JP2006034452A - X-ray television receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray television receiver capable of matching the position of an optical image with an X-ray transmission image and compositing and displaying them in simple constitution. <P>SOLUTION: This X-ray television receiver is provided with: an X-ray tube 1 for generating X-rays toward a testee body; an X-ray detector 2 for detecting the X-rays transmitted through the testee body; an optical camera 10 installed so that its optical axis matches with or approximates the center axis of the X-rays; and a compositing receiver 6 for compositing the X-ray transmission image detected by the X-ray detector 2 and the optical image photographed by the optical camera 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray television apparatus that converts an X-ray transmission image into an electric signal and displays it on a display device.

  An “X-ray television apparatus” is well known as a typical means for easily observing the inside of the body in real time. Up to now, a combination of an image intensifier and a CCD camera has been used as a means of acquiring X-ray transmission images in real time, but recently, it has been called “flat panel detector”. The so-called small and lightweight solid state detector is beginning to be used. As a result, X-ray television apparatuses that can be easily used in an operating room have been developed and commercialized.

  For example, in orthopedic surgery, the surgeon may proceed with the operation by immediately judging the X-ray transmission image displayed and displayed by X-ray transmission while comparing it with the observation result with the naked eye, that is, the visible light optical image. is there. Conventionally, a visible light optical image is associated with an X-ray transmission image only in the surgeon's head.

  According to Non-Patent Document 1, using an optical position measurement device and a display device using a half mirror, “monitor position”, “operator's viewpoint position and line-of-sight direction”, and “observed diseased part position” are determined. Projection seen from the operator's line of sight from three-dimensional images such as X-ray computed tomography and magnetic resonance imaging devices that have been fixed in place for each measurement marker and have been imaged in advance based on that information An apparatus for calculating an image and displaying the image superimposed on a display apparatus using the half mirror has been developed. This is a technique classified as a method called Integral Photography, which superimposes a projection image such as an X-ray transmission image on a visible light optical image with the naked eye.

  Prior to the appearance of these devices, as described above, for example, in the case of orthopedic surgery, the surgeon checks the X-ray transmission image taken with the X-ray television device on the monitor and the state of the affected part viewed with the naked eye. It was in a state of proceeding with surgery while associating images only in the head.

  In the above-described apparatus, it is necessary to measure in real time all relative positional relationships related to “monitor position”, “operator's viewpoint position and line-of-sight direction”, and “observed affected part position”. As a means for performing this in a non-contact manner, a marker coated with a recursive paint (a paint that reflects light in the direction in which the light came) is fixed at a position that does not line up in the above three locations and is aligned with infrared rays. There is known an apparatus for optically measuring the marker position three-dimensionally while irradiating the beam. The surgeon has always had to wear such a marker, and has previously had a trouble of registering the relative positional relationship between the affected area and the marker (registration).

In addition, since 3D image data acquired in advance by an X-ray computed tomography apparatus or a magnetic resonance imaging apparatus is used, as soon as surgery progresses and deformation occurs in the affected area, the 3D image data is simply “before surgery”. This is only “reference data” and requires the work of acquiring the latest image data again, that is, the work of moving the patient to an X-ray computed tomography apparatus or magnetic resonance imaging apparatus and taking a 3D image again. There were also problems such as lack of sex.
"Real-time three-dimensional image navigation as intraoperative support" (Hongen LIAO, Nakajima Satoshi, Iwahara Makoto, Kobayashi Hidetsuko, Sakuma Ichiro, Yahagi Naoki, Dohi Takemi; IEICE, IEICE Technical Report 2001-04)

  An object of the present invention is to provide an X-ray television apparatus capable of displaying an optical image in alignment with an X-ray transmission image with a simple configuration.

  The present invention relates to an X-ray generation source that generates X-rays toward a subject, an X-ray detector that detects the X-rays that have passed through the subject, and an optical axis that is relative to the central axis of the X-rays An optical camera installed so as to coincide or approximate, an X-ray transmission image detected by the X-ray detector, and a synthesizing device that synthesizes the optical image taken by the optical camera.

