Image reconstruction method, apparatus and device
By obtaining the total eccentricity of the CT scan object and adjusting the sampling angle using a preset curve, the problem of insufficient projection data caused by eccentricity in CT images is solved, and high-quality image reconstruction is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NEUSOFT MEDICAL SYST CO LTD
- Filing Date
- 2021-09-13
- Publication Date
- 2026-05-29
AI Technical Summary
In existing CT reconstruction algorithms, when the scanned part of the human body is off-center from the center of the scanning field of view, insufficient projection data is generated, resulting in artifacts and reduced image resolution.
By obtaining the total eccentricity of the object to be detected, the current sampling angle is adjusted using the correction parameters in the preset curve to ensure that enough projection data is scanned for image reconstruction.
The sampling angle is adaptively adjusted to avoid resource waste, maintain image resolution, reduce artifacts, and improve image quality.
Smart Images
Figure CN113971705B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of medical imaging technology, and in particular to an image reconstruction method, apparatus and device. Background Technology
[0002] Computed tomography (CT) is widely used in medical, industrial, and other fields. It acquires projection data from different sampling views through scanning, and uses computer technology and CT reconstruction algorithms to obtain tomographic images of the object being inspected. Traditional CT reconstruction algorithms require a sufficient number of sampling views of projection data to generate good images. Insufficient projection data from sampling views often leads to a decrease in reconstructed image quality, and even severe streaking artifacts.
[0003] Ideally, the scanned area of the human body is located at the center of the scanning field of view, and all sampling angles pass through the center, allowing for sufficient projection data from multiple angles to be acquired during CT image reconstruction. However, in practice, it is difficult to avoid situations where the scanned area of the human body deviates from the center of the scanning field of view. This deviation from the center of the scanning field of view leads to insufficient projection data for the reconstruction algorithm, resulting in artifacts and reducing the resolution of the CT image. Summary of the Invention
[0004] In view of this, this application provides an image reconstruction method, apparatus and device, the main purpose of which is to solve the problem in the prior art that when the scanned part of the human body is deviated from the center of the scanning field of view, the projection data used for reconstruction algorithm is insufficient, thereby producing artifacts and reducing the resolution of CT images.
[0005] According to a first aspect of this application, an image reconstruction method is provided, the method comprising:
[0006] Obtain the total eccentricity of the object to be detected;
[0007] Based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve, the current sampling angle of the object to be detected is determined. The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities.
[0008] The object to be detected is scanned according to the current sampling perspective, and the tomographic image of the object to be detected is reconstructed using the scanned projection data.
[0009] Furthermore, obtaining the total eccentricity of the object to be detected specifically includes:
[0010] Obtain the degree of placement eccentricity of the object to be tested;
[0011] Obtain the image eccentricity of the object to be detected;
[0012] The total eccentricity of the object under test is calculated based on the placement eccentricity and the imaging eccentricity of the object under test.
[0013] Furthermore, obtaining the placement eccentricity of the object to be detected specifically includes:
[0014] Scan the flat section information of the object to be inspected to obtain the various parts of the object to be inspected;
[0015] Determine the centroid of the object to be tested based on the various parts of the object;
[0016] The positional difference between the centroid of the object to be tested and the preset rotation center is calculated to obtain the degree of placement eccentricity of the object to be tested.
[0017] Furthermore, determining the centroid of the object to be detected based on its various parts specifically includes:
[0018] Different major and minor axis ratios are set for different parts, and each part of the object to be tested is equivalent to a water model of a preset shape with the same attenuation.
[0019] The centroid of the object to be tested is determined by constructing an equivalent water model of a preset shape with the same attenuation.
[0020] Furthermore, the acquisition of the imaging eccentricity of the object to be detected specifically includes:
[0021] Based on the imaging location selected by the user, obtain the imaging center of the object to be detected;
[0022] The positional difference between the imaging center of the object to be detected and the preset rotation center is calculated to obtain the imaging eccentricity of the object to be detected.
