Fast-cutting dual-energy cone-beam CT scanning method, system, equipment and medium

Abstract

The invention relates to a CT (Computed Tomography) scanning technology, and discloses a fast-switching dual-energy oral cone beam CT scanning method, which comprises the following steps of: acquiring low-energy attenuation projection data and high-energy attenuation projection data of forward short scanning and reverse short scanning of a ray emitter around a preset central point by utilizing a flat panel detector, calculating a first base material density integral and a second base material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data, and performing three-dimensional reconstruction according to the first base material density integral and the second base material density integral, and obtaining a first base material density image and a second base material density image, and synthesizing the first base material density image and the second base material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image. The invention further provides a fast-cutting dual-energy oral cavity cone beam CT scanning device, equipment and a medium. The CT imaging quality can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of CT scanning, and particularly to a fast-switching dual-energy dental cone-beam CT scanning method, system, device and medium. Background Art

[0002] Cone-beam CT (CBCT) has the advantages of high resolution and low radiation dose, and is widely used in oral and maxillofacial imaging examinations. However, the X-ray used is usually a mixed multi-color energy X-ray, and the low-energy ray part is easily absorbed to varying degrees after passing through the scanned object, resulting in low accuracy of the attenuation coefficient obtained by tomographic imaging, and usually accompanied by serious beam hardening artifacts or metal artifacts, etc., causing certain troubles to doctors' clinical examinations and diagnoses.

[0003] In view of this phenomenon, the dual-energy CT device widely used in spiral CT at present can obtain single-energy information, and thus has a better imaging effect, while the dual-energy CBCT applied to dental cone-beam CT is relatively less. Usually, the fast-switching scanning scheme of CT uses the method of instantaneously and rapidly switching the kilovolt of the X-ray tube to realize the scanning of two energy rays. The same ray source realizes the scanning of two energy X-rays. However, due to the difficulty in realizing the fast switching of tube current, the difference in high- and low-energy noise levels is relatively large, affecting the imaging quality. Therefore, the present invention provides a fast-switching dual-energy dental cone-beam CT scanning system based on short scanning, which can better adjust the scanning conditions of the X-ray tube and obtain projection data that meets the imaging requirements. Summary of the Invention

[0004] The present invention provides a fast-switching dual-energy dental cone-beam CT scanning method, system, device and medium, and its main purpose is to solve the problem of low imaging quality of the existing fast-switching scanning scheme of CT.

[0005] To achieve the above purpose, a fast-switching dual-energy dental cone-beam CT scanning method provided by the present invention includes:

[0006] Obtaining low-energy attenuation projection data of a forward short scan of a preset ray emitter around a preset center point by using a preset flat panel detector;

[0007] After switching the high-energy scanning conditions of the ray emitter, obtaining high-energy attenuation projection data of a reverse short scan of the ray emitter around the center point after the high-energy scanning condition switching by using the flat panel detector;

[0008] Calculating a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data;

[0009] Perform three-dimensional reconstruction based on the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image;

[0010] Synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0011] Optionally, the obtaining of the low-energy attenuation projection data by using a preset flat panel detector for forward short scanning of a preset ray emitter around a preset center point includes:

[0012] Control the ray emitter to emit an X-ray beam according to preset low-energy scanning conditions;

[0013] Control the ray emitter to perform a circular motion around the center from a preset scanning start point to a preset scanning end point;

[0014] During the ray emitter moving from the preset scanning start point to the preset scanning end point, control the flat panel detector to perform a circular motion around the center point synchronously with the ray emitter, and use the flat panel detector to obtain signals after the X-ray beam emitted by the ray emitter passes through the target object at a preset acquisition interval to obtain low-energy attenuation projection data.

[0015] Optionally, the switching of the high-energy scanning conditions for the ray emitter includes:

[0016] Calculate the high-energy tube current according to a preset high-energy tube voltage by using the following formula:

[0017]

[0018] where I h is the high-energy tube current, U l is the preset low-energy tube voltage, I l is the preset low-energy tube current, U h is the high-energy tube voltage, and α is a preset filtration equivalent coefficient;

[0019] Optionally, the obtaining of the high-energy attenuation projection data by using the flat panel detector for reverse short scanning of the ray emitter around the center point after switching of the high-energy scanning conditions includes:

[0020] Control the ray emitter to emit an X-ray beam according to the high-energy scanning conditions;

[0021] Control the ray emitter to perform a circular motion around the center from the scanning end point to the scanning start point;

[0022] During the movement of the ray emitter from the scanning end point to the scanning start point, control the flat panel detector to perform a circular motion synchronously with the ray emitter around the center point, and use the flat panel detector to acquire the signal after the X-ray beam emitted by the ray emitter passes through the target object at the acquisition interval, so as to obtain high-energy attenuation projection data.

