JP4682898B2 - X-ray equipment - Google Patents

Description

  The present invention relates to an X-ray imaging apparatus that generates a long image by connecting a plurality of projection images obtained by imaging a subject. In particular, in addition to a long image, a long image for stereoscopic display is also included. It is related to the technology that can be acquired.

  Conventionally, as this type of apparatus, there is an X-ray imaging apparatus as shown in FIG. In FIG. 5, an X-ray tube 51 and a flat panel X-ray detector (hereinafter referred to as “FPD” as appropriate) 53 are arranged to face each other with a subject M placed on a top board 55 interposed therebetween. A shielding plate 57 is attached to the X-ray tube 51, and a narrow X-ray transmission portion 59 extending in a direction intersecting the longitudinal direction of the top plate 55 is formed on the shielding plate 57. Further, the X-ray tube 51 and the FPD 53 are respectively held at the upper end and the lower end of the holding and moving mechanism 61, and are configured to be horizontally movable in the longitudinal direction of the top board 55 in a state of facing each other. At this time, the shielding plate 57 also moves together with the X-ray tube 51.

  The movement control unit 63 operates the holding movement mechanism 61 to change the imaging position by the X-ray tube 51 and the FPD 53. When the imaging position is changed, the imaging control unit 65 irradiates cone beam-shaped X-rays from the X-ray tube 51. The irradiated X-rays pass through the X-ray transmission part 59 and become narrow X-rays that spread only in the short direction of the top plate 55, pass through the subject M, and are detected by the FPD 53. When such shooting is performed, the holding and moving mechanism 61 changes the shooting position, and the shooting control unit 65 repeatedly performs shooting at a new shooting position. In this specification, such an imaging method is referred to as slot scan imaging. The image processing unit 67 collects a plurality of X-ray images from the FPD 53 by slot scan imaging, extracts a projection image corresponding to the X-ray transmission unit 59 from these X-ray images, and connects the extracted projection images to obtain a long image. Generate an image. The monitor 69 displays the generated long image.

FIG. 6 is a schematic diagram of a long image of the subject M obtained by slot scan imaging. In the figure, the alternate long and short dash line indicates the joint of the projected images. Since this long image connects a plurality of projection images obtained by photographing the subject M from vertically above, a long image of the subject M without distortion in the longitudinal direction of the top board 55 can be acquired. Therefore, an image of a long part such as the spinal column or the lower limb can be suitably obtained (see, for example, Patent Document 1).
JP 2004-242928 A

However, the conventional example having such a configuration has the following problems.
That is, the conventional apparatus uses only the X-rays transmitted through the X-ray transmission part 59 among the cone-beam X-rays irradiated from the X-ray tube 51. For this reason, only one long image can be acquired by slot scan imaging.

  This invention is made in view of such a situation, Comprising: When acquiring a long image, it aims at providing the X-ray imaging apparatus which can also acquire the long image for stereoscopic display. To do.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 is provided with a top plate on which the subject to be imaged is placed, an X-ray generation source that irradiates the subject with cone-beam X-rays, and the X-ray generation source. A shielding member that shields X-rays, and three or more narrow X-ray transmitting portions extending in a direction crossing the longitudinal direction of the top plate are formed side by side along the longitudinal direction of the top plate . A shielding member, an X-ray detection means for detecting X-rays transmitted through the X-ray transmission part and the subject, the X-ray generation source, the shielding member and the X-ray detection means relative to the top plate Moving means for changing the imaging position by displacing the top plate in the longitudinal direction, and imaging control means for imaging the subject by irradiating X-rays from the X-ray generation source for each imaging position changed by the moving means And a plurality of X-ray images obtained based on the detection results of the X-ray detection means A projection image corresponding to each X-ray transmission part is extracted, and the projection image is connected to each X-ray transmission part to generate one long image, and a set of two stereoscopic display long images And image processing means for generating one or more pairs.

  [Operation / Effect] According to the invention described in claim 1, since the shielding member is formed with three or more narrow X-ray transmitting portions extending in a direction intersecting the longitudinal direction of the top plate, The subject can be irradiated with X-rays that travel in three different directions while spreading in the short direction of the top plate in the radiographing. For this reason, the image processing means can generate a pair of long images for stereoscopic display in addition to one long image from a plurality of X-ray images obtained by photographing at each photographing position. .