[0023] Further, determining the current sampling angle of the object to be detected based on the correction parameter corresponding to the total eccentricity of the object in the preset curve specifically includes:
[0024] Determine whether the total eccentricity of the object to be detected exceeds a preset threshold;
[0025] If so, the initial sampling angle of the object to be detected is adjusted according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve to obtain the current sampling angle of the object to be detected;
[0026] Otherwise, the initial sampling viewpoint is selected as the current sampling viewpoint of the object to be detected.
[0027] Further, the step of adjusting the initial sampling angle of the object to be detected according to the correction parameter corresponding to the total eccentricity of the object in the preset curve to obtain the current sampling angle of the object to be detected specifically includes:
[0028] Based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve, query the target correction parameters required for the initial sampling viewpoint;
[0029] The initial sampling angle is adjusted using the target correction parameter as an adjustment factor to obtain the current sampling angle of the object to be detected.
[0030] According to a second aspect of this application, an image reconstruction apparatus is provided, the apparatus comprising:
[0031] The acquisition unit is used to acquire the total eccentricity of the object to be detected.
[0032] The determining unit is used to determine the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve. The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities.
[0033] The reconstruction unit is used to scan the object to be detected according to the current sampling perspective and reconstruct the tomographic image of the object to be detected using the scanned projection data.
[0034] Furthermore, the acquisition unit includes:
[0035] The first acquisition module is used to acquire the degree of placement eccentricity of the object to be detected.
[0036] The second acquisition module is used to acquire the imaging eccentricity of the object to be detected.
[0037] The calculation module is used to calculate the total eccentricity of the object to be detected based on the placement eccentricity and the imaging eccentricity of the object to be detected.
[0038] Furthermore, the first acquisition module includes:
[0039] The scanning submodule is used to scan the flat surface information of the object to be inspected, and obtain the various parts of the object to be inspected.
[0040] The determination submodule is used to determine the centroid of the object to be detected based on the various parts of the object to be detected;
[0041] The first calculation submodule is used to calculate the positional difference between the centroid of the object to be detected and the preset rotation center, so as to obtain the degree of placement eccentricity of the object to be detected.
[0042] Furthermore, the determining submodule is specifically used to set different major and minor axis ratios for each part, and to convert each part of the object to be detected into a preset shape water model with the same attenuation.
[0043] The determining submodule is further used to determine the centroid of the object to be detected based on a preset shape water model with the same attenuation.
[0044] Furthermore, the second acquisition module includes:
[0045] The acquisition submodule is used to obtain the imaging center of the object to be detected based on the imaging location selected by the user.
[0046] The second calculation submodule is used to calculate the positional difference between the imaging center of the object to be detected and the preset rotation center, so as to obtain the imaging eccentricity of the object to be detected.
[0047] Furthermore, the determining unit includes:
[0048] The judgment module is used to determine whether the total eccentricity of the object to be detected exceeds a preset threshold.
[0049] The adjustment module is used to adjust the initial sampling angle of the object to be detected according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve if the condition is met, so as to obtain the current sampling angle of the object to be detected.
[0050] The selection module is used otherwise to select the initial sampling viewpoint as the current sampling viewpoint of the object to be detected.
[0051] Furthermore, the adjustment module includes:
[0052] The query submodule is used to query the target correction parameters required for the initial sampling angle based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve.
[0053] The adjustment submodule is used to adjust the initial sampling perspective using the target correction parameter as the adjustment factor to obtain the current sampling perspective of the object to be detected.
[0054] According to a third aspect of this application, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described image reconstruction method.
[0055] According to a fourth aspect of this application, an image reconstruction apparatus is provided, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the program to implement the image reconstruction method described above.
[0056] By employing the above technical solutions, the image reconstruction method, apparatus, and device provided in this application, compared with the existing methods that use a sufficient number of sampling angle projection data for image reconstruction, obtains the total eccentricity of the object to be detected, determines the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in a preset curve, and records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities, further scans the object to be detected according to the current sampling angle, and reconstructs the tomographic image of the object to be detected using the scanned projection data. This allows for adaptive adjustment of the sampling angle according to the total eccentricity of the object to be detected, without wasting sampling resources, ensuring that sufficient projection data is collected for image reconstruction, thereby achieving the purpose of maintaining image resolution, reducing artifacts, and improving image quality.