[0023] Optionally, calculate a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data, including:

[0024] Use the following formula to calculate a high-energy attenuation integral and a low-energy attenuation integral according to the low-energy attenuation projection data and the high-energy attenuation projection data:

[0025]

[0026] where p h is the high-energy attenuation integral, I h is the number of detected photons under high-energy conditions included in the high-energy attenuation projection data, I h0 is the number of incident photons of the scanned object under high-energy conditions included in the high-energy attenuation projection data, p l is the low-energy attenuation integral, I l is the number of detected photons under low-energy conditions included in the low-energy attenuation projection data, I l0 is the number of incident photons of the scanned object under low-energy conditions included in the low-energy attenuation projection data

[0027] Use the following formula to construct a mapping relationship between the high-energy attenuation integral and the low-energy attenuation integral and the first basis material density integral and the second basis material density integral, and calculate and solve to obtain the first basis material density integral and the second basis material density integral:

[0028]

[0029] where p h is the high-energy attenuation integral, S h (E) is a preset high-energy spectrum distribution curve, ρ A is the density of the first basis material water, ρ B is the density of the second basis material bone, is the mass attenuation coefficient of the first basis material water at energy level E, ∫ρ A (l)dl is the density integral of the first basis material water with respect to thickness l, p l is the low-energy attenuation integral, S l (E) is a preset low-energy spectrum distribution curve, is the mass attenuation coefficient of the second basis material bone at energy level E, ∫ρB (l)dl) is the density integral of the second base material bone with respect to the thickness l.

[0030] Optionally, performing three-dimensional reconstruction based on the first base material density integral and the second base material density integral to obtain a first base material density image and a second base material density image, including:

[0031] Performing ramp filtering on the first base material density integral and the second base material density integral to obtain a first filtered density integral and a second filtered density integral;

[0032] Performing cosine weighting on the first filtered density integral and the second filtered density integral to obtain a first cosine density integral and a second cosine density integral;

[0033] Performing Parker weighting on the first cosine density integral and the second cosine density integral to obtain a first weighted density integral and a second weighted density integral;

[0034] Performing backprojection on the first weighted density integral and the second weighted density integral to obtain a first base material density image and a second base material density image.

[0035] Optionally, synthesizing the first base material density image and the second base material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image, including:

[0036] Representing the virtual monoenergetic attenuation image using the following formula:

[0037]

[0038] where μ E is the virtual monoenergetic attenuation image, is the mass attenuation coefficient of the first base material water at energy level E, is the mass attenuation coefficient of the second base material bone at energy level E, P A is the first base material density image, P B is the second base material density image.

[0039] To solve the above problems, the present invention also provides a fast-switching dual-energy dental cone beam CT scanning device, the device includes:

[0040] A forward short-scanning module, configured to obtain low-energy attenuation projection data of a preset ray emitter performing forward short-scanning around a preset center point by using a preset flat panel detector;

[0041] A reverse short scan module, configured to, after switching the high-energy scan condition for the ray emitter, use the flat panel detector to obtain high-energy attenuation projection data of the ray emitter performing a reverse short scan around the central point after the high-energy scan condition is switched;

[0042] A data calculation module, configured to calculate a high-energy attenuation integral and a low-energy attenuation integral based on the low-energy attenuation projection data and the high-energy attenuation projection data, and calculate a first basis material density integral and a second basis material density integral based on the high-energy attenuation integral and the low-energy attenuation integral;

[0043] A three-dimensional reconstruction module, configured to perform three-dimensional reconstruction based on the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image;

[0044] An image synthesis module, configured to synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0045] To solve the above problems, the present invention also provides an electronic device, which includes:

[0046] At least one processor;

[0047] And a memory communicatively connected to the at least one processor;

[0048] Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the fast-switching dual-energy dental cone beam CT scanning method described above.

[0049] To solve the above problems, the present invention also provides a computer-readable storage medium, in which at least one computer program is stored, and the at least one computer program is executed by a processor in an electronic device to implement the fast-switching dual-energy dental cone beam CT scanning method described above.

[0050] In an embodiment of the present invention, low-energy attenuation projection data obtained by a preset flat panel detector for forward short scanning of a preset ray emitter around a preset center point is utilized. After switching the ray emitter to a high-energy scanning condition, high-energy attenuation projection data obtained by the flat panel detector for reverse short scanning of the ray emitter around the center point after the high-energy scanning condition is switched is utilized. A first basis material density integral and a second basis material density integral are calculated based on the low-energy attenuation projection data and the high-energy attenuation projection data. Three-dimensional reconstruction is performed based on the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image. The first basis material density image and the second basis material density image are synthesized according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image, so as to improve the quality of the virtual monoenergetic attenuation image. Therefore, the fast-switching dual-energy dental cone beam CT scanning method, device, electronic device, and computer-readable storage medium proposed by the present invention can solve the problem of low imaging quality in the existing fast-switching scanning scheme of CT. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flowchart of a fast-switching dual-energy dental cone beam CT scanning method provided by an embodiment of the present invention;

[0052] Figure 2 It is a schematic diagram of a short scanning trajectory provided by an embodiment of the present invention;

[0053] Figure 3 It is another schematic diagram of a short scanning trajectory provided by an embodiment of the present invention;

[0054] Figure 4 It is a functional module diagram of a fast-switching dual-energy dental cone beam CT scanning device provided by an embodiment of the present invention;

[0055] Figure 5 It is a schematic diagram of the structure of an electronic device for implementing the fast-switching dual-energy dental cone beam CT scanning method provided by an embodiment of the present invention.

