CN114587398B - Device for single photon emission tomography and method for processing projection data - Google Patents

Device for single photon emission tomography and method for processing projection data Download PDF

Info

Publication number
CN114587398B
CN114587398B CN202210256815.0A CN202210256815A CN114587398B CN 114587398 B CN114587398 B CN 114587398B CN 202210256815 A CN202210256815 A CN 202210256815A CN 114587398 B CN114587398 B CN 114587398B
Authority
CN
China
Prior art keywords
hole
projection data
aliasing
projection
data
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
Application number
CN202210256815.0A
Other languages
Chinese (zh)
Other versions
CN114587398A (en
Inventor
孙立风
吕振雷
马天予
刘辉
刘伟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Nuclear Energy Tianjin Equipment Co ltd
Original Assignee
China Nuclear Energy Tianjin Equipment Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by China Nuclear Energy Tianjin Equipment Co ltd filed Critical China Nuclear Energy Tianjin Equipment Co ltd
Priority to CN202210256815.0A priority Critical patent/CN114587398B/en
Publication of CN114587398A publication Critical patent/CN114587398A/en
Priority to PCT/CN2023/072030 priority patent/WO2023173921A1/en
Application granted granted Critical
Publication of CN114587398B publication Critical patent/CN114587398B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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]
    • A61B6/037—Emission tomography
    • 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
    • A61B6/06—Diaphragms
    • 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
    • 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
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5205—Devices using data or image processing specially adapted for radiation diagnosis involving processing of raw data to produce diagnostic data
    • 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
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
    • 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
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5258—Devices using data or image processing specially adapted for radiation diagnosis involving detection or reduction of artifacts or noise

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • Pathology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Physics & Mathematics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Veterinary Medicine (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biomedical Technology (AREA)
  • Biophysics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Abstract

The embodiment of the invention provides a device for single photon emission tomography and a processing method of projection data, wherein the device comprises a collimator and a shielding mechanism, the collimator comprises a receiving part and a shielding part, at least two through holes are formed on the surface of the receiving part in a recessed mode, a containing cavity is formed around the receiving part by the shielding part, rays enter the containing cavity through the through holes, the shielding mechanism is movably arranged in the containing cavity and used for shielding the rays, limiting the projection range of the through holes, dividing the projection of each through hole, avoiding artifacts in reconstructed images caused by the projection aliasing of the through holes, ensuring the integrity of imaging vision, and solving the problem that the imaging vision of each through hole is missing.

