CN111067558A - Image reconstruction method, device and equipment and multilayer spiral CT system - Google Patents
Image reconstruction method, device and equipment and multilayer spiral CT system Download PDFInfo
- Publication number
- CN111067558A CN111067558A CN201911233005.8A CN201911233005A CN111067558A CN 111067558 A CN111067558 A CN 111067558A CN 201911233005 A CN201911233005 A CN 201911233005A CN 111067558 A CN111067558 A CN 111067558A
- Authority
- CN
- China
- Prior art keywords
- detection
- detection module
- detector
- received signal
- layer
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 31
- 238000001514 detection method Methods 0.000 claims abstract description 271
- 230000005484 gravity Effects 0.000 claims abstract description 46
- 238000003384 imaging method Methods 0.000 claims abstract description 28
- 230000002285 radioactive effect Effects 0.000 claims abstract description 9
- 230000005855 radiation Effects 0.000 claims description 34
- 238000009825 accumulation Methods 0.000 claims description 24
- 238000009826 distribution Methods 0.000 claims description 14
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 238000002591 computed tomography Methods 0.000 description 14
- 238000010586 diagram Methods 0.000 description 12
- 238000003860 storage Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000002583 angiography Methods 0.000 description 1
- 230000000747 cardiac effect Effects 0.000 description 1
- 230000003788 cerebral perfusion Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000001959 radiotherapy Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
- A61B6/03—Computed tomography [CT]
- A61B6/032—Transmission computed tomography [CT]
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/44—Constructional features of apparatus for radiation diagnosis
- A61B6/4476—Constructional features of apparatus for radiation diagnosis related to motor-assisted motion of the source unit
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/54—Control of apparatus or devices for radiation diagnosis
- A61B6/547—Control of apparatus or devices for radiation diagnosis involving tracking of position of the device or parts of the device
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Medical Informatics (AREA)
- Optics & Photonics (AREA)
- Biomedical Technology (AREA)
- Biophysics (AREA)
- High Energy & Nuclear Physics (AREA)
- Veterinary Medicine (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Public Health (AREA)
- Pathology (AREA)
- Radiology & Medical Imaging (AREA)
- Physics & Mathematics (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Pulmonology (AREA)
- Theoretical Computer Science (AREA)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
The disclosure discloses an image reconstruction method, an image reconstruction device, image reconstruction equipment and a multilayer spiral CT system. The method comprises the following steps: the method comprises the steps that detection data output by a detector when a radioactive source irradiates in a set middle range of the detector in the z direction are collected in advance; determining the gravity center position of a received signal of each detection module according to the detection data, and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal; acquiring the target position of each detection module according to the initial position and the offset distance of each detection module; and scanning the detected body, acquiring detection data corresponding to the target position of each detection module, and reconstructing an image according to the detection data. According to the method and the device, the target position is obtained by combining the offset data and the initial position of the detector to reconstruct the image, so that the positioning of the detector data for imaging is more accurate, and the imaging quality is improved.
Description
Technical Field
The present disclosure relates to the field of medical equipment technologies, and in particular, to an image reconstruction method, an image reconstruction device, an image reconstruction apparatus, and a multi-layer helical CT system.
Background
The multilayer spiral CT (computed tomography) has larger scanning coverage, shortened scanning time and higher z-axis resolution, can obtain better three-dimensional reconstruction images, is applied to the fields of human body three-dimensional imaging, angiography imaging, cardiac imaging, cerebral perfusion imaging and the like, and also has important functions in the aspects of computer-aided technology (virtual endoscope technology), radiotherapy planning and the like.
When reconstructing an image using projection data, detector acquisition data at an ideal position derived from a projection relationship is generally used, however, positions of different detection modules in the z direction may have a deviation, thereby affecting accuracy of positioning of the obtained detector acquisition data, and causing a reduction in imaging quality.
Disclosure of Invention
The present disclosure provides an image reconstruction scheme. According to an aspect of the present disclosure, an image reconstruction method is provided, which is applied to an imaging device of a multislice CT system, the system further including a radiation source, a detector including a plurality of detection modules arranged around a center of rotation; the method comprises the following steps: the method comprises the steps that detection data output by a detector when a radioactive source irradiates in a set middle range of the detector in the z direction are collected in advance; determining the gravity center position of a received signal of each detection module according to the detection data, and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal; obtaining the target position of each detection module according to the initial position of each detection module and the offset distance, wherein the initial position is determined according to the position of the detection module converted to the rotation center; and scanning the detected body, acquiring detection data corresponding to the target position of each detection module, and reconstructing an image according to the detection data.