[0056] The realization, functional features, and advantages of the objectives of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0058] An embodiment of the present application provides a fast-switching dual-energy oral cone-beam CT scanning method. The execution subject of the fast-switching dual-energy oral cone-beam CT scanning method includes, but is not limited to, at least one of electronic devices such as a server, a terminal, etc. that can be configured to execute the method provided by the embodiment of the present application. In other words, the fast-switching dual-energy oral cone-beam CT scanning method can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to: a single server, a server cluster, a cloud server, or a cloud server cluster, etc. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, Content Delivery Network (CDN), and big data and artificial intelligence platforms.

[0059] Referring to Figure 1 As shown, it is a schematic flowchart of the fast-switching dual-energy oral cone-beam CT scanning method provided by an embodiment of the present invention. In this embodiment, the fast-switching dual-energy oral cone-beam CT scanning method includes:

[0060] S1. Use a preset flat panel detector to obtain low-energy attenuation projection data of a preset ray emitter performing a forward short scan around a preset center point.

[0061] In an embodiment of the present invention, the ray emitter is a device that can emit an X-ray beam, and the ray emitter can emit at least two different energy levels of X-ray beams.

[0062] The flat panel detector of the present invention is a device that can receive an X-ray beam, and the flat panel detector can receive at least two different energy levels of X-ray beams, and the flat panel detector is perpendicular to the X-ray beam emitted by the ray emitter.

[0063] In an embodiment of the present invention, the preset center point can be a preset specific position on the connection line between the ray emitter and the flat panel detector as the common rotation center point of the ray emitter and the flat panel detector.

[0064] In an embodiment of the present invention, the forward short scan means that the ray emitter makes a circular motion in the clockwise direction and emits an X-ray beam.

[0065] In an embodiment of the present invention, the step of obtaining low-energy attenuation projection data by using a preset flat panel detector when a preset ray emitter performs a forward short scan around a preset center point means that the ray emitter and the flat panel detector move in a circular motion around the center point, and the ray emitter is under low-energy scanning conditions at this time. After the ray emitter moves from a preset scan start point to a preset scan end point, the signals received by the flat panel detector are low-energy attenuation projection data.

[0066] Specifically, the position of the center point can be the position of the patient's oral cavity, and the low-energy attenuation projection data can be the low-energy attenuation projection data of the patient's oral cavity.

[0067] Specifically, the ray emitter moves uniformly from the preset scan start point to the preset scan end point at a preset speed.

[0068] Specifically, the scanning angle between the preset scan start point and the preset scan end point is 180 + 2θ degrees, where θ represents the maximum angle between the horizontal plane of the ray reconstruction point passing through the edge of the detector field of view and the central ray.

[0069] Further, the ray emitter needs to accelerate to the preset speed before reaching the preset scan start point.

[0070] In an embodiment of the present invention, the step of obtaining low-energy attenuation projection data by using a preset flat panel detector when a preset ray emitter performs a forward short scan around a preset center point includes:

[0071] Controlling the ray emitter to emit an X-ray beam according to preset low-energy scanning conditions;

[0072] Controlling the ray emitter to move in a circular motion around the center from the preset scan start point to the preset scan end point;

[0073] During the process of the ray emitter moving from the preset scan start point to the preset scan end point, controlling the flat panel detector to perform a circular motion around the center point synchronously with the ray emitter, and using the flat panel detector to obtain the signals of the X-ray beam emitted by the ray emitter passing through the target object at a preset acquisition interval, so as to obtain low-energy attenuation projection data.

[0074] In an embodiment of the present invention, the step of controlling the ray emitter to move in a circular motion around the center from the preset scan start point to the preset scan end point is to control the ray emitter to move in a clockwise direction.

[0075] Specifically, the low-energy scanning conditions mean no filtration, a preset tube voltage of 80 kV, and a tube current of 9 mA.

[0076] Specifically, the preset acquisition interval may be that the ray emitter collects data once every 0.6 degrees of movement.

[0077] In an embodiment of the present invention, by using a preset flat panel detector to obtain low-energy attenuation projection data of a preset ray emitter performing a forward short scan around a preset center point, the accuracy of subsequent three-dimensional reconstruction can be improved.