  In the invention described above, the X-ray transmission part includes a central transmission part through which the cone beam-shaped X-ray irradiation axis passes, and one or more sets of side transmission parts symmetrical with respect to the irradiation axis, It is preferable that the long image is generated based on a projection image corresponding to the central transmission part, and the long image for stereoscopic display is generated based on a projection image corresponding to the side transmission part. 2). Since the central transmission part is provided at a position where the irradiation axis of the X-ray generation source passes, the X-ray transmitted through the central transmission part transmits the subject from directly above, and is long without distortion in the longitudinal direction of the top plate. Images can be acquired. In addition, since the lateral transmission part is provided at a position that is symmetric with respect to the irradiation axis, the X-rays transmitted through the lateral transmission part are transmitted through the subject from opposite directions at the same inclination angle, for stereoscopic observation. A suitable long image for stereoscopic display can be acquired.

  In the above-described invention, the X-ray transmission part is preferably an opening. An X-ray transmissive part can be easily formed.

  In the above-described invention, it is preferable that the length of the short side of the projection image corresponding to each X-ray transmission part is substantially the same. By changing the imaging position once, projection images corresponding to the respective X-ray transmission parts can be acquired while having continuity.

  According to the X-ray imaging apparatus of the present invention, since three or more narrow X-ray transmission portions extending in the direction intersecting the longitudinal direction of the top plate are formed side by side on the shielding member, The subject can be irradiated with X-rays that travel in three different directions while spreading in the short direction of the top plate. For this reason, the image processing means can generate a pair of long images for stereoscopic display in addition to one long image from a plurality of X-ray images obtained by photographing at each photographing position. .

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of an X-ray imaging apparatus according to an embodiment, FIG. 2A is a perspective view of a shielding plate, and FIG. 2B is a cross-sectional view of the shielding plate. FIG. 3 is a schematic configuration diagram of the stereoscopic display device.

  The X-ray imaging apparatus according to the embodiment includes, as an imaging system, a top plate 1, an X-ray tube 3, a flat panel X-ray detector (hereinafter abbreviated as “FPD”) 5, a shielding plate 7, Holding and moving mechanism 9. In addition, a movement control unit 11, a photographing control unit 13, an image processing unit 15, a monitor 17, and a stereoscopic observation device 19 are provided.

  The top plate 1 is arranged substantially horizontally and places the subject M thereon. The X-ray tube 3 is provided on one end side (the upper end in the present embodiment) of the movement holding mechanism 9 and irradiates the subject M with cone-beam-shaped X-rays. The FPD 5 is provided on the other end side (lower end in the present embodiment) of the movement holding mechanism 9 and detects X-rays transmitted through the subject M. Then, an X-ray detection signal corresponding to the intensity of the incident X-ray is output. The shielding plate 7 is attached to the X-ray tube 3. The shield plate 7 has three openings 21a, 21b, and 21c. Below, according to the position of each opening part, while distinguishing and describing from the center opening part 21a and the side opening parts 21b and 21c, when not distinguishing these, it only describes as the opening part 21. The X-ray tube 3 and the FPD 5 correspond to the X-ray generation source and the X-ray detection means in this invention.

  Here, the shielding plate 7 will be described in more detail. Each opening 21 formed in the shielding plate 7 has a narrow rectangular shape extending in a direction intersecting with the longitudinal direction of the top plate 1, and is provided side by side in the longitudinal direction of the top plate 1. The central opening 21 a is disposed at a position where the irradiation axis E of the X-ray tube 3 passes. The side openings 21b and 21c are arranged at positions that are symmetric with respect to the irradiation axis E. In this embodiment, the inner wall of each opening 21 is inclined according to the angle at which X-rays enter each opening 21. As the material of the shielding plate 7, a substance having a high X-ray absorption rate is preferable. Specifically, lead etc. are illustrated.

  Such a shielding plate 7 transmits X-rays radiated from the X-ray tube 3 through the openings 21 and shields X-rays other than the openings 21. At this time, the field of view allowed by each opening 21 has a substantially rectangular shape with a narrow width in the short direction of the top plate 1, but the size of each opening 21 is substantially the same. Is preferably determined. In particular, it is preferable that the dimensions of the openings 21 are determined so that the lengths of the short sides of the field of view are substantially the same. Thereby, the length of the short side of the projected image projected onto the FPD 5 according to each opening 21 can be made substantially the same. As the length of the short side of the projected image, for example, a value of several mm to several cm is exemplified. However, the present invention is not limited to this range, and the design may be appropriately changed beyond this range. The central opening 21a corresponds to the central transmission part in the present invention, and the side openings 21b and 21c correspond to a set of side transmission parts in the present invention.