[0057] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0058] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0059] Figure 1 A schematic flowchart of an image reconstruction method provided in an embodiment of this application is shown;
[0060] Figure 2 A flowchart illustrating another image reconstruction method provided in an embodiment of this application is shown;
[0061] Figure 3 A schematic diagram of the process for determining the centroid of an object to be detected, provided in an embodiment of this application, is shown.
[0062] Figure 4 This paper shows a schematic diagram of the structure of an image reconstruction apparatus provided in an embodiment of this application;
[0063] Figure 5 A schematic diagram of another image reconstruction apparatus provided in an embodiment of this application is shown. Detailed Implementation
[0064] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.
[0065] In related technologies, projection data from different sampling views is acquired through scanning. Computer technology and CT reconstruction algorithms can then be used to obtain tomographic images of the object being inspected. Ideally, the scanned area of the human body is located at the center of the scanning field of view, and all sampling views pass through the center, allowing for the acquisition of sufficient projection data from multiple views during CT image reconstruction. However, in practice, it is difficult to avoid situations where the scanned area of the human body deviates from the center of the scanning field of view. This deviation leads to insufficient projection data for the reconstruction algorithm, resulting in artifacts and reduced resolution of the CT image.
[0066] To address this problem, this embodiment provides an image reconstruction method, such as... Figure 1 As shown, this method can be applied to the server side of a medical platform and includes the following steps:
[0067] 101. Obtain the total eccentricity of the object to be detected.
[0068] The object to be detected is the object scanned in computed tomography (CT) imaging. In different fields, the object to be detected can be different objects; in the medical field, it can be a part of the human body, while in the engineering field, it can be luggage or other items. Here, by scanning a specific part of the object to be detected with X-rays of a certain thickness, projection data of the object can be obtained. From this projection data, a tomographic image of the object can be reconstructed.
[0069] It is understandable that the grayscale distribution in a tomographic image corresponds to the attenuation coefficient distribution of X-rays at that energy level within the object being examined. After passing through the object, the energy of the X-rays is significantly attenuated. The degree of attenuation within the object depends on both the internal material and the path taken by the X-rays. This means that the X-ray photons emitted after passing through the object not only carry attenuation information from within the object but also indirectly carry some spatial positioning information. By detecting the number of attenuated X-ray photons, the projection data of the object at a certain sampling angle can be initially obtained. To ensure the quality of the tomographic image of the object, sufficient projection data from multiple sampling angles needs to be obtained during X-ray scanning. Only then can a high-resolution tomographic image be reconstructed for the object.
[0070] In practical applications, too few sampling angles will cause a decrease in the quality of the tomographic image and the appearance of artifacts, while too many sampling angles will cause a heavy computational burden during the image reconstruction process. It is necessary to determine an appropriate sampling angle to ensure the quality of the tomographic image.
[0071] Specifically, based on the planar image information of the object to be inspected, the degree of eccentricity of the object in different positional states can be obtained. The total eccentricity of the object is calculated by summing the eccentricity of the object in different positional states. These different positional states can include the placement position and imaging position of the object, and more positional states can be set; this is not limited here. In the specific calculation of the total eccentricity of the object, the Euclidean distance between the eccentricity of the object in different positional states can be used, or the product of the eccentricity of the object in different positional states can be used to calculate the total eccentricity; this is not limited here. For example, if the eccentricity of the object in the first positional state is A1, the eccentricity in the second positional state is A2, and the eccentricity in the third positional state is A3, then the total eccentricity of the object is A = A1 * A2 * A3.
