CN110680372A

CN110680372A - Computed tomography method and system

Info

Publication number: CN110680372A
Application number: CN201911035556.3A
Authority: CN
Inventors: 金阿水
Original assignee: Individual
Current assignee: Shanghai tongxinze technology development partnership (L.P.)
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2020-01-14

Abstract

The invention relates to a computer tomography method, which uses at least one CT frame to realize exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the method comprises the steps that a CT frame is arranged on a frame base and can linearly move along a scanning base to form an imaging system, and a housing with a ray shielding effect is arranged outside the imaging system; during scanning, a scanning object is placed in the housing and is static relative to the housing, and the CT machine frame makes linear motion on the machine frame base to complete scanning on the scanning object. Based on the scanning method, the CT system with small system floor area, low scanning dose and/or good shielding performance can be constructed. Correspondingly, the invention also provides a computed tomography system constructed on the basis of the scanning method.

Description

Computed tomography method and system

Technical Field

The invention relates to a computed tomography technology, in particular to a computed tomography method and a computed tomography system constructed based on the computed tomography method.

Background

The CT gantry and the housing of existing computed tomography systems (CT scanning systems) are relatively stationary, the CT gantry is fixed to the housing, and the central plane of the beam does not move relative to the housing during scanning. During scanning, a scanning object is placed on a special scanning bed, and scanning is completed by moving a bed surface to enable a detection object to pass through a scanning ray plane. In another design, the scan object is placed on a stationary couch top, and during scanning, the scanning is performed by moving the entire system (with the CT gantry and housing fixed) so that the scanning beam plane moves across the scan object.

In the case that the scanning bed and the CT gantry are considered, and the collision interference between the scanning object and the CT gantry is considered, the whole CT system has a relatively high requirement on the floor space, and a general medical CT system needs at least 2.5 × 4M²The area space of (a).

In addition, because the bed surface of the scanning bed and the collision risk which may be generated when the scanning object placed on the bed surface moves relative to the housing are considered, the central opening of the system is generally designed to be much larger than the size of the scanning object, for example, in a medical CT system, the aperture of the system is generally designed to be larger than 65cm, so as to ensure that the mutual collision caused by the relative movement during the scanning process is avoided, because when a collision condition occurs, the system can cause personal injury to the patient or cause the scanning failure; due to the aperture limitation, the distance from the focal point to the detector surface is generally larger than 90 cm; for certain applications, such as when scanning only the arm or leg, an aperture of 25-30cm is sufficiently large that the focal point to detector surface distance can be reduced to less than 45 cm; since the attenuation of the X-ray is proportional to the square of the distance, reducing the distance from the focal spot to the detector surface can greatly reduce the power of the system, thereby greatly reducing the scanning dose, and simplifying and reducing the design requirements. Furthermore, because the opening of a general CT system is open to allow objects to pass through conveniently in consideration of the collision risk that may occur when the bed surface of the scanning bed and the scanning object placed thereon move relative to the housing, but this also means that complete radiation shielding of the whole system cannot be achieved, a general medical CT requires to be used in a room with radiation shielding, and the CT room needs to cost hundreds of thousands of renminbi additionally in order to shield X-rays, which is high in use cost.

Furthermore, when the existing CT system scans some special detection objects, the scanning manner provided by the existing CT system is not optimized enough, so that some body parts that are not necessarily examined are also irradiated by the radiation. For example, even if only one arm needs to be checked, the corresponding upper body can be scanned together during scanning.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a computed tomography method. Based on the scanning method, the CT system with small system floor area, low scanning dose and/or good shielding performance can be constructed. Correspondingly, the invention also provides a computed tomography system constructed on the basis of the scanning method.

For the scanning method, the technical scheme of the invention is as follows: the computed tomography method comprises the steps of using at least one CT frame to carry out exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the method is characterized in that a CT frame is arranged on a frame base and can do linear motion along a scanning base to form an imaging system, and the imaging system is covered by a cover; during scanning, a scanning object is placed in the housing and is static relative to the housing, and the CT machine frame makes linear motion on the machine frame base to complete scanning on the scanning object.