[0078] S2. After switching the ray emitter to the high-energy scanning condition, use the flat panel detector to obtain high-energy attenuation projection data of the ray emitter performing a reverse short scan around the center point after the high-energy scanning condition is switched.

[0079] In an embodiment of the present invention, the high-energy scanning condition means setting a tin filtration with a thickness of 0.3 mm, setting the tube voltage to 120 kV, and the tube current needs to be adaptively calculated and set.

[0080] Specifically, the tin filtration is a technique used in CT imaging. By filtering out low-energy photons, the energy spectrum of the X-ray beam becomes more concentrated, increasing the separation between the low-energy and high-energy spectra, which can improve spectral separation, reduce radiation dose, and improve image quality.

[0081] In an embodiment of the present invention, to switch the ray emitter to the high-energy scanning condition, the ray source needs to be switched to the high-energy scanning condition by a fast-switching tube.

[0082] Specifically, the fast-switching tube is an X-ray tube technology that can quickly switch between different energy levels. This technology allows the CT scanner to quickly change the energy of the X-ray during a single rotation, thereby obtaining image data at different energy levels.

[0083] In an embodiment of the present invention, the step of using the flat panel detector to obtain high-energy attenuation projection data of the ray emitter performing a reverse short scan around the center point after the high-energy scanning condition is switched means that the ray emitter and the flat panel detector perform a circular motion around the center point in the counterclockwise direction. The ray emitter is in the high-energy scanning condition at this time. When the ray emitter moves uniformly from the preset scanning end point to the preset scanning start point, the signal received by the flat panel detector is the high-energy attenuation projection data.

[0084] In an embodiment of the present invention, the step of switching the ray emitter to the high-energy scanning condition includes:

[0085] Calculate the high-energy tube current according to the preset high-energy tube voltage using the following formula:

[0086]

[0087] where I his the high-energy tube current, U l is the preset low-energy tube voltage, I l is the preset low-energy tube current, U h is the high-energy tube current, and α is the preset filtration equivalent coefficient;

[0088] Switch the high-energy scanning conditions of the ray emitter according to the tube voltage and the high-energy tube current.

[0089] Specifically, the filtration equivalent coefficient can be 0.7.

[0090] In an embodiment of the present invention, when the ray emitter enters the motion buffer stage after passing through the preset scanning end point, that is, the ray emitter needs to be decelerated. After the ray emitter decelerates to 0, the ray emitter is then accelerated counterclockwise. Before the ray emitter reaches the scanning end point, the ray emitter needs to be accelerated to the preset speed.

[0091] In an embodiment of the present invention, the method for using the flat panel detector to obtain the high-energy attenuation projection data of the ray emitter performing a reverse short scan around the center point after the high-energy scanning conditions are switched includes:

[0092] Control the ray emitter to emit an X-ray beam according to the high-energy scanning conditions;

[0093] Control the ray emitter to perform a circular motion around the center from the scanning end point to the scanning start point;

[0094] During the period when the ray emitter moves from the scanning end point to the scanning start point, control the flat panel detector to perform a circular motion around the center point synchronously with the ray emitter, and use the flat panel detector to obtain the signal after the X-ray beam emitted by the ray emitter passes through the target object according to the acquisition interval, so as to obtain the high-energy attenuation projection data.

[0095] In an embodiment of the present invention, the method for using the flat panel detector to obtain the high-energy attenuation projection data of the ray emitter performing a reverse short scan around the center point after the high-energy scanning conditions are switched can also be to control the ray emitter to perform a circular motion around the center point in the clockwise direction and move uniformly from the preset second scanning start point to the preset second scanning end point. Among them, the scanning angle between the second scanning start point and the second scanning end point is 180 + 2θ degrees, where the included angle between the second scanning start point and the scanning end point is 90 - 2θ degrees, and θ represents the maximum included angle between the ray reconstruction point passing through the edge of the detector field of view and the central ray in the horizontal plane. The ray emitter performs a high-energy scanning condition switch after passing through the scanning end point and before reaching the second scanning start point.

[0096] In the embodiment of the present invention, by using the flat panel detector to obtain the high-energy attenuation projection data of the ray emitter performing reverse short scanning around the center point after the high-energy scanning condition is switched, the accuracy of the subsequent reconstructed image can be improved.

[0097] S3. Calculate a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data.

