstruction image, generating an air reconstruction image corresponding to each initial reconstructed image includes:

[0131] According to the acquisition positions of the M-circle projection data, the initial air reconstruction images corresponding to the N-circle air projection data are copied to obtain air reconstruction images corresponding to the initial reconstruction images one by one.

[0132] In an embodiment of the present application, in order to further improve the generation speed of air reconstruction images, each initial air reconstruction image can be copied according to the acquisition position of M circles of projection data before generating the air reconstruction image based on each initial air reconstruction image. The copying method can be to select a circle of padded air projection data for a certain circle of projection data, and copy each initial air reconstruction image of the circle of padded air projection data to the position where the circle of projection data is located, so that the positional relationship between each initial air reconstruction image after copying and the acquisition position of the circle of projection data is the same as the positional relationship between each initial air reconstruction image and the acquisition position of the padded air projection data before copying, such as Figure 8 shown.

[0133] The method of selecting the filling air projection data may be to select the air projection data whose acquisition position is closest to the acquisition position of the projection data of the current circle, or to select the air projection data with the best imaging quality, etc., which is not specifically limited in the embodiment of the present application. After copying the initial air reconstruction image, the corresponding initial air projection data may be selected for each initial reconstruction image in accordance with the method of the aforementioned embodiment.

[0134] It should be further explained that in special cases such as overlapping scans, since the amount of data used to reconstruct the initial reconstructed image is not necessarily the same as the amount of data used to reconstruct the initial air reconstructed image (for example, the initial overlapping image of the overlapping area may use 2 circles of projection data, but the initial air reconstructed image may only use 1 circle of air projection data), the imaging position corresponding to the initial air reconstructed image after copying may not necessarily correspond to the imaging position of the initial reconstructed image (for example, Figure 8 ). In this special case, after copying the initial air reconstruction image, an interpolation process may be performed based on each current initial air reconstruction image to obtain an initial air reconstruction image corresponding to the imaging position of each initial reconstructed image.

[0135] In one embodiment, referring to Fig.11 , when the M circles of projection data overlap with each other, the initial air reconstruction images corresponding to the N circles of air projection data are copied according to the acquisition positions of the M circles of projection data to obtain air reconstruction images corresponding to the initial reconstruction images one by one, including:

[0136] Determine an overlapping reconstruction range and a non-overlapping reconstruction range in a coverage range of the projection data according to acquisition positions of two adjacent circles of the projection data in the M circles of projection data;

[0137] Determine 2 circles of target air projection data according to the N circles of air projection data, wherein the 2 circles of target air projection data have overlapping areas;

[0138] Interpolating the initial air reconstruction images of the overlapping area corresponding to the two circles of target air projection data to obtain the target air reconstruction image corresponding to the overlapping area;

[0139] The target air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain air reconstructed images corresponding one to one to each of the initial reconstructed images.

[0140] In the embodiment of the present application, in the overlapping scanning scenario, there will be an overlapping reconstruction range (a range reconstructed using more than one circle of projection data) and a non-overlapping reconstruction range (a range reconstructed using one circle of projection data) in the projection data coverage range of the M circles of projection data. Since the different amounts of data used during reconstruction will affect the imaging quality, in order to improve the air correction accuracy, two circles of overlapping target air projection data can be determined from the N circles of air projection data, and the target air reconstruction image corresponding to the overlapping reconstruction range is interpolated and generated based on the initial air reconstruction image in the overlapping area of ​​the two circles of target air projection data.

[0141] The embodiment of the present application does not specifically limit how to determine the target air projection data. For example, the air projection data with the largest overlap or the best data acquisition quality can be determined from the overlapping air projection data of each circle as the target air projection data.

[0142] It should be noted that, if there is no overlapping air projection data among the N circles of air projection data, two circles of air projection data can be determined from the N circles of air projection data (for example, the air projection data with the closest distance to each other are determined), and then one circle of air projection data is copied so that the copied air projection data overlaps with the other circle of air projection data, thereby obtaining two circles of target air projection data with overlapping. When N is equal to 1, the one circle of air projection data can also be copied so that the copied air projection data overlaps with itself, thereby obtaining two circles of target air projection data with overlapping.