In connection with any one of the embodiments provided by the present disclosure, each of the detection modules includes N layers of detection units in the z-direction; the determining the gravity center position of the received signal of each detection module according to the detection data, and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal, includes: for a detection module, determining the gravity center position of a received signal of the detection module according to detection values output by detection units of each layer and the distribution positions of the detection units of each layer in the detection module; and obtaining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal and the physical width of each layer of detection unit.
In combination with any one of the embodiments provided by the present disclosure, determining a barycentric location of a received signal of the detection module according to detection values output by each layer of detection units and distribution positions of each layer of detection units in the detection module includes:
accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result;
accumulating the detection values output by each detection unit to obtain a second accumulation result;
and dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
In combination with any of the embodiments provided by the present disclosure, the method further includes irradiating the radiation source within a set middle range of the detector in the z-direction using a slit-type beam limiter.
According to an aspect of the present disclosure, an image reconstruction apparatus is provided, which is applied to an imaging device of a multislice CT system, the system further including a radiation source, a detector, the detector including a plurality of detection modules arranged around a rotation center; the device comprises: the acquisition unit is used for acquiring detection data output by the detector when the radioactive source irradiates in a set middle range of the detector in the z direction in advance; the determining unit is used for determining the gravity center position of the received signal of each detection module according to the detection data and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal; an obtaining unit, configured to obtain a target position of each detection module according to an initial position of the detection module corresponding to the rotation center in the z direction and the offset distance; and the reconstruction unit is used for scanning the detected body, acquiring detection data corresponding to the target position of each detection module and reconstructing an image according to the detection data.
In connection with any one of the embodiments provided by the present disclosure, each of the detection modules includes N layers of detection units in the z-direction; when the determining unit is configured to determine the barycentric location of the received signal of each detection module, the determining unit is specifically configured to: for a detection module, determining the distribution position of the gravity center of a received signal of the detection module according to the detection values output by the detection units of each layer and the distribution positions of the detection units of each layer in the detection module; and acquiring the gravity center position of the received signal of the detection module according to the distribution position of the gravity center of the received signal and the physical width of each layer of detection unit.
In combination with any embodiment provided by the present disclosure, when the determining unit is configured to determine the barycentric location of the received signals of the detection modules according to the detection values output by the detection units of each layer and the distribution positions of the detection units of each layer in the detection modules, the determining unit is specifically configured to:
accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result;
accumulating the detection values output by each detection unit to obtain a second accumulation result;
and dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
In conjunction with any of the embodiments provided by the present disclosure, the apparatus further employs a slit-type beam limiter to cause the radiation source to irradiate within a set middle range of the detector in the z-direction.
According to an aspect of the present disclosure, there is provided an image forming apparatus including: the imaging device comprises a memory for storing computer instructions executable on a processor, the processor for implementing the image reconstruction method described above when executing the computer instructions.
According to an aspect of the present disclosure, there is provided an imaging apparatus including a radiation source, a detector, and the imaging apparatus described above.
According to the image reconstruction method, the device, the imaging equipment and the multilayer spiral CT system, when the radiation source irradiates in the set middle range of the detector in the z direction, the detection data output by the detector determines the gravity center position of the received signal of each detector module, so that the offset distance of each detection module relative to the set center of the detector in the z direction is determined, and the offset data and the initial position for image reconstruction are combined to obtain the target position for image reconstruction, so that the positioning of the detector data for imaging is more accurate, and the imaging quality is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the specification.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present specification and together with the description, serve to explain the principles of the specification.
Fig. 1 is a schematic structural diagram of a multi-slice helical CT system according to at least one embodiment of the present disclosure;
FIG. 2 is a schematic imaging diagram of a multislice CT system in accordance with at least one embodiment of the present disclosure;
FIG. 3A is a schematic diagram of an ideal arrangement of the detection modules, and FIG. 3B is a schematic diagram of an actual arrangement of the detection modules;
fig. 4 is a flowchart of an image reconstruction method according to at least one embodiment of the present disclosure;
fig. 5 is a schematic working diagram of a slit-type beam limiter in an image reconstruction method according to at least one embodiment of the present disclosure;
fig. 6 is a schematic diagram of a detection module in an image reconstruction method according to at least one embodiment of the present disclosure;
fig. 7 is a graph of an output signal of a detection module in an image reconstruction method according to at least one embodiment of the present disclosure;
fig. 8 is a schematic diagram of an image reconstruction apparatus according to at least one embodiment of the present disclosure;
fig. 9 is a schematic structural diagram of an imaging apparatus according to at least one embodiment of the present disclosure.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present specification. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the specification, as detailed in the appended claims.
