CN106344053B

CN106344053B - Imaging method and positioning device of X-ray imaging equipment

Info

Publication number: CN106344053B
Application number: CN201610816158.5A
Authority: CN
Inventors: 虞倩倩
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2016-09-09
Filing date: 2016-09-09
Publication date: 2021-01-22
Anticipated expiration: 2036-09-09
Also published as: CN106344053A

Abstract

The invention provides an imaging method of an X-ray imaging device, wherein the X-ray imaging device comprises an X-ray bulb tube and a detector, and an imaging field of view is arranged between the X-ray bulb tube and the detector, and the imaging method is characterized by comprising the following steps: placing an object to be detected in an imaging field of view; imaging the object to be detected at least at two different positions to obtain an image of the object to be detected; acquiring a region of interest in an image; calculating the spatial position of the region of interest according to the region of interest in the image; and adjusting the imaging position of the X-ray imaging equipment according to the position relation between the spatial position of the region of interest and the imaging field of view. The imaging position determining method can obtain the position of the ROI in the space, and the imaging position of the X-ray imaging equipment in any direction is calculated according to the space position of the ROI so as to ensure that the ROI is positioned in the imaging visual field range.

Description

Imaging method and positioning device of X-ray imaging equipment

Technical Field

The invention relates to the field of medical imaging equipment, in particular to a method and a device for determining an imaging position of X-ray imaging equipment.

Background

In the current design of all C-arm machines, regardless of whether the C-arm rotates in an isocenter or a non-isocenter, images at different positions deviate to different degrees when the C-arm rotates. FIG. 1 is a schematic view of a C-arm machine rotating in an isocentric rotation; as shown in fig. 1, the isocentric rotation means that the center line of a beam formed between the X-ray emission bulb 20 and the detector 10 passes through the Isocenter (Isocenter) when the X-ray emitted from the X-ray emission bulb is received by the detector, and the center line of the beam passes through the Isocenter all the time during the rotation of the C-arm machine. If a region of interest (ROI) is not in the isocenter when the isocenter of the C-arm machine rotates, the region of interest deviates from an imaging visual field or is not in a reasonable position of an image after the C-arm machine rotates for a certain angle; fig. 2 is a schematic view of the rotation of the C-arm machine with non-isocentric rotation, as shown in fig. 2, when the X-ray emitted from the X-ray emitting tube 20 is received by the detector 10, the center line of the beam formed between the two does not pass through the isocenter, and the center line of the beam does not pass through the isocenter all the time during the rotation of the C-arm machine. In this case, regardless of whether the region of interest is isocentric, after the C-arm machine is rotated by a certain angle, the ROI may deviate from the imaging field of view or may not be at a reasonable position in the image. This results in that when the C-arm machine is adjusted in angle during actual use, the C-arm machine not only needs to rotate by a corresponding angle, but also needs to adjust the ROI in the imaging field of view by moving up, down, left, and right. However, frequent switching of different angles during the operation complicates the switching operation of the positions for each shot, and also requires verification by an image, and the patient and the doctor inevitably receive unnecessary radiation.

Disclosure of Invention

The invention aims to solve the problems that an interested area deviates from an imaging visual field and an imaging position cannot be determined in the rotating process of a C-arm machine.

In order to solve the above problem, the present invention provides an imaging method of an X-ray imaging apparatus, the X-ray imaging apparatus including an X-ray tube and a detector, the X-ray tube and the detector having an imaging field of view therebetween, the method including:

placing an object to be detected in an imaging field of view;

imaging the object to be detected at least at two different positions to obtain an image of the object to be detected;

acquiring a region of interest in an image;

calculating the spatial position of the region of interest according to the region of interest in the image;

and adjusting the imaging position of the X-ray imaging equipment according to the position relation between the spatial position of the region of interest and the imaging field of view.

Optionally, the different positions include a first position and a second position, the imaging angles of the first position and the second position are different,

x-rays passing through the region of interest while imaging at a first position are first line segments;

the X-ray passing through the region of interest when imaging at the second position is a second line segment;

the intersection of the first line segment and the second line segment is the spatial position of the region of interest.

Optionally, acquiring the region of interest in the image includes,

acquiring a region of interest in an image acquired at a first location;

and determining the region of interest in the image acquired at the second position according to the region of interest in the image acquired at the first position.