[0072] The execution subject of this invention can be an image reconstruction device, specifically configured on the server side of a medical platform. By obtaining the total eccentricity of the object to be detected, the eccentricity of the object to be detected can be used as a basis for determining whether the object to be detected is in a suitable sampling angle. This can avoid scanning too much projection data or useless projection data to a certain extent, so as to ensure that the projection data scanned at the current sampling angle is more conducive to the process of reconstructing the tomographic image.
[0073] 102. Determine the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object in the preset curve.
[0074] The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. The initial sampling angle is the sampling angle used by the device to initially scan the object to be detected. This sampling angle can be adjusted by rotating the device. Scanning different sampling angles can scan the projection data of the object to be detected at different angular positions. The preset curve can be a curve determined by linear transformation, a curve determined by Gaussian transformation, or a custom-set curve, etc., without limitation. The X-axis corresponding to the preset curve can represent the total eccentricity of the object to be detected, and the Y-axis can represent the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. For example, when the total eccentricity of the object to be detected is 10, the correction parameter required for the initial sampling angle is approximately 1.0.
[0075] It is understandable that, due to the continuity of the preset curve, the correction parameter may not be a regular value in the preset curve. In this case, the current sampling angle determined by using the correction parameter to the initial sampling angle will also be affected. Here, a correction parameter that retains an integer value can be selected to determine the current sampling angle to ensure the flexibility of the current sampling angle.
[0076] In determining the current sampling angle of the object to be detected, the current sampling angle can be obtained by calculating the calibration parameter and the initial sampling angle. The calculation method can be determined according to the magnitude set by the calibration parameter in the preset curve. For example, if the preset curve is a proportional curve, it means that the magnitude set by the calibration parameter is the multiple of the sampling angle, and the calculation method is further determined to be multiplication. The current sampling angle of the object to be detected can be obtained by multiplying the calibration parameter by the initial sampling angle. If the preset curve is a quantitative curve, it means that the magnitude set by the calibration parameter is the superposition of the sampling angles, and the calculation method is further determined to be addition. The current sampling angle of the object to be detected can be obtained by adding the calibration parameter to the initial sampling angle. Here, the magnitude set by the calibration parameter in the preset curve is not limited.
[0077] 103. Scan the object to be detected according to the current sampling perspective, and reconstruct the tomographic image of the object to be detected using the scanned projection data.
[0078] It is understandable that the current sampling angle is an adjusted sampling angle, specifically determined by the total deviation of the object to be detected. On the one hand, it can obtain a sufficient amount of projection data for image reconstruction, and on the other hand, it will not collect too much projection data, thus avoiding the computational burden of the image reconstruction process. The sampling angle can be adaptively adjusted according to the total eccentricity of the object to be detected during scanning, thereby reducing artifacts and improving the quality of the reconstructed tomographic image.
[0079] The image reconstruction method provided in this application, compared with the existing method of using a sufficient number of sampling angle projection data for image reconstruction, obtains the total eccentricity of the object to be detected, determines the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in a preset curve, and records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. The object to be detected is further scanned according to the current sampling angle, and the tomographic image of the object to be detected is reconstructed using the scanned projection data. This method can adaptively adjust the sampling angle according to the total eccentricity of the object to be detected, without wasting sampling resources, and ensures that enough projection data is collected for image reconstruction, thereby achieving the purpose of maintaining image resolution, reducing artifacts, and improving image quality.
[0080] Furthermore, as a refinement and extension of the specific implementation methods of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, this embodiment provides another image reconstruction method, such as... Figure 2 As shown, the method includes:
[0081] 201. Obtain the degree of placement eccentricity of the object to be tested.
[0082] The degree of placement eccentricity of the object under test can characterize its placement within the target area. This can be determined by setting the center point of the target area and judging the positional difference between the center point of the object under test and the center point of the target area. Here, the center point of the target area is the rotation center of the CT scanner, i.e., the center of the gantry. The center point of the object under test can be the centroid of the object or the coordinates of the object's center point. As one implementation method, this can be achieved by scanning the planar radiographs of the object under test to obtain various parts of the object. These planar radiographs are image images obtained using the equipment. Each part of the object under test corresponds to a scanned location. For example, when the object is a human body, the various parts are the head, shoulders, torso, hips, and lower limbs. When the human body is on the scanning bed, the received X-rays can determine the positions of these parts. Furthermore, based on these parts, the centroid of the object is determined, and the positional difference between the centroid and the preset rotation center is calculated to obtain the degree of placement eccentricity. This positional difference represents the relative distance between the two points.
