CN117838169B - Imaging method, system and equipment based on standing position CBCT - Google Patents
Imaging method, system and equipment based on standing position CBCT Download PDFInfo
- Publication number
- CN117838169B CN117838169B CN202410263429.3A CN202410263429A CN117838169B CN 117838169 B CN117838169 B CN 117838169B CN 202410263429 A CN202410263429 A CN 202410263429A CN 117838169 B CN117838169 B CN 117838169B
- Authority
- CN
- China
- Prior art keywords
- imaging
- scanned
- cbct
- scanning
- view
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003384 imaging method Methods 0.000 title claims abstract description 158
- 238000007408 cone-beam computed tomography Methods 0.000 title claims abstract description 91
- 238000012545 processing Methods 0.000 claims abstract description 39
- 238000001514 detection method Methods 0.000 claims abstract description 36
- 238000000034 method Methods 0.000 claims abstract description 32
- 230000008569 process Effects 0.000 claims description 12
- 238000001914 filtration Methods 0.000 claims description 9
- 238000012805 post-processing Methods 0.000 claims description 7
- 230000011218 segmentation Effects 0.000 claims description 4
- 238000010276 construction Methods 0.000 claims description 3
- 230000000007 visual effect Effects 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 230000005855 radiation Effects 0.000 description 5
- 210000003127 knee Anatomy 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 239000000523 sample Substances 0.000 description 4
- 238000005070 sampling Methods 0.000 description 4
- 210000001519 tissue Anatomy 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 210000001624 hip Anatomy 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 210000000544 articulatio talocruralis Anatomy 0.000 description 2
- 238000013170 computed tomography imaging Methods 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 210000004394 hip joint Anatomy 0.000 description 2
- 210000000629 knee joint Anatomy 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000003759 clinical diagnosis Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000002059 diagnostic imaging Methods 0.000 description 1
- 210000003414 extremity Anatomy 0.000 description 1
- 210000000610 foot bone Anatomy 0.000 description 1
- 230000005865 ionizing radiation Effects 0.000 description 1
- 230000003902 lesion Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Apparatus For Radiation Diagnosis (AREA)
Abstract
The application discloses an imaging method, a system and equipment based on standing position CBCT, wherein the method comprises the following steps: measuring a region to be scanned where a target to be scanned is located; constructing an imaging scheme of an object to be scanned; obtaining a first imaging center point and a first imaging radius of a first field of view circle, and a second imaging center point and a second imaging radius of a second field of view circle; the positions of the ray source and the detection plate are adjusted through the double mechanical arms, and the CBCT equipment is controlled to perform first CBCT scanning in the first view circle area; the positions of the ray source and the detection plate are adjusted through the double mechanical arms again, and the CBCT equipment is controlled to perform second CBCT scanning in the second view circle area; obtaining scanning projection in a region comprising a first view circle and a second view circle after the scanning is finished; and carrying out reconstruction processing on the scanning projection to obtain a CBCT image of the target to be scanned. The application expands the imaging visual field of the standing position CBCT by adjusting the equipment imaging center.
Description
Technical Field
The application relates to the field of CT imaging processing, in particular to an imaging method, an imaging system and imaging equipment based on standing position CBCT.
Background
Cone-beam computed tomography (Cone Beam Computed Tomography, CBCT for short) is one of the important diagnostic aids for clinical assessment. The key to the CBCT imaging process is a rotating gantry with two ends fixed to the X-ray source and the detector plate, respectively. The rotating gantry directs a divergent pyramidal or conical source of ionizing radiation through the center of the region of interest onto the X-ray detector on the other side. The X-ray source and detector rotate about a pivot point fixed at the center of the region of interest. During rotation, sequential planar projection images of a plurality of Field of View (FOV) angles are acquired in partial or complete arcs.
Among them, small C-arm machines are mostly used based on extremity and hand, foot bone imaging. The patient takes a standing position, a sitting position, a projection or a supine position for scanning. Compared with the supine position scanning, the standing position scanning can observe and evaluate the true condition of the lesion more omnidirectionally, and the radiation quantity is lower.
Because of the limitations of the probe plate size and imaging parameters of the actual equipment, standing CBCT is often limited in imaging field of view and typically covers only the range of a single knee. This is because in standing CBCT, the source and detector always maintain opposite circular scan trajectories, resulting in a relatively small field of view for imaging, and may occur with inadequate scan range.
Disclosure of Invention
In order to solve the technical problems, the application provides an imaging method, an imaging system and imaging equipment based on standing position CBCT, which expand the imaging field of the standing position CBCT by adjusting the imaging center of the equipment, provide a wider observation range and improve the accuracy and the comprehensiveness of clinical diagnosis.
Specifically, the technical scheme of the application is as follows:
in a first aspect, the application discloses an imaging method based on standing position CBCT, comprising the following steps:
Measuring a region to be scanned where a target to be scanned is located;
Constructing an imaging scheme of the target to be scanned; obtaining a first imaging center point and a first imaging radius of a constructed first field of view circle, and a second imaging center point and a second imaging radius of a constructed second field of view circle;
The positions of a ray source and a detection plate are adjusted through a double mechanical arm, and the ray source and the detection plate are controlled to perform first CBCT scanning of a first view circle area;
the positions of the ray source and the detection plate are adjusted through the double mechanical arms again, and the ray source and the detection plate are controlled to carry out second CBCT scanning of a second view circle area;
Obtaining scanning projection comprising the first view circle region and the second view circle region after the scanning is finished;
and carrying out reconstruction processing on the scanning projection to obtain a CBCT image of the target to be scanned.