Optionally, if the first line segment and the second line segment do not have an intersection, the region of interest in the image is reacquired.

Optionally, if the first line segment and the second line segment do not have an intersection, the middle position of the two line segments, which is closest to the two points, is used as the spatial position of the region of interest.

Optionally, if the first line segment and the second line segment do not have an intersection, comparing a distance between two points on the two line segments that are closest to each other with a preset threshold, if the distance is smaller than the preset threshold, taking a middle position of the two line segments that are closest to each other as a spatial position of the region of interest, and if the distance is larger than the preset threshold, re-acquiring the region of interest in the image.

Optionally, an X-ray passing through a central point of the region of interest during imaging at the first position is a first line segment; the X-ray passing through the central point of the region of interest while imaging at the second position is a second line segment.

Optionally, the distance from the X-ray tube to the region of interest of the imaging position is greater than the distance from the region of interest to the detector.

The present invention also provides a positioning device of an X-ray imaging apparatus, comprising:

an imaging unit that images an object to be detected;

a region-of-interest position calculation unit that calculates a spatial position of the region of interest based on an imaging result of the imaging unit;

a position determination unit that determines a position where the imaging device is located;

an imaging position calculation unit for calculating an imaging position based on the spatial position of the region of interest and the position of the apparatus, an

A driving unit that drives the image forming apparatus according to an image forming position.

Optionally, the positioning device of the X-ray imaging apparatus further includes:

and a guide unit providing movement path information moved to the imaging position.

Compared with the prior art, the invention has the advantages that: the system calculates the spatial position of the region of interest through the region of interest defined by the user on the image, and then calculates the movement distance or angle in each direction when the angle of the C-arm machine is adjusted, and rotates around the region of interest to ensure that the region of interest is positioned in the imaging view field. By the scheme, repeated operation of a user and repeated confirmation work of images can be reduced, workflow is simplified, operation time is saved, and radiation to the patient and the user can be reduced.

Drawings

FIG. 1 is a schematic view of a C-arm machine rotating in an isocentric rotation;

FIG. 2 is a schematic view of a rotation of a C-arm machine with non-isocentric rotation;

FIG. 3 is a schematic view of an imaging process in first and second positions;

FIG. 4 is a schematic view of the imaging process in the second and third positions;

FIG. 5 is a schematic diagram of an imaging process when the ROI area in the image is marked as a region;

FIG. 6-a is a schematic view of an X-ray tube imaging at various positions on the beam centerline;

FIG. 6-b is a schematic view of an X-ray tube imaging at various positions perpendicular to the beam centerline;

FIG. 7 is a schematic view of a positioning device module of the imaging apparatus of the present invention;

fig. 8 is a schematic view of another imaging device positioning apparatus module of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The invention can be implemented in a number of ways different from those described herein and similar generalizations can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

Generally, in order to guide the operation during the operation, the operation process is photographed in real time by an X-ray imaging device, guided and confirmed. The X-ray imaging apparatus includes: an X-ray tube for emitting X-rays; and the detector receives the X-ray passing through the object to be detected, and the X-ray bulb tube and the detector are arranged oppositely. The most common X-ray imaging device used during surgery is the C-arm machine, mainly because the support connecting the X-ray tube and the detector is shaped like the letter C.

As shown in fig. 1 and 2, the C-arm machine includes a C-shaped support 30, and an X-ray tube 20 and a detector 10 respectively located at two ends of the C-shaped support, where the X-ray tube 20 and the detector 10 are disposed opposite to each other. This C-shaped configuration facilitates moving the patient to be examined between the X-ray tube 20 and the detector 10 for imaging.

The C-arm machine can be divided into a movable type, a suspension type, a floor type and the like. The C-shaped support is fixed on a movable trolley, and an operator can push the trolley to move the C-arm machine (or move the C-arm machine through a driving device arranged on the trolley) and shoot a patient at a required position; the C-shaped bracket is generally slightly larger than the movable C-shaped bracket in a suspension type, is fixed on a ceiling through a fixed bracket, can be provided with a guide rail on the ceiling and moves along the guide rail under the driving of a driving device, and can also rotate freely in the horizontal or vertical direction in the suspension type; the floor type is similar to the mobile type, and is different from the floor type in that the floor type is connected with a fixed support on the ground and cannot be pushed away to move.