Description

Device for single photon emission tomography and method for processing projection data
Technical Field
The invention relates to the technical field of single photon emission tomography (single photon emission computed tomography, SPECT), in particular to a device for single photon emission tomography and a method for processing projection data.
Background
In single photon emission tomography, a collimator assembly is required to be placed between the human body and the detector. The multi-pinhole collimator is one of the collimators commonly used in clinic at present, the multi-pinhole collimator is generally designed into a round hole or an elliptical hole, in order to improve the detection efficiency as much as possible in the design process, the detection area of the detector is fully utilized, a certain amount of aliasing exists in the projection area of different pinholes on the detector, each pinhole imaging visual field can be lost, and certain artifacts appear on the final image.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide a device and a projection data processing method, and aims to solve the problem that the imaging field of view of each through hole in a multi-pinhole collimator in the prior art is missing.
In one aspect, an embodiment of the present invention provides an apparatus for single photon emission tomography, including: the collimator comprises a receiving part and a shielding part, the receiving part comprises at least two through holes, the at least two through holes are arranged on the surface of the receiving part at intervals, the receiving part is used for receiving rays through the through holes, and the shielding part surrounds the receiving part to form a containing cavity; the shielding mechanism is movably arranged in the accommodating cavity and used for shielding rays.
According to one aspect of the invention, the shielding mechanism comprises at least two shielding members, each shielding member being independently movable within the receiving cavity.
According to one aspect of the invention, the shielding member is rotatably and/or translationally arranged within the receiving chamber.
According to one aspect of the invention, the apparatus further comprises a detector comprising a detection surface for receiving the radiation, the detection surface being arranged towards the receiving portion such that the radiation passing through the through hole is imaged on the detection surface.
On the other hand, the invention also provides a projection data processing method, which comprises the steps that a shielding mechanism is arranged in a collimator, the collimator comprises a receiving part and a shielding part, the receiving part comprises a first through hole and a second through hole, projections of the first through hole and the second through hole on a detection surface are at least partially overlapped to form an aliasing area, the receiving part is used for receiving rays, the shielding part surrounds the receiving part to form a containing cavity, and the shielding mechanism is movably arranged in the containing cavity;
enabling the shielding mechanism to shield projection of the first through hole in the aliasing area, and collecting projection data of the first through hole and the second through hole in the aliasing area as C1 in a first period of t 0;
enabling the shielding mechanism to shield the projection of the second through hole in the aliasing area, and collecting projection data of the first through hole and the second through hole in the aliasing area as C2 in the second section t 0;
the shielding mechanism is enabled to shield the projection of the first through hole in the aliasing area, and in a third time period
Figure BDA0003548921660000021
In time, collecting projection data P3 on a detection surface through the first through hole and the second through hole;
the shielding mechanism shields the projection of the second through hole in the aliasing area in a fourth time period
Figure BDA0003548921660000022
In time, acquiring projection data P4 on a detection surface through the first through hole and the second through hole by using a probe;
partial acquisition data of the first via and the second via in a time (t-2 t 0) is determined from the projection data P3 and the projection data P4.
According to one aspect of the invention, the data processing method further comprises:
and determining projection data of the first through hole and the second through hole in the time (t-2 t 0) under the condition of no aliasing according to the partial acquired data.
According to one aspect of the invention, determining projection data of the first via and the second via without aliasing from the partial acquisition data comprises:
the projection data P3 and the projection data P4 satisfy the following relation:
P3＝P A3 ∪P C3 ∪P B3 (1)
P4＝P A4 ∪P C4 ∪P B4 (2)
wherein P is A P being the unaliased region of the first via on the detector B For the unaliased region of the second via on the detector, P C An aliasing region for the first via and the second via;
P A ∪P C for the projection area of the first through hole on the detector, P B ∪P C A projection area of the second through hole on the detector;
P C3 is the data of the aliasing area in the projection data P3, P A3 Data for unaliased region in the first via, P B3 Data of non-aliasing area in the second via, P C4 Is the data of the aliasing area in the projection data P4, P A4 Data for unaliased region in the first via, P B4 Data for the unaliased region in the second via;
in the time (t-2×t0), the projection data of the first via and the second via without aliasing satisfies the following relationship:
Figure BDA0003548921660000031
Figure BDA0003548921660000032
wherein P is First through hole Is projection data of the first through hole without aliasing in (t-2 x t 0) time, P Second through hole Is the projection data for the second via without aliasing in time (t-2 t 0).
According to one aspect of the present invention, in the step of making the shielding mechanism shield the projection of the first through hole in the aliasing area, during the first period t0, collecting the projection data of the first through hole and the second through hole in the aliasing area as C1, the method further includes: acquiring projection data P1 on a detection surface through the first through hole and the second through hole;