[0143] Furthermore, the target air reconstruction image can be copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstruction image can be copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain an air reconstruction image corresponding to each of the initial reconstructed images one by one. The copied target air reconstruction image can be a certain specific target air reconstruction image, or the target air reconstruction image corresponding to each initial reconstructed image can be determined in the manner of the aforementioned embodiment, and then the target air reconstruction image corresponding to each initial reconstructed image can be copied to the imaging position corresponding to each initial reconstructed image. Similarly, the copied initial air reconstruction image can also be a certain specific initial air reconstruction image, or the initial air reconstruction image corresponding to each initial reconstructed image can be determined in the manner of the aforementioned embodiment, and then the initial air reconstruction image corresponding to each initial reconstructed image can be copied to the imaging position corresponding to each initial reconstructed image.

[0144] The CT image correction method provided in the embodiment of the present application, in an overlapping scanning scenario, obtains a target air reconstructed image corresponding to the overlapping reconstruction area in the overlapping scan by interpolating the initial air reconstructed image corresponding to the two circles of air projection data, which is equivalent to enabling the target air reconstructed image to refer to the information of the two circles of air projection data, simulating the effect of reconstruction using two circles of overlapping projection data, and thus enabling the imaging quality of the target air reconstructed image to be close to the imaging quality of the initial reconstructed image in the overlapping reconstruction area, thereby improving the effect of using the target air reconstructed image to perform CT image correction on the initial reconstructed image.

[0145] In one embodiment, Fig. 9 As shown, in step 106, CT image reconstruction is performed on the projection data coverage range based on N circles of air projection data to obtain air reconstructed images corresponding to each initial reconstructed image, including:

[0146] Step 902, filling the projection data coverage range based on N circles of air projection data to obtain target air projection data;

[0147] Step 904 , performing CT image reconstruction on the target air projection data to obtain air reconstructed images corresponding one-to-one to each initial reconstructed image.

[0148] In the embodiment of the present application, N circles of air projection data are first used to fill the projection data coverage range so that each position in the projection data coverage range has corresponding air projection data, and then a CT image is reconstructed for the target air projection data obtained after filling.

[0149] The embodiment of the present application does not specifically limit the method of filling the projection data coverage range based on N circles of air projection data. For example, the air projection data missing range without corresponding air projection data in the projection data coverage range can be determined first according to the air projection data coverage range and the projection data coverage range, and then for each air projection data missing range, the air projection data in the air projection data missing range can be interpolated according to the air projection data at both ends of the air projection data missing range. Alternatively, one circle of air projection data whose acquisition position is closest to the air projection data missing range can be selected, and the circle of air projection data can be copied to the air projection data missing range.

[0150] In one embodiment, Fig.10 As shown, in step 902, the projection data coverage range is filled based on N circles of air projection data to obtain target air projection data, including:

[0151] Step 1002, determining at least one circle of filled air projection data from N circles of air projection data;

[0152] Step 1004 , copy the filled air projection data to the collection position of the M-circle projection data to obtain the target air projection data.

[0153] In the embodiment of the present application, at least one circle of filling air projection data may be first determined from the N circles of air projection data, and then the filling air projection data may be copied to the acquisition position of the M circles of projection data. The method for determining the filling air projection data may be to select the air projection data with the best acquisition quality, to select the air projection data with the acquisition position closest to the average position of the acquisition position of the M circles of projection data, etc., which is not specifically limited in the embodiment of the present application.

[0154] After copying the padded air projection data to the acquisition position of the M-circle projection data, the target air projection data composed of the padded air projection data can be obtained. Since the acquisition position of each circle of padded air projection data in the target air projection data corresponds one-to-one with the acquisition position of the projection data, when the target air projection data and the projection data are reconstructed using the same reconstruction algorithm, the imaging position of the reconstructed air reconstruction image and the imaging position of the initial reconstructed image will also correspond one-to-one. For special scenarios such as overlapping scanning, when using this method, there is no need to consider the different amounts of data used during reconstruction, which leads to the imaging position of the air reconstructed image not corresponding to the imaging position of the initial reconstructed image, which can further improve the efficiency of air correction.