[0098] In the embodiment of the present invention, the calculating the first basis material density integral and the second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data includes:

[0099] Calculate a high-energy attenuation integral and a low-energy attenuation integral according to the low-energy attenuation projection data and the high-energy attenuation projection data by using the following formula:

[0100]

[0101] where p h is the high-energy attenuation integral, I h is the number of detected photons under the high-energy condition included in the high-energy attenuation projection data, I h0 is the number of incident photons of the scanned object under the high-energy condition included in the high-energy attenuation projection data, p l is the low-energy attenuation integral, I l is the number of detected photons under the low-energy condition included in the low-energy attenuation projection data, I l0 is the number of incident photons of the scanned object under the low-energy condition included in the low-energy attenuation projection data

[0102] Construct a mapping relationship between the high-energy attenuation integral and the low-energy attenuation integral and the first basis material density integral and the second basis material density integral by using the following formula, and calculate and solve to obtain the first basis material density integral and the second basis material density integral:

[0103]

[0104] where p h is the high-energy attenuation integral, S h (E) is a preset high-energy spectrum distribution curve, ρ A is the density of the first basis material water, ρ B is the density of the second basis material bone, is the mass attenuation coefficient of the first basis material water at energy level E, ∫ρ A (l)dl is the density integral of the first basis material water for thickness l, p l is the low-energy attenuation integral, S l (E) is a preset low-energy spectrum distribution curve, is the mass attenuation coefficient of the second base material bone at energy level E, and ∫ρ B (l)dl) is the density integral of the second base material bone with respect to thickness l.

[0105] In the embodiments of the present invention, a look-up relationship of density integral can be established by establishing calculation formulas for the density of water, the density of bone, the above-mentioned high-energy attenuation integral, and the low-energy attenuation integral, and then the density integral of the first base material and the density integral of the second base material can be obtained according to the calculated high-energy attenuation integral, low-energy attenuation integral, and the look-up relationship.

[0106] In the embodiments of the present invention, by calculating the high-energy attenuation integral and the low-energy attenuation integral according to the low-energy attenuation projection data and the high-energy attenuation projection data, the efficiency of calculating the density integral of the first base material and the density integral of the second base material is improved. By calculating the density integral of the first base material and the density integral of the second base material according to the high-energy attenuation integral and the low-energy attenuation integral, the accuracy and efficiency of subsequent three-dimensional reconstruction are improved.

[0107] S4. Perform three-dimensional reconstruction according to the density integral of the first base material and the density integral of the second base material to obtain a density image of the first base material and a density image of the second base material.

[0108] In the embodiments of the present invention, the three-dimensional reconstruction according to the density integral of the first base material and the density integral of the second base material is to perform three-dimensional reconstruction according to the density integral of the first base material and the density integral of the second base material by using the three-dimensional FDK reconstruction method.

[0109] Specifically, the three-dimensional FDK reconstruction method reconstructs a three-dimensional image by means of filtering and weighted backprojection.

[0110] In the embodiments of the present invention, the three-dimensional reconstruction according to the density integral of the first base material and the density integral of the second base material to obtain a density image of the first base material and a density image of the second base material includes:

[0111] Perform ramp filtering on the density integral of the first base material and the density integral of the second base material to obtain a first filtered density integral and a second filtered density integral;

[0112] Perform cosine weighting on the first filtered density integral and the second filtered density integral to obtain a first cosine density integral and a second cosine density integral;

[0113] Perform Parker weighting on the first cosine density integral and the second cosine density integral to obtain a first weighted density integral and a second weighted density integral;

[0114] Back-project the first weighted density integral and the second weighted density integral to obtain a first basis material density image and a second basis material density image.

[0115] Specifically, the ramp filtering process is an important technique in the field of image reconstruction. Generally, a ramp filter is required. First, the original projection data needs to be transformed to the Fourier space through Fourier transform. The purpose of this step is to convert the information in the spatial domain to the frequency domain, making the frequency components of the data obvious and facilitating subsequent processing. In the Fourier space, the projection data is weighted and corrected using a specific filter function. Smaller weights are given to the low-frequency components, while larger weights are given to the high-frequency components, thereby reducing the image blurring caused by the low-frequency components and enhancing the edge information of the image. In addition, in the Fourier space, the edge information is associated with the high-frequency components. By enhancing these high-frequency components, the edges of the image can be made clearer, improving the contrast and recognizability of the image. After the weighted correction, the data in the Fourier space is transformed back to the spatial domain to form a reconstructed image.

[0116] Specifically, the Parker weighting is a technique used in computer tomography (CT) image reconstruction. It suppresses the artifacts generated due to chordogram truncation by applying an appropriate weighting scheme to the projection data. Its core lies in preprocessing the projection data to compensate for the data incompleteness caused by insufficient scanning angles.

[0117] Specifically, the back-projection process is to calculate the paths of the rays passing through the object at each projection angle and evenly distribute the filtered projection data back along these paths to obtain a preliminary reconstructed image.

[0118] In the embodiments of the present invention, by performing three-dimensional reconstruction based on the first basis material density integral and the second basis material density integral, a first basis material density image and a second basis material density image are obtained, improving the efficiency of subsequent synthesis of virtual monoenergetic attenuation images.

[0119] S5. Synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0120] In the embodiments of the present invention, the attenuation coefficient includes the mass attenuation coefficients of water and bone at the energy level E.