Compared with the prior art, the scanning method of the invention realizes scanning by adopting the mode that the scanning object is static relative to the housing and the CT frame moves relative to the housing, which is beneficial to constructing the CT system with small system occupation area, low scanning dose and/or good shielding performance, and comprises the following steps:

(1) under the condition that the hole depth of the housing is long enough, the function of the scanning bed can be directly integrated on the housing, so that a special scanning bed is not needed any more, and the design of the scanning bed integrated on the housing is simpler; meanwhile, because the independently placed scanning bed is removed, the floor area of the whole CT system can be greatly reduced;

(2) the aperture of the system can be realized to be far smaller than the slender aperture of the existing common CT, and the collision problem caused by too small aperture is not needed to be worried about, the system with the aperture can be used as a special scanning device for human limbs, for example, the scanning dose of the CT system can be greatly reduced when the distance from the focus to the surface of a detector is reduced, and the scanning can be completed by the scanning dose far smaller than the common CT in the design;

(3) the housing can be made of ray shielding materials, or the ray shielding materials are additionally superposed on the shell; when scanning, the opening is shielded by the ray shielding component, thereby realizing the complete ray shielding of the whole system.

For a scanning system, the invention provides the following technical scheme: the computer tomography system comprises at least one CT frame, wherein the CT frame can realize exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the CT machine frame is arranged on the scanning base and can do linear motion along the scanning base to form an imaging system; the imaging system is arranged in the imaging system; at least one end of the housing is opened, so that a scanning object can be placed on the scanning bed and enter the housing through moving the bed surface of the scanning bed.

Compared with the prior art, the computed tomography system can realize 100% ray shielding by adopting the ray shielding material to manufacture the housing or overlapping the ray shielding material on the housing and arranging the shielding component at the opening part during scanning, thereby not needing to shield a machine room, not only having low use cost, but also having wider application range.

Preferably, in the computed tomography system, only one end of the housing is open, so as to form a blind hole structure. At the moment, 100% ray shielding can be realized only by arranging the shielding component at one end of the opening, and the use is more convenient and easier.

Preferably, in the computed tomography system, the scanning bed is integrated on the housing. The design can reduce the floor space of the CT system.

Preferably, in the computed tomography system, the scanning base is fixedly connected to the housing. The scanning base is fixedly connected to the housing, the integrity is good, the field installation and debugging are simple, the number of parts of the whole machine is less, and the control of the manufacturing cost is facilitated. Further, the cover is arranged on a movable chassis system. Therefore, the whole CT system can be moved, is convenient to carry and has wider application range.

Preferably, in the CT scanning system, the CT gantry is coupled to the scanning base through a guide rail and can be driven by the electric lead screw to move along the guide rail. The design has the advantages of high reliability of the mechanical structure and easy implementation.

Preferably, in the computed tomography system, the scanning base is provided with more than two independent CT frames. At this time, different scanning combinations can be realized, and backup can be performed mutually, or the working efficiency can be improved.

For the scanning system, the invention also provides the following technical scheme: the computer tomography system comprises at least one CT frame, wherein the CT frame can realize exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the CT machine frame is arranged on the scanning base and can do linear motion along the scanning base to form an imaging system; the imaging system is arranged in the imaging system; the end of the cover casing is provided with an opening with the size matched with the size of the scanning object, so that the scanning object can enter the interior of the cover casing.

Compared with the prior art, the aperture of the computed tomography system can be realized to be far smaller than the slender aperture of the existing common CT, the collision problem caused by too small aperture is not worried about, the system with the aperture can be used as a special scanning device for human limbs, the scanning dose of the CT system can be greatly reduced when the distance from the focus to the surface of the detector is reduced, and the design can complete scanning by the scanning dose far smaller than the common CT.

Preferably, in the computed tomography system, the casing has a structure capable of supporting a scanning object therein. Thereby, the scanning object is effectively supported.