  The movement holding mechanism 9 is provided on one side of the longitudinal side of the top plate 1 and is configured to be movable back and forth linearly in the longitudinal direction of the top plate 1. The movement control unit 11 operates the holding movement mechanism 9 to change the imaging positions of the X-ray tube 3 and the FPD 5. At this time, the pitch is changed to a step with a pitch amount slightly shorter than the length of the short side of the projection image corresponding to each opening 21 described above. The movement holding mechanism 9 corresponds to the moving means in this invention.

  The imaging control unit 13 irradiates cone beam-shaped X-rays from the X-ray tube 3 for each changed imaging position in cooperation with the movement control unit 11. The photographing control unit 13 corresponds to the photographing control means in this invention.

  The image processing unit 15 acquires an X-ray image based on the X-ray detection signal output from the FPD 5. And the projection image according to each transmission part 21 is extracted from the acquired X-ray image. Furthermore, the extracted projection image is connected to each transmission unit 21 with reference to the control of the movement control unit 9 to generate a single long image, and a set of two long images for stereoscopic display. A pair is generated. The generated long image and stereoscopic display long image are stored in a storage unit (not shown) as appropriate, and are output to the monitor 17 or the stereoscopic display device 19. The image processing unit 15 corresponds to the image processing means in this invention.

  The movement control unit 11, the imaging control unit 13, and the image processing unit 15 described above each have a central processing unit (CPU) that reads and executes a predetermined program, a RAM (Random-Access Memory) that stores various types of information, This is realized by a storage unit such as a fixed disk.

  As shown in FIG. 3, the stereoscopic display device 19 includes one liquid crystal display 31 a and 31 b and a pair of observation mirrors 33 a and 33 b arranged to face each other for the left eye and the right eye. A pair of long images for stereoscopic display are displayed on the liquid crystal displays 31a and 31b, respectively, so that stereoscopic observation can be performed through the observation mirrors 33a and 33b.

  Next, the operation of the X-ray imaging apparatus according to the first embodiment will be described separately for slot scan imaging and image processing.

<Slot scan shooting>
With the subject M placed on the top 1, the movement control unit 11 operates the holding and moving mechanism 9 to move the X-ray tube 3 and the FPD 5 to the first imaging position. At this time, the shielding plate 7 also moves together with the X-ray tube 3. Subsequently, the imaging control unit 13 emits X-rays from the X-ray tube 3. The X-ray tube 3 emits cone-beam X-rays. The irradiated X-rays pass through each opening 21 and become narrow X-rays that spread only in the short direction of the top 1. Here, the X-rays transmitted through the central opening 21a travel substantially vertically downward. On the other hand, the X-rays that have passed through the side openings 21b and 21c fall in directions opposite to each other at substantially the same inclination angle with respect to the longitudinal direction of the top plate 1. Therefore, the X-rays transmitted through the central openings 21a pass through the subject M from directly above and enter the FPD 5. The X-rays transmitted through the side openings 21b and 21c are transmitted through the subject M at substantially the same inclination angle from opposite directions, and enter the FPD 5. The FPD 5 outputs an X-ray detection signal according to the intensity of the incident X-ray. The image processing unit 15 collects X-ray images based on the X-ray detection signal output from the FPD 5. Then, referring to the control of the movement control unit 11, the acquired X-ray image is associated with the imaging position and stored in the storage unit included in the image processing unit 15. This completes the shooting at the first shooting position.

  Subsequently, the movement control unit 13 operates the holding movement mechanism 9 to change the photographing position in the longitudinal direction of the top 1 by a predetermined pitch amount. When the X-ray tube 3, the FPD 5, and the shielding plate 7 move to a new imaging position, the imaging control unit 13 irradiates the X-rays again from the X-ray tube 3. The image processing unit 15 acquires an X-ray image based on the detection result from the FPD 5 and stores it in the storage unit. Thus, the shooting at the next shooting position is completed.