[0121] In the embodiments of the present invention, the step of synthesizing the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image includes:

[0122] The virtual monoenergetic attenuation image is represented by the following formula:

[0123]

[0124] where μ E is the virtual monoenergetic attenuation image, is the mass attenuation coefficient of water at energy level E, is the mass attenuation coefficient of bone at energy level E, P A is the first basis material density image, P B is the second basis material density image.

[0125] In the embodiments of the present invention, by synthesizing the first basis material density image and the second basis material density image according to a preset attenuation coefficient, a virtual monoenergetic attenuation image is obtained, improving the accuracy of the virtual monoenergetic attenuation image.

[0126] In the embodiments of the present invention, referring to Figure 2 shown, is a schematic diagram of a short scan trajectory provided in this embodiment, where s1 is the scan start point, s2 is the scan end point, and θ represents the maximum angle in the horizontal plane between the ray reconstruction point passing through the edge of the detector field of view and the central ray.

[0127] In the embodiments of the present invention, referring to Figure 3 shown, is another schematic diagram of a short scan trajectory provided in this embodiment, where s1 is the scan start point, s2 is the scan end point, s3 is the second scan start point, s4 is the second scan end point, and θ represents the maximum angle in the horizontal plane between the ray reconstruction point passing through the edge of the detector field of view and the central ray.

[0128] As Figure 4 shown, is a functional module diagram of a fast-switching dual-energy dental cone beam CT scanning device provided in an embodiment of the present invention.

[0129] The fast-switching dual-energy dental cone beam CT scanning device 100 of the present invention can be installed in an electronic device. According to the functions achieved, the fast-switching dual-energy dental cone beam CT scanning device 100 can include a forward short scan module 101, a reverse short scan module 102, a data calculation module 103, a three-dimensional reconstruction module 104, and an image synthesis module 105. The modules of the present invention can also be referred to as units, which refer to a series of computer program segments that can be executed by a processor of an electronic device and can complete fixed functions, and are stored in the memory of the electronic device.

[0130] In this embodiment, the functions of each module / unit are as follows:

[0131] The forward short scan module 101 is configured to obtain low-energy attenuation projection data of a forward short scan of a preset ray emitter around a preset center point by using a preset flat panel detector;

[0132] The reverse short scan module 102 is configured to, after switching the high-energy scan condition of the ray emitter, obtain high-energy attenuation projection data of a reverse short scan of the ray emitter around the center point by using the flat panel detector;

[0133] The data calculation module 103 is configured to calculate a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data;

[0134] The three-dimensional reconstruction module 104 is configured to perform three-dimensional reconstruction according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image;

[0135] The image synthesis module 105 is configured to synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0136] Specifically, each module in the fast-switching dual-energy dental cone beam CT scanning device 100 in the embodiment of the present invention adopts the same technical means as those Figures 1 to 3 described in the above-mentioned fast-switching dual-energy dental cone beam CT scanning method, and can produce the same technical effects, which will not be elaborated here.

[0137] As Figure 5 shown, it is a schematic structural diagram of an electronic device for the fast-switching dual-energy dental cone beam CT scanning method provided by an embodiment of the present invention.

[0138] The electronic device 1 may include a processor 10, a memory 11, a communication bus 12, and a communication interface 13, and may further include a computer program stored in the memory 11 and executable on the processor 10, such as a fast-switching dual-energy dental cone beam CT scanning program.

[0139] Among them, in some embodiments, the processor 10 may be composed of an integrated circuit. For example, it may be composed of a single packaged integrated circuit, or may be composed of multiple packaged integrated circuits with the same or different functions, including a combination of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control core (Control Unit) of the electronic device, connecting various components of the entire electronic device through various interfaces and circuits. By running or executing programs or modules (such as the fast-switch dual-energy dental cone beam CT scanning program, etc.) stored in the memory 11, and by calling the data stored in the memory 11, it can execute various functions of the electronic device and process data.

[0140] The memory 11 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, mobile hard disks, multimedia cards, card-type memories (such as SD or DX memories, etc.), magnetic memories, magnetic disks, optical discs, etc. In some embodiments, the memory 11 may be an internal storage unit of the electronic device, such as the mobile hard disk of the electronic device. In some other embodiments, the memory 11 may also be an external storage device of the electronic device, such as a plug-in mobile hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the electronic device. Further, the memory 11 may also include both the internal storage unit and the external storage device of the electronic device. The memory 11 can not only be used to store application software installed on the electronic device and various types of data, such as the code of the fast-switch dual-energy dental cone beam CT scanning program, etc., but can also be used to temporarily store data that has been output or will be output.

[0141] The communication bus 12 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. The bus is set to achieve connection communication between the memory 11 and at least one processor 10, etc.