[0083] It is understandable that the various parts of the object to be inspected are usually irregularly shaped. In the process of determining the centroid of the object based on its various parts, each part can be equivalent to a regular shape, such as an ellipse or rectangle. The centroid of the object can then be determined based on these equivalent regular shapes. Specifically, different major and minor axis ratios can be set for each part, making each part of the object equivalent to a preset shape water model with the same attenuation. The centroid of the object can then be determined based on this equivalent preset shape water model with the same attenuation.
[0084] As one implementation method, the process of determining the centroid of the object to be detected described above can be as follows: Figure 3 As shown, each part of the object to be detected includes ad, and the scanning range is ad. The attenuation area of the scanned object can be calculated and equivalently represented as an elliptical water model with the same attenuation. The centroid of the ellipse is then calculated. It is understandable that, considering that different parts have different shape proportions, different major and minor axis ratios can be set for different parts for equivalence.
[0085] 202. Obtain the image eccentricity of the object to be detected.
[0086] The imaging eccentricity of the object to be detected can characterize the imaging status of the object within the target area. This can be achieved by setting a center point for the target area, allowing the user to select an imaging center, and determining the positional difference between the imaging center of the object and the center point of the target area to determine the imaging eccentricity. The imaging center of the object is equivalent to the center point set in the reconstructed image, which is typically located within the target area. As one implementation method, the imaging center of the object to be detected can be obtained based on the imaging position selected by the user, and the positional difference between the imaging center of the object and a preset rotation center can be calculated to obtain the imaging eccentricity of the object. This positional difference represents the relative distance between the two points.
[0087] 203. Calculate the total eccentricity of the object to be tested based on the placement eccentricity and the imaging eccentricity of the object to be tested.
[0088] Taking into account both the placement eccentricity and the imaging eccentricity of the object to be detected, the total eccentricity of the object can be calculated as EccenDis = Bias1 * Bias2, based on the placement eccentricity Bias1 and the imaging eccentricity Bias2. This calculation is not limited to the product method; Euclidean distance, etc., can also be used.
[0089] 204. Determine whether the total eccentricity of the object to be detected exceeds a preset threshold.
[0090] Understandably, based on actual conditions, when the total eccentricity of the object to be detected is small, the slowly increasing projection data scanned by the sampling angle can meet the resolution requirements of the reconstructed image. As the total eccentricity increases, the sampling angle needs to increase significantly to scan enough projection data to meet the resolution requirements of the reconstructed image. Here, a preset threshold can be set to assess whether the total eccentricity of the object to be detected will affect the amount of projection data, and thus determine whether the sampling angle needs to be adjusted.
[0091] 205a. If so, the initial sampling angle of the object to be detected is adjusted according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve to obtain the current sampling angle of the object to be detected.
[0092] When the total eccentricity of the object under test is large, exceeding the preset threshold, it indicates that the initial sampling angle of the device prevents many rays from passing through the central channel or from penetrating the area to be scanned. This results in insufficient effective projection data for the reconstructed scanned area, requiring more projection data to be acquired. In this case, the sampling angle can be adjusted to ensure that the device can scan more projection data. Specifically, the target correction parameter required for the initial sampling angle can be found by querying the correction parameter corresponding to the total eccentricity of the object under test in the preset curve. The initial sampling angle is then adjusted using the target correction parameter as the adjustment factor to obtain the current sampling angle of the object under test.
[0093] It is understandable that the current sampling viewpoint here is obtained by adjusting the target multiple as the initial sampling viewpoint, and can be rounded to an integer multiple of the number of focal points. For example, when using the fly-focus technique, if there are two focal points in the scan, the correction parameter should be a multiple of 2.
