CN116196027A

CN116196027A - CT scanning equipment and scanning method for reducing CT radiation in adaptive scanning area

Info

Publication number: CN116196027A
Application number: CN202310474005.7A
Authority: CN
Inventors: 王嘉毅
Original assignee: Sinovision Technology Beijing Co ltd
Current assignee: Sinovision Technology Beijing Co ltd
Priority date: 2023-04-28
Filing date: 2023-04-28
Publication date: 2023-06-02
Anticipated expiration: 2043-04-28
Also published as: CN116196027B

Abstract

The application discloses CT scanning equipment and scanning method for reducing CT radiation in self-adaptive scanning area, the CT scanning equipment comprises: a CT main body comprising a bulb, a detector and a collimator; the collimator comprises two collimating blades, and the two collimating blades can move along the X-axis direction so that the distance between the two collimating blades can be adjusted; a couch plate drivably entering the CT main body along a Z-axis and drivably moving along an X-axis direction so that a projection of a focal position on the detector is located in the middle of the detector; the Z axis is the pushing direction of the bed board, and the X axis is the horizontal direction and is perpendicular to the Z axis. The method solves the problems that the scanning device in the related art can bear redundant ray radiation when scanning local organs, and the imaging position of the local organs after scanning is positioned at the edge of the detector, so that the image quality is poor.

Description

CT scanning equipment and scanning method for reducing CT radiation in adaptive scanning area

Technical Field

The present application relates to the technical field of CT apparatuses, and in particular, to a CT scanning apparatus and a scanning method for reducing CT radiation in an adaptive scanning region.

Background

The traditional CT system image chain consists of a bulb tube, a collimator, a scanning bed and a detector. The bulb tube, the collimator and the detector are integrated on the rotating part of the scanning frame to rotate in a following way, and the scanning bed is carried on a patient to perform Z-direction movement. The scanning process can be simply described as the tube emitting X-rays, the collimator controlling the fan angle of the rays, the rays passing through the patient lying on the couch plate, the detector receiving the rays to complete the scanning process.

The angle of the ray fan emitted by the bulb is determined by the size of the slit of the blade in the collimator, and the design of the current blade is mainly divided into two types:

1. the collimator comprises two blades capable of independently moving in the Z direction, and the angle of a ray fan passing through the collimator is controlled by the distance between the end faces of the blades.

2. Comprises a blade with a plurality of slits, and different widths correspond to different fan angles.

The scanning bed needs to carry the patient and move to the scanning center, so that the focus area is positioned in the scanning fan angle, and the rays completely pass through the focus to finish scanning. However, when local organs such as heart, lung, limbs and the like are scanned, the focal region is located on one side of the patient, so that the other side of the patient does not have an imaging effect, the patient can bear redundant radiation, the health of the patient is endangered, and the imaging position of the local organs after scanning is located at the edge of the detector, so that the image quality is poor.

Disclosure of Invention

The main objective of the present application is to provide a CT scanning apparatus, so as to solve the problem that the patient receives excessive radiation when the scanning apparatus in the related art scans a local organ, and the image quality is poor because the imaging position of the local organ after scanning is located at the edge of the detector.

In order to achieve the above object, the present application provides a CT scanning apparatus comprising:

a CT main body comprising a bulb, a detector and a collimator;

the collimator comprises two collimating blades, and the two collimating blades can move along the X-axis direction so that the distance between the two collimating blades can be adjusted;

a couch plate drivably entering the CT main body along a Z-axis and drivably moving along an X-axis direction so that a projection of a focal position on the detector is located in the middle of the detector;

the Z axis is the pushing direction of the bed board, and the X axis is the horizontal direction and is perpendicular to the Z axis.

Further, the collimator still includes the top cap and locates first drive assembly on the top cap, the collimating blade is located on the top cap, first drive assembly with the collimating blade is connected, is used for the drive the collimating blade moves along X axis direction.

Further, a sliding rail is arranged on the top cover along the X-axis direction, and the collimating blades are arranged in the sliding rail in a sliding manner.