Referring to fig. 1, a schematic structural diagram of a multi-slice helical CT system according to at least one embodiment of the present disclosure includes a radiation source 10, a detector 12, a stage 13, and an image processing device 14.
Wherein the radiation source 10 is used for emitting X-rays and the detector 11 is used for detecting the intensity of the X-rays penetrating the object to be examined. Based on the absorption coefficient of X-rays by each voxel in the object 15, e.g., a human body, the detector 12 can obtain projection data corresponding to each voxel. The radiation source 10 continuously rotates around the subject and is exposed, and the detector 12 may be configured to be symmetrical with the radiation source 10 with respect to the rotation center thereof and to rotate together with the radiation source 10, or may be disposed at other positions. The image processing device 14 is used to acquire projection data of the detector 12 and reconstruct a CT image based on the receipt.
FIG. 2 is an imaging schematic diagram of a multislice CT system according to at least one embodiment of the present disclosure, in which, as shown in FIG. 2, a radiation source 20 moves spirally along a rotation center line OO', a detector 21 includes a plurality of detection modules 211 arranged around the rotation center, each detection module 211 includes a plurality of layers of detection units, the detector 21 is a virtual area array detector centered on the rotation axis, theoretically, a connection line between a focal point and the rotation center of the radiation source is perpendicular to the detector, wherein, the connection line between the radiation source and the rotation center is a central channel, an angle between the central channel and an x-axis is β, which represents a circumferential sampling angle during the rotation of the radiation source, γ represents an angle between a connection line between each detection unit and the radiation source and the central channel, which is called a channel angle, an angle of an entire radiation beam emitted by the radiation source is called a fan angle, and β ∈ [0, 2 π ] projection data can be used to reconstruct an image of a slice.
The image reconstruction data f (x, y, z) can be calculated by, for example, formula (2):
where x, y, z represent the coordinates of the reconstruction pixel, β represents the circumferential sampling angle, γ represents the channel angle, R represents the radius of the helical scan, q represents the z position at which the projection data used by the reconstruction pixel (x, y, z) is located,
in order to be able to project the data,
in image reconstruction, detection data is typically acquired using a theoretically derived detector z-position q' (x, y, z, β). The theoretical detector z-position is calculated by the following equation:
wherein, R represents the radius of the helical scan, i.e. the radius of rotation, and D is the focal length, i.e. the distance from the focal point of the radiation source to the detector (physical detector) actually performing the detection.
In an ideal case, the plurality of detection modules arranged around the center of rotation are horizontally arranged, i.e., the respective detection modules are aligned in the z-direction, as shown in fig. 3A. However, in the actual arrangement of the detector, due to the difference in manufacturing and assembling precision, the detection modules cannot be aligned completely in the z direction, that is, the detection units of the layers in the detection modules are not located at the same position in the z direction, and a step (step) occurs between the modules. Since the degree of deviation of each detection module from the ideal center position in the z direction (the position indicated by the dotted line in fig. 3A and 3B, which is the center position set according to the arrangement of all detection modules) is not uniform, the accuracy of layer direction data positioning in the image reconstruction process is affected.
FIG. 4 is a flowchart of an image reconstruction method applicable to an imaging device of a multislice CT system according to at least one embodiment of the present disclosure, and the method may include steps 401 to 404:
in step 401, detection data output by a detector when the radiation source irradiates within a set middle range of the detector in the z direction is collected in advance.
In the embodiment of the present disclosure, the radiation source irradiates the set middle range of the detector in the z direction, that is, the detector can completely receive the X-ray in the middle part layer, and the X-ray is not received at two sides of the detector, that is, the part where the step of the detection module exists. The set intermediate range is set by taking an ideal center position of the detector (as shown in fig. 3A and 3B) as a center, and the specific range can be determined according to the arrangement of the detector.