In some embodiments, there is an intersection between the first field of view circle and the second field of view circle;
A union exists between the first field of view circle and the second field of view circle; the union region has ideal ellipses;
The union region covers the region to be scanned;
Or, the ideal elliptical region covers the region to be scanned.
In some embodiments, the constructing the imaging scheme of the target to be scanned includes the following steps:
And constructing at least two view circles on the basis of the to-be-scanned area, wherein the view circles comprise a first view circle and a second view circle, and a union area between the first view circle and the second view circle covers the to-be-scanned area.
In other embodiments, the constructing the imaging scheme of the object to be scanned includes the following steps:
On the basis of the area to be scanned, at least two view circles are constructed, wherein the view circles comprise a first view circle and a second view circle, a union exists between the first view circle and the second view circle, and an ideal ellipse exists in the union area, so that the ideal ellipse area covers the area to be scanned.
In some embodiments, the region size of the ideal ellipse is calculated by the following formula:
；
；
wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r1 is the size of the first imaging radius; r2 is the size of the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
In some embodiments, when the first imaging radius is equal in size to the second imaging radius, the area size of the ideal ellipse is calculated by the following formula:
；
；
Wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r is the size of the first imaging radius or the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
In some embodiments, the reconstructing the scanned projection to obtain a CBCT image of the target to be scanned includes the following steps:
Acquiring imaging geometric parameters of the scanning projection;
Based on the imaging geometric parameters, carrying out short-scan parker function weighting processing and ramp filtering processing on the scan projection;
performing FDK reconstruction processing on the processed scanning projection to obtain a first reconstruction result of the target to be scanned;
Threshold segmentation is carried out on the first reconstruction result to obtain a binary mask of the target to be scanned, and orthographic projection is carried out on the binary mask to obtain a second scanning projection;
based on the imaging geometric parameters, carrying out short-scan park function weighting processing and ramp filtering processing on the second scan projection;
Performing FDK reconstruction processing on the processed second scanning projection to obtain a second reconstruction result of the phantom;
Dividing the first reconstruction result by the second reconstruction result to obtain balanced intensity weight; and merging the balance intensity weight into the back projection processing process of the first projection parameter, and reconstructing to obtain the CBCT image of the target to be scanned.
In a second aspect, the present application further discloses an imaging system based on standing CBCT, where the imaging system is configured to implement the imaging method based on standing CBCT described in any one of the foregoing embodiments, and the imaging system includes:
the sensing module is used for measuring a region to be scanned where a target to be scanned is located;
the scheme construction module is used for constructing an imaging scheme of the target to be scanned; obtaining a first imaging center point and a first imaging radius of a constructed first field of view circle, and a second imaging center point and a second imaging radius of a constructed second field of view circle;
The mechanical arm control module is used for adjusting the positions of the ray source and the detection plate through double mechanical arms;
The CBCT scanning module is used for controlling the ray source and the detection plate to perform first CBCT scanning of the first field of view circular area;
The mechanical arm control module is also used for adjusting the positions of the ray source and the detection plate through the double mechanical arms;
The CBCT scanning module is also used for controlling the ray source and the detection plate to carry out second CBCT scanning of the second view circle area;
the image post-processing module is used for acquiring scanning projection comprising the first field-of-view circular area and the second field-of-view circular area, which are generated by the CBCT scanning module, after the scanning is finished;
the image post-processing module is further used for carrying out reconstruction processing on the scanning projection to obtain a CBCT image of the target to be scanned.
In some embodiments, there is an intersection between the first field of view circle and the second field of view circle;
A union exists between the first field of view circle and the second field of view circle; the union region has ideal ellipses;
The union region covers the region to be scanned;
Or, the ideal elliptical region covers the region to be scanned.
In a third aspect, the present application also discloses a standing position CBCT-based imaging apparatus, which comprises the standing position CBCT-based imaging system described in any of the above embodiments.
Compared with the prior art, the application has at least one of the following beneficial effects:
1. the application aims at the standing position CBCT equipment with the double mechanical arms, utilizes the mobility of the double mechanical arms, effectively enlarges the imaging field of the CBCT by adjusting the imaging center, enlarges the circular field of view to an elliptical area, and can meet the complete imaging requirements of the knees and the hips. The method provides a wider observation range, so that the standing position CBCT has wider application prospect in the fields of medical imaging and the like.
2. In the application, when the scanning projection of the target to be scanned is reconstructed, an FDK reconstruction method for balancing voxel intensity is adopted, namely, a phantom with uniform density is adopted to obtain an auxiliary weight to assist image reconstruction, so that the problem of over-strong back projection intensity caused by over-sampling of an overlapped part can be solved, and the problems of over-small low beam source reconstruction voxel intensity and over-large high beam source voxel intensity in the traditional FDK reconstruction can be solved.