[0094] In practical applications, the preset curve is used for the overall scanning of the object to be detected and the evaluation of dosage, etc. The following curve can be set to control the degree of adaptability of the sampling perspective, and the formula is shown below:
[0095]
[0096] Where ViewNum is the current sampling view, N base As the initial sampling perspective, ScaleFactor r The specific formula for correcting the parameters is as follows:
[0097]
[0098] Where α is the upper limit control parameter, β is used to control the maximum sampling angle, is the eccentricity magnitude correction parameter, and B is the curve slope control parameter.
[0099] The corresponding step to step 205a is step 205b; otherwise, the initial sampling viewpoint is selected as the current sampling viewpoint of the object to be detected.
[0100] When the total eccentricity of the object to be detected is small, i.e. less than the preset threshold, it means that the deviation is not significant. The amount of data scanned by the device using the initial sampling perspective is sufficient to support the image reconstruction process, so the deviation can be ignored and there is no need to adjust the initial sampling perspective.
[0101] It is understandable that in the process of comparing the total eccentricity of the object to be detected with the preset threshold, if the total eccentricity is greater than the preset threshold, the initial sampling angle needs to be adjusted using the preset curve. If the total eccentricity is less than the preset threshold, the initial sampling angle can be used for scanning, or the initial sampling angle can be reduced appropriately to optimize the speed.
[0102] 206. Scan the object to be detected according to the current sampling perspective, and reconstruct the tomographic image of the object to be detected using the scanned projection data.
[0103] The image reconstruction method provided by this invention can automatically identify the total eccentricity of the object to be detected and adaptively calculate the current sampling angle based on the total eccentricity, so as to ensure that the reconstructed image can obtain sufficient effective projection data, thereby reducing artifacts and optimizing image quality.
[0104] Furthermore, as Figures 1-2 To specifically implement the method, this application provides an image reconstruction apparatus, such as... Figure 4 As shown, the device includes: an acquisition unit 31, a determination unit 32, and a reconstruction unit 33.
[0105] The acquisition unit 31 can be used to acquire the total eccentricity of the object to be detected.
[0106] The determining unit 32 can be used to determine the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve. The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities.
[0107] The reconstruction unit 33 can be used to scan the object to be detected according to the current sampling perspective and reconstruct the tomographic image of the object to be detected using the scanned projection data.
[0108] The image reconstruction apparatus provided in this invention, compared with the existing method of using a sufficient number of sampling angle projection data for image reconstruction, obtains the total eccentricity of the object to be detected, determines the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in a preset curve, and records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. Furthermore, the object to be detected is scanned according to the current sampling angle, and the tomographic image of the object to be detected is reconstructed using the scanned projection data. It can adaptively adjust the sampling angle according to the total eccentricity of the object to be detected, without wasting sampling resources, and ensures that enough projection data is collected for image reconstruction, thereby achieving the purpose of maintaining image resolution, reducing artifacts, and improving image quality.
[0109] In specific application scenarios, such as Figure 5 As shown, the acquisition unit 31 includes:
[0110] The first acquisition module 311 can be used to acquire the degree of placement eccentricity of the object to be detected.
[0111] The second acquisition module 312 can be used to acquire the imaging eccentricity of the object to be detected.
[0112] The calculation module 313 can be used to calculate the total eccentricity of the object to be detected based on the placement eccentricity and the imaging eccentricity of the object to be detected.
[0113] In specific application scenarios, such as Figure 5 As shown, the first acquisition module 311 includes:
[0114] The scanning submodule 3111 can be used to scan the flat surface information of the object to be inspected, and obtain various parts of the object to be inspected.
[0115] The determination submodule 3112 can be used to determine the centroid of the object to be detected based on the various parts of the object to be detected;
[0116] The first calculation submodule 3113 can be used to calculate the positional difference between the centroid of the object to be detected and the preset rotation center to obtain the degree of placement eccentricity of the object to be detected.
