WO2012040930A1

WO2012040930A1 - Point-by-point scanning device and method uesd in x ray imaging

Info

Publication number: WO2012040930A1
Application number: PCT/CN2010/077521
Authority: WO
Inventors: 屈俊健; 梁石磊; 周晓丽; 仇晨东
Original assignee: 上海英迈吉东影图像设备有限公司
Priority date: 2010-09-30
Filing date: 2010-09-30
Publication date: 2012-04-05
Also published as: CN103649734A

Abstract

A point-by-point scanning device used in X ray imaging comprises: a ray source (13), a ray source collimator (14) and a rotating mechanism (15). The ray source collimator (14) is arranged on the beam output window of the ray source (13), the rotating mechanism (15) is connected with the ray source (13) and drives the ray source (13) to rotate. Besides, a point-by-point scanning method used in X ray imaging comprises the following steps: a rotating mechanism (15) drives a ray source (13) to rotate; the ray source (13) generates the ray; the ray is emitted from the beam output window of the ray source (13) via a ray source collimator (14) and falls on an object to be detected; the ray falling on the object to be detected moves with time, forming a point-by-point scanning.

Description

Point-by-point scanning device and method for X-ray imaging

The present invention relates to an X-ray imaging technique, including backscatter imaging and transmission imaging, and more particularly to a point-by-point scanning apparatus and method for X-ray imaging. Background technique

At present, there are mainly three methods for point-by-point scanning for X-ray imaging in the prior art, and the three scanning methods are briefly introduced below.

First, please refer to FIG. 1. FIG. 1 is a prior art X-ray imaging point-by-point scanning device. In FIG. 1, the radiation source 2 is connected to the left and right cutting wheels 1, and the left and right cutting wheels 1 are evenly arranged along the radial direction. a collimating hole 8, a ray source fixing support frame 6 and the ray source 2 are connected to each other for supporting, and the motor 7 is located below the left and right tangential wheels 1 to provide main power, and two backscattering detectors 5 are placed On both sides of the left and right cutting wheel 1, the rays emitted from the center of the circle are formed along the collimating hole 8 to form a pencil beam 9 to be emitted onto the object to be inspected to form a circular spot, that is, a flying spot, and the other object 3 to be inspected On the side, a transmission detector 4 is placed to observe the scanning result. The method is simple and practical, but on the emission surface of the X-ray, there is a problem that the intensity of the X-ray is not uniform, which causes the ray intensity of the scanning point to be inconsistent, thereby affecting the accuracy of the scanning result.

Next, please refer to the second example of the prior art flying point technology. An X-ray source, like any source, produces an energy field, like a concentrated beam or a plane. Most systems use a collimator to confine the output ray to a very narrow plane. The collimator is made of lead or other protective material and has a narrow, straight slit that allows X-rays to pass. At each moment, only a small part of the baggage can be seen; the collimator effectively divides the baggage into small straight areas, or scan lines. A detector array is used to divide the exposed area (the line that is illuminated) into many small parts and produce a pixel image. Using this method, the image (pixel) is limited by the number of array detectors, although the lateral results can be controlled by changing the speed of the conveyor. In addition, the increase in the number of sensors on the detector means an increase in the overall system cost. The American Science and Technology Engineering Corporation (AS&E) paper "Based on the Automatic Explosives Inspection Model of the AS&E101ZZ System" A different, more efficient method of obtaining discrete points of illumination on an object. There is a collimator, a broken flywheel made of protective material, placed on the X-ray path. There are 4 slots on the flywheel to rotate at a fixed speed. The result is that the flywheel interrupts the collimated X-ray surface and forms a very thin beam. As the flywheel rotates, the beam moves from the bottom surface to the top surface, scanning a complete vertical line. The moving beam forms a pixel image that reduces the cost of the sensor array. Some large photomultiplier tubes have been used. Controlling horizontal and vertical results with a sliding beam reduces the cost of the system with very few expensive detector components. Although the method reduces the cost, when the flywheel is turned to a certain angle, the flywheel itself has blocked the X-rays, and the X-rays cannot work normally.