in the step, the shielding mechanism shields the projection of the second through hole in the aliasing area, and in the second time period t0, the projection data of the first through hole and the second through hole in the aliasing area are collected as C2, and the method further comprises the following steps: acquiring projection data P2 on a detection surface through the first through hole and the second through hole;
the projection data processing method further includes:
replacing the projection data P3 in the formula (1) with the projection data P1, and replacing the projection data P4 in the formula (2) with the projection data P2;
in (2×t0) time, the projection data of the first via and the second via without aliasing satisfies the following relationship:
P′ first through hole ＝(P A1 +P A2 )∪C2
P′ Second through hole ＝(P B1 +P B2 )∪C1
Wherein P' First through hole Is (2 x t 0) projection data of the first through hole without aliasing, P' Second through hole Is (2×t0) projection data of the second via without aliasing in time;
let P First through hole +P’ First through hole Obtaining complete projection data of the first through hole without aliasing in t time;
let P Second through hole +P’ Second through hole And obtaining complete projection data of the second through hole without aliasing in t time.
According to an aspect of the present invention, the receiving portion further includes a third through hole, and an aliasing area is present in a projection on the detection plane between the second through hole and a side of the second through hole facing away from the first through hole, and the data processing method further includes:
and determining complete projection data of the second through hole and the third through hole without aliasing.
According to one aspect of the present invention, the data acquisition method further comprises:
calculating under the condition that the shielding mechanism is in each state
Figure BDA0003548921660000041
And->
Figure BDA0003548921660000042
And determining the position of the shielding mechanism according to the proportion.
In the device of the invention, the device comprises a collimator and a shielding mechanism, the collimator comprises a receiving part and a shielding part, at least two through holes are formed on the surface of the receiving part, a containing cavity is formed around the receiving part by the shielding part, and rays enter the containing cavity through the through holes. The shielding mechanism is movably arranged in the accommodating cavity, the shielding mechanism can limit the projection range of the through holes by shielding rays, the shielding mechanism can shield the projection of each through hole in the aliasing area more accurately by moving, the projection of each through hole is separated, the aliasing area is not existed any more, the obtained projection image of a single through hole is more accurate, the artifacts in the reconstructed image caused by the projection aliasing of the through hole are avoided, the integrity of the imaging view field is ensured, and the problem that the imaging view field of each through hole is missing is solved.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings, in which like or similar reference characters designate like or similar features.
FIG. 1 is a schematic view of an apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a detection surface according to an embodiment of the present invention;
FIG. 3 is a schematic view of a projection of a first via and a second via provided in an embodiment of the present invention;
fig. 4 is a flow chart of a method for processing projection data according to an embodiment of the present invention;
fig. 5 is a flowchart of a method for processing projection data according to an embodiment of the present invention.
Reference numerals illustrate:
10. a collimator; 20. a detector; 30. a shielding mechanism; 40. a ray;
100. a receiving section; 101. a through hole; 101a, a first through hole; 101b, a second through hole; 110. a shielding part; 120. a receiving chamber;
200. a detection surface; 201. an aliasing region;
300. a shielding member.
Detailed Description
Features and exemplary embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by showing examples of the invention. In the drawings and the following description, at least some well-known structures and techniques have not been shown in detail in order not to unnecessarily obscure the present invention; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
In the description of the present invention, it should be noted that, unless otherwise indicated, the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicate or are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements in question must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The directional terms appearing in the following description are all directions shown in the drawings and do not limit the specific structure of the embodiment of the present invention. In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed", "connected" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected or integrally connected; can be directly connected or indirectly connected. The specific meaning of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.
For a better understanding of the present invention, the apparatus of the embodiments of the present invention will be described in detail with reference to fig. 1 to 3.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an apparatus for single photon emission tomography according to an embodiment of the present invention.
According to the present invention there is provided an apparatus comprising: a collimator 10, the collimator 10 including a receiving portion 100 and a shielding portion 110, the receiving portion 100 including at least two through holes 101, the through holes 101 being disposed on a surface of the receiving portion 100 at intervals, the receiving portion 100 being configured to receive the radiation 40 through the through holes 101, the shielding portion 110 forming a receiving cavity 120 around the receiving portion 100; the shielding mechanism 30, the shielding mechanism 30 is movably disposed in the accommodating cavity 120, and the shielding mechanism 30 is used for shielding the ray 40.