  According to the present invention, it is possible to provide an X-ray television apparatus capable of combining and displaying an optical image in alignment with an X-ray transmission image with a simple configuration.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the X-ray television apparatus according to this embodiment includes, for example, a C-shaped arm 3. The C-arm 3 is supported rotatably and movable on an arm stand (not shown) that is reduced in size and weight in order to suppress movement to the operating room and interference with surgical operations in the operating room. An X-ray tube 1 is attached to one end of the arm 3, and an X-ray flat detector (also referred to as a flat panel detector) 2 is attached to the other end in a direction facing the X-ray tube 1. The X-ray flat panel detector 2 has a plurality of direct conversion types that directly convert incident X-rays into electric signals or indirect conversion types that convert incident X-rays into light with a phosphor and convert the light into electric signals. A semiconductor detection element is included. The plurality of semiconductor detection elements are arranged in a two-dimensional lattice pattern. The X-ray flat panel detector 2 can be replaced with a combination of an image intensifier and an optical camera. At the time of imaging, the affected part of the subject (patient) placed on the top plate of the bed is placed between the X-ray tube 1 and the flat detector 2.

  An X-ray diaphragm device 16 is attached to the X-ray emission window of the X-ray tube 1. X-rays emitted from the X-ray emission window of the X-ray tube 1 are reduced to a cone or a pyramid by the X-ray aperture device 16. Positional relationship between the X-ray tube 1 and the flat detector 2 so that the central axis OA1 of the X-ray narrowed into a cone or a pyramid is orthogonal to and passes through the detection surface of the flat detector 2 Is fixed. The center of the detection surface of the flat detector 2 coincides with the center of the X-ray transmission image generated according to the output of the flat detector 2.

  The X-ray television apparatus according to the present embodiment is equipped with an optical camera 10 such as a CCD camera (charge-coupled device camera) in order to acquire an optical image of the affected surface. The optical camera 10 is attached with an illumination light source 9 for illuminating the affected area. The illumination light source 9 may be one using “optical fiber and halogen light source” or one using “white LED (white light emitting diode)”. The optical camera 10 typically captures a visible light image, but may be of a type that captures an infrared or ultraviolet image. In addition, for example, a case where 5-ALA (tumor accumulation property, a substance that emits fluorescence in a wavelength region near infrared rays when irradiated with ultraviolet rays) is administered to a patient in advance and surgery is performed while observing after a certain period of time has elapsed. The maximum sensitivity wavelength of the optical camera 10 may have a maximum sensitivity other than visible light (for example, in the infrared or ultraviolet region).

  The optical camera 10 is disposed via the half mirror 8 with respect to the subject. The half mirror 8 is made of a metal-deposited resin (made of acrylic), and has a property of almost transmitting X-rays but reflecting visible light. The half mirror 8 is disposed between the X-ray tube 1 and the subject with an inclination of about 45 ° with respect to the X-ray central axis OA1. The positional relationship between the X-ray tube 1, the mirror 8, and the optical camera 10 is such that the optical axis OA2 of the optical camera 10 substantially coincides with the X-ray central axis OA1 and can be maintained. It is fixed by an E or F-shaped high-rigidity frame (bridge) 12. As a result, the center of the optical image of the affected surface imaged by the optical camera 10 is matched with the center of the X-ray transmission image, thereby achieving anatomical positional alignment between the optical image and the X-ray transmission image. be able to.

  The X-ray diagnostic apparatus controller 4 is provided to control generation of X-rays from the X-ray tube 1 and signal reading of the flat detector 2. The X-ray transmission image data output from the flat detector 2 via the X-ray diagnostic apparatus controller 4 is combined with the optical image data output from the optical camera 10 via the camera control unit 11 together with the image composition apparatus. 6 is supplied.

  The image synthesis device 6 synthesizes (superimposes) the X-ray transmission image and the optical image into one image. The monitor 7 is provided to display a composite image (superimposed image) of the X-ray transmission image and the optical image generated by the image composition device 6.