[0117] In specific application scenarios, the determining submodule 3112 can be used to set different major and minor axis ratios for each part, and to make each part of the object to be detected equivalent to a preset shape water model with the same attenuation.
[0118] The determining submodule 3112 can also be used to determine the centroid of the object to be detected based on a preset shape water model with the same attenuation.
[0119] In specific application scenarios, such as Figure 5 As shown, the second acquisition module 312 includes:
[0120] The acquisition submodule 3121 can be used to obtain the imaging center of the object to be detected based on the imaging position selected by the user.
[0121] The second calculation submodule 3122 can be used to calculate the positional difference between the imaging center of the object to be detected and the preset rotation center to obtain the imaging eccentricity of the object to be detected.
[0122] In specific application scenarios, such as Figure 5 As shown, the determining unit 32 includes:
[0123] The judgment module 321 can be used to determine whether the total eccentricity of the object to be detected exceeds a preset threshold.
[0124] The adjustment module 322 can be used to adjust the initial sampling angle of the object to be detected according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve if the condition is met, so as to obtain the current sampling angle of the object to be detected.
[0125] Module 323 can be used otherwise to select the initial sampling viewpoint as the current sampling viewpoint of the object to be detected.
[0126] In specific application scenarios, such as Figure 5 As shown, the adjustment module 322 includes:
[0127] The query submodule 3221 can be used to query the target correction parameters required for the initial sampling angle based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve.
[0128] The adjustment submodule 3222 can be used to adjust the initial sampling angle using the target correction parameter as the adjustment factor to obtain the current sampling angle of the object to be detected.
[0129] It should be noted that other corresponding descriptions of the functional units involved in the image reconstruction device applicable to the server side provided in this embodiment can be found in [reference]. Figure 1 and Figure 2 The corresponding descriptions in [the document] will not be repeated here.
[0130] Based on the above, Figures 1-2 Accordingly, this application embodiment also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method. Figures 1-2 The image reconstruction method shown;
[0131] Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This software product can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, or portable hard drive), and includes several instructions to cause a computer device (such as a personal computer, server, or network device) to execute the methods described in the various implementation scenarios of this application.
[0132] Based on the above, Figures 1-2 The method shown, and Figures 4-5To achieve the above objectives, the present application also provides a server-side physical device, specifically a computer, server, or other network device, as shown in the virtual device embodiment. This physical device includes a storage medium and a processor; the storage medium stores a computer program; the processor executes the computer program to implement the above-described... Figures 1-2 The image reconstruction method shown.
[0133] Optionally, the aforementioned physical devices may also include a user interface, a network interface, a camera, radio frequency (RF) circuitry, sensors, audio circuitry, a Wi-Fi module, etc. The user interface may include a display screen, input units such as a keyboard, etc., and optional user interfaces may also include USB interfaces, card reader interfaces, etc. The network interface may optionally include standard wired interfaces, wireless interfaces (such as Wi-Fi interfaces), etc.
[0134] Those skilled in the art will understand that the physical device structure for image reconstruction provided in this embodiment does not constitute a limitation on the physical device, and may include more or fewer components, or combine certain components, or have different component arrangements.
[0135] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the image reconstruction device, supporting the operation of information processing programs and other software and / or programs. The network communication module is used to enable communication between the various components within the storage medium, as well as communication with other hardware and software in the information processing device.
[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms, or it can be implemented by hardware. By applying the technical solution of this application, compared with the existing methods, this application can adaptively adjust the sampling angle according to the total eccentricity of the object to be detected, without wasting sampling resources, ensuring that enough projection data is collected for image reconstruction, thereby achieving the purpose of maintaining image resolution, reducing artifacts, and improving image quality.
[0137] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the modules in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be modified to be located in one or more apparatuses different from this embodiment. The modules of the above-described embodiment can be combined into one module, or further divided into multiple sub-modules.
[0138] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.