In the device according to the embodiment of the present invention, the device includes a collimator 10 and a shielding mechanism 30, the collimator 10 includes a receiving portion 100 and a shielding portion 110, the shielding portion 110 forms a receiving cavity 120 around the receiving portion 100, at least two through holes 101 are formed through a surface of the receiving portion 100, and the radiation 40 enters the receiving cavity 120 through the through holes 101. The shielding mechanism 30 is movably arranged in the accommodating cavity 120, the shielding mechanism 30 moves in the accommodating cavity 120, the projection of each through hole 101 in the aliasing area 201 can be shielded more accurately by moving the shielding mechanism 30, the projections of each through hole 101 are separated, the aliasing area 201 is not existed any more, the obtained projection image of a single through hole 101 is more accurate, the artifact in the reconstructed image caused by the projection aliasing of the through hole 101 is avoided, the integrity of the imaging view is ensured, and the problem that the imaging view of each through hole 101 is missing is solved.
In some alternative embodiments, the shutter mechanism 30 includes at least two shutter members 300, each shutter member 300 being independently movable within the receiving chamber 120.
In these alternative embodiments, the shielding member 300 moves in the accommodating chamber 120 to shield the rays 40 passing through the through hole 101. The shielding members 300 move to different positions in the accommodating cavity 120 according to requirements, so that rays 40 of the through holes 101 are shielded simultaneously, the projection range of the through holes 101 is limited, the projection aliasing of the through holes 101 is avoided, and the obtained projection images of the through holes are more accurate.
In some alternative embodiments, the shutter member 300 is rotatably and/or translationally disposed within the receiving cavity 120.
In these alternative embodiments, the shielding member 300 may be moved within the accommodating chamber 120 by rotation and/or translation, so as to change the shielding area or position of the shielding member 300, and thus change the projection range of each through hole 101, and by moving the shielding member 300, it may be possible to arbitrarily divide the area occupied by different through holes 101 in the aliasing area 201.
In some alternative embodiments, the apparatus further comprises a detector 20, the detector 20 comprising a detection surface 200 for receiving the radiation 40, the detection surface 200 being arranged towards the receiving portion 100 such that the radiation 40 passing through the through hole 101 is imaged at the detection surface 200.
In these alternative embodiments, the radiation 40 passes through the through hole 101 of the receiving portion 100 to form a projection on the detector 20, and the detecting surface 200 faces the receiving portion 100, so that the radiation 40 forms an image on the detecting surface 200, and according to the projection formed on the detecting surface 200, the shielding range of the shielding component 300 can be changed in real time, so as to flexibly adjust the area occupied by the through hole 101 corresponding to the projection of the aliasing area 201 on the detecting surface 200.
Referring to fig. 1 to 5, fig. 2 is a schematic structural diagram of a detection surface provided by an embodiment of the present invention, fig. 3 is a schematic projection diagram of a first through hole 101a and a second through hole 101b provided by an embodiment of the present invention, fig. 4 is a schematic flow diagram of a method for processing projection data provided by an embodiment of the present invention, and fig. 5 is a schematic flow diagram of a method for processing projection data provided by an embodiment of the present invention. The second embodiment of the present invention further provides a method for processing projection data, where the method is completed by using the apparatus of any one of the above embodiments, and the processing method includes:
step S1: a shielding mechanism 30 is provided in the collimator 10.
As described above, the collimator 10 includes the receiving portion 100 and the shielding portion 110, the receiving portion 100 includes the first through hole 101a and the second through hole 101b, projections of the first through hole 101a and the second through hole 101b on the detection surface 200 overlap at least partially to form the aliasing area 201, the receiving portion 100 is configured to receive the radiation 40, the shielding portion 110 forms the accommodating cavity 120 around the receiving portion 100, and the shielding mechanism 30 is movably disposed in the accommodating cavity 120.
Step S2: the shielding mechanism 30 is caused to shield the projection of the first through hole 101a in the aliasing area 201. During a first period t0, projection data C1 of the first via 101a and the second via 101b in the aliasing area 201 are acquired.
As described above, the projection obtained by the detection surface 200 is the projection of the second through hole 101b and the projection of the first through hole 101a without the aliasing area 201, and the data obtained in step S2 is the projection data of the second through hole 101b and the projection data of the first through hole 101a without the aliasing area 201, so that the aliasing of the first through hole 101a and the second through hole 101b is avoided, and the obtained projection data is more accurate.
Step S3: the shielding mechanism 30 is caused to shield the projection of the second through hole 101b in the aliasing area 201, and in the second period t0, projection data C2 of the first through hole 101a and the second through hole 101b of the second through hole 101a and the first through hole 101a in the aliasing area 201 are acquired.