In some embodiments, a slit-type beam limiter, such as a thin-slice slit, may be utilized. The size of the slit-type beam limiter in the z direction is, for example, 2 x 0.625mm, which means that the slit-type beam limiter limits the coverage of the formed radiation beam on the flat panel detector equivalent to the center of rotation, i.e. covers two layers, each layer is 0.625mm, and covers 1.25mm in total. With the slit-type beam limiter, the radiation source can be made to irradiate within a set middle range of the detector in the z-direction, as shown in fig. 5.
In response to receiving radiation from the radiation source within a set mid-range in the z-direction, the detector outputs detection data that is pre-collected for subsequent processing.
In step 402, the center of gravity position of the received signal of each detection module is determined according to the detection data, and the offset distance of each detection module in the z direction relative to the set center of the detector is determined according to the center of gravity position of the received signal.
The position of the center of gravity of the received signal is the position where the received radiation is the strongest, and the detection data output by the detector at the position is the best data for performing image reconstruction.
In the case where the center of the detector does not coincide with the center of the slit-type beam limiter, the signal received by the middle layer of the detector may be blocked, and the other layers may be irradiated, so that the position of the peak of the signal generated by the beam limiter is changed. The layer to which the beam limiter is aligned can be judged according to the strength of the signal of the detector, and the position receiving the strongest irradiation can be judged by determining the center position in the layer direction to which the signal of the beam limiter is aligned, namely the gravity center position of the received signal is determined.
Since the detection modules are not aligned in the z direction, the irradiation range of the radiation source is different, and the gravity center position of the received signal is different. The received signal center of gravity position of the detection module may be determined by various methods, for example, a position where the detection value is the highest is determined as the received signal center of gravity position, and the like, which is not limited by the present disclosure.
In the case where the geometric barycentric position is determined, the offset distance of each detection module in the z-direction with respect to the set center of the detector (the ideal center position shown in fig. 3A and 3B) can be determined from the received signal barycentric position.
In step 403, a target position of each detection module is obtained according to an initial position of each detection module determined according to the position of the detection module converted to the rotation center and the offset distance.
In this step, by converting the detection module to the rotation center, that is, translating the plane of the detection module to the position of the rotation center along the direction of the connection line between the focal point of the radiation source and the rotation center (as mentioned above, the connection line between the focal point of the radiation source and the rotation center is perpendicular to the detection module), the initial position of the detection module corresponding to the rotation center in the z direction, that is, the theoretical detector z position calculated by equation (3), is obtained. By adding the theoretical detector z-position to the offset distance obtained in step 402, the target z-position of each detection module, i.e. the detector z-position at which the output detection data most closely matches the actual situation, can be obtained.
The steps 401 to 403 are processing performed in a pre-scanning stage to determine the target position of each detection module. Next, the subject is scanned to obtain detection data for image reconstruction.
In step 404, the subject is scanned, detection data corresponding to the target positions of the respective detection modules is acquired, and image reconstruction is performed based on the detection data.
According to the target position of each detection module determined in step 403, the detection data corresponding to the position is obtained.
During reconstruction, the beam limiter is usually considered to be aligned with the center position of each detection module in the z direction, but in practice, the deviation is common. In the embodiment of the disclosure, the target position of each detection module takes into account the deviation in the z direction, and the influence of the deviation on the intensity of the received signal is eliminated, so that the detection data corresponding to the target position of each detection module is used for image reconstruction, and the imaging quality can be improved.
In the embodiment of the disclosure, when the radiation source irradiates in the set middle range of the detector in the z direction, the detection data output by the detector determines the barycentric position of the received signal of each detector module, so as to determine the offset distance of each detection module in the z direction relative to the set center of the detector, and image reconstruction is performed by combining the offset data and the target position obtained by combining the initial position for image reconstruction, so that the positioning of the detector data for imaging is more accurate, and the imaging quality is improved.
In some embodiments, each of the detection modules comprises N layers of detection units in the z-direction. In this case, the offset distance of each detection module in the z-direction with respect to the detector set center can be determined according to the following method:
firstly, for a detection module, determining the gravity center position of a received signal of the detection module according to detection values output by detection units of each layer and distribution positions of the detection units of each layer in the detection module.
Fig. 6 shows exemplary detection modules, each of which, as shown in fig. 6, includes detection units 1 to N, that is, the detection units have layer number index values i, i ═ 1,2, …, N.