Claims
1. An image reconstruction method, characterized in that, Applied to a server equipped with computational tomography imaging equipment, the method includes: Obtain the total eccentricity of the object to be detected in different positional states, where different positional states include placement eccentricity and imaging eccentricity; Based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve, the current sampling angle of the object to be detected is determined. The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. The correction parameters are used to adjust the number of initial sampling angles. The object to be detected is scanned according to the current sampling perspective, and the tomographic image of the object to be detected is reconstructed using the scanned projection data. Based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve, the current sampling angle of the object to be detected is determined, specifically including: Determine whether the total eccentricity of the object to be detected exceeds a preset threshold; If so, the initial sampling angle of the object to be detected is adjusted according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve to obtain the current sampling angle of the object to be detected, wherein the number of current sampling angles is greater than the number of initial sampling angles. Otherwise, the initial sampling viewpoint is selected as the current sampling viewpoint of the object to be detected.
2. The method according to claim 1, characterized in that, The acquisition of the total eccentricity of the object to be detected specifically includes: Obtain the degree of placement eccentricity of the object to be tested; Obtain the image eccentricity of the object to be detected; The total eccentricity of the object under test is calculated based on the placement eccentricity and the imaging eccentricity of the object under test.
3. The method according to claim 2, characterized in that, The process of obtaining the placement eccentricity of the object to be detected specifically includes: Scan the flat section information of the object to be inspected to obtain the various parts of the object to be inspected; Determine the centroid of the object to be tested based on the various parts of the object; The positional difference between the centroid of the object to be tested and the preset rotation center is calculated to obtain the degree of placement eccentricity of the object to be tested.
4. The method according to claim 3, characterized in that, The step of determining the centroid of the object to be detected based on various parts of the object specifically includes: Different major and minor axis ratios are set for different parts, and each part of the object to be tested is equivalent to a water model of a preset shape with the same attenuation. The centroid of the object to be tested is determined by constructing an equivalent water model of a preset shape with the same attenuation.
5. The method according to claim 2, characterized in that, The acquisition of the imaging eccentricity of the object to be detected specifically includes: Based on the imaging location selected by the user, obtain the imaging center of the object to be detected; The positional difference between the imaging center of the object to be detected and the preset rotation center is calculated to obtain the imaging eccentricity of the object to be detected.
6. The method according to claim 1, characterized in that, The step of adjusting the initial sampling angle of the object to be detected according to the correction parameter corresponding to the total eccentricity of the object in the preset curve to obtain the current sampling angle of the object to be detected specifically includes: Based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve, query the target correction parameters required for the initial sampling viewpoint; The initial sampling angle is adjusted using the target correction parameter as an adjustment factor to obtain the current sampling angle of the object to be detected.
7. An image reconstruction apparatus, characterized in that, The device is applied to a server equipped with computational tomography imaging equipment, and includes: The acquisition unit is used to acquire the total eccentricity of the object to be detected in different position states, wherein the different position states include placement eccentricity and imaging eccentricity. The determining unit is used to determine the current sampling angle of the object to be detected based on the correction parameters corresponding to the total eccentricity of the object to be detected in the preset curve. The preset curve records the correction parameters required for the initial sampling angle when the object to be detected is at different total eccentricities. The correction parameters are used to adjust the number of initial sampling angles. The reconstruction unit is used to scan the object to be detected according to the current sampling perspective and reconstruct the tomographic image of the object to be detected using the scanned projection data; The determining unit includes: The judgment module is used to determine whether the total eccentricity of the object to be detected exceeds a preset threshold. The adjustment module is used to adjust the initial sampling angle of the object to be detected according to the correction parameter corresponding to the total eccentricity of the object to be detected in the preset curve if the condition is met, so as to obtain the current sampling angle of the object to be detected, wherein the number of current sampling angles is greater than the number of initial sampling angles. The selection module is used otherwise to select the initial sampling viewpoint as the current sampling viewpoint of the object to be detected.
8. A storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the image reconstruction method according to any one of claims 1 to 6.
9. An image reconstruction apparatus, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, characterized in that, When the processor executes the program, it implements the image reconstruction method according to any one of claims 1 to 6.