  In the composition processing in the image composition device 6, as described above, the center of the optical image is matched with the center of the X-ray transmission image. Thereby, anatomical positional alignment between the X-ray transmission image and the optical image can be achieved. In the image composition device 6, the anatomical size is matched between the X-ray transmission image and the optical image. The magnification at the time of capturing an X-ray transmission image is uniquely determined by the ratio of the distance from the X-ray tube 1 to the flat detector 2 to the distance between the X-ray tube 1 and the affected part. The position of the affected part can be almost estimated from the position (height) of the couch top. Accordingly, the positions of the three members of the X-ray tube 1, the top plate, and the flat detector 2 are measured by a position sensor using an encoder or the like, and the image composition device 6 has the same magnification as the X-ray transmission image according to the result. Thus, the enlargement process can be applied to the optical image. As the enlargement process, simple enlargement with a uniform enlargement ratio may be used, but a variable enlargement process in which the enlargement ratio increases radially from the center of the image is preferable, similar to the enlargement principle during X-ray imaging.

When the X-ray transmission image and the optical image are combined by the image combining device 6, the combining ratio can be arbitrarily changed. That is, from the X-ray transmission image It (x, y) and the optical image Io (x, y), the composite image Ic (x, y) is
Ic (x, y) = a.It (x, y) + (1-a) .Io (x, y)
However, 0 <a <1
And the operator can arbitrarily manipulate the coefficient a. As an initial setting, the coefficient a is selectively set to 1 or 0.5. In the present X-ray television apparatus, an on / off switch 5 is provided. For the on / off switch 5, for example, a foot switch that can be operated by a surgeon is employed. When the on / off switch 5 is turned on, the coefficient a is set to 0.5 (or its approximate value) in the synthesizing device 6 under the control of the controller 4. Thereby, the X-ray transmission image is combined with the optical image at an equal ratio, and the X-ray transmission image is displayed together with the optical image. Only when the on / off switch 5 is turned on, the controller 4 applies a high voltage to the X-ray tube 1 from a high voltage generator (not shown) so as to generate X-rays and irradiate the subject. Control the high voltage generator. In other words, when the on / off switch 5 is in the off state, the controller 4 applies a high voltage to the X-ray tube 1 so as to stop generation of X-rays and stop irradiation of the subject. The high voltage generator is controlled to stop the operation. When the on / off switch 5 is in the off state, the coefficient a is set to 0 (or its approximate value) in the synthesizer 6. Thereby, the X-ray transmission image is not substantially displayed, and the optical image is displayed alone.

  In a practical use site, after the start of shooting by the optical camera 10 is instructed, shooting by the optical camera 10 is continued. Initially, the on / off switch 5 is in an off state. Thereby, X-ray imaging is not performed, and the coefficient is set to 0, so that substantially only the optical image is displayed. The surgeon turns on the on / off switch 5 only when an X-ray transmission image is required during the operation. Thereby, X-rays are generated, and an X-ray transmission image is generated accordingly. Further, since the coefficient is set to 0.5, a composite image of the X-ray transmission image and the optical image is displayed. Of course, the value of the coefficient when the on / off switch 5 is turned on is not limited to 0.5, and can be arbitrarily changed between 0 and 1. In addition, although the real-time property is lost, when a stereo image with respect to the composite image of the optical image and the X-ray transmission image is necessary, the C-arm may be moved to acquire a stereoscopic image and display it for the left and right eyes. .

  As described above, the problem that the viewpoint position of the surgeon deviates from the display position of the monitor screen is considered when the operation is performed while looking at the monitor screen in surgery using a laparoscope or endoscope ( Considering that an emergency can be observed with the naked eye of the surgeon, it seems to be well tolerated. In addition, although the defect that the images of the CT and MRI apparatuses cannot be superimposed remains, considering the fact that there are merits such as real-time characteristics, ease of handling, and simplification of the apparatus configuration, it is sufficient to compensate for this defect. It is considered a thing.

Furthermore, since the X-ray transmission image and the optical image can be combined and displayed, the following merits (1) and (2) are newly generated as compared with the conventional case where only the X-ray transmission image is displayed.
(1) It is no longer necessary to measure all the relative positional relationships in relation to “monitor position”, “operator's viewpoint position and line-of-sight direction”, and “position of affected area to be observed”, and a marker is attached to the affected area for registration. This frees you from the hassle of working and the surgeon wearing a marker.