A detection signal curve of one detection module in the z direction is shown in fig. 7, in which the horizontal axis represents the index value in the layer direction, and the vertical axis represents the detection value output by each detection unit. Assuming that the detector has M detection modules, each module having N detection units, the detector includes M × N detection units. The detection units are distributed in the Z direction, namely N layers are arranged in the Z direction; the detection modules are distributed in the X direction, namely, M channels are arranged in the X direction.
In one example, the position of the center of gravity of the received signal of the detection module may be calculated by: firstly, accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result; accumulating the detection values output by the detection units to obtain a second accumulation result; and finally, dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
That is, the received signal center of gravity position C of the detection module can be determined according to formula (1):
wherein, N is the number of layers of the detection units included in the detection module, i is the index value of the number of layers of the detection units in the detection module, which represents the distribution position of the detection units in the detection module, and P is the detection value output by the detection unit. The position of the center of gravity of the received signal determined according to the formula (1) is represented by the number of layers of the detection unit. Taking the example that the detection module includes 20 layers of detection units, assuming that the received signal gravity center position C calculated by equation (1) is 12.6, since the widths of the detection units of each layer are the same, C-12.6 indicates that the received signal gravity center position falls at the 12.6 layer position.
Next, according to the barycentric position of the received signals and the physical width of each layer of detection units, obtaining the barycentric position of the received signals to determine the offset distance of each detection module relative to the set center of the detector in the z direction.
As shown in fig. 6, the offset distance Δ Z between the barycentric position of the received signal and the set center AA ' of the detector can be determined by multiplying the number of layers between the barycentric position C of the received signal and the set center AA ' of the detector and the physical width of the detecting units of each layer, that is, the number of layers between the barycentric position C of the received signal and the set center AA ' of the detector by the physical width of the detecting units of each layer.
Referring to fig. 8, a schematic structural diagram of an image reconstruction apparatus according to at least one embodiment of the present disclosure is provided. The device is applied to imaging equipment of a multilayer spiral CT system, the system also comprises a radioactive source and a detector, and the detector comprises a plurality of detection modules which are arranged around a rotation center; the device comprises: the acquisition unit 801 is used for acquiring detection data output by the detector when the radioactive source irradiates in a set middle range of the detector in the z direction in advance; a determining unit 802, configured to determine, according to the detection data, a barycentric position of a received signal of each detection module, and determine, according to the barycentric position of the received signal, an offset distance of each detection module in the z direction with respect to a set center of the detector; an obtaining unit 803, configured to obtain a target position of each detection module according to an initial position of each detection module and the offset distance, where the initial position is determined according to a position of the detection module converted to the rotation center; a reconstruction unit 804, configured to scan a subject, acquire detection data corresponding to the target position of each detection module, and perform image reconstruction according to the detection data.
In some embodiments, each of the detection modules comprises N layers of detection units in the z-direction; the determining unit 802 is specifically configured to: for a detection module, determining the gravity center position of a received signal of the detection module according to detection values output by detection units of each layer and the distribution positions of the detection units of each layer in the detection module; and obtaining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal and the physical width of each layer of detection unit.
In some embodiments, the determining unit, when configured to determine the barycentric location of the received signals of the detection modules according to the detection values output by the detection units of each layer and the distribution positions of the detection units of each layer in the detection modules, is specifically configured to: accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result; accumulating the detection values output by each detection unit to obtain a second accumulation result; and dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
In some embodiments, the apparatus further employs a slit-type beam limiter to cause the radiation source to impinge within a set mid-range of the detector in the z-direction.
Referring to fig. 9, a schematic structural diagram of an imaging apparatus provided for at least one embodiment of the present disclosure is a workstation, where the workstation includes a memory and a controller, the memory unit is used for storing computer instructions executable on a processor, and the processor is used for implementing an image reconstruction method according to any embodiment of the present disclosure when executing the computer instructions.
In the disclosed embodiments, the computer readable storage medium may take many forms, such as, in various examples: a RAM (random Access Memory), a volatile Memory, a non-volatile Memory, a flash Memory, a storage drive (e.g., a hard drive), a solid state drive, any type of storage disk (e.g., an optical disk, a dvd, etc.), or similar storage medium, or a combination thereof. In particular, the computer readable medium may be paper or another suitable medium upon which the program is printed. Using these media, the programs can be electronically captured (e.g., optically scanned), compiled, interpreted, and processed in a suitable manner, and then stored in a computer medium.
The above description is only exemplary of the present disclosure and should not be taken as limiting the disclosure, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.