Further, the slide rail comprises a first rail strip and a second rail strip, sliding grooves are formed in the opposite sides of the first rail strip and the second rail strip, and two sides of the collimating blade are in sliding connection with the sliding grooves.

Further, the first driving assembly comprises a driving motor, a first connecting piece and a second connecting piece;

the output end of the driving motor is provided with a gear;

the first connecting piece is connected with one collimating blade, the second connecting piece is connected with the other collimating blade, a rack meshed with the first side of the gear is arranged on the first connecting piece, and a rack meshed with the second side of the gear is arranged on the second connecting piece.

Further, the movable bed plate comprises a base, a second driving assembly is arranged on the base, and the second driving assembly is used for driving the bed plate to move along the X-axis direction.

Further, the base comprises a lifting assembly and a lower frame, and an upper frame is arranged at the lower end of the bed board;

the lower layer frame is arranged at the output end of the lifting assembly, the second driving assembly is arranged in the lower layer frame, the upper layer frame is arranged on the lower layer frame and can move along the X-axis direction, and the second driving assembly is connected with the upper layer frame.

Further, the second driving assembly comprises a linear motor, and the linear motor is in transmission connection with the upper frame.

According to another aspect of the present application, there is provided a scanning method for reducing CT radiation in an adaptive scan region, using the above CT scanning apparatus, and the following steps:

performing one or more scans and obtaining a scanning result;

calculating a ROI section parameter and a position based on the scan result;

determining a moving stroke of the bed plate in the X-axis direction based on the ROI section parameters and the position;

controlling the bed board to move based on the moving stroke, so that the projection of the focus position on the detector is positioned in the middle of the detector;

and determining whether a small FOV scanning mode is met or not based on the ROI section parameters and the positions, and if so, adjusting the distance between the two collimating blades to enable the scanning boundary to be attached to the focus section and executing scanning.

Further, based on the ROI cross-section parameters and location, determining whether a small FOV scan mode is met, if not,

and adjusting the collimating blade to move in the Z-axis direction and executing scanning.

In the embodiment of the application, the CT main body comprises a bulb tube, a detector and a collimator; the collimator comprises two collimating blades, and the two collimating blades can move along the X-axis direction so that the distance between the two collimating blades can be adjusted; the bed board can enter the CT main body along the Z axis in a driven way and can move along the X axis direction in a driven way, so that the projection of the focus position on the detector is positioned in the middle of the detector; the Z axis is the pushing direction of the bed board, the X axis is the horizontal direction and is vertical to the Z axis, the purpose that focus can be imaged in the middle of the detector after scanning by adjusting the position of the bed board in the X axis direction is achieved, the scanning range of rays passing through the collimating blades can be matched with the focus cross section by adjusting the distance between the two collimating blades is achieved, the image quality of a reconstruction mode is improved, the scanning of a local focus area of a patient can be completed with smaller scanning dose, the technical effect of radiation born by the patient is reduced, the problem that the image quality is poor because the patient can bear redundant radiation when scanning equipment in the related art scans a local organ and the imaging position of the local organ after scanning is located at the edge of the detector is solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the application and to provide a further understanding of the application with regard to the other features, objects and advantages of the application. The drawings of the illustrative embodiments of the present application and their descriptions are for the purpose of illustrating the present application and are not to be construed as unduly limiting the present application. In the drawings:

FIG. 1 is a schematic view of a structure in which a bed deck is not moved according to an embodiment of the present application;

FIG. 2 is a schematic view of a structure of a bed deck after moving according to an embodiment of the present application;

FIG. 3 is a schematic view of a collimator according to an embodiment of the present application;

FIG. 4 is a schematic view of a structure of a base according to an embodiment of the present application;

the device comprises a bulb tube 1, a focus position 3, a bed board 4, a detector 5, a top cover 101, a driving motor 102, a first connecting piece 103, a second connecting piece 104, a first track bar 105, a second track bar 106, a collimating blade 107, a gear 108, a lifting component 201, a lower frame 202, an upper frame 203 and a second driving component 204.