Drawings
The above features, technical features, advantages and implementation of the present application will be further described in the following description of preferred embodiments with reference to the accompanying drawings in a clear and easily understood manner.
FIG. 1 is a schematic diagram of a standing position imaging device based on a dual mechanical arm provided by the application;
FIG. 2 is a flow chart of steps of one embodiment of a method provided by the present application;
FIG. 3 is a schematic diagram of movement and imaging principles of an imaging device in one embodiment of the application;
FIG. 4 is a schematic view of an imaging range in one embodiment of the application;
FIG. 5 is a schematic diagram of movement and imaging principles of an imaging device in another embodiment of the application;
FIG. 6 is a schematic view of an imaging range in another embodiment of the present application;
FIG. 7 is a flow chart of the substeps of step S600 in another embodiment of the method provided by the present application;
FIG. 8 is a schematic diagram illustrating an image reconstruction effect achieved by the balanced intensity FDK reconstruction technique according to another embodiment of the present application;
FIG. 9 is a schematic diagram of an image reconstruction effect achieved by the FDK reconstruction technique in the prior art;
FIG. 10 is a graph comparing pixel intensities of a balanced intensity FDK reconstruction technique and a conventional FDK technique in accordance with an embodiment of the present application;
Fig. 11 is a schematic structural diagram of an embodiment of a system provided in the present application.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
For simplicity of the drawing, only the parts relevant to the invention are schematically shown in each drawing, and they do not represent the actual structure thereof as a product. Additionally, in order to simplify the drawing for ease of understanding, components having the same structure or function in some of the drawings are shown schematically with only one of them, or only one of them is labeled. Herein, "a" means not only "only this one" but also "more than one" case.
It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
In this context, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
In addition, in the description of the present application, the terms "first," "second," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following description will explain the specific embodiments of the present application with reference to the accompanying drawings. It is evident that the drawings in the following description are only examples of the application, from which other drawings and other embodiments can be obtained by a person skilled in the art without inventive effort.
CBCT scanners are devices that produce a three-dimensional volumetric image by integrating an emitted cone beam X-ray tube and a digital Flat Panel Detector (FPD) in a gantry and rotating the gantry one revolution around the patient. This process differs from conventional medical CT imaging in that individual image slices of the FOV are acquired using a fan-shaped X-ray beam that is helical, and then the slices are stacked to obtain a 3D representation. Each slice of a CT image requires separate scanning and 2D reconstruction processes. In contrast, since CBCT involves multiple (150 to 600) Field of View (FOV) for a single scan, only one rotation sequence of the gantry is required to acquire enough data for image reconstruction.
Referring to fig. 1 of the drawings, fig. 1 provides a standing position CBCT apparatus 100 based on a dual robot arm. The standing CBCT apparatus 100 includes: a first mechanical arm 11 and a radiation source 10 arranged on the first mechanical arm 11; and a second robot arm 12 and a detector 20 provided on the second robot arm 12. The first mechanical arm 11 and the second mechanical arm 12 drive the radiation source 10 and the detector 20 to perform a semicircular spiral reciprocating scanning around the Z axis.
On the basis of the dual-mechanical arm standing position CBCT equipment shown in fig. 1, one embodiment of the imaging method based on standing position CBCT provided by the application, referring to fig. 2 of the specification, comprises the following steps:
S100, measuring a region to be scanned where a target to be scanned is located; specifically, the target to be scanned is typically a living tissue that needs CBCT scanning. The sensing device can comprise the existing equipment such as a laser sensor, a range finder or an image sensor and the like, so that the measurement of the data such as the size, the length and the width, the occupied area and the like of the target to be scanned is realized. In other embodiments, the calibration may also be performed by manual measurement.
S200, constructing an imaging scheme of the target to be scanned; a first imaging center point and a first imaging radius R1 of the constructed first field of view circle and a second imaging center point and a second imaging radius R2 of the constructed second field of view circle are obtained.
S300, adjusting positions of a ray source and a detection plate through a double mechanical arm, controlling the ray source and the detection plate to take a first imaging center point as an imaging center, and taking a first imaging radius R1 as an imaging radius to perform first CBCT scanning in a first view circle area.
S400, adjusting the positions of the ray source and the detection plate through the double mechanical arms again, controlling the ray source and the detection plate to take a second imaging center point as an imaging center, taking a second imaging radius R2 as an imaging radius, and carrying out second CBCT scanning in a second view circle area; specifically, an intersection exists between the first field of view circle and the second field of view circle; a union exists between the first field of view circle and the second field of view circle. The union region has an ideal ellipse.
The union region covers the region to be scanned; or, the ideal elliptical region covers the region to be scanned.
The imaging field of view of a CBCT apparatus is related to the distance between the radiation source of the apparatus and the detection plate. In the data acquisition process, an object to be scanned is positioned on a scanning platform of the device, and the X-ray source and the detector perform rotary scanning or reciprocating scanning of more than 180 degrees around the object to be scanned. The X-ray source generates a cone-beam which is received by the detector after passing through the object to be scanned. The detector converts the received X-rays into electric signals and transmits the electric signals to a computer for processing. During the reconstruction process, the computer processes and analyzes the received large amount of projection data. And (3) reconstructing the projection data of each angle through a computer algorithm to reconstruct a three-dimensional image of the target to be scanned. The imaging field of view of a single CBCT is generally circular.