Claims (10)
1. The image reconstruction method is characterized by being applied to imaging equipment of a multilayer spiral CT system, wherein the system further comprises a radioactive source and a detector, and the detector comprises a plurality of detection modules which are arranged around a rotation center; the method comprises the following steps:
the method comprises the steps that detection data output by a detector when a radioactive source irradiates in a set middle range of the detector in the z direction are collected in advance;
determining the gravity center position of a received signal of each detection module according to the detection data, and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal;
obtaining the target position of each detection module according to the initial position of each detection module and the offset distance, wherein the initial position is determined according to the position of the detection module converted to the rotation center;
and scanning the detected body, acquiring detection data corresponding to the target position of each detection module, and reconstructing an image according to the detection data.
2. The method of claim 1, wherein each of the detection modules comprises N layers of detection units in the z-direction; the determining the gravity center position of the received signal of each detection module according to the detection data, and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal, includes:
for a detection module, determining the gravity center position of a received signal of the detection module according to detection values output by detection units of each layer and the distribution positions of the detection units of each layer in the detection module;
and obtaining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal and the physical width of each layer of detection unit.
3. The method according to claim 2, wherein determining the position of the gravity center of the received signal of the detection module according to the detection values output by the detection units of each layer and the distribution positions of the detection units of each layer in the detection module comprises:
accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result;
accumulating the detection values output by each detection unit to obtain a second accumulation result;
and dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
4. A method according to any one of claims 1 to 3, further comprising irradiating the radiation source with a slit-type beam limiter within a set mid-range of the detector in the z-direction.
5. An image reconstruction device is characterized by being applied to imaging equipment of a multi-layer spiral CT system, the system further comprises a radioactive source and a detector, and the detector comprises a plurality of detection modules which are arranged around a rotation center; the device comprises:
the acquisition unit is used for acquiring detection data output by the detector when the radioactive source irradiates in a set middle range of the detector in the z direction in advance;
the determining unit is used for determining the gravity center position of the received signal of each detection module according to the detection data and determining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal;
an obtaining unit configured to obtain a target position of each detection module according to an initial position of each detection module determined according to a position of the detection module converted to the rotation center and the offset distance;
and the reconstruction unit is used for scanning the detected body, acquiring detection data corresponding to the target position of each detection module and reconstructing an image according to the detection data.
6. The apparatus of claim 5, wherein each of the detection modules comprises N layers of detection units in the z-direction; the determining unit is specifically configured to:
for a detection module, determining the gravity center position of a received signal of the detection module according to detection values output by detection units of each layer and the distribution positions of the detection units of each layer in the detection module;
and obtaining the offset distance of each detection module relative to the set center of the detector in the z direction according to the gravity center position of the received signal and the physical width of each layer of detection unit.
7. The apparatus according to claim 5, wherein the determining unit, when configured to determine the barycentric location of the received signals of the detection modules according to the detection values output by the detection units of each layer and the distribution positions of the detection units of each layer in the detection modules, is specifically configured to:
accumulating the result of multiplying the layer number index value of each layer detection unit in the detection module by the output detection value to obtain a first accumulation result;
accumulating the detection values output by each detection unit to obtain a second accumulation result;
and dividing the first accumulation result by the second accumulation result to obtain the gravity center position of the received signal of the detection module.
8. The apparatus of any one of claims 5 to 7, further comprising a slit-type beam limiter to enable the radiation source to irradiate within a set middle range of the detector in the z-direction.
9. An imaging device, characterized in that the workstation comprises a memory for storing computer instructions executable on a processor for implementing the method of any one of claims 1 to 4 when executing the computer instructions.