Detailed Description

In order to make the present application solution better understood by those skilled in the art, the following description will be made in detail and with reference to the accompanying drawings in the embodiments of the present application, it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

In the CT scanning process, the scanning bed needs to carry the patient and move to the scanning center, so that the focus area is positioned in the scanning fan angle, and the rays completely pass through the focus to finish scanning. However, when a local organ such as heart, lung, limb, etc. is scanned, the focal region is located on one side of the patient, and thus the other side of the patient is not imaged, resulting in the patient being subjected to excessive radiation (including the radiation of the effective region and the radiation of the ineffective region as shown in fig. 1), which is harmful to the health of the patient, and the image quality is poor because the imaging position of the local organ after scanning is located at the edge of the detector.

To solve the above technical problems, as shown in fig. 2, an embodiment of the present application provides a CT scanning apparatus, including:

a CT main body comprising a bulb tube 1, a detector 5 and a collimator;

the collimator comprises two collimating vanes 107, wherein the two collimating vanes 107 can move along the X-axis direction, so that the distance between the two collimating vanes 107 can be adjusted;

a couch 4 drivably entering the CT main body along the Z-axis, and the couch 4 drivably moving along the X-axis direction so that the projection of the focus position 3 on the detector 5 is located in the middle of the detector 5;

the Z axis is the pushing direction of the bed board 4, and the X axis is the horizontal direction and is vertical to the Z axis.

In this embodiment, the CT scanning apparatus is mainly composed of two parts, a CT main body and a couch board 4, wherein the CT main body is mainly composed of a bulb tube 1, a detector 5 and a collimator. The collimator and the detector 5 are integrated on the rotating part of the scanning frame to rotate in a following way, and the bed board 4 carries the patient to move in the Z-axis direction. The scanning process can be described simply as the tube 1 emitting X-rays, the collimator controlling the fan angle of the rays, the rays passing through the patient lying on the couch 4, the detector 5 receiving the rays to complete the scanning process. The patient generally lies in the middle of the couch 4, and the bulb 1 and the detector 5 are respectively located directly above and below the patient, so in order to enable a lesion located in a non-middle position of the patient to acquire a better quality image after scanning, it is necessary to move the patient in the X-axis direction to move the lesion position 3 to a position opposite to the middle of the detector 5, i.e., to make the projection of the lesion position 3 on the detector 5 located in the middle of the detector 5 (as shown in fig. 1 and 2). In order to facilitate the movement of the patient, the couch board 4 in the embodiment can move in the X-axis direction according to the focal position 3 in addition to the conventional scanning in the Z-axis direction, so that the focal position 3 can move to be opposite to the middle of the detector 5, thereby always enabling the focal zone to be at the scanning center, improving the image quality of the reconstruction mode over the FOV edge.

On the basis of this, the two collimating vanes 107 in the collimator of the present application can also be moved in the X-axis direction, so that the distance between the two collimating vanes 107 can be adjusted. When the two collimator leaves 107 are close to each other, the scanning range formed by the rays passing through the two collimator leaves 107 decreases, and when the two collimator leaves 107 are distant from each other, the scanning range formed by the rays passing through the two collimator leaves 107 increases. For scanning of a local focal zone, the distance between the two collimating blades 107 may be adjusted according to the size of the focal cross section, so that the formed scanning range is close to the edge of the focal cross section, and thus the non-focal zone is not contacted with scanning rays, and the ray bearing capacity of the patient is reduced (as shown by the dotted line in fig. 2).

The present embodiment achieves the purposes that the focus can be imaged in the middle of the detector 5 after scanning by adjusting the position of the bed board 4 in the X-axis direction, and the scanning range of the rays passing through the collimating blades 107 can be matched with the focus cross section by adjusting the distance between the two collimating blades 107, so that the image quality of the reconstruction mode is improved, the scanning of the local focus area of the patient can be completed with smaller scanning dose, the technical effect of the radiation born by the patient is reduced, and the problem that the patient can bear redundant radiation when the scanning device in the related art scans the local organ is solved, and the imaging position of the local organ after scanning is positioned at the edge of the detector 5, so that the image quality is poor is solved.