As described above, the projection obtained by the detection surface 200 is the projection of the first through hole 101a and the projection of the second through hole 101b without the aliasing area 201, and the data obtained in step S3 is the projection data of the first through hole 101a and the projection data of the second through hole 101b without the aliasing area 201, so that the aliasing of the first through hole 101a and the second through hole 101b is avoided, and the obtained projection data is more accurate. Step S4: the shielding mechanism shields the projection of the first through hole 101a in the aliasing area in a third time period
Figure BDA0003548921660000081
In time, projection data P3 on the detection surface through the first through hole 101a and the second through hole 101b are acquired.
As described above, the projection obtained by the detection surface 200 is the projection of the second through hole 101b and the projection of the first through hole 101a without the aliasing area 201, and the data obtained in step S4 is the projection data of the second through hole 101b and the projection data of the first through hole 101a without the aliasing area 201, so that the aliasing of the first through hole 101a and the second through hole 101b is avoided, and the obtained projection data is more accurate.
Step S5: the shielding mechanism shields the projection of the second through hole 101b in the aliasing area in the fourth time period
Figure BDA0003548921660000082
In time, projection data P4 on the detection surface through the first through hole 101a and the second through hole 101b are acquired.
As described above, the projection obtained by the detection surface 200 is the projection of the first through hole 101a and the projection of the second through hole 101b without the aliasing area 201, and the data obtained in step S5 is the projection data of the first through hole 101a and the projection data of the second through hole 101b without the aliasing area 201, so that the aliasing of the first through hole 101a and the second through hole 101b is avoided, and the obtained projection data is more accurate.
The sequence of step S2 and step S3 is not limited. Step S2 may be performed prior to step S3, or step S3 may be performed prior to step S2. The sequence of step S4 and step S5 is not limited. Step S4 may be performed prior to step S5, or step S5 may be performed prior to step S4. As long as it is ensured that the corresponding acquisition data can be obtained.
Step S6: partial acquisition data of the first via 101a and the second via 101b in the (t-2 t 0) time is determined from the projection data P3 and the projection data P4.
In the above step S2, in the first period t0, when the shielding mechanism 30 shields the projection of the first through hole 101a in the aliasing area 201, the obtained projection data is the projection data of the second through hole 101b and the first through hole 101a not including the aliasing area 201, and at this time, the projection data of the first through hole 101a in the aliasing area 201 cannot be obtained. Similarly, in step S3, in the second period t0, when the shielding mechanism 30 shields the projection of the second through hole in the aliasing area 201, the obtained projection data is the projection data of the first through hole 101a and the second through hole 101b which do not include the aliasing area 201, and at this time, the projection data of the second through hole 101b in the aliasing area 201 cannot be obtained. The duration of the first section t0 time and the second section t0 time are both t0.
In step S4 and step S5, the time distribution is performed according to the ratio of C1 to C2, and the projection data P3 and the projection data P4 are acquired, where the projection data P3 is the projection data P3 of the second through hole 101b and the first through hole 101a not including the aliasing area 201, and the projection data P4 is the projection data P4 of the first through hole 101a and the second through hole 101b not including the aliasing area 201, and the time distribution is performed according to the ratio of C1 to C2, so that the acquisition efficiency is improved, and the image quality is improved.
As described above, the projection data of the first through hole 101a and the second through hole 101b without aliasing in the time (t-2 t 0) can be determined according to the obtained partial acquired data, so as to determine the respective complete projection data of the first through hole 101a and the second through hole 101b in the time t, thereby facilitating the reconstruction of a complete image. Therefore, in the embodiment of the present invention, during the data acquisition process, the shielding mechanism 30 is made to shield the projection of the first through hole 101a and the second through hole 101b in the aliasing area 201, and then acquire the projection data of the first through hole 101a and the second through hole 101b on the detection surface 200, and determine the partial acquired data in the time (t-2 t 0) according to the projection data, so as to determine the projection data of each through hole of the first through hole 101a and the second through hole 101b in the time (t-2 t 0) without aliasing according to the partial acquired data. The shielding mechanism 30 shields the projections of the first through hole 101a and the second through hole 101b in the aliasing area 201 respectively, so that artifacts in the reconstructed image caused by the aliasing of the projections of the through hole 101 are avoided, the loss of the imaging field of view is avoided, and the integrity of the imaging field of view is ensured.
In some alternative embodiments, the projection data processing method further comprises step S7: projection data of the first through hole 101a and the second through hole 101b without aliasing in a time (t-2 t 0) are determined from the partial acquisition data.
In these optional embodiments, by using the shielding component 300 to shield the projection of the first through hole 101a and the second through hole 101b in the aliasing area 201 respectively, collecting the partial collected data in the (t-2×t0) time, determining the projection data of the first through hole 101a and the second through hole 101b in the (t-2×t0) time without aliasing according to the partial collected data, further avoiding the artifact in the reconstructed image caused by the projection aliasing of the through hole 101, avoiding the lack of the imaging field of view, and ensuring the integrity of the imaging field of view.