[0155] In one embodiment, Fig.11 As shown, a CT image correction method is provided, comprising:

[0156] S1, collecting M circles of projection data for a target object, and after the collection of the M circles of projection data is completed, moving the imaging device out of the range of the target object to collect one circle of air projection data.

[0157] There is overlap between the M circles of projection data, that is, the scanning mode used for the target object is overlapping scanning. The moving distance of the imaging device of the mobile CT is the same between collecting two circles of projection data, that is, the overlapping area of ​​two adjacent circles of projection data is the same.

[0158] In practical applications, the real-time correction control on mode and off mode can be set on the mobile CT. When the mobile CT is in the real-time correction control on mode, air correction is performed in the manner provided in the embodiment of the present application after M-circle projection data are collected. When the mobile CT is in the real-time correction control off mode, air correction is performed based on the air correction file pre-stored in the mobile CT after M-circle projection data are collected.

[0159] S2, reconstructing the CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images.

[0160] S3, performing CT image reconstruction on one circle of air projection data to obtain a plurality of initial air reconstruction images.

[0161] S4, based on the moving distance of the imaging device between collecting two circles of projection data, copying multiple initial air reconstruction images corresponding to one circle of air projection data, so that the distance between the initial air reconstruction image and the image after the initial air reconstruction image is copied is equal to the moving distance.

[0162] S5 , for the initial air reconstruction images in the overlapping reconstruction area corresponding to the two circles of projection data, interpolation processing is performed on each initial air reconstruction image according to the imaging position to obtain a target air reconstruction image corresponding to the imaging position of each initial reconstructed image.

[0163] The reason for interpolation is to enable the air reconstructed image to refer to the information of two circles of air projection data at the same time, so that the reconstruction quality of the air reconstructed image is as close as possible to the effect of CT reconstruction using two circles of overlapping projection data.

[0164] S6, copying the initial air reconstructed image to the non-overlapping reconstruction area of ​​the M-circle projection data, and copying the target air reconstructed image to the overlapping reconstruction area of ​​the M-circle projection data, to obtain an air reconstructed image corresponding one-to-one to the initial reconstructed image.

[0165] S7, respectively using each air reconstructed image to perform correction processing on each initial reconstructed image to obtain a target reconstructed image.

[0166] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0167] Based on the same inventive concept, the embodiment of the present application also provides a CT image correction device for implementing the CT image correction method involved above. The implementation solution provided by the device to solve the problem is similar to the implementation solution recorded in the above method, so the specific limitations in one or more CT image correction device embodiments provided below can refer to the limitations of the CT image correction method above, and will not be repeated here.

[0168] In one embodiment, Fig.12 As shown, a CT image correction device 1200 is provided, comprising: an acquisition module 1202, a first reconstruction module 1204, a second reconstruction module 1206, and a correction module 1208, wherein:

[0169] The acquisition module 1202 is used to acquire M circles of projection data for the target object and N circles of air projection data, where M and N are both positive integers, and M is greater than N;

[0170] A first reconstruction module 1204 is used to reconstruct a CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images;

[0171] A second reconstruction module 1206 is used to determine a projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and to perform CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images;

[0172] The correction module 1208 is used to respectively use the air reconstructed images to perform correction processing on the initial reconstructed images to obtain a target reconstructed image.

[0173] The CT image correction device provided in the embodiment of the present application, when performing a CT scan on a target object, collects M circles of projection data and N circles of air projection data less than M at the same time, and reconstructs a CT image of the range covered by the M circles of projection data based on the N circles of air projection data, obtains an air reconstructed image corresponding to each initial reconstructed image within the projection data coverage range, and uses the air reconstructed image to perform correction processing on the initial reconstructed image. The embodiment of the present application can collect air projection data for air correction while performing a CT scan on the target object, and the number of circles of air projection data collected is less than the number of circles of projection data, which can improve the collection efficiency of air projection data, and thus improve the efficiency of air correction.

[0174] In one embodiment, the second reconstruction module 1206 is further configured to:

[0175] Reconstructing CT images for each circle of the air projection data to obtain a plurality of initial air reconstruction images corresponding to each circle of the air projection data;

[0176] Based on the initial air reconstruction images, air reconstruction images corresponding to the initial reconstruction images are generated.