In order to control the linear movement of the collimating vane 107 in the X-axis direction, as shown in fig. 3, the collimator in this embodiment further includes a top cover 101 and a first driving assembly disposed on the top cover 101, where the collimating vane 107 is disposed on the top cover 101, and the first driving assembly is connected to the collimating vane 107 and is used for driving the collimating vane 107 to move along the X-axis direction.

In this embodiment, the first driving assembly is used to drive the two collimating vanes 107 to move linearly in the X-axis direction, so the first driving assembly may be any structure capable of outputting linear motion, and may be used by a connecting rod, a linear motor, a cylinder, a hydraulic cylinder, or the like. It will be appreciated that the two collimating vanes 107 may be driven by the same first drive assembly or may be driven by separate first drive assemblies. In this embodiment, the collimating vanes 107 are tungsten sheets.

In order to improve the stability of the linear movement of the collimating vane 107, in this embodiment, a sliding rail is provided on the top cover 101 along the X-axis direction, and the collimating vane 107 is slidably disposed in the sliding rail. Further, the slide rail includes a first track bar 105 and a second track bar 106, and a chute is provided on opposite sides of the first track bar 105 and the second track bar 106, and two sides of the collimating vane 107 are slidably connected with the chute.

To facilitate controlling the synchronous movement of the two collimating vanes 107, the first driving assembly in this embodiment comprises a driving motor 102, a first connecting member 103 and a second connecting member 104; the output end of the driving motor 102 is provided with a gear 108; the first connecting piece 103 is connected with one of the alignment blades 107, the second connecting piece 104 is connected with the other alignment blade 107, a rack meshed with the first side of the gear 108 is arranged on the first connecting piece 103, and a rack meshed with the second side of the gear 108 is arranged on the second connecting piece 104.

In this embodiment, the driving motor 102 is installed on one side of the top cover 101, and the driving motor 102 can drive the gear 108 to rotate in a fixed axis manner, so as to drive the first connecting piece 103 and the second connecting piece 104 engaged with two sides of the gear 108 to move relatively or move oppositely, and further drive the two collimating vanes 107 to move relatively or move oppositely. The movement of the two collimating vanes 107 is accurate and synchronous through the cooperation of the gear 108 and the rack, the center of the scanning range and the center of the detector 5 can be always kept consistent, and the radiation quantity born by a patient can be reduced to the greatest extent while a high-quality image can be acquired after the focus position 3 moves to the center.

Further, as the bed board 4 can move to the scanning center along the X-axis direction, the collimator can drive the X-axis direction to move in a mirror image manner by the single driving motor 102 to perform collimation shooting, the structure is simplified, the matched movement of the collimator and the bed board 4 is decoupled, and the control flow is simplified.

In order to realize the movement of the bed board 4, as shown in fig. 4, the embodiment further includes a base, and a second driving assembly 204 is disposed on the base, for driving the bed board 4 to move along the X-axis direction. The second driving unit 204 is also configured to drive the bed plate 4 to move linearly in the X-axis direction, and various structures having a linear movement output function in the related art may be employed, such as a screw, a link, an air cylinder, a linear motor, and the like.

Since the bed board 4 needs to have the functions of moving linearly along the Z axis, lifting along the vertical direction (Y axis) and moving linearly along the X axis during use, the base in this embodiment includes a lifting assembly 201 and a lower frame 202, and an upper frame 203 is disposed at the lower end of the bed board 4;

the lower frame 202 is disposed at an output end of the lifting assembly 201, the second driving assembly 204 is disposed in the lower frame 202, the upper frame 203 is disposed on the lower frame 202 and can move along the X-axis direction, and the second driving assembly 204 is connected with the upper frame 203. The second driving assembly 204 includes a linear motor in driving connection with the upper frame 203.