Referring to fig. 3, in some alternative embodiments, step S7 further includes:
the projection data P3 and the projection data P4 satisfy the following relation:
P3＝P A3 ∪P C3 ∪P B3 (1)
P4＝P A4 ∪P C4 ∪P B4 (2)
wherein P is A For the unaliased region, P, of the first via 101a on the detector 20 B For the unaliased region, P, of the second via 101b on the detector 20 C An aliasing region 201 for the first via 101a and the second via 101 b;
P A ∪P C p is the projection area of the first through hole 101a on the detector 20 B ∪P C Is the projection area of the second through hole 101b on the detector 20;
P C3 for the number of projectionsAccording to the data of the aliasing area 201 in P3, P A3 Data for the unaliased region in the first via 101a, P B3 Data of the unaliased area in the second via 101b, P C4 Is the data of the aliasing area 201 in the projection data P4, P A4 Data for the unaliased region in the first via 101a, P B4 Data for the unaliased region in the second via 101 b;
in the time (t-2×t0), the projection data of the first via 101a and the second via 101b in the absence of aliasing satisfies the following relationship:
Figure BDA0003548921660000101
Figure BDA0003548921660000102
wherein P is First through hole Is projection data of the first via 101a without aliasing in (t-2 x t 0), P Second through hole Is the projection data of the second via 101b without aliasing in the (t-2 x t 0) time.
In these alternative embodiments, P A 、P B And P C The projection data of the region can be directly obtained according to the spatial position projected on the detection plane 200, and the projection data of the aliasing region 201 in the time (t-2×t0) is corrected according to the acquisition time, so that the projection data of the aliasing region 201 missing from the first through hole 101a and the second through hole 101b in step S4 and step S5 can be obtained, and thus the complete projection data of each through hole 101 in the time (t-2×t0) without aliasing can be obtained by calculation.
In some alternative embodiments, in step S2, further comprising: acquiring projection data P1 on the detection surface 200 through the first through hole 101a and the second through hole 101 b;
in step S3, further comprising: acquiring projection data P2 on the detection surface 200 through the first through hole 101a and the second through hole 101 b;
the projection data processing method further includes:
step S8: replacing the projection data P3 in the formula (1) with the projection data P1, and replacing the projection data P4 in the formula (2) with the projection data P2; in the (2×t0) time, the projection data of the first via 101a and the second via 101b in the absence of aliasing satisfies the following relationship:
P′ first through hole ＝(P A1 +P A2 )∪C2
P′ Second through hole ＝(P B1 +P B2 )∪C1
Wherein P' First through hole Is (2×t0) projection data of the first via 101a without aliasing in time, P' Second through hole Is the projection data of the second via 101b without aliasing in (2×t0) time;
step S9: let P First through hole +P’ First through hole Obtaining complete projection data of the first through hole 101a without aliasing in t time;
step S10: let P Second through hole +P’ Second through hole And obtaining complete projection data of the second through hole 101b without aliasing in the t time.
As described above, in step S8, the projection data of the aliasing area 201 in the time (2×t0) is corrected according to the acquisition time, so that the projection data of the aliasing area 201 in which the first via hole 101a and the second via hole 101b are missing in step S2 and step S3 can be obtained, and thus the complete projection data of each via hole 101 in the time (2×t0) without aliasing can be calculated. The same method as in step S7 is used to accumulate the obtained projection data P1 and P2 into the projection data of the through hole 101, step S9 obtains the complete projection data of the first through hole 101a in the t time under the condition of no aliasing, step S10 obtains the complete projection data of the first through hole 101a in the t time under the condition of no aliasing, and the complete projection data of all through holes 101 under the condition of no aliasing is obtained, so that the image reconstruction is performed by using the conventional nuclear medicine image reconstruction algorithm, the final reconstructed image is obtained, and the defect of imaging vision is further avoided.
In some alternative embodiments, the receiving part 100 further includes a third through hole, and the projection on the detection surface 200 between the second through hole 101b and the second through hole 101b on a side facing away from the first through hole 101a has an aliasing area 201, and the data processing method further includes step S11: the complete projection data of the second and third vias without aliasing is determined.
In these alternative embodiments, the projection of the first through hole 101a, the second through hole 101b and the third through hole in the aliasing area 201 is respectively blocked by using the blocking mechanism 30, and the data is acquired by using the probe, so that the complete projection data of each through hole 101 under the condition of no aliasing is determined, the projection data acquisition of a plurality of through holes 101 is realized, and the integrity of the imaging field of view is further ensured.
In some alternative embodiments, the data processing method further comprises step S12:
calculation with the occlusion mechanism 30 in each state
Figure BDA0003548921660000121
And->
Figure BDA0003548921660000122
The ratio, the position of the shutter mechanism 30 is determined according to the ratio.
In these alternative embodiments, the projection data is used in accordance with the data
Figure BDA0003548921660000123
And->
Figure BDA0003548921660000124
The optimal shielding position of the shielding mechanism 30 is determined according to the proportion, so that an optimal acquisition scheme is ensured, the acquisition efficiency is improved, and the image quality is improved.
In accordance with the above embodiments of the invention, these embodiments are not exhaustive of all details, nor are they intended to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and the full scope and equivalents thereof.