Next, please refer to FIG. 2 for a third example of the prior art. FIG. 2 is a schematic diagram of a prior art flying spot forming apparatus. In the invention patent entitled "A Flying Point Forming Apparatus and Method for Radiographic Imaging", the following is disclosed: The apparatus mainly comprises a flywheel 31 and a collimator 32, wherein the flywheel 31 has a curved groove 31 1 The number of curved grooves in FIG. 4 is three, and the flywheel 31 is made of a material that can block rays. When the radiation is irradiated onto the flywheel 31, only the rays passing through the curved groove 311 can pass through the flywheel 31, and the remaining rays are blocked by the flywheel 31. . The collimator 32 has a rectangular slit 321 which is also made of a material that blocks radiation. When the radiation strikes the collimator 32, only the rays passing through the slit 321 can pass through the collimator 32. The remaining rays are blocked by the collimator 32. The difference between this method and the third example is that the fine grooves on the flywheel are not straight, but curved. Referring to Figures 3 and 4, in fact, when the linear groove is rotated to the position of Figure 3, the linear groove of the same width has blocked the passage of the X-ray. When a curved groove is used, as shown in Figure 4, the ray can pass through the curved groove smoothly. There is no occlusion. Figure 4 is a big improvement on the basis of Figure 3, but there are still some shortcomings, please refer to Figure 5, Figure 5 is the relationship between X-ray exit angle and intensity, as in the first example, the prior art The disadvantage of the third example is that there is a problem of uneven X-ray intensity on the emission fan surface of the X-ray, which causes the ray intensity of the scanning point to be inconsistent. Summary of the invention

The problem solved by the present invention is that the X-ray intensity in the point-by-point scanning of the X-ray imaging in the prior art is not uniform, which causes the problem that the ray intensity of the scanning point is inconsistent.

In order to achieve the above object, the present invention provides a point-by-point scanning apparatus for X-ray imaging, which mainly includes: a ray source and a ray source collimator, wherein the ray source collimator is located at the ray source The beam window, the point-by-point scanning device further includes a rotating mechanism, and the rotating mechanism is coupled to the radiation source to drive the radiation source to rotate.

Optionally, the ray source collimator is provided with at least one collimating hole.

Optionally, the number of the collimating holes is two, four or eight.

Optionally, the collimating hole is conical, and the bottom surface of the conical shape faces outward.

Optionally, the rotating mechanism drives the rotation of the radiation source through a belt.

In order to achieve the above object, the present invention also provides a point-by-point scanning method for X-ray imaging, comprising the following steps: a rotating mechanism drives a radiation source to rotate; a radiation source generates a radiation; and the radiation passes through the beam exit window The ray source collimator is emitted and falls on the object to be inspected; the ray falling on the object to be inspected moves with time to form a point-by-point scan.

Optionally, the number of the collimating holes is two, four or eight.

Optionally, the rotating mechanism drives the radiation source to rotate through a belt.

Since the above technical solution is adopted, the present invention has the following advantages compared with the prior art: The present invention uses the rotating mechanism to drive the rotation of the radiation source, thereby ensuring that the intensity of the X-ray source irradiated onto the object is uniform in one scan. Providing more accurate data for subsequent imaging and discrimination of material properties; the invention provides a plurality of collimating holes on the ray source collimator, which avoids the situation that the ray source rotates once to scan the object once, shortens the scanning period, and improves The accuracy of subsequent imaging.

DRAWINGS

1 is a prior art apparatus for point-by-point scanning of X-ray imaging.

2 is a schematic view of a prior art flying spot forming apparatus.

3 and 4 are schematic views of the prior art in which the flywheel is turned to a certain position. Fig. 5 is a graph showing the relationship between the X-ray exit angle and the intensity. 6 is a schematic view showing the structure of a device for a point-by-point scanning apparatus and method for X-ray imaging according to the present invention. 7 is a flow chart showing the method of a point-by-point scanning apparatus and method for X-ray imaging according to the present invention. 8 is a partial view of a device of a point-by-point scanning apparatus and method for X-ray imaging according to the present invention. 9 is a partial view of a device of an embodiment of a point-by-point scanning apparatus and method for X-ray imaging according to the present invention.

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, please refer to FIG. 6. FIG. 6 is a schematic structural diagram of a device for a point-by-point scanning apparatus and method for X-ray imaging according to the present invention. As can be seen from the figure, the point-by-point scanning device for X-ray imaging of the present invention The invention comprises: a radiation source 13 and a radiation source collimator 14 for generating radiation, the radiation source collimator 14 is located at a beam exit window of the radiation source 13, and the point-by-point scanning device further comprises a rotation The mechanism 15 is connected to the radiation source 13 to drive the radiation source 13 to rotate. The ray source collimator 14 is provided with at least one collimating hole. Preferably, the number of the collimating holes is two, four or eight. If the ray source rotates clockwise, if there is only one collimation Hole, the source can be scanned once to rotate the object once, and the number of collimation holes can be increased to shorten the scanning period. The collimating holes are conical, and the bottom surface of the conical shape faces outward, so that the rays can be emitted to the utmost to avoid interference by the side walls. The rotating mechanism 15 drives the rotation of the radiation source through a belt 16.