However, the existing C-arm machines do not have the function of adjusting the shooting position, especially for the imaging during the operation, the manual adjustment of the shooting position often causes the region of interest to deviate from the imaging field of view or not be at the reasonable position of the image, so that the shooting needs to be repeated for obtaining the ideal image, the patient and the doctor are exposed to unnecessary radiation, and the treatment effect is affected. The C-arm machine provided by the invention is adjusted to an imaging position according to the spatial position of the target area and the angle to be shot, or guides a doctor to adjust the imaging equipment, so that the target area can be positioned in the imaging visual field when shooting at any angle is achieved. The operation of a doctor is facilitated, and the treatment efficiency is improved.

In order to achieve the above object, an imaging method of an X-ray imaging apparatus of the present invention, the X-ray imaging apparatus including an X-ray tube and a detector having an imaging field of view therebetween, includes: placing an object to be detected in an imaging field of view; imaging the object to be detected at least at two different positions to obtain an image of the object to be detected; acquiring a region of interest in an image; calculating the spatial position of the region of interest according to the region of interest in the image; and adjusting the imaging position of the X-ray imaging equipment according to the position relation between the spatial position of the region of interest and the imaging field of view. The imaging position of the X-ray imaging device comprises an angle to be shot and an optimal shooting position under the angle. Generally, in the treatment process, a patient is positioned on a sickbed and cannot move, so that the spatial position of the ROI of a part to be detected is unchanged, the position of the X-ray imaging device with a changeable position can record the position change of the X-ray imaging device, the spatial coordinate of the ROI can be calculated only by shooting at different positions for a plurality of times because the spatial position of the ROI is unchanged, and after the spatial position of the ROI is determined, the X-ray imaging device can calculate the optimal shooting position by combining the current angle, so that the region of interest is always positioned in the middle of an imaging visual field.

The determination of the spatial coordinates of the ROI can be generally achieved by only two times of imaging at different positions, and the step of determining the spatial coordinates of the ROI includes: the X-ray passing through the center point of the ROI at the first imaging position is taken as a first line segment position; the X-ray passing through the center point of the ROI at the second imaging position is a second line segment position; the intersection of the first line segment and the second line segment is the spatial position of the ROI. FIG. 3 is a schematic view of the imaging process in the first and second positions, as shown in FIG. 3, with the X-ray tube at A₁At a first position, at A₂The position is a second position, and A is known according to the self position determining function of the X-ray imaging device₁The spatial coordinates of the points, the position of the ROI (indicated by the point R in the figure) on the detector after passing through the object to be detected, are C₁(position on image), likewise, B can be known from the own position determining function of the X-ray imaging apparatus₁Spatial coordinates of points, B₁As the center point of the detector, according to B₁Point and C₁The position relation of the point on the detector can be calculated to obtain C₁Spatial coordinates of points, from two known points A₁、C₁Calculate the connection stationThe line segment positions of the two points can be calculated₁C₁In the spatial position, A 'is the position when only the X-ray bulb tube is considered to rotate but not to move forwards and backwards, upwards and downwards and leftwards and rightwards, the rotation angle beta can be known according to the self position determining function of the equipment, the spatial coordinate of the point A' can be represented by beta, and A₂Is a position after up-down, left-right, and back-and-forth movement based on the angle of rotation β, the movement can also be known from the self position determination function of the apparatus, therefore a₂The position of (A) can also be expressed by a parameter such as beta, and likewise B₂The spatial coordinates of the points may also pass through A₂Spatial coordinate representation of points, C₂The spatial coordinates of the points can be represented by A₂Spatial sum of points B₂The spatial coordinates of the points are linked such that the straight line A₂C₂Can also be expressed when determining A₁C₁And A₂C₂The coordinates of the ROI in space can then be determined by calculating the position of the intersection.