[0177] In one embodiment, the second reconstruction module 1206 is further configured to:

[0178] Respectively determining the imaging position corresponding to each of the initial reconstructed images, and determining the imaging position corresponding to each of the initial air reconstructed images;

[0179] Based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, respectively determining at least one initial air reconstructed image corresponding to each of the initial reconstructed images;

[0180] For any of the initial reconstructed images, an air reconstructed image corresponding to the initial reconstructed image is determined according to each of the initial air reconstructed images corresponding to the initial reconstructed image.

[0181] In one embodiment, the second reconstruction module 1206 is further configured to:

[0182] For any of the initial reconstructed images, an initial air reconstructed image whose distance between the imaging position and the imaging position of the initial reconstructed image is less than a preset distance threshold is used as the initial air reconstructed image corresponding to the initial reconstructed image.

[0183] In one embodiment, the second reconstruction module 1206 is further configured to:

[0184] In the case where the initial reconstructed image corresponds to one initial air reconstructed image, using the initial air reconstructed image as the air reconstructed image corresponding to the initial reconstructed image; or,

[0185] In the case that the initial reconstructed image corresponds to more than one initial air reconstructed image, the air reconstructed image corresponding to the imaging position of the initial reconstructed image is interpolated according to the imaging position of each initial air reconstructed image.

[0186] In one embodiment, the second reconstruction module 1206 is further configured to:

[0187] According to the acquisition positions of the M circles of projection data, the initial air reconstruction images corresponding to the N circles of air projection data are copied to obtain air reconstruction images corresponding to the initial reconstruction images one by one.

[0188] In one embodiment, when the M circles of projection data overlap each other, the second reconstruction module 1206 is further configured to:

[0189] Determine an overlapping reconstruction range and a non-overlapping reconstruction range in a coverage range of the projection data according to acquisition positions of two adjacent circles of the projection data in the M circles of projection data;

[0190] Determine 2 circles of target air projection data according to the N circles of air projection data, wherein the 2 circles of target air projection data have overlapping areas;

[0191] Interpolating the initial air reconstruction images of the overlapping area corresponding to the two circles of target air projection data to obtain the target air reconstruction image corresponding to the overlapping area;

[0192] The target air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain air reconstructed images corresponding one to one to each of the initial reconstructed images.

[0193] In one embodiment, the second reconstruction module 1206 is further configured to:

[0194] Filling the projection data coverage range based on the N circles of air projection data to obtain target air projection data;

[0195] Perform CT image reconstruction on the target air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images.

[0196] In one embodiment, the second reconstruction module 1206 is further configured to:

[0197] Determine at least one circle of filled air projection data from the N circles of air projection data;

[0198] The filled air projection data is copied to the acquisition position of the M-circle projection data to obtain the target air projection data.

[0199] Each module in the above device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module above.

[0200] In one embodiment, a mobile CT device is provided. The mobile CT device may be a server, and its internal structure diagram may be as follows: Fig.13 As shown. The mobile CT device includes a processor, a memory and a network interface connected through a system bus. The processor of the mobile CT device is used to provide computing and control capabilities. The memory of the mobile CT device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the mobile CT device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a CT image correction method is implemented.

[0201] Those skilled in the art will understand that Fig.13 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0202] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0203] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0204] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0205] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0206] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0207] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0208] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A CT image correction method, characterized in that: The method comprises: Collect M circles of projection data for the target object and N circles of air projection data, where M and N are both positive integers, and M is greater than N; Reconstructing a CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images; Determine the projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and perform CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images; Each of the air reconstructed images is used to perform correction processing on each of the initial reconstructed images to obtain a target reconstructed image.

2. The method according to claim 1, characterized in that The performing CT image reconstruction on the projection data coverage range based on the N-circle air projection data to obtain air reconstructed images corresponding to each of the initial reconstructed images comprises: Reconstructing CT images for each circle of the air projection data to obtain a plurality of initial air reconstruction images corresponding to each circle of the air projection data; Based on the initial air reconstruction images, air reconstruction images corresponding to the initial reconstruction images are generated.