Drawings

FIG. 1 is a schematic diagram of a conventional CT system of the prior art;

FIG. 2 is a schematic structural view of a CT gantry;

FIG. 3 is a schematic diagram of a CT system according to the present invention;

FIG. 4 is a front view of an imaging system of the CT system of the present invention;

FIG. 5 is a schematic diagram of a back side view of the imaging system of the CT system of FIG. 4 of the present invention;

FIG. 6 is a schematic diagram of a CT system with two CT frames constructed according to the method of the present invention;

FIG. 7 is a schematic structural diagram of a CT system specially used for a scanning head and constructed based on the method of the invention;

FIG. 8 is a schematic structural diagram of a CT system specially used for scanning an ear-nose part and constructed based on the method of the invention;

FIG. 9 is a schematic structural diagram of a CT system constructed based on the method of the present invention and used for scanning a hand and an arm;

FIG. 10 is a schematic structural diagram of a CT system constructed based on the method of the present invention and used for scanning feet and legs;

FIG. 11 is a schematic structural diagram of a CT system constructed based on the method of the present invention and used for scanning children;

fig. 12 is a schematic view of the CT system of fig. 11 integrated with a scanning table.

The labels in the figures are: 1-scanning the object; 2-CT frame, 201-X ray source, 202-X ray detector, 203-high voltage generator, 204-functional module, 205-mechanical electronic module, 206-rotating bearing, 207-rotating sensor, 208-slip ring system; 3-a housing; 4-scanning base, 401-guide rail, 402-electric screw rod; 5-user interface and computer system; 6-a chassis system; 7-scanning the bed; 8-key and switch module, 9-shell.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

Referring to fig. 1, a conventional prior art CT system is shown: during operation of a conventional CT gantry 2, the CT gantry 2 has only a circumferential rotational movement inside the housing 9, and otherwise has no relative displacement in the axial direction. Referring to fig. 2, the CT gantry 2 is provided with an X-ray source 201, an X-ray detector 202, a high voltage generator 203 for supplying power to the X-ray source, a functional module 204 for controlling and processing the rotating components and data thereof, and a mechanical electronic module 205 for controlling and driving the gantry to rotate. The CT gantry 2 is directly fixedly connected to the housing 9. During the scanning process, the scanning object 1 (shown as a human body in the figure) is scanned by the bed plate of the scanning bed 7 at a certain speed through the CT frame 2.

Referring to fig. 3 to 12, the computed tomography method of the present invention performs exposure scanning on a scanning object using at least one CT gantry 2 in a circumferentially stationary manner or a rotating manner; the method comprises the steps that a CT frame 2 is arranged on a frame base 4 and can linearly move along a scanning base 4 to form an imaging system, and a housing 3 with a ray shielding function is arranged outside the imaging system; during scanning, a scanning object is placed in the housing 3 and is static relative to the housing 3, and the CT frame 2 performs linear motion on the frame base 4 to scan the scanning object.

Referring to fig. 3-12, a CT scanning system constructed in accordance with the method of the present invention includes at least a CT gantry 2, a gantry base 4 for allowing the CT gantry 2 to move thereon, a housing 3 for enclosing the CT gantry 2 and the gantry base 4, and a set of components for user interaction and data processing. For a CT system using a rotating gantry, during scanning, the CT gantry 2 moves inside the housing 3 while rotating, and the scanning object 1 may be placed on the housing 3 or on a table that is stationary with respect to the housing 3. The gantry base 4 is provided with a mechanical limit mechanism and an electronic limit switch to ensure that the CT gantry 2 does not collide with the housing 3 during the movement. The housing 3 may be provided with a fixedly mounted or movable chassis, the chassis of the housing 3 and the rack base 4 may be the same component or two components fixedly connected together, when the chassis of the housing 3 is movable, depending on the placement of the scanning object 1, the CT rack 2 may move relative to the rack base 4, and the chassis of the housing 3 is stationary relative to the ground; or the CT frame 2 is static relative to the frame base 4, and the chassis of the cover 3 moves relative to the ground; it is also possible that the chassis of the housing 3 moves relative to the ground while the CT gantry 2 moves relative to the gantry base 4. In a special application scenario, two or more CT racks 2 may be simultaneously disposed inside the same housing 3.

The system can be designed to use the energy storage component to supply power to each component of the system, or only a low-power mains supply input interface is reserved, and the energy storage component is added for high-power application, so that the system is changed into a mobile CT and can be applied to different working scenes. In the case of a rotating energy storage component, the rotating part of the system can be charged through a slip ring type charging interface.