In the above process, the position of the ROI is determined by the operator in the images taken at different positions, e.g. the operator determines C in the first image after the first image 40 has been generated at the first position₁Point according to said C₁Determining line segment A₁C₁Determining C in the second image after generating the second image 50 at the second location₂Points from which the line segment A is determined₂C₂. To simplify the above steps, the present invention further provides that C is determined from the first image 40₁Point identification C of the second image 50₂And therefore, the operator is not required to determine twice. E.g. finding out ROI area in the second image according to the characteristic analysis of the gray value of ROI in the image, thereby determining C₂And (4) point. In other embodiments, the position of the ROI may be automatically calculated by the device, for example, by placing a marker in the target region, the position of the marker is the position of the ROI, and the position of the marker in the image may be calculated by the image recognition algorithm.

In addition, when A₁C₁And A₂C₂When the line segments do not have intersection, two line segments are usedThe middle position between the two points that are closest to each other is taken as the spatial position of the ROI. Further issuing a false alarm when the distance between said two points closest to each other exceeds a preset threshold, requiring the re-acquisition of the region of interest in the image.

After determining the spatial coordinates of the ROI, the imaging angle around the ROI device can be adjusted according to the user's needs. Fig. 4 is a schematic view of the imaging process in the second and third positions. Wherein the third position is the angle required by the operator to take the image, and the center position C of the image known by the function is determined according to the position of the equipment₃(center position of detector) and position A of X-ray tube₃Since the spatial position of R is also calculated by the above steps, it is only necessary to calculate the translation distance such that A is₃C₃The ROI may be located at a reasonable position on the image by R.

In view of the practical application, the physician may want the ROI to be as close to the side of the detector as possible, since the ROI can be viewed in a larger and more detailed manner, which is helpful for diagnosis. However, because the imaging area is too thick, the imaging area can not be too close to the detector, therefore, the R point is at A in the invention₃C₃The position of (A) can be empirically determined in advance when the point R is determined to be at A₃C₃After the position is shown, the point can be located at A according to the R point₃C₃To finally determine a passing through the R point₃C₃The spatial position of (a). That is, in the present invention A₃C₃The spatial position of A is adjusted according to the preset spatial position of the R point₃C₃So that A is₃C₃The R point is also as close to the detector side as possible while passing through the R point. Considering the position relation between the R point and the detector, the R point finally determined by the invention is A₃C₃At a position on satisfies A₃R length greater than RC₃。

In the above process, the spatial coordinates of the ROI are determined by the intersection of two line segments when the ROI is a point (the ROI region is marked as a point by the operator in the image) or a region marked as a small region in the image (the region is represented by the center point of the region). In order to obtain the intersection point of the line segments in the above scheme, it is necessary to avoid the line segments being parallel or partially overlapping, the shooting angles of the first position and the second position cannot be the same, and when the ROI is marked as a larger region in the image, the shooting angles of the first position and the second position may be the same, but the heights of the X-ray tube and the detector along the central line of the beam are changed, or the X-ray tube and the detector are changed in a translation manner along the plane of the detector.

Fig. 5 is a schematic diagram of the imaging process when the ROI area in the image is marked as a region, and as shown in fig. 5, when the ROI is a large block, it appears as a slice of the region in the image. Fig. 6-a is an imaging schematic diagram of different positions of the X-ray tube on the central line of the beam, wherein:

to obtain

To obtain

A₄H＝A₅H+A₄A₅

Wherein A is₄B₄，A₅B₅，B₄D₄，B₅D₅，A₄A₅HR is known and can therefore be calculated₂Same method HR₁It can also be calculated by obtaining R₁And R₂Further, the approximate position of the ROI in space (in R) can be calculated₁R₂Representation).

FIG. 6-b is a schematic view of an X-ray tube imaging at different positions perpendicular to the beam centerline, wherein:

to obtain

To obtain

H₅R₂＝H₄R₂+B₅B₄

Wherein A is₅B₅，A₄B₄，B₅D₅，B₄D₄Known as A₅H₅＝A₄H₄Can calculate A₅H₅、A₄H₄H can also be calculated₄R₂And H₅R₂In the same way, H can be calculated₅R₁、H₄R₁By obtaining R₁And R₂Further, the approximate position of the ROI in space (in R) can be calculated₁R₂Representation).