  Thereafter, the X-ray image of the subject M is collected in the same manner by repeating the imaging while changing the imaging position in the stepwise direction by the pitch amount in the longitudinal direction of the top 1. Then, when all of the region of interest (for example, the spinal column) of the subject M is imaged, the slot scan imaging ends.

<Image processing>
The image processing unit 15 reads out the X-ray images collected from the storage unit and extracts a projection image of the subject M. At this time, although three projected images are projected on one X-ray image, the corresponding opening 21 is determined according to the position of the extracted projected image on the X-ray image. In this manner, projection images corresponding to the respective openings 21 are also extracted from other X-ray images obtained by slot scan imaging.

  And the projection image according to the center opening part 21a is connected in order of an imaging position, and one long image is produced | generated. In addition, the projection images corresponding to the side openings 21b and 21c are connected in the order of the photographing positions to generate a pair of two long images for stereoscopic display.

  FIG. 4 is a schematic diagram of a pair of long images for stereoscopic display obtained by slot scan imaging. Here, FIG. 4A is a long image for stereoscopic display generated based on a projection image corresponding to the side opening 21b, and is an image viewed obliquely downward from the foot side. FIG. 4B is a long 3D display image generated based on a projection image corresponding to the side opening 21c, and is an image of the subject M seen obliquely downward from the head side. ing. A pair of long images for stereoscopic display is formed by a set of two images shown in FIGS. 4 (a) and 4 (b). In the figure, the alternate long and short dash line schematically shows the joint of the projected images.

  The generated long image and the pair of stereoscopic display long images are stored in the storage unit included in the image processing unit 15. Then, based on the operator's instruction, it is output to the monitor 17 or the stereoscopic display device 19 as appropriate.

  As described above, according to the X-ray imaging apparatus according to the first embodiment, the shielding plate 7 includes the three narrow opening portions 21 extending in the direction intersecting the longitudinal direction of the top plate 1. One long image and a pair of long images for stereoscopic display can be acquired by slot scanning photographing.

  Further, since the central opening 21a is disposed at a position where the irradiation axis E of the X-ray tube 3 passes, a long image without distortion in the longitudinal direction of the top plate 1 can be generated. Moreover, since the side openings 21b and 21c are arranged at positions symmetrical with respect to the irradiation axis E, a pair of long images for stereoscopic display suitable for stereoscopic observation can be acquired.

  Moreover, since the length of the short side of the projection image corresponding to each opening 21 is substantially the same, the projection image corresponding to each opening 21 has continuity by changing the photographing position once. Can be obtained. Furthermore, the photographing position is configured to be changed in steps with a pitch amount slightly shorter than the length of the short side of the projection image corresponding to each opening 21, so that the projection image can be obtained with a slight overlap. Can do.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In the above-described embodiment, the X-ray transmission part is configured by the opening 21 formed in the shielding plate 7, but is not limited thereto. For example, the X-ray transmission part may be configured with a material that transmits X-rays satisfactorily, or the X-ray transmission part may be configured with a filter that adjusts the X-ray quality.

  (2) In the embodiment described above, the central opening 21a is disposed at a position that passes through the X-ray irradiation axis E, but is not limited thereto. The central opening 21a may be provided at a position deviated from the irradiation axis E as long as a long image in which a necessary amount of distortion is eliminated can be obtained in observation diagnosis. Further, the side openings 21b and 21c are arranged at positions symmetrical to the irradiation axis E. However, if the stereoscopic display device 19 can perform stereoscopic observation, the side openings 21b and 21c are strictly symmetrical to the irradiation axis E. It does not have to be asymmetrical.

  (3) In the embodiment described above, the number of the opening portions 21 formed in the shielding plate 7 is three. However, the number of openings may be further increased. As a result, a plurality of pairs of stereoscopic display long images can be generated.

  (4) In the above-described embodiment, the X-ray tube 3 and the FPD 5 are held by the holding and moving mechanism 9 and moved integrally. However, the present invention is not limited to this. For example, the X-ray tube 3 and the FPD 5 may be held by separate holding mechanisms, and the X-ray tube 3 and the FPD 5 may be moved in synchronization with each other. Moreover, you may comprise so that the X-ray tube 3 and FPD5 may be hold | maintained fixedly and the mechanism which moves the top plate 1 to a longitudinal direction may be provided. Also by this, the X-ray tube 3, the shielding plate 7, and the FPD 5 can be displaced relative to the top plate 1 to change the imaging position.