[0142] The communication interface 13 is used for communication between the above-mentioned electronic device and other devices, including a network interface and a user interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a WI-FI interface, a Bluetooth interface, etc.), and is generally used to establish a communication connection between this electronic device and other electronic devices. The user interface may be a display, an input unit (such as a keyboard), and optionally, the user interface may also be a standard wired interface or a wireless interface. Optionally, in this embodiment, the display may be an LED display, a liquid crystal display, a touch liquid crystal display, and an OLED (Organic Light-Emitting Diode) toucher, etc. Among them, the display may also be appropriately referred to as a display screen or a display unit, and is used to display the information processed in the electronic device and to display a visual user interface.

[0143] Only the electronic device with components is shown in the figure. Those skilled in the art can understand that the structure shown in the figure does not constitute a limitation on the electronic device, and it may include fewer or more components than shown in the figure, or combine some components, or have different component arrangements.

[0144] For example, although not shown, the electronic device may further include a power source (such as a battery) for supplying power to each component. Preferably, the power source may be logically connected to the at least one processor 10 through a power management device, so as to implement functions such as charge management, discharge management, and power consumption management through the power management device. The power source may also include any components such as one or more DC or AC power sources, a recharge device, a power failure detection circuit, a power converter or an inverter, and a power status indicator. The electronic device may also include a variety of sensors, a Bluetooth module, a Wi-Fi module, etc., which will not be elaborated here.

[0145] It should be understood that the above embodiments are only for illustrative purposes and are not limited by this structure in the scope of the patent application.

[0146] The fast-switching dual-energy dental cone beam CT scanning program stored in the memory 11 in the electronic device 1 is a combination of multiple instructions, and when running in the processor 10, it can:

[0147] Utilize a preset flat panel detector to obtain low-energy attenuation projection data of a forward short scan of a preset ray emitter around a preset center point;

[0148] After switching the high-energy scanning conditions of the ray emitter, utilize the flat panel detector to obtain high-energy attenuation projection data of a reverse short scan of the ray emitter around the center point after the high-energy scanning condition switch;

[0149] Calculate a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data;

[0150] Perform three-dimensional reconstruction according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image;

[0151] Synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0152] Specifically, the specific implementation method of the processor 10 for the above instructions can refer to the description of the relevant steps in the corresponding embodiments of the attached drawings, which will not be elaborated here.

[0153] Further, if the modules / units integrated in the electronic device 1 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile. For example, the computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory).

[0154] The present invention also provides a computer-readable storage medium, and the readable storage medium stores a computer program, which when executed by a processor of an electronic device, can implement:

[0155] Obtain low-energy attenuation projection data of a forward short scan of a preset ray emitter around a preset center point by using a preset flat panel detector;

[0156] After switching the high-energy scanning conditions of the ray emitter, obtain high-energy attenuation projection data of a reverse short scan of the ray emitter around the center point by using the flat panel detector;

[0157] Calculate a first basis material density integral and a second basis material density integral according to the low-energy attenuation projection data and the high-energy attenuation projection data;

[0158] Perform three-dimensional reconstruction according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image;

[0159] Synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

[0160] In the embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation.

[0161] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0162] In addition, in each embodiment of the present invention, the functional modules can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a combination of hardware and software functional modules.

[0163] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms.

[0164] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0165] The embodiments of the present application can acquire and process relevant data based on artificial intelligence technology. Among them, artificial intelligence (AI) is a theory, method, technology, and application system that uses a digital computer or a machine controlled by a digital computer to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use knowledge to obtain the best results.

[0166] In addition, obviously, the word "including" does not exclude other units or steps, and the singular does not exclude the plural. The multiple units or devices stated in the system claims can also be implemented by one unit or device through software or hardware. Words such as first and second are used to represent names and do not represent any specific order.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A fast-cutting dual-energy oral cone-beam CT scanning method, characterized in that: The method comprises: Using a preset flat panel detector, low-energy attenuation projection data of a preset ray emitter performing a forward short scan around a preset center point is acquired; After the high-energy scanning condition is switched on the ray emitter, the high-energy attenuation projection data of the reverse short scan around the center point of the ray emitter after the high-energy scanning condition is switched is acquired by using the flat panel detector; Calculating a first basis material density integral and a second basis material density integral according to the low energy attenuation projection data and the high energy attenuation projection data; Performing three-dimensional reconstruction according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image; The first basis material density image and the second basis material density image are synthesized according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

2. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 1, characterized in that: The method of using a preset flat panel detector to obtain low-energy attenuation projection data of a preset ray emitter performing a forward short scan around a preset center point includes: Controlling the ray emitter to emit an X-ray beam according to a preset low-energy scanning condition; Controlling the ray emitter to move in a circle around the center from a preset scanning starting point to a preset scanning end point; During the movement of the ray emitter from a preset scanning start point to a preset scanning end point, the flat panel detector is controlled to perform circular motion around the center point synchronously with the ray emitter, and the flat panel detector is used to acquire the signal of the X-ray beam emitted by the ray emitter after passing through the target object according to a preset acquisition interval to obtain low-energy attenuation projection data.

3. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 1, characterized in that: The step of switching the high-energy scanning condition of the ray emitter comprises: The high energy tube current is calculated according to the preset high energy tube voltage using the following formula: Among them, I h is the high energy tube current, U l is the preset low energy tube voltage, I l is the preset low energy tube current, U h is the high energy tube current, and α is the preset filtration equivalent coefficient.

4. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 2, characterized in that: The method of using the flat panel detector to obtain high-energy attenuation projection data of the ray emitter performing a reverse short scan around the center point after the high-energy scanning condition is switched includes: Controlling the ray emitter to emit an X-ray beam according to the high-energy scanning condition; Controlling the ray emitter to move in a circle around the center from the scanning end point to the scanning start point; During the movement of the ray emitter from the scanning end point to the scanning start point, the flat panel detector is controlled to perform circular motion around the center point synchronously with the ray emitter, and the flat panel detector is used to acquire the signal of the X-ray beam emitted by the ray emitter after passing through the target object according to the acquisition interval to obtain high-energy attenuation projection data.

5. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 1, characterized in that: Calculating a first basis material density integral and a second basis material density integral according to the low energy attenuation projection data and the high energy attenuation projection data includes: The high energy attenuation integral and the low energy attenuation integral are calculated according to the low energy attenuation projection data and the high energy attenuation projection data using the following formula: Among them, p h is the high energy decay integral, I h is the number of detected photons under high energy conditions contained in the high energy attenuation projection data, I h0 is the number of incident photons on the object under high energy conditions contained in the high energy attenuation projection data, p l is the low energy decay integral, I l is the number of detected photons under low energy conditions contained in the low energy attenuation projection data, I l0 is the number of incident photons of the object scanned under low energy conditions contained in the low energy attenuation projection data The mapping relationship between the high energy attenuation integral and the low energy attenuation integral and the first basis material density integral and the second basis material density integral is constructed using the following formula, and the first basis material density integral and the second basis material density integral are obtained by calculation and solution: Among them, p h is the high energy decay integral, S h (E) is the preset high energy spectrum distribution curve, ρ A is the density of the first base substance water, ρ B is the density of the second base substance, bone, is the mass attenuation coefficient of the first base substance water at energy level E, ∫ρ A (l)dl, is the density integral of the first base substance water over the thickness l, p l is the low energy decay integral, S l (E) is the preset low energy spectrum distribution curve, is the mass attenuation coefficient of the second basis material bone at energy level E, ∫ρ B (l)dl) is the integral density of the second base material bone with thickness l.

6. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 1, characterized in that: The three-dimensional reconstruction is performed according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image, including: Performing ramp filtering on the first basis material density integral and the second basis material density integral to obtain a first filtered density integral and a second filtered density integral; Performing cosine weighted processing on the first filter density integral and the second filter density integral to obtain a first cosine density integral and a second cosine density integral; Performing Parker weighting processing on the first cosine density integral and the second cosine density integral to obtain a first weighted density integral and a second weighted density integral; The first weighted density integral and the second weighted density integral are back-projected to obtain a first basis material density image and a second basis material density image.

7. The fast-cutting dual-energy oral cone-beam CT scanning method according to claim 1, characterized in that: The synthesizing the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image includes: The virtual monoenergetic attenuation image is expressed by the following formula: Among them, μ E is the virtual monoenergetic attenuation image, is the mass attenuation coefficient of the first base substance water at energy level E, is the mass attenuation coefficient of the second base material bone at energy level E, P A is the first basis material density image, P B is the second basis material density image.

8. A fast-cutting dual-energy oral cone-beam CT scanning device, characterized in that: The device comprises: A forward short scanning module, used for acquiring low-energy attenuation projection data of a forward short scanning performed by a preset ray emitter around a preset center point using a preset flat panel detector; A reverse short scanning module, used for obtaining high-energy attenuation projection data of the reverse short scanning around the center point of the ray emitter after the high-energy scanning condition is switched to the ray emitter using the flat panel detector; a data calculation module, configured to calculate a high energy attenuation integral and a low energy attenuation integral according to the low energy attenuation projection data and the high energy attenuation projection data, and to calculate a first basis material density integral and a second basis material density integral according to the high energy attenuation integral and the low energy attenuation integral; A three-dimensional reconstruction module, configured to perform three-dimensional reconstruction according to the first basis material density integral and the second basis material density integral to obtain a first basis material density image and a second basis material density image; An image synthesis module is used to synthesize the first basis material density image and the second basis material density image according to a preset attenuation coefficient to obtain a virtual monoenergetic attenuation image.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively coupled to the at least one processor; Wherein, the memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the fast-cutting dual-energy oral cone-beam CT scanning method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the fast-cutting dual-energy oral cone-beam CT scanning method according to any one of claims 1 to 7 is implemented.

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