  (2) Since an X-ray transmission image and an optical image can be acquired in real time, even if surgery progresses and the affected part deforms, it can be monitored in real time while always superimposing the latest image.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, as shown in FIG. 2, by providing moving mechanisms 13, 14, and 15 for moving the optical camera 10 and the mirror 8 in parallel with the optical axis OA2, the positional consistency between the X-ray transmission image and the optical image is provided. The optical camera 10 and the mirror 8 can be moved relative to the affected part of the subject, the X-ray tube 1 and the detector 2 while maintaining the above. By making the optical camera 10 and the mirror 8 movable, when the optical camera 10 and the mirror 8 interfere with the operator's work during the operation, the positions of the subject affected area, the X-ray tube 1 and the detector 2 are fixed. The optical camera 10 and the mirror 8 alone can be retreated to a position where they do not interfere with each other.

  Further, as shown in FIG. 3, the optical camera 10 may be provided near the X-ray tube 1 without using the mirror 8 for the purpose of downsizing the apparatus and further simplifying the structure. . In this case, the optical axis OA2 of the optical camera 10 is not at the center of the detection surface of the detector 2, but at a position closer to the X-ray tube 1 than the detection surface of the detector 2 by a predetermined distance close to the height of the affected part. The optical camera 10 is attached to the bridge 12 with a slight inclination with respect to the X-ray central axis OA1 so as to intersect the central axis OA1. As a result, the positional consistency between the X-ray transmission image and the optical image is lost, but the shift is suppressed to some extent.

The figure which shows the structure of the X-ray television apparatus by embodiment of this invention. The figure which shows the modification of the X-ray television apparatus of FIG. The figure which shows the other modification of the X-ray television apparatus of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... X-ray tube, 2 ... Planar detector, 3 ... C arm, 4 ... X-ray diagnostic apparatus controller, 5 ... On / off switch, 6 ... Image composition apparatus, 7 ... Monitor, 8 ... Half mirror, 9 ... Light source, 10 ... optical camera, 11 ... camera control unit, 12 ... bridge.

Claims (13)

An X-ray source that generates X-rays toward the subject;
An X-ray detector for detecting the X-ray transmitted through the subject;
An optical camera installed such that the optical axis coincides with or approximates the central axis of the X-ray;
An X-ray television apparatus comprising: a combining device that combines an X-ray transmission image detected by the X-ray detector and an optical image photographed by the optical camera. The X-ray television apparatus according to claim 1, further comprising an optical mirror inclined with respect to a central axis of the X-ray between the subject and the optical camera. The X-ray television apparatus according to claim 2, wherein the optical mirror is inclined at approximately 45 ° with respect to a central axis of the X-ray. 3. The X-ray television apparatus according to claim 2, wherein the optical mirror is a metal-deposited resin plate. The X-ray television apparatus according to claim 1, further comprising a bridge for fixing a position of the optical camera with respect to the X-ray generation source. The X-ray television apparatus according to claim 2, further comprising a bridge for fixing positions of the optical camera and the mirror with respect to the X-ray generation source. 2. The X-ray television apparatus according to claim 1, further comprising a mechanism for supporting the optical camera so as to be movable in parallel with the optical axis. The X-ray television apparatus according to claim 2, further comprising a mechanism that supports the optical camera and the mirror so as to be movable in parallel with the optical axis. The X-ray television apparatus according to claim 1, wherein the optical camera is attached to the X-ray generation source. The said synthesizing | combining apparatus aligns the position between the said X-ray transmissive image and the said optical image by making the center of the said optical image correspond with the center of the said X-ray transmissive image. X-ray television equipment. The synthesizing apparatus is configured such that a size between the X-ray transmission image and the optical image is based on an X-ray enlargement ratio based on a positional relationship among the X-ray generation source, the subject, and the X-ray detector. The X-ray television apparatus according to claim 10, wherein the heights are matched. The X-ray television apparatus according to claim 1, wherein the optical camera captures an image of visible light, infrared light, or ultraviolet light. The X-ray television apparatus according to claim 1, further comprising a switch for instructing to display one of the X-ray transmission image and the optical image independently.

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