  (5) In the embodiment described above, the image processing unit 15 associates the imaging position with the X-ray image by referring to the control of the movement control unit 11, but is not limited thereto. If the projection image can be connected in the subsequent processing, the movement control unit 11 may not be linked. For example, you may change so that the imaging | photography frequency counted in scanning imaging | photography may be matched with an X-ray image.

  (6) In the above-described embodiment, the image processing unit 15 stores the X-ray image obtained from the FPD 5 in the storage unit, but is not limited thereto. For example, the projection image may be sequentially extracted from the X-ray image, and the extracted projection image may be stored. In the embodiment described above, in the explanation of the operation, for the convenience of explaining the slot scan shooting and the image processing separately, it has been described that the processing for generating the long image is started after the slot scan shooting is finished. The long image generation process may be started during slot scan shooting.

  (7) In the above-described embodiment, the X-ray imaging apparatus includes the stereoscopic display device 19, but the X-ray imaging apparatus may include a stereoscopic display device that is separate from the X-ray imaging apparatus. Further, the stereoscopic display device 19 is a four-mirror type, but is not limited thereto. For example, the display device can be appropriately changed to a known stereoscopic display device such as a stereoscopic display device that generates optical images for the right eye and the left eye by the lens action of the lenticular lens.

  (8) In the above-described embodiments, the medical X-ray imaging apparatus is used, but the present invention is not limited to this. For example, the present invention can be applied to industrial fields such as non-destructive inspection, RI (Radio Isotope) inspection, and optical inspection, and X-ray imaging apparatuses used in the nuclear power field. In each embodiment, the subject M is described, but the subject M is not limited to the human body.

It is a block diagram which shows schematic structure of the X-ray imaging device which concerns on an Example. 2A is a perspective view of the shielding plate, and FIG. 2B is a cross-sectional view of the shielding plate. It is the schematic of a three-dimensional display apparatus. It is a schematic diagram of a pair of long images for stereoscopic display obtained by the X-ray imaging apparatus according to the present embodiment. It is a block diagram which shows schematic structure of the X-ray imaging apparatus which concerns on a prior art example. It is a schematic diagram of the long image obtained by the X-ray imaging apparatus which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Top plate 3 ... X-ray tube 5 ... Flat panel type X-ray detector (FPD)
DESCRIPTION OF SYMBOLS 7 ... Shielding board 9 ... Holding | maintenance moving mechanism 11 ... Movement control part 13 ... Imaging | photography control part 15 ... Image processing part 19 ... 3D display device 21a ... Center opening part 21b, 21c ... Side opening part

Claims (4)

There are a top plate on which a subject to be imaged is placed, an X-ray generation source that irradiates the subject with cone-beam X-rays, and a shielding member that is attached to the X-ray generation source and shields the X-rays. A shielding member in which three or more narrow X-ray transmission portions extending in a direction intersecting with the longitudinal direction of the top plate are arranged along the longitudinal direction of the top plate , the X-ray transmission portion, and the cover. X-ray detection means for detecting X-rays transmitted through the specimen, and the X-ray generation source, the shielding member, and the X-ray detection means are displaced in the longitudinal direction of the top plate relative to the top plate. A detection unit that changes the imaging position, an imaging control unit that irradiates X-rays from the X-ray generation source for each imaging position changed by the moving unit, and a detection result of the X-ray detection unit. A projection image corresponding to each X-ray transmission part is extracted from a plurality of X-ray images obtained based on And an image processing means for generating one long image by connecting the projection images for each of the X-ray transmission parts and generating one or more pairs of long images for stereoscopic display. An X-ray imaging apparatus characterized by that.   2. The X-ray imaging apparatus according to claim 1, wherein the X-ray transmission unit includes a central transmission unit through which the cone beam-shaped X-ray irradiation axis passes and at least one set of side surfaces symmetrical with respect to the irradiation axis. The long image is generated based on a projection image corresponding to the central transmission portion, and the stereoscopic display long image is generated based on a projection image corresponding to the side transmission portion. An X-ray imaging apparatus.   The X-ray imaging apparatus according to claim 1, wherein the X-ray transmission part is an opening.   4. The X-ray imaging apparatus according to claim 1, wherein the short sides of the projection images corresponding to the respective X-ray transmission parts have substantially the same length. 5.

Images