3. The method according to claim 2, characterized in that The step of generating, based on each of the initial air reconstruction images, air reconstruction images corresponding to each of the initial reconstructed images in a one-to-one manner comprises: Respectively determining the imaging position corresponding to each of the initial reconstructed images, and determining the imaging position corresponding to each of the initial air reconstructed images; Based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, respectively determining at least one initial air reconstructed image corresponding to each of the initial reconstructed images; For any of the initial reconstructed images, an air reconstructed image corresponding to the initial reconstructed image is determined according to each of the initial air reconstructed images corresponding to the initial reconstructed image.

4. The method according to claim 3, characterized in that The determining, based on the imaging positions corresponding to the initial reconstructed images and the imaging positions corresponding to the initial air reconstructed images, at least one initial air reconstructed image corresponding to each of the initial reconstructed images comprises: For any of the initial reconstructed images, an initial air reconstructed image whose distance between the imaging position and the imaging position of the initial reconstructed image is less than a preset distance threshold is used as the initial air reconstructed image corresponding to the initial reconstructed image.

5. The method according to claim 4, characterized in that The step of determining, for any of the initial reconstructed images, the air reconstructed image corresponding to the initial reconstructed image according to each of the initial air reconstructed images corresponding to the initial reconstructed image, comprises: In the case where the initial reconstructed image corresponds to one initial air reconstructed image, using the initial air reconstructed image as the air reconstructed image corresponding to the initial reconstructed image; or, In the case that the initial reconstructed image corresponds to more than one initial air reconstructed image, the air reconstructed image corresponding to the imaging position of the initial reconstructed image is interpolated according to the imaging position of each initial air reconstructed image.

6. The method according to claim 2, characterized in that The step of generating, based on each of the initial air reconstruction images, air reconstruction images corresponding to each of the initial reconstructed images in a one-to-one manner comprises: According to the acquisition positions of the M circles of projection data, the initial air reconstruction images corresponding to the N circles of air projection data are copied to obtain air reconstruction images corresponding to the initial reconstruction images one by one.

7. The method according to claim 6, characterized in that In the case where the M circles of projection data overlap with each other, the initial air reconstruction images corresponding to the N circles of air projection data are copied according to the acquisition positions of the M circles of projection data to obtain air reconstruction images corresponding to the initial reconstruction images one by one, including: Determine an overlapping reconstruction range and a non-overlapping reconstruction range in a coverage range of the projection data according to acquisition positions of two adjacent circles of the projection data in the M circles of projection data; Determine 2 circles of target air projection data according to the N circles of air projection data, wherein the 2 circles of target air projection data have overlapping areas; Interpolating the initial air reconstruction images of the overlapping area corresponding to the two circles of target air projection data to obtain the target air reconstruction image corresponding to the overlapping area; The target air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the overlapping reconstruction range, and the initial air reconstructed image is copied to the imaging position corresponding to each of the initial reconstructed images in the non-overlapping reconstruction range, so as to obtain air reconstructed images corresponding one to one to each of the initial reconstructed images.

8. The method according to claim 1, characterized in that: The performing CT image reconstruction on the projection data coverage range based on the N-circle air projection data to obtain air reconstructed images corresponding to each of the initial reconstructed images comprises: Filling the projection data coverage range based on the N circles of air projection data to obtain target air projection data; Perform CT image reconstruction on the target air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images.

9. The method according to claim 8, characterized in that The filling process of the projection data coverage range based on the N-circle air projection data to obtain target air projection data includes: Determine at least one circle of filled air projection data from the N circles of air projection data; The filled air projection data is copied to the acquisition position of the M-circle projection data to obtain the target air projection data.

10. A CT image correction device, characterized in that: The device comprises: A collection module, used for collecting M circles of projection data for the target object and N circles of air projection data, wherein M and N are both positive integers, and M is greater than N; A first reconstruction module, used for reconstructing a CT image according to the M-circle projection data to obtain a plurality of initial reconstructed images; A second reconstruction module is used to determine the projection data coverage range based on the acquisition positions corresponding to the M circles of projection data, and to perform CT image reconstruction on the projection data coverage range based on the N circles of air projection data to obtain air reconstructed images corresponding one-to-one to each of the initial reconstructed images; The correction module is used to respectively use the air reconstructed images to perform correction processing on the initial reconstructed images to obtain a target reconstructed image.

11. A mobile CT device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

Images