Claims (7)

1. An apparatus for single photon emission tomography, comprising:
the collimator comprises a receiving part and a shielding part, wherein the receiving part comprises at least two through holes, the at least two through holes are arranged on the surface of the receiving part at intervals, the receiving part is used for receiving rays through the through holes, and the shielding part surrounds the receiving part to form a containing cavity;
the shielding mechanism is movably arranged in the accommodating cavity and used for shielding the rays;
the detector comprises a detection surface for receiving the rays, the detection surface is arranged towards the receiving part, so that rays passing through the through holes are imaged on the detection surface, projections of two adjacent through holes on the detection surface are at least partially overlapped to form an aliasing area, and the shielding mechanism is only used for shielding the projection of one of the two adjacent through holes on the aliasing area.
2. The device of claim 1, wherein the shielding mechanism comprises at least two shielding members, each of the shielding members being independently movable within the receiving cavity.
3. The device according to claim 2, wherein the shielding member is rotatably and/or translatably arranged within the receiving cavity.
4. A method of processing projection data, comprising:
a shielding mechanism is arranged in the collimator, the collimator comprises a receiving part and a shielding part, the receiving part comprises a first through hole and a second through hole, projections of the first through hole and the second through hole on a detection surface are at least partially overlapped to form an aliasing area, the receiving part is used for receiving rays, a containing cavity is formed around the receiving part by the shielding part, and the shielding mechanism is movably arranged in the containing cavity;
enabling the shielding mechanism to shield projection of the first through hole in the aliasing area, and collecting projection data in the aliasing area as C1 in a first period of time t 0;
enabling the shielding mechanism to shield the projection of the second through hole in the aliasing area, and collecting projection data in the aliasing area as C2 in the time of a second section t 0;
enabling the shielding mechanism to shield the projection of the first through hole in the aliasing area, and enabling the shielding mechanism to shield the projection of the first through hole in the aliasing area in a third time period
Figure FDA0004241076530000011
In time, collecting projection data P3 on the detection surface through the first through hole and the second through hole;
the shielding mechanism shields the projection of the second through hole in the aliasing area in a fourth time period
Figure FDA0004241076530000021
Collecting projection data P4 on the detection surface through the first through hole and the second through hole in time;
determining partial acquisition data of the first through hole and the second through hole in (t-2 t 0) time according to the projection data P3 and the projection data P4;
determining projection data of the first through hole and the second through hole in the (t-2 t 0) time under the condition of no aliasing according to the partial acquired data;
wherein determining (t-2 t 0) projection data of the first via and the second via in the absence of aliasing in time from the partial acquisition data comprises:
the projection data P3 and the projection data P4 satisfy the following relation:
P3＝P A3 ∪P C3 ∪P B3 (1)
P4＝P A4 ∪P C4 ∪P B4 (2)
wherein P is A P being the unaliased region of the first via on the detector B P for the unaliased region of the second via on the detector C The aliasing region for the first via and the second via;
P A ∪P C p is the projection area of the first through hole on the detector B ∪P C A projection area of the second through hole on the detector;
P C3 is the data of the aliasing area in the projection data P3, P A3 P is the data of the unaliased region in the first via B3 P is the data of the unaliased region in the second via C4 Is the data of the aliasing area in the projection data P4, P A4 P is the data of the unaliased region in the first via B4 Data for the unaliased region in the second via;
in (t-2×t0), the projection data of the first via and the second via without aliasing satisfies the following relationship:
Figure FDA0004241076530000022
Figure FDA0004241076530000023
wherein P is First through hole For the projection data of the first via without aliasing in the (t-2 t 0) time, P Second through hole Is the projection data of the second via without aliasing in the (t-2 x t 0) time.
5. The projection data processing method of claim 4, wherein,
in the step of enabling the shielding mechanism to shield the projection of the first through hole in the aliasing area, collecting projection data of the first through hole and the second through hole in the aliasing area as C1 in a first period of time t0, the method further comprises the following steps: acquiring projection data P1 on the detection surface through the first through hole and the second through hole;
in the step of enabling the shielding mechanism to shield the projection of the second through hole in the aliasing area, collecting projection data of the first through hole and the second through hole in the aliasing area as C2 in a second period of time t0, the method further comprises the following steps: acquiring projection data P2 on the detection surface through the first through hole and the second through hole;
the projection data processing method further includes:
replacing the projection data P3 in the formula (1) with the projection data P1, and replacing the projection data P4 in the formula (2) with the projection data P2;
in (2×t0) time, projection data of the first via and the second via in the absence of aliasing satisfies the following relationship:
P′ first through hole ＝(P A1 +P A2 )∪C2
P′ Second through hole ＝(P B1 +P B2 )∪C1
Wherein P' First through hole For the projection data of the first via without aliasing in the (2×t0) time, P' Second through hole Projection data for the second via without aliasing for the (2 x t 0) time;
let P First through hole +P’ First through hole Obtaining complete projection data of the first through hole without aliasing in the t time;
let P Second through hole +P′ Second through hole And obtaining complete projection data of the second through hole without aliasing in the t time.
6. The projection data processing method according to claim 5, wherein the receiving portion further includes a third through hole, the aliasing area exists in a projection on the detection surface between the second through hole and the second through hole on a side of the second through hole facing away from the first through hole, the data processing method further comprising:
and determining complete projection data of the second through hole and the third through hole without aliasing.
7. The projection data processing method of claim 5, further comprising:
calculating under the state that the shielding mechanism is in each state
Figure FDA0004241076530000041
And->
Figure FDA0004241076530000042
And determining the position of the shielding mechanism according to the proportion.
CN202210256815.0A 2022-03-16 2022-03-16 Device for single photon emission tomography and method for processing projection data Active CN114587398B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202210256815.0A CN114587398B (en) 2022-03-16 2022-03-16 Device for single photon emission tomography and method for processing projection data
PCT/CN2023/072030 WO2023173921A1 (en) 2022-03-16 2023-01-13 Apparatus for single photon emission computed tomography, and processing method for projection data