10. A multislice CT system, wherein the system comprises a radiation source, a detector, and the imaging device of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911233005.8A CN111067558B (en) | 2019-12-05 | 2019-12-05 | Image reconstruction method, device, equipment and multi-layer spiral CT system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911233005.8A CN111067558B (en) | 2019-12-05 | 2019-12-05 | Image reconstruction method, device, equipment and multi-layer spiral CT system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111067558A true CN111067558A (en) | 2020-04-28 |
| CN111067558B CN111067558B (en) | 2023-05-02 |
Family
ID=70312984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911233005.8A Active CN111067558B (en) | 2019-12-05 | 2019-12-05 | Image reconstruction method, device, equipment and multi-layer spiral CT system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111067558B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112903728A (en) * | 2021-01-18 | 2021-06-04 | 浙江华电器材检测研究所有限公司 | Non-destructive testing device and method for insulation piercing connector based on CT tomography |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6049216A (en) * | 1997-10-27 | 2000-04-11 | Industrial Technology Research Institute | Contact type prober automatic alignment |
| US20100150421A1 (en) * | 2008-12-11 | 2010-06-17 | Kabushiki Kaisha Toshiba | X-ray computed tomography apparatus, medical image processing apparatus, x-ray computed tomography method, and medical image processing method |
| CN104337530A (en) * | 2013-07-23 | 2015-02-11 | 上海西门子医疗器械有限公司 | Method and system for determining central position of detector module of X-ray detector |
| CN104997529A (en) * | 2015-06-30 | 2015-10-28 | 大连理工大学 | Method for correcting cone beam CT system geometric distortion based on symmetrically repetitive template |
-
2019
- 2019-12-05 CN CN201911233005.8A patent/CN111067558B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6049216A (en) * | 1997-10-27 | 2000-04-11 | Industrial Technology Research Institute | Contact type prober automatic alignment |
| US20100150421A1 (en) * | 2008-12-11 | 2010-06-17 | Kabushiki Kaisha Toshiba | X-ray computed tomography apparatus, medical image processing apparatus, x-ray computed tomography method, and medical image processing method |
| CN101744632A (en) * | 2008-12-11 | 2010-06-23 | 株式会社东芝 | X-ray computed tomography apparatus, medical image processing apparatus, x-ray computed tomography method, and medical image processing method |
| CN104337530A (en) * | 2013-07-23 | 2015-02-11 | 上海西门子医疗器械有限公司 | Method and system for determining central position of detector module of X-ray detector |
| CN104997529A (en) * | 2015-06-30 | 2015-10-28 | 大连理工大学 | Method for correcting cone beam CT system geometric distortion based on symmetrically repetitive template |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112903728A (en) * | 2021-01-18 | 2021-06-04 | 浙江华电器材检测研究所有限公司 | Non-destructive testing device and method for insulation piercing connector based on CT tomography |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111067558B (en) | 2023-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jaffray et al. | A radiographic and tomographic imaging system integrated into a medical linear accelerator for localization of bone and soft-tissue targets | |
| EP2331945B1 (en) | Method and apparatus to improve ct image acquisition using a displaced geometry | |
| US8320518B2 (en) | Methods, apparatus, and computer-program products for increasing accuracy in cone-beam computed tomography | |
| US8873703B2 (en) | X ray imaging system with scatter radiation correction and method of using same | |
| US9237874B2 (en) | Method and system for non-invasive imaging of a target region | |
| JP6009755B2 (en) | Diagnostic imaging apparatus and method | |
| CN106340340B (en) | X-ray filtering | |
| US20100308229A1 (en) | Movable wedge for improved image quality in 3d x-ray imaging | |
| KR20070051758A (en) | X-ray ct apparatus and x-ray ct fluoroscopic apparatus | |
| CN111728632B (en) | Radiation detection device, radiation detection method and CT image reconstruction method | |
| US10719961B2 (en) | Systems and methods for improved PET imaging | |
| CN103417233B (en) | Source side monitoring device for an imaging system | |
| US20070274581A1 (en) | Methods and apparatus for BIS correction | |
| US6876718B2 (en) | Scatter correction methods and apparatus | |
| CN102271587B (en) | Method and apparatus to filter x-ray beams generated using a CT apparatus with displaced geometry | |
| EP2194876B1 (en) | Computer tomography apparatus | |
| US11432783B2 (en) | Methods and systems for beam attenuation | |
| CN111067558A (en) | Image reconstruction method, device and equipment and multilayer spiral CT system | |
| US20160174917A1 (en) | Adjustable bow-tie filter for achieving optimal snr in helical computed tomography | |
| Deng et al. | Investigation of transmission computed tomography (CT) image quality and x-ray dose achievable from an experimental dual-mode benchtop x-ray fluorescence CT and transmission CT system | |
| JP6629158B2 (en) | X-ray CT system | |
| US20190274653A1 (en) | Method and apparatus for artifact reduction for joint region in step and shoot computed tomography | |
| US20240000403A1 (en) | Region of interest computed tomography imaging using one or more static collimators | |
| KR101517770B1 (en) | The computed tomography apparatus and the meay generator and the method of operating the same | |
| US20230380782A1 (en) | Systems and methods for an integrated filter assembly with two carriages |
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 |