The relationship between the radius of the imaging field of view circle and the position of the radiation source and the position of the detection plate can be deduced by the following formula:
；
wherein R is the radius of the imaging view circle; d is the distance from the ray source to the rotation center; w is the width of the detection plate; d SD is the distance of the source from the detector plate.
More preferably, in the imaging scheme obtained in step S200, the center point position and radius of the imaging field circle are known. Knowing that the width of the probe plate is a fixed width, the distance D of the source to the center of rotation and the distance D SD of the source to the probe plate can be calculated. And adjusting the positions of the ray source and the detection plate through the double mechanical arms, so that the CBCT equipment scans according to a pre-constructed imaging scheme.
S500, obtaining scanning projection comprising the first field-of-view circular area and the second field-of-view circular area after the scanning is finished.
S600, reconstructing the scanning projection to obtain the CBCT image of the target to be scanned.
In another embodiment of the imaging method based on standing CBCT of the present application, on the basis of the above one embodiment of the imaging method based on standing CBCT, S200 is: constructing an imaging scheme of the target to be scanned, which comprises the following steps:
s211, constructing at least two view circles on the basis of the area to be scanned, wherein the view circles comprise a first view circle and a second view circle;
S212, enabling a union area between the first field of view circle and the second field of view circle to cover the area to be scanned.
S213, obtaining a first imaging center point and a first imaging radius of the constructed first field of view circle, and a second imaging center point and a second imaging radius of the constructed second field of view circle.
Specifically, in this embodiment, the region to be scanned needs to be included in the union region of the two images.
In another embodiment of the imaging method based on standing CBCT of the present application, on the basis of the above one embodiment of the imaging method based on standing CBCT, S200 is: constructing an imaging scheme of the target to be scanned, which comprises the following steps:
S221, constructing at least two view circles on the basis of the region to be scanned, wherein the view circles comprise a first view circle and a second view circle, a union exists between the first view circle and the second view circle, and ideal ellipses exist in the union region, so that the ideal ellipses cover the region to be scanned.
S222, a union exists between the first view circle and the second view circle, and an ideal ellipse exists in the union area, so that the ideal ellipse area covers the area to be scanned.
S223, obtaining a first imaging center point and a first imaging radius of the constructed first field of view circle, and a second imaging center point and a second imaging radius of the constructed second field of view circle.
Specifically, in this embodiment, the region to be scanned needs to be included in the ideal elliptical region range in the union region of the two images.
Preferably, the oval coverage area characteristics conform to the distribution of human skeleton structures, such as knee joints, hip joints and ankle joints, which are all characterized by long transverse axis and short longitudinal axis on the cross section. The ideal elliptical area is arranged to cover the area to be scanned, so that the area utilization rate of the imaging visual field can be further improved.
In one implementation of this embodiment, when the first imaging radius is equal to the second imaging radius, the area size of the ideal ellipse is calculated by the following formula:
；
；
Wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r is the size of the first imaging radius or the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
Specifically, referring to fig. 3 of the specification, in this embodiment, the first imaging radius is equal to the second imaging radius, which is equivalent to: after the first half scanning, the mechanical arm drives the ray source and the detector to move together and translate along the tangential direction for L distance. So that the imaging center range is also offset by a distance of L.
The blue rectangle on the left side in fig. 3 is the detection plate, and the detection plate and the ray source perform 180-degree reciprocating motion around the imaging center point. In fig. 3, the first imaging range is a blue circular area, that is, a first field of view circular area. The second imaging range is a yellow circular area, namely a second field of view circular area.
The union region of the first view circle region and the second view circle region comprises ideal ellipses; reference is made to fig. 4 of the specification, wherein the green area is the ideal elliptical area. The ideal ellipse is the largest area ellipse present within the union region.
The characteristic of the coverage area of the ellipse accords with the distribution of human skeleton structures, such as knee joints, hip joints and ankle joints, and the characteristics of larger length and smaller width are presented. When an imaging protocol is constructed, it is desirable that the region to be scanned needs to be contained within the ideal elliptical region. Therefore, all targets in the area to be scanned can be ensured to be irradiated by more than 180 degrees of light rays, and the targets can be comprehensively detected by CBCT.
Taking actual data as an example, assume that the distance D SD between the ray source and the detection plate is 1000mm during the first projection; the distance D from the ray source to the first imaging center point is 500mm; the width W of the detection plate is 430mm; in the second projection, the linear distance L between the first imaging center point and the second imaging center point is 100mm; the imaging field of view radius is 102mm.
Under the above conditions, the imaging field area of single projection is 32684mm 2; the major half axis of the ideal ellipse obtained by double projection is 152mm; the short axis is 89mm; the imaging field of view area is 42500mm 2. When the requirements of complete imaging of the knee and the hip are met, the double projection imaging area utilization rate is higher.