Since the housing 3 is much larger than the volume of the CT gantry 2 itself, this design itself helps the system to dissipate heat, and more air can take away the heat dissipated by the heat generating components on the CT gantry 2. Since the CT gantry 2 itself can be moved, the movement itself can achieve the effect of exhausting hot air outside the housing 3 while sucking cold air inside the housing 3. Thus, for low power systems designed with the present invention, specialized heat removal systems (such as fans, or heat sinks) can be eliminated. In addition, because all the moving parts are wrapped inside the housing 3, the cooling device can be designed more flexibly, one realization mode is that the cooling fan of the system is arranged on the inner wall of the housing 3, but not necessarily arranged on the CT frame 2, thus bringing about the advantages that the CT frame 2 with a rotating part can be moved, the cooling device (such as a fan) arranged at a specific position of the housing 3 can be used for cooling different heat generating parts, and when the system detects that a part is overheated, the part can be aligned with the cooling device through rotation and displacement so as to achieve the best cooling effect. For a gantry of a static CT, the same is true as with a rotating gantry, except that no rotation is required.

The rotating part of the system can use visible light or other light wave signals insensitive to directionality to realize reliable signal transmission (such as an emergency stop signal) with high requirements on instantaneity.

Example 1:

referring to fig. 3-5, this embodiment shows a CT system constructed according to the method of the present invention, which can be used in medical, security and industrial applications. The CT system comprises a CT rack 2, wherein the CT rack 2 can realize exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the CT machine frame 2 is arranged on the scanning base 4 and can do linear motion along the scanning base 4 to form an imaging system; the CT frame 2 consists of an X-ray source 201, an X-ray detector 202, a high-voltage generator 203 for supplying power to the X-ray source, a functional module 204 for controlling and processing a rotating component and data thereof, a mechanical electronic module 205 for controlling and driving the frame to rotate, a rotating bearing 206, a rotating sensor 207, a slip ring system 208 and the like; a guide rail 401 and an electric screw rod 402 are arranged on the scanning base 4, and the CT frame 2 can be driven by the electric screw rod 402 to move along the guide rail 401; also includes a housing 3 which houses the entire imaging system; the housing 3 is made of ray shielding materials, one end of the housing 3 is opened to form a blind hole structure, so that a scanning object 1 can be placed on the scanning bed 7 and enter the housing 3 by moving the bed surface of the scanning bed 7. The scanning base 4 is fixedly connected to the housing 3. The housing 3 is arranged on a movable chassis system 6. Meanwhile, the CT system is also provided with a set of user interface and computer system 5 interacting with the user, and a key and switch module 8 for adjusting the position and controlling the emergency stop.

During scanning, the scanning object 1 is placed in the housing 3 and is stationary relative to the housing 3, and the CT gantry 2 moves along the rail to complete scanning of the scanning object 1. When in use, the device can also be used as a common CT device, namely the CT rack 2 and the cover 3 do not horizontally move relative to the ground, and the scanning object 1 moves along with the bed surface of the scanning bed 7 and passes through the scanning ray plane to complete scanning; alternatively, the scan object 1 is placed on the bed surface of the scanning bed 7, the bed surface of the scanning bed 7 is stationary, and the CT gantry 2 and the housing 3 move together, so that the scan ray plane moves through the scan object 1 to complete the scan.

Example 2:

referring to fig. 6, which shows an optimized CT system according to the present invention, unlike the embodiment 1, the CT system of the present embodiment has two independently arranged CT frames 2. Therefore, different scanning combinations can be realized, backup can be realized, the working efficiency is improved, and the like.

Example 3:

referring to fig. 7-8, there is shown a CT system optimized in accordance with the present invention for CT scanning of objects in the range of teeth, ears, nose, head or the like. It can be seen that the optimized system size can be significantly reduced compared to conventional CT, which means improved radiation efficiency and reduced requirements for individual components, and significantly reduced product cost. At the same time the reduction in size makes it easy to install the system in different ways: the wall can be fixed by one side, or the wall can be erected on the ground, and the wall can also be hung on a ceiling. For the CT used for medical examination, the patient can easily complete the examination by sitting on a chair and bending backwards or extending forwards, even standing and the like. In this case the aperture may be in the form of a blind hole and a radiation shielding fabric or other radiation shielding structure may be used to achieve a hundred percent radiation shielding at the aperture on the neck side of the human body.