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210256815.0A CN114587398B (en) 2022-03-16 2022-03-16 Device for single photon emission tomography and method for processing projection data

Publications (2)

Publication Number Publication Date
CN114587398A CN114587398A (en) 2022-06-07
CN114587398B true CN114587398B (en) 2023-07-04

Family

ID=81818657

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210256815.0A Active CN114587398B (en) 2022-03-16 2022-03-16 Device for single photon emission tomography and method for processing projection data

Country Status (2)

Country Link
CN (1) CN114587398B (en)
WO (1) WO2023173921A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114587398B (en) * 2022-03-16 2023-07-04 中核高能(天津)装备有限公司 Device for single photon emission tomography and method for processing projection data

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6438195B1 (en) * 2001-01-26 2002-08-20 Ge Medical Systems Global Technology Company, Llc Methods and apparatus for compensating for view aliasing artifacts
US7166846B2 (en) * 2004-06-30 2007-01-23 Siemens Medical Solutions Usa, Inc. Multi-pinhole collimation for nuclear medical imaging
US8577113B2 (en) * 2009-10-22 2013-11-05 Koninklijke Philips N.V. Image reconstruction for truncated detector array
EP2707750B1 (en) * 2011-05-10 2016-01-06 Universiteit Gent Methods and systems for collimating
CN202408923U (en) * 2011-11-25 2012-09-05 母治平 Collimation device for transmitting chromatography
CN104095643A (en) * 2013-04-08 2014-10-15 上海联影医疗科技有限公司 X-ray imaging device
CN205433722U (en) * 2015-12-25 2016-08-10 上海联影医疗科技有限公司 Collimator
DE102016205176A1 (en) * 2016-03-30 2017-10-05 Siemens Healthcare Gmbh Apparatus and method for creating an X-ray panoramic image
HUP1600577A2 (en) * 2016-10-14 2018-06-28 Mediso Medical Imaging Systems Kft Imaging device with tomography apparatus
ES2757984B2 (en) * 2018-10-31 2021-02-16 Univ Valencia Politecnica DEVICE FOR THE DETECTION OF GAMMA RAYS WITH ACTIVE SEALS
ES2850778B2 (en) * 2020-02-28 2023-02-21 Consejo Superior Investigacion GAMMA RAY DETECTOR WITH MULTI-HOLE COLLIMATOR AND VARIABLE SAMPLING REGION
CN111803112A (en) * 2020-07-23 2020-10-23 佛山原子医疗设备有限公司 Multi-ring collimator imaging structure and imaging device of full-ring SPECT
CN111992514B (en) * 2020-08-06 2022-03-25 北京霍里思特科技有限公司 Double-light-source signal acquisition unit and signal acquisition method of wide intelligent sorting equipment
CN114587398B (en) * 2022-03-16 2023-07-04 中核高能(天津)装备有限公司 Device for single photon emission tomography and method for processing projection data

Also Published As

Publication number Publication date
CN114587398A (en) 2022-06-07
WO2023173921A1 (en) 2023-09-21

Similar Documents

Publication Publication Date Title
CN105078495B (en) PET-CT scanning imaging method and related imaging method
US3927318A (en) Cross-sectional fluorescent imaging system
Townsend et al. The SMART scanner: a combined PET/CT tomograph for clinical oncology
US9044189B2 (en) Method and computed tomography system for generating weighted tomographic image datasets
US8373135B2 (en) Counting detector and computed tomography system
US20080302950A1 (en) System and Method for Performing Single Photon Emission Computed Tomography (Spect) with a Focal-Length Cone-Beam Collimation
US10646176B2 (en) Layered radiation detector
Case et al. Taking the perfect nuclear image: quality control, acquisition, and processing techniques for cardiac SPECT, PET, and hybrid imaging
Nömayr et al. Anatomical accuracy of hybrid SPECT/spiral CT in the lower spine
CN114587398B (en) Device for single photon emission tomography and method for processing projection data
JP7254322B2 (en) Collimator for medical image processing system and its image reconstruction method
US7476025B2 (en) Shadow mask for an X-ray detector, computed tomography unit having a shadow mask, and a method for adjusting a shadow mask
Dey Improvement of performance of cardiac SPECT camera using curved detectors with pinholes
Inoue et al. Accuracy of standardized uptake value measured by simultaneous emission and transmission scanning in PET oncology
CN102988070B (en) Produce method and the computer-tomographic system of tomographic image data group
Takahashi et al. Attenuation correction of myocardial SPECT images with X-ray CT: effects of registration errors between X-ray CT and SPECT
JP2004166923A (en) X-ray computed tomography imaging apparatus
CN106232008A (en) Computer tomography (CT) blended data collection
Scarfone et al. Breast tumour imaging using incomplete circular orbit pinhole SPET: A phantom study
Almquist et al. Clinical implication of down-scatter in attenuation-corrected myocardial SPECT
JP2000139893A (en) Ct device
Nichols et al. Instrumentation quality assurance and performance
Seret et al. 180 Pinhole SPET with a tilted detector and OS-EM reconstruction: phantom studies and potential clinical applications
EP0747728B1 (en) Improved gamma camera imaging system
Britten et al. Motion detection and correction using multi-rotation 180 single-photon emission tomography for thallium myocardial imaging

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