In one implementation of this embodiment, when the first imaging radius is not equal to the second imaging radius, the area size of the ideal ellipse is calculated by the following formula:
；
；
wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r1 is the size of the first imaging radius; r2 is the size of the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
Specifically, in this embodiment, the first imaging radius and the second imaging radius are not equal in size, and referring to fig. 5 of the specification, it can be seen that the first imaging radius (blue circle radius) is smaller than the second imaging radius (yellow circle radius). Since the relationship between the radius of the imaging field circle and the source position and the detector plate position can be derived by the following formula:
；
wherein R is the radius of the imaging view circle; d is the distance from the ray source to the rotation center; w is the width of the detection plate; d SD is the distance of the source from the detector plate.
Therefore, the real-time mode changes the imaging center between two half scans, and simultaneously enlarges the radius of the imaging visual field by reducing the distance from the detection plate to the rotation center. Imaging field of view reference is made to figure 6 of the specification. Wherein the blue circle is a first field circle, and the yellow circle is a second field circle. Wherein the green ellipse is the field circle and the ideal circle in the region of the collection.
In this embodiment, the probe plate is moved diagonally so that the second field of view circle area is larger than the first field of view circle area. Thereby achieving the purpose of further expanding the imaging field of view. As in the previous embodiment, each pixel within the green ellipse is illuminated by more than 180 degrees of light source, so that sufficiency conditions for reconstructing the desired projection data are satisfied. When an imaging protocol is constructed, it is desirable that the region to be scanned needs to be contained within the ideal elliptical region. Therefore, all targets in the area to be scanned can be ensured to be irradiated by more than 180 degrees of light rays, and the targets can be comprehensively detected by CBCT.
More preferably, compared with single projection, the double projection effectively enlarges the imaging visual field, enlarges the circular visual field to an elliptical area, and can basically meet the complete imaging requirements of the knees and the hips as shown in fig. 4 and 6.
In another embodiment of the imaging method based on standing CBCT of the present application, referring to fig. 7 of the specification, based on one embodiment of the imaging method based on standing CBCT, the step S600 is: and reconstructing the scanning projection to obtain a CBCT image of the target to be scanned, and further comprising the following sub-steps:
S610, acquiring imaging geometric parameters of the scanning projection.
S620, performing short-scan park function weighting processing and ramp filtering processing on the scan projection based on the imaging geometric parameters.
S630, performing FDK reconstruction processing on the processed scanning projection to obtain a first reconstruction result of the target to be scanned; specifically, in this embodiment, the first reconstruction result needs to be further improved. In other implementations of this embodiment, the step S600 includes the steps S610-S630 described above.
And S640, performing threshold segmentation on the first reconstruction result to obtain a binary mask of the target to be scanned, and performing orthographic projection on the binary mask to obtain a second scanning projection. Specifically, using a phantom with uniform density, and performing the same scanning treatment as the target to be scanned; obtaining a second scanning projection of the phantom; and acquiring the imaging geometric parameters of the second scanning projection and the imaging geometric parameters of the first scanning projection to be consistent. The model body (generally called as water model in radiology) is a model body with different shapes and composed of special materials and substances, and in order to accurately judge the density of the internal tissue structure of the human body, standard compact bone parameters can be input into a computer of CT in advance. When CT examination is carried out, the CT machine can convert the tissue density in the human body into CT images according to the standard, and conversely, a doctor can use the CT values on the standard measurement images to infer the change of the tissue structure density in the human body so as to achieve the corresponding purpose.
S650, performing short-scan park function weighting processing and ramp filtering processing on the second scan projection based on the imaging geometric parameters.
And S660, performing FDK reconstruction processing on the processed second scanning projection to obtain a second reconstruction result of the phantom.
And S670, dividing the first reconstruction result by the second reconstruction result to obtain balanced intensity weight. And (3) merging the balance intensity weight into the step S630, namely reconstructing to obtain the CBCT image of the target to be scanned in the back projection processing process of the first projection parameter.
Specifically, the FDK reconstruction algorithm approximately treats all cone beam projection data which do not pass through the geometric center plane as projection data obtained by tilting a fan beam of the geometric center plane by an angle, then corrects the projection data, and finally reconstructs by using a fan beam filtering back projection algorithm.
Because of the track specificity of the dual-center scanning in the embodiment of the application, overlapping part redundant scanning between two circles is caused, which can cause the problem of central image data interception, and furthermore, because the reconstruction of FDK in the semi-scanning track can cause too little sampling of a low beam source to cause errors in the back projection interpolation process, the processing operation of balanced intensity back projection is introduced, and the operation of balanced intensity back projection weight is carried out on the problems of voxels and uneven sampling of light redundancy irradiation. Specifically, a Voxel (Voxel) refers to a volume unit corresponding to a pixel, and is different from a pixel in that the Voxel is a three-dimensional concept, and has a thickness difference, and a layer thickness corresponding to an image is a "height" of the Voxel. In this embodiment, the balanced intensity back projection is a special reconstruction method designed for the track, and the balanced intensity weight is obtained by dividing the first reconstruction result by the second reconstruction result and is integrated into the FDK reconstruction process. Referring to fig. 8 and 9 of the specification, fig. 8 is a diagram illustrating a balanced intensity FDK reconstruction technique according to the present application, and fig. 9 is an imaging effect of a conventional FDK reconstruction technique in the prior art. Comparing the image effects of fig. 8 and fig. 9, it can be seen that the balanced intensity back projection FDK reconstruction technique of the present application has a clearer effect, especially, the intersection region of the two projections can achieve a better processing effect, and the problem of interpolation error in FDK reconstruction due to insufficient sampling of the near light source segment is solved.