In this embodiment, the lifting assembly 201 may control the lifting of the bed board 4 in the vertical direction, and the lifting assembly 201 may adopt a scissor lift structure. The lower frame 202 is provided with a slide rail for the linear movement of the upper frame 203, and the opening direction of the slide rail is the X-axis direction, so that the upper frame 203 with the bed board 4 mounted thereon can move on the lower frame 202 along the X-axis, i.e., the bed board 4 can move along the X-axis. The lifting assembly 201, the lower frame 202, the upper frame 203 and the bed board 4 may be integrally mounted on the Z-axis translation structure, and the Z-axis translation structure may be a structure of a CT apparatus in the related art, which is not described in detail in this embodiment.

performing one or more scans and obtaining a scanning result;

calculating the parameters and the positions of the cross sections of the ROI based on the scanning result, namely determining the focus position 3 and the parameters of each cross section of the focus in the Z-axis direction according to the scanning result;

determining a moving stroke of the bed plate 4 in the X-axis direction based on the ROI section parameters and the position, namely determining the moving stroke of the bed plate 4 in the X-axis direction when scanning each focus section according to each section parameter and the position of the focus, wherein in the scanning process, each section of the focus can be projected to the middle part of the detector 5 when the bed plate 4 moves according to the moving stroke;

based on the ROI cross section parameters and the positions, it is determined whether a small FOV scanning mode is satisfied, that is, whether the acquired focus cross section parameters and positions are within a scanning range when the distance between the two collimating blades 107 is maximum, if yes, the distance between the two collimating blades 107 is adjusted according to the parameters of the focus cross section, so that the scanning boundary fits the focus cross section and scanning is performed. For example, when the lesion cross section parameter is smaller than the scan range formed by the current two collimating vanes 107, the two collimating vanes 107 may be moved closer to each other by the first drive assembly to the scan range proximate the lesion cross section.

The pitch of the collimating blades 107 is calculated based on the lesion cross section parameters in the following manner: after the parameters of the focus cross section are obtained, the emitting point of the bulb tube 1 is taken as the upper vertex of the triangle, and two sides of the focus cross section are taken as the vertices of two sides of the triangle to form the triangle. The line connecting the two collimating vanes 107 in the X-axis direction and the two sides of the triangle have an intersection point respectively, and the distance between the two intersection points is equal to the distance between the collimating vanes 107 after moving along the X-axis direction.

When the obtained parameters and positions of the focus cross section are not in the scanning range of the two collimating vanes 107 when the distance is maximum, the size of the focus on the surface is larger than the maximum scanning range of the CT main body, and multiple times of scanning are needed, so that the collimator can be adjusted to move in the Z-axis direction and a normal scanning process can be executed.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modifications, equivalent substitutions, improvements, or the like, which are within the spirit and principles of the present application, are intended to be included within the scope of the present application.

Claims

1. A CT scanning apparatus, comprising:

a CT main body comprising a bulb, a detector and a collimator;

2. The CT scanning instrument of claim 1, wherein the collimator further comprises a top cover and a first driving assembly disposed on the top cover, the collimating blades are disposed on the top cover, and the first driving assembly is connected to the collimating blades and is configured to drive the collimating blades to move along the X-axis direction.

3. The CT scanner of claim 2, wherein the top cover has a sliding rail disposed thereon along an X-axis direction, and the collimating vane is slidably disposed in the sliding rail.

4. The CT scanning apparatus of claim 3 wherein the slide rail comprises a first rail bar and a second rail bar, the opposing sides of the first rail bar and the second rail bar are provided with a chute, and the two sides of the collimating vane are slidably coupled to the chute.

5. The CT scanning device of any of claims 2 to 4, wherein the first drive assembly comprises a drive motor, a first connector and a second connector;

the output end of the driving motor is provided with a gear;

6. The CT scanning apparatus of claim 1 further comprising a base having a second drive assembly disposed thereon for driving the couch plate to move in the X-axis direction.

7. The CT scanning apparatus of claim 6 wherein the base comprises a lifting assembly and a lower frame, the lower end of the couch plate being provided with an upper frame;

8. The CT scanning apparatus of claim 7 wherein the second drive assembly comprises a linear motor drivingly connected to the upper frame.

9. A scanning method for reducing CT radiation in an adaptive scan region, characterized by using a CT scanning apparatus according to any of claims 1 to 8, and by the steps of:

performing one or more scans and obtaining a scanning result;

calculating a ROI section parameter and a position based on the scan result;

10. The method of claim 9, wherein determining whether a small FOV scan mode is met is based on the ROI cross-section parameter and the position, and if not,