Example 4

Referring to fig. 9-10, there is shown a CT system that is optimized for use in CT scanning of elongated objects such as human limbs, according to the present invention. It can be seen that the optimized system size can be significantly reduced compared to conventional CT, which means that the radiation efficiency is improved and the requirements for the individual components are reduced, and the product cost is significantly reduced. At the same time the reduction in size allows the system to be easily installed in different ways. Similar to the example of fig. 5, such a system may also be designed in the form of blind holes, where a radiation shielding fabric or other radiation shielding structure may be used to achieve a hundred percent radiation shielding at the aperture on the side near the human body. Meanwhile, only the examination object is irradiated by the rays during the examination, unlike the ordinary CT scanning, the adjacent parts of the body are simultaneously irradiated by the rays while the arms or the legs and the feet are examined.

Example 5

Referring to fig. 11-12, there is shown an optimized CT system according to the present invention that can be used for CT scanning of younger children or objects of comparable size. It can be seen that the optimized system size, especially the aperture, can be reduced considerably compared to conventional CT, which means an increase in the radiation efficiency and a reduction in the requirements on the individual components, since the attenuation of the X-rays is proportional to the square of the distance, it can easily be calculated that the radiation efficiency can be increased by a factor when the distance from the focal spot to the detector surface is reduced from around 1 meter to 0.6 meter, which also means that the product costs can be reduced considerably. Similar to the previous example, this elongated aperture design can be easily used to achieve a hundred percent radiation shielding at both ends of the aperture with a radiation shielding fabric or other radiation shielding structure. The scanning bed 7 may be integrated into the outer housing of the system for ease of operation. Especially for the examination of children, because the children of the patient can not feel any movement in the scanning process, the emotion is easier to calm, and the scanning failure caused by the shaking of the body due to the psychological uneasiness caused by the movement of the human body following the bed surface in the common CT examination can be avoided.

The above general description of the invention and the description of the specific embodiments thereof, as referred to in this application, should not be construed as limiting the technical solutions of the invention. Those skilled in the art can add, reduce or combine the technical features disclosed in the general description and/or the specific embodiments (including the examples) to form other technical solutions within the protection scope of the present application according to the disclosure of the present application without departing from the structural elements of the present invention.

Claims

1. A computed tomography method, characterized by: the method uses at least one CT frame (2) to realize exposure scanning on a scanning object (1) in a circumferential static mode or a rotating mode; the method is characterized in that a CT frame (2) is arranged on a frame base (4) and can do linear motion along a scanning base (4) to form an imaging system, and the imaging system is covered by a cover (3); during scanning, a scanning object (1) is placed in the housing (3) and is static relative to the housing (3), and the CT machine frame (2) does linear motion on the machine frame base (4) to complete scanning on the scanning object (1).

2. A computed tomography system, characterized by:

the device comprises at least one CT machine frame (2), wherein the CT machine frame (2) can realize exposure scanning on a scanning object in a circumferential static mode or a rotating mode; the CT machine frame (2) is arranged on the scanning base (4) and can do linear motion along the scanning base (4) to form an imaging system;

further comprising a housing (3) housing the imaging system; at least one end of the housing (3) is opened, so that a scanning object (1) can be placed on the scanning bed (7) and enter the housing (3) by moving the bed surface of the scanning bed (7).

3. The computed tomography system of claim 2, wherein: only one end of the housing (3) is opened to form a blind hole structure.

4. The computed tomography system of claim 2, wherein: the scanning bed (7) is integrally arranged on the housing (3).

5. The computed tomography system of claim 2, wherein: the scanning base (4) is fixedly connected to the housing (3).

6. The computed tomography system of claim 5, wherein: the housing (3) is arranged on a movable chassis system (6).

7. The computed tomography system of any of claims 2-6, wherein: the CT machine frame (2) is connected with the scanning base (4) through a guide rail (401) and can be driven by an electric screw rod (402) to move along the guide rail (401).

8. The computed tomography system of any of claims 2-6, wherein: more than two independent CT machine frames (2) are arranged on the scanning base (4).

9. A computed tomography system, characterized by:

further comprising a housing (3) housing the imaging system; the end of the housing (3) is provided with an opening with the size matched with that of the scanning object (1), so that the scanning object (1) can enter the interior of the housing (3).

10. The computed tomography system of claim 9, wherein: the housing (3) has a structure capable of supporting a scanning object (1) therein.