More preferably, referring to fig. 10 of the drawings, fig. 10 provides a plot of pixel intensities at line 260 (of a random row) of a 260 th slice of a real three-dimensional object versus a conventional FDK reconstruction technique, a balanced intensity FDK reconstruction technique of the present application, and the like. In the figure, the three curves of green, red and blue represent: traditional FDK, FDK of the application, true benchmark. The closer the curve is to the intensity curve of the real object, the more accurate the reconstruction method is proved, and the image effect realized by the balanced intensity FDK reconstruction technology provided by the application is obviously higher than that of the traditional FDK, so that the balanced intensity FDK reconstruction technology provided by the application has obvious progress in the related field.
The present application provides another embodiment of an imaging method based on standing CBCT, wherein the scanning method includes three or more projections based on any one of the above embodiments. Wherein the principles are the same as those described in the above embodiments and are not described in detail herein.
Based on the same technical conception, the application also discloses an imaging system based on standing position CBCT, which can be used for realizing any one of the imaging methods based on standing position CBCT, and concretely, an embodiment of the imaging system based on standing position CBCT of the application is shown in the accompanying drawing 9 with reference to the specification, and comprises the following steps:
The sensing module is used for measuring the area to be scanned where the target to be scanned is located.
And the scheme construction module is used for constructing an imaging scheme of the target to be scanned. A first imaging center point and a first imaging radius of the constructed first field of view circle and a second imaging center point and a second imaging radius of the constructed second field of view circle are obtained.
And the mechanical arm control module is used for adjusting the positions of the ray source and the detection plate through double mechanical arms.
And the CBCT scanning module is used for controlling the ray source and the detection plate to perform first CBCT scanning of the first field of view circular area.
The mechanical arm control module is also used for adjusting the positions of the ray source and the detection plate through the double mechanical arms.
The CBCT scanning module is also used for controlling the ray source and the detection plate to carry out second CBCT scanning of the second view circle area.
And the image post-processing module is used for acquiring the scanning projection comprising the first field-of-view circular region and the second field-of-view circular region, which is generated by the CBCT scanning module, after the scanning is finished.
The image post-processing module is further used for carrying out reconstruction processing on the scanning projection to obtain a CBCT image of the target to be scanned.
Specifically, there is an intersection between the first field of view circle and the second field of view circle.
A union exists between the first field of view circle and the second field of view circle. The union region has an ideal ellipse.
The union region covers the region to be scanned.
Or, the ideal elliptical region covers the region to be scanned.
Based on the same technical conception, the application also discloses imaging equipment based on standing position CBCT, which is characterized in that: the imaging apparatus comprises a stand-on CBCT based imaging system as described in any of the system embodiments above.
The imaging method, the imaging system and the imaging equipment based on standing position CBCT have the same technical conception, the technical details of the three embodiments can be mutually applicable, and the repetition is reduced, so that the repeated description is omitted.
It will be apparent to those skilled in the art that the above-described program modules are only illustrated in the division of the above-described program modules for convenience and brevity, and that in practical applications, the above-described functional allocation may be performed by different program modules, i.e., the internal structure of the apparatus is divided into different program units or modules, to perform all or part of the above-described functions. The program modules in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one processing unit, where the integrated units may be implemented in a form of hardware or in a form of a software program unit. In addition, the specific names of the program modules are also only for distinguishing from each other, and are not used to limit the protection scope of the present application.
In the foregoing embodiments, the descriptions of the embodiments are focused on, and the parts of a certain embodiment that are not described or depicted in detail may be referred to in the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The above-described embodiments of the apparatus are exemplary only, and exemplary, the division of the modules or units is merely a logical function division, and there may be additional divisions in actual implementation, exemplary, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (7)
1. An imaging method based on standing position CBCT is characterized by comprising the following steps:
Measuring a region to be scanned where a target to be scanned is located;
Constructing an imaging scheme of the target to be scanned; obtaining a first imaging center point and a first imaging radius of a constructed first field of view circle, and a second imaging center point and a second imaging radius of a constructed second field of view circle; an intersection exists between the first field of view circle and the second field of view circle; a union exists between the first field of view circle and the second field of view circle; the union region has ideal ellipses; the union region covers the region to be scanned; or, the ideal elliptical area covers the area to be scanned;
The positions of a ray source and a detection plate are adjusted through a double mechanical arm, and the ray source and the detection plate are controlled to perform first CBCT scanning of a first view circle area;
the positions of the ray source and the detection plate are adjusted through the double mechanical arms again, and the ray source and the detection plate are controlled to carry out second CBCT scanning of a second view circle area;
Obtaining scanning projection comprising the first view circle region and the second view circle region after the scanning is finished;
Acquiring imaging geometric parameters of the scanning projection;
Based on the imaging geometric parameters, carrying out short-scan parker function weighting processing and ramp filtering processing on the scan projection;
Performing FDK reconstruction processing on the processed scanning projection to obtain a first reconstruction result of the target to be scanned;
Threshold segmentation is carried out on the first reconstruction result to obtain a binary mask of the target to be scanned, and orthographic projection is carried out on the binary mask to obtain a second scanning projection;
based on the imaging geometric parameters, carrying out short-scan park function weighting processing and ramp filtering processing on the second scan projection;
Performing FDK reconstruction processing on the processed second scanning projection to obtain a second reconstruction result of the phantom;
Dividing the first reconstruction result by the second reconstruction result to obtain balanced intensity weight; and merging the balance intensity weight into the back projection processing process of the processed scanning projection, and reconstructing to obtain the CBCT image of the target to be scanned.