The invention also provides an X-ray imaging device, a positioning device of the imaging device, comprising: an imaging unit 11 that images an object to be detected; an ROI position calculation unit 12 that calculates a spatial position of the region of interest based on the imaging result of the imaging unit 11; a position determination unit 13 that determines a position where the imaging device is located; an imaging position calculation unit 14 that calculates an imaging position based on the spatial position of the region of interest and the position where the apparatus is located, and a drive unit 15 that drives the imaging apparatus based on the imaging position.

Further, the X-ray imaging apparatus may further include a guiding unit 16, and the guiding unit 16 may be a display screen, and displays an optimal position suitable for exposure through the display screen, and prompts a path. The guiding unit 16 can also be a guiding unit 16 combining voice and display, and the movement operation can be completed more conveniently by an operator through the display of the display screen and the combination of voice prompt.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.

Claims

1. An imaging method of an X-ray imaging apparatus comprising an X-ray tube and a detector with an imaging field of view therebetween, comprising:

optionally placing the object to be detected in the imaging field of view;

imaging an object to be detected at a first position to obtain a first image of the object to be detected, wherein an X ray passing through a central point of a part of interest of the object to be detected is a first line segment when the first position is imaged;

selecting a first region of interest in the first image, wherein the first region of interest comprises a region of interest equivalent to one point, or the region of interest of the first region of interest is represented by a central point of the first region of interest;

imaging the object to be detected at a second position to obtain a second image of the object to be detected, wherein an X ray passing through the central point of the interested part is a second line segment when imaging at the second position, and the imaging angles of the first position and the second position are different;

acquiring a second region of interest in the second image, wherein the second region of interest includes a region of interest equivalent to a point or represents the region of interest of the second region of interest by a central point of the second region of interest, and the first region of interest and the second region of interest both include a central point of the region of interest;

determining the position of the first line segment according to a first region of interest in the first image, and determining the position of the second line segment according to a second region of interest in the second image;

determining the intersection of the first line segment and the second line segment according to the position of the first line segment and the position of the second line segment, and taking the intersection as the spatial position of the interested part;

and adjusting the imaging position of the X-ray imaging equipment according to the position relation between the spatial position of the interested part and the imaging field of view.

2. The imaging method according to claim 1, wherein if the first line segment and the second line segment do not have an intersection, the first region of interest of the first image and the second region of interest of the second image are re-acquired.

3. The imaging method according to claim 1, wherein if the first line segment and the second line segment do not have an intersection, a middle position of two points closest to each other on the two line segments is used as the spatial position of the region of interest.

4. The imaging method according to claim 1, wherein if the first line segment and the second line segment have no intersection, the distance between two points on the two line segments that are closest to each other is compared with a preset threshold, if the distance is smaller than the preset threshold, the middle position of the two points on the two line segments that are closest to each other is used as the spatial position of the region of interest, and if the distance is larger than the preset threshold, the region of interest in the first image and the second image is re-acquired.

5. The imaging method according to claim 1,

the X-ray passing through the central point of the interested part during the imaging at the first position is a first line segment;

and the X-ray passing through the central point of the interested part during the imaging at the second position is a second line segment.

6. The imaging method of claim 1, wherein the distance from the X-ray tube to the region of interest is greater than the distance from the region of interest to the detector.

7. A positioning device of an X-ray imaging apparatus, characterized by comprising:

the imaging unit is used for imaging an interested part of an object to be detected at any first position and any second position in an imaging field of view so as to correspondingly obtain a first image and a second image, wherein X-rays passing through the central point of the interested part of the object to be detected are first line segments when the first position is imaged, X-rays passing through the central point of the interested part of the object to be detected are second line segments when the second position is imaged, and the imaging angles of the first position and the second position are different;

a region-of-interest position calculation unit that determines a position of the first line segment from a first region of interest of the first image, and, determining the position of the second line segment according to a second region of interest of a second image, determining the intersection of the first line segment and the second line segment according to the position of the first line segment and the position of the second line segment, and taking the intersection as the spatial position of the interested part, wherein the first region of interest includes a region of interest equivalent to a point or a region of interest representing the first region of interest with a center point of the first region of interest, the second region of interest includes a region of interest equivalent to a point or a region of interest representing the second region of interest with a center point of the second region of interest, the first region of interest and the second region of interest each comprise a center point of the site of interest;

8. The positioning apparatus of an X-ray imaging device according to claim 7, further comprising,