In normal operation, the rotating mechanism 15 drives the radiation source 13 through the belt 16, and the radiation source 13 generates radiation, which is incident into the radiation source collimator 14 through the exit window of the radiation source 13, and then exits from the radiation source collimator 14. Two scatter detectors 12 are disposed on both sides of the ray source collimator 14. The scatter detectors 12 are arranged to ensure that the observation and recording are not disturbed, and the reliability of the results is ensured. After the ray is emitted, it is hit on the object to be inspected 11, and the X-ray is irradiated onto the object as a small point. As the X-ray rotates, the point that falls on the object moves over the object over time, forming a point-by-point scan. The transmission detector 10 is located on one side of the object 11 to be inspected and recorded as a result.

Next, please refer to FIG. 7. FIG. 7 is a point-by-point scanning device for X-ray imaging according to the present invention. A schematic diagram of a method flow of the method. As can be seen from the figure, a method for a point-by-point scanning apparatus and method for X-ray imaging of the present invention comprises the following steps: Step 21: - a rotating mechanism drives the radiation source to rotate, The rotating mechanism drives the radiation source to rotate by a belt; Step 22: The radiation source generates radiation; Step 23: The radiation is emitted from the beam exit window through the radiation source collimator and falls on the object to be inspected; Step 24: The ray falling on the object to be inspected moves with time to form a point-by-point scan. When the source is rotated clockwise, if there is only one collimation hole, the source can be scanned once to rotate the object once. When there are two or more beams, the scanning period will be greatly shortened.

Please refer to FIG. 8 and FIG. 9. FIG. 8 is a partial view of a device for a point-by-point scanning device and method for X-ray imaging according to the present invention. In FIG. 8, the source collimator 14 is located at the source 13 of the source. The beam window, the source collimator 14 is provided with a collimating hole 17, the collimating hole is conical, and the bottom surface of the conical shape faces outward, so that the radiation can be emitted to the utmost to avoid being Sidewall interference. The radiation source collimator is provided with at least one collimating hole, and the number of the collimating holes may be two, four or eight. FIG. 9 is a point-by-point scanning device for X-ray imaging according to the present invention. In the apparatus partial method diagram of an embodiment of the method, in FIG. 9, the collimator is provided with two collimating holes, the collimating holes are still conical, and the bottom surface of the conical shape faces outward, respectively After the first beam of light 18 of the collimating aperture has been scanned, the second beam 19 can continue to scan the object.

By improving the point-by-point scanning apparatus and method for X-ray imaging, the present invention ensures that the intensity of the X-ray source irradiated onto the object is uniform in one scan. Provides more accurate data for subsequent imaging and discrimination of material properties.

Although the invention has been disclosed above in the preferred embodiments, the invention is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the scope defined by the appended claims.

Claims

Claim

A point-by-point scanning device for X-ray imaging, comprising: a ray source and a ray source collimator, the ray source collimator being located at a beam exit window of the ray source, wherein: The point-by-point scanning device further includes a rotating mechanism, and the rotating mechanism is coupled to the radiation source to drive the radiation source to rotate.

The point-by-point scanning device for X-ray imaging according to claim 1, wherein: the radiation source collimator is provided with at least one collimating hole.

The point-by-point scanning device for X-ray imaging according to claim 2, wherein the number of the collimating holes is two, four or eight.

The point-by-point scanning device for X-ray imaging according to claim 2, wherein the collimating hole has a conical shape, and a bottom surface of the conical shape faces outward.

5. The point-by-point scanning apparatus for X-ray imaging according to claim 1, wherein: said rotating mechanism drives said radiation source to rotate by a belt.

6. A point-by-point scanning method for X-ray imaging, characterized in that it comprises the following steps: a rotating mechanism drives the radiation source to rotate;

The radiation source produces radiation;

The ray is emitted from the beam exit window through the ray source collimator and falls on the object to be inspected; the ray falling on the object to be inspected moves with time to form a point-by-point scan.

The point-by-point scanning method for X-ray imaging according to claim 6, wherein: the radiation source collimator is provided with at least one collimating hole.

The point-by-point scanning method for X-ray imaging according to claim 7, wherein the number of the collimating holes is two, four or eight.

The point-by-point scanning method for X-ray imaging according to claim 7, wherein: the collimating hole has a conical shape, and a bottom surface of the conical shape faces outward.

The point-by-point scanning method for X-ray imaging according to claim 6, wherein: the rotating mechanism drives the radiation source to rotate by a belt.