2. A standing position CBCT based imaging method according to claim 1, wherein said constructing an imaging plan of said object to be scanned comprises the steps of:
Constructing at least two view circles on the basis of the area to be scanned, wherein the view circles comprise a first view circle and a second view circle;
Such that a union region between the first field of view circle and the second field of view circle covers the region to be scanned.
3. A standing position CBCT based imaging method according to claim 1, wherein said constructing an imaging plan of said object to be scanned comprises the steps of:
Constructing at least two view circles on the basis of the area to be scanned, wherein the view circles comprise a first view circle and a second view circle;
A union exists between the first view circle and the second view circle, and a perfect ellipse exists in the union region;
so that the ideal elliptical area covers the area to be scanned.
4. A standing position CBCT based imaging method according to claim 1, characterized in that the area size of the ideal ellipse is calculated by the following formula:
；
；
wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r1 is the size of the first imaging radius; r2 is the size of the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
5. The standing position CBCT based imaging method of claim 4, wherein when said first imaging radius is equal to said second imaging radius, calculating a region size of said ideal ellipse by:
；
；
Wherein A is the major axis radius of the ideal ellipse; b is the minor axis radius of the ideal ellipse; r is the size of the first imaging radius or the second imaging radius; l is a linear distance between the first imaging center point and the second imaging center point.
6. An imaging system based on standing CBCT, comprising:
the sensing module is used for measuring a region to be scanned where a target to be scanned is located;
The scheme construction module is used for constructing an imaging scheme of the target to be scanned; obtaining a first imaging center point and a first imaging radius of a constructed first field of view circle, and a second imaging center point and a second imaging radius of a constructed second field of view circle; an intersection exists between the first field of view circle and the second field of view circle; a union exists between the first field of view circle and the second field of view circle; the union region has ideal ellipses; the union region covers the region to be scanned; or, the ideal elliptical area covers the area to be scanned;
The mechanical arm control module is used for adjusting the positions of the ray source and the detection plate through double mechanical arms;
The CBCT scanning module is used for controlling the ray source and the detection plate to perform first CBCT scanning of the first field of view circular area;
The mechanical arm control module is also used for adjusting the positions of the ray source and the detection plate through the double mechanical arms;
The CBCT scanning module is also used for controlling the ray source and the detection plate to carry out second CBCT scanning of the second view circle area;
the image post-processing module is used for acquiring scanning projection comprising the first field-of-view circular area and the second field-of-view circular area, which are generated by the CBCT scanning module, after the scanning is finished;
The image post-processing module is further used for reconstructing the scanning projection to obtain a CBCT image of the target to be scanned;
the image post-processing module is specifically configured to execute the following operation steps:
Acquiring imaging geometric parameters of the scanning projection;
Based on the imaging geometric parameters, carrying out short-scan parker function weighting processing and ramp filtering processing on the scan projection;
Performing FDK reconstruction processing on the processed scanning projection to obtain a first reconstruction result of the target to be scanned;
Threshold segmentation is carried out on the first reconstruction result to obtain a binary mask of the target to be scanned, and orthographic projection is carried out on the binary mask to obtain a second scanning projection;
based on the imaging geometric parameters, carrying out short-scan park function weighting processing and ramp filtering processing on the second scan projection;
Performing FDK reconstruction processing on the processed second scanning projection to obtain a second reconstruction result of the phantom;
Dividing the first reconstruction result by the second reconstruction result to obtain balanced intensity weight; and merging the balance intensity weight into the back projection processing process of the processed scanning projection, and reconstructing to obtain the CBCT image of the target to be scanned.
7. An imaging device based on standing CBCT, characterized in that: the imaging apparatus comprising the stand CBCT-based imaging system of claim 6 above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410263429.3A CN117838169B (en) | 2024-03-08 | 2024-03-08 | Imaging method, system and equipment based on standing position CBCT |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410263429.3A CN117838169B (en) | 2024-03-08 | 2024-03-08 | Imaging method, system and equipment based on standing position CBCT |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117838169A CN117838169A (en) | 2024-04-09 |
| CN117838169B true CN117838169B (en) | 2024-05-24 |
Family
ID=90534759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410263429.3A Active CN117838169B (en) | 2024-03-08 | 2024-03-08 | Imaging method, system and equipment based on standing position CBCT |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117838169B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5784481A (en) * | 1996-06-25 | 1998-07-21 | General Electric Company | CT cone beam image reconstruction with circle and line scan path |
| JP2006003122A (en) * | 2004-06-15 | 2006-01-05 | Shimadzu Corp | X-ray ct scanner |
| CN1788684A (en) * | 2004-09-29 | 2006-06-21 | 株式会社东芝 | Image reconstruction method and x-ray computed tomography apparatus |
| CN1865954A (en) * | 2006-06-13 | 2006-11-22 | 北京航空航天大学 | Wide view-field three-D CT imaging method |
| CN101175439A (en) * | 2005-05-12 | 2008-05-07 | 皇家飞利浦电子股份有限公司 | Continuous computer tomography performing super-short-scans and stronger weighting of most recent data |
| CN101398397A (en) * | 2007-09-30 | 2009-04-01 | 首都师范大学 | CT imaging method of multitime scanning mode |
| CN101505658A (en) * | 2006-08-17 | 2009-08-12 | 皇家飞利浦电子股份有限公司 | Computed tomography image acquisition |
| CN103945764A (en) * | 2011-11-11 | 2014-07-23 | 皇家飞利浦有限公司 | C-arm system with extended field of view |
| CN105596022A (en) * | 2006-02-27 | 2016-05-25 | 罗切斯特大学 | Method and apparatus of cone beam CT dynamic imaging |
| CN115607175A (en) * | 2021-07-12 | 2023-01-17 | 江苏一影医疗设备有限公司 | Imaging device, imaging method, electronic apparatus, imaging system, and storage medium |
| CN116543071A (en) * | 2023-07-06 | 2023-08-04 | 有方（合肥）医疗科技有限公司 | Large-field CT imaging method and device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103349556B (en) * | 2009-01-21 | 2015-09-23 | 皇家飞利浦电子股份有限公司 | For Large visual angle imaging and the detection of motion artifacts and the method and apparatus of compensation |
-
2024
- 2024-03-08 CN CN202410263429.3A patent/CN117838169B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5784481A (en) * | 1996-06-25 | 1998-07-21 | General Electric Company | CT cone beam image reconstruction with circle and line scan path |
| JP2006003122A (en) * | 2004-06-15 | 2006-01-05 | Shimadzu Corp | X-ray ct scanner |
| CN1788684A (en) * | 2004-09-29 | 2006-06-21 | 株式会社东芝 | Image reconstruction method and x-ray computed tomography apparatus |
| CN101175439A (en) * | 2005-05-12 | 2008-05-07 | 皇家飞利浦电子股份有限公司 | Continuous computer tomography performing super-short-scans and stronger weighting of most recent data |
| CN105596022A (en) * | 2006-02-27 | 2016-05-25 | 罗切斯特大学 | Method and apparatus of cone beam CT dynamic imaging |
| CN1865954A (en) * | 2006-06-13 | 2006-11-22 | 北京航空航天大学 | Wide view-field three-D CT imaging method |
| CN101505658A (en) * | 2006-08-17 | 2009-08-12 | 皇家飞利浦电子股份有限公司 | Computed tomography image acquisition |
| CN101398397A (en) * | 2007-09-30 | 2009-04-01 | 首都师范大学 | CT imaging method of multitime scanning mode |
| CN103945764A (en) * | 2011-11-11 | 2014-07-23 | 皇家飞利浦有限公司 | C-arm system with extended field of view |
| CN115607175A (en) * | 2021-07-12 | 2023-01-17 | 江苏一影医疗设备有限公司 | Imaging device, imaging method, electronic apparatus, imaging system, and storage medium |
| CN116543071A (en) * | 2023-07-06 | 2023-08-04 | 有方（合肥）医疗科技有限公司 | Large-field CT imaging method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117838169A (en) | 2024-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10548549B2 (en) | Measuring breast density using breast computed tomography | |
| AU767518B2 (en) | Apparatus and method for cone beam volume computed tomography breast imaging | |
| EP3143935B1 (en) | Tomography apparatus and method of reconstructing tomography images | |
| CN105030266B (en) | X ray computed tomographics device and scan plan set supporting device | |
| AU2002215340B2 (en) | System and method for cone beam volume computed tomography using circle-plus-multiple-ARC orbit | |
| US9001962B2 (en) | Method and apparatus for multiple X-ray imaging applications | |
| RU2550542C2 (en) | Method and device for shaping computer tomographic images using geometries with offset detector | |
| US7340032B2 (en) | System for dynamic low dose x-ray imaging and tomosynthesis | |
| JP5802044B2 (en) | Method and apparatus for computerized tomography | |
| EP3420907A2 (en) | Variable distance imaging | |
| WO2007074772A1 (en) | X-ray ct device | |
| WO2017213150A1 (en) | X-ray ct apparatus | |
| KR20170105876A (en) | Tomography apparatus and method for reconstructing a tomography image thereof | |
| JP5022690B2 (en) | Radiography equipment | |
| JP2004113785A (en) | Image formation method and ct unit for implementing the same in computerized tomography | |
| GB2408343A (en) | Image reconstruction with projected images aquired in a non-circular arc | |
| CN117838169B (en) | Imaging method, system and equipment based on standing position CBCT | |
| CN111839574A (en) | CT ultralow-dose automatic three-dimensional positioning scanning method and system | |
| EP3908186B1 (en) | Adaptive helical computed tomography | |
| CN217408833U (en) | Multi-source flat panel detector CT system | |
| JP7179497B2 (en) | X-ray CT apparatus and image generation method | |
| CN117731313A (en) | Scanning method of standing position imaging equipment and image reconstruction method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |