JP6459775B2 - Radioscopy equipment - Google Patents

Description

  According to the present invention, an image including a marker placed in the body of a subject or an image including a specific part of the subject is acquired from two different directions to move with the body movement of the subject. The present invention relates to a radioscopic apparatus such as an X-ray fluoroscopic apparatus that detects the position of a marker or a specific part.

  A head for irradiating a treatment beam and a gantry for rotating the head about the subject are provided, and radiation treatment is performed by irradiating a treatment beam such as an X-ray or an electron beam to an affected part such as a tumor. In a radiotherapy apparatus, it is necessary to accurately irradiate the affected area with radiation. However, not only the subject may move the body, but the affected part itself may move. For example, a tumor near the lung moves greatly based on respiration. For this reason, in Patent Document 1, a radiotherapy apparatus having a configuration in which a gold marker is arranged near a tumor, the position of the marker is detected by an X-ray fluoroscope, and irradiation of therapeutic radiation is controlled is proposed. Has been.

  As such a radiotherapy apparatus, Patent Document 2 discloses an X-ray fluoroscopic apparatus for identifying the position of a marker by fluoroscopically viewing an image including the marker placed in the body of a subject. . The X-ray fluoroscopic apparatus described in Patent Document 2 includes a first X-ray tube that irradiates X-rays from the floor side and a first X-ray detector that detects X-rays passing through the subject from the ceiling side. 1 imaging system and a second X-ray system that includes a second X-ray tube that irradiates X-rays from the floor side and a second X-ray detector that detects X-rays passing through the subject from the ceiling side, A marker embedded in the body is detected by template matching or the like. Then, three-dimensional position information is obtained using a two-dimensional perspective image photographed by the first photographing system and a two-dimensional perspective image photographed by the second photographing system. By continuously executing such an operation and calculating the three-dimensional position information of the marker in real time, the marker of the part accompanying movement is detected with high accuracy. Then, by controlling the irradiation of the therapeutic radiation based on the position information of the marker, it becomes possible to execute the radiation irradiation with high accuracy according to the movement of the tumor.

  At this time, since it is necessary to irradiate the treatment beam from various directions toward the affected area depending on the position of the affected area of the subject, as described above, the head that irradiates the treatment beam is the subject. It can be rotated around the center. For this reason, in the X-ray fluoroscopic apparatus described in Patent Document 2, it is necessary for the first imaging system and the second imaging system to perform fluoroscopy from a position where the X-ray is not blocked by the head. In order to make this possible, in the X-ray fluoroscopic apparatus described in Patent Document 2, the first X-ray tube and the first X-ray detector, and the second X-ray tube and the second X-ray detector can be moved along the rail. With this configuration, it is possible to perform X-ray fluoroscopy from three preset positions.

Japanese Unexamined Patent Publication No. 2000-167072 Japanese Patent Application Laid-Open No. 2014-128412

  As described above, in an X-ray fluoroscopic apparatus having a plurality of imaging systems, it is necessary to perform a so-called daily check process for confirming whether each imaging system is misaligned every day. When confirming the positional deviation of this imaging system, a marker is set at the isocenter that is the intersection of a pair of laser beams, and this marker is imaged by each imaging system. When the marker image captured by each imaging system is arranged in the center of the image, it can be determined that each imaging system is correctly arranged.

  However, in order to perform such a confirmation work, it is necessary to specify an isocenter and accurately place a marker on the isocenter with an accuracy of the order of mm, which requires a very long time. In addition, even if you intend to install the marker correctly at the isocenter, if the image of the marker is misaligned in any of the imaging systems, whether the marker is misaligned or not It is impossible to specify with certainty whether or not a positional deviation has occurred, and the operation is repeated again. It is extremely complicated to perform such work every day.

  The present invention has been made in order to solve the above-described problems, and provides a radiation fluoroscopy device capable of easily determining the presence or absence of a positional shift of an imaging system having a radiation irradiation unit and a radiation detector. Objective.

  According to a first aspect of the present invention, an image including a marker placed in the body of a subject or an image including a specific part of the subject is acquired from two different directions, thereby accompanying the body movement of the subject. A radioscopy apparatus that detects a position of the marker or the specific part that moves and includes a radiation irradiation unit and a radiation detector that detects radiation irradiated from the radiation irradiation unit and transmitted through the subject. The image processing apparatus includes three or more photographing systems and a determination unit that determines whether or not the coordinate positions of the reference marks photographed by the three or more photographing systems match each other.

  According to a second aspect of the present invention, the determination unit captures the reference mark with two of the three or more imaging systems, calculates a three-dimensional coordinate of the reference mark, and calculates the three or more of the reference marks. Whether or not the three-dimensional coordinate and the two-dimensional coordinate are matched by photographing the reference mark by a photographing system other than the photographing system that photographed the reference mark in the photographing system and calculating the two-dimensional coordinate of the reference mark. Determine whether.

According to a third aspect of the invention, the determination unit photographs the reference mark by the three or more photographing systems, and connects the focus of the radiation irradiating unit and the photographed reference mark in the three or more photographing systems. Each straight line is calculated, and it is determined whether each calculated straight line converges to one point.

  According to the first to third aspects, by determining whether or not the coordinate positions of the reference marks photographed by three or more photographing systems coincide with each other, it is possible to easily determine whether or not there is a positional deviation that occurs in each photographing system. It becomes possible to judge.

1 is a schematic diagram of an X-ray fluoroscopy device as a radioscopy device according to the present invention. It is a block diagram which shows the control system of the X-ray fluoroscope which concerns on 1st Embodiment of this invention. It is explanatory drawing explaining the basic view of the detection operation | movement which detects the presence or absence of position shift about a 1st imaging system, a 2nd imaging system, a 3rd imaging system, and a 4th imaging system in a X-ray fluoroscope. 6 is a flowchart illustrating a detection operation according to the first embodiment for detecting the presence or absence of a positional shift for a first imaging system, a second imaging system, a third imaging system, and a fourth imaging system. It is a flowchart which shows the detection operation which concerns on 2nd Embodiment for detecting the presence or absence of position shift about a 1st imaging | photography system, a 2nd imaging | photography system, a 3rd imaging | photography system, and a 4th imaging system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an X-ray fluoroscopy device as a radioscopy device according to the present invention. FIG. 2 is a block diagram showing a control system of the X-ray fluoroscopic apparatus according to the first embodiment of the present invention.

  FIG. 1 shows a state in which the reference mark 10 is placed on the table 19 on which the subject is to be placed. The reference mark 10 is also called a calibration phantom, and has a configuration in which a metal sphere is arranged at the center of a resin rectangular parallelepiped such as acrylic. In addition, the position of the reference mark 10 in this specification means the position of a metal sphere in the reference mark 10.

  This X-ray fluoroscopic apparatus is a radiotherapy for performing radiotherapy by irradiating an affected part of a subject with radiation such as an X-ray or an electron beam while the subject is placed on a table 19. Used with the device. During such radiotherapy, it is necessary to accurately irradiate the affected part that moves with the body movement of the subject. For this reason, a marker is installed near the affected area of the subject. Then, the so-called moving body tracking, in which the marker is detected with high accuracy by continuously seeing through the marker embedded in the body of the subject by X-ray fluoroscopy and calculating the three-dimensional position information of the marker. It is configured to do. In addition, instead of placing a marker in the vicinity of the affected part in the subject, markerless tracking that uses an image of a specific site such as a tumor in the subject instead of the marker may be employed.

  The X-ray fluoroscopic apparatus includes a first X-ray tube 11, a second X-ray tube 12, a third X-ray tube 13, a fourth X-ray tube 14 that function as a radiation irradiation unit according to the present invention, and a radiation detector according to the present invention. A functioning first flat panel detector 21, a second flat panel detector 22, a third flat panel detector 23, and a fourth flat panel detector 24 are provided. X-rays as radiation emitted from the first X-ray tube 11 pass through the subject on the table 19 and are then detected by the first flat panel detector 21. The first X-ray tube 11 and the first flat panel detector 21 constitute a first imaging system. X-rays irradiated from the second X-ray tube 12 pass through the subject on the table 19 and then detected by the second flat panel detector 22. The second X-ray tube 12 and the second flat panel detector 22 constitute a second imaging system. X-rays irradiated from the third X-ray tube 13 pass through the subject on the table 19 and then detected by the third flat panel detector 23. The third X-ray tube 13 and the third flat panel detector 23 constitute a third imaging system. X-rays irradiated from the fourth X-ray tube 14 pass through the subject on the table 19 and then detected by the fourth flat panel detector 24. The fourth X-ray tube 14 and the fourth flat panel detector 24 constitute a fourth imaging system.

  The X-ray fluoroscopic apparatus includes a first power supply unit 28 and a second power supply unit 29. The first power supply unit 28 and the second power supply unit 29 are also called high-voltage devices. The first power supply unit 28 selectively supplies a tube voltage and a tube current necessary for irradiating X-rays to the first X-ray tube 11 or the second X-ray tube 12. The second power supply unit 29 selectively supplies a tube voltage and a tube current necessary for irradiating X-rays to the third X-ray tube 13 or the fourth X-ray tube 14.

  For this reason, the first X-ray tube 11 and the second X-ray tube 12 cannot simultaneously irradiate X-rays, and the third X-ray tube 13 and the fourth X-ray tube 14 simultaneously irradiate X-rays. It is not possible. Therefore, the first imaging system and the second imaging system described above cannot be used at the same time, and the third imaging system and the fourth imaging system cannot be used at the same time. On the other hand, at the time of tracking the moving object described above, in order to calculate the three-dimensional position information of a marker or a specific part (hereinafter collectively referred to as “marker”), the marker needs to be seen through from two directions. Therefore, in this X-ray fluoroscopic apparatus, X-ray fluoroscopy at the first position using the first imaging system and the third imaging system, and the second position using the first imaging system and the fourth imaging system. X-ray in the third position using the second imaging system and the third imaging system, and X-ray in the fourth position using the second imaging system and the fourth imaging system It is possible to perform X-ray fluoroscopy in four patterns, including fluoroscopy.

  Furthermore, this X-ray fluoroscopic apparatus is equipped with a CPU that executes logical operations, a ROM that stores an operation program necessary for controlling the apparatus, a RAM that temporarily stores data during control, and the like, and controls the entire apparatus. The control unit 30 is provided. The control unit 30 is connected to the first flat panel detector 21, the second flat panel detector 22, the third flat panel detector 23, and the fourth flat panel detector 24 described above. The control unit 30 is connected to the first power supply unit 28 and the second power supply unit 29 described above.

  The control unit 30 includes an image processing unit 31 for processing images captured by the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system. In the image processing unit 31, the marker is detected using two imaging systems among the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system. That is, the image processing unit 31 includes, for example, an image including a marker placed in the body of the subject photographed by the first photographing system, the second photographing system, the third photographing system, and the fourth photographing system, and a preset setting. The three-dimensional position information of the marker is calculated by template matching that compares the template image. Further, as will be described later, the control unit 30 determines whether or not the positions of the reference marks 10 photographed by the first photographing system, the second photographing system, the third photographing system, and the fourth photographing system coincide with each other. A determination unit 34 is provided.

  FIG. 3 illustrates a basic concept of a detection operation for detecting the presence or absence of a positional shift for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system in the above-described X-ray fluoroscopic apparatus. It is explanatory drawing.

  In this X-ray fluoroscopic apparatus, a first imaging system comprising a first X-ray tube 11 and a first flat panel detector 21, a second imaging system comprising a second X-ray tube 12 and a second flat panel detector 22, The coordinate position of the reference mark 10 imaged by the third imaging system consisting of the 3X-ray tube 13 and the third flat panel detector 23 and the fourth imaging system consisting of the fourth X-ray tube 14 and the fourth flat panel detector 24 is Whether or not they match each other is determined by the determination unit 34, and when the coordinate positions match, it is determined that no positional deviation has occurred in the four imaging systems.

  In a state in which the coordinate positions of the reference marks 10 photographed by the four photographing systems coincide with each other and no positional deviation occurs in the four photographing systems, as shown in FIG. The optical axis of the first imaging system reaching the 1 flat panel detector 21, the optical axis of the second imaging system extending from the second X-ray tube 12 to the second flat panel detector 22, and the third flat panel detector from the third X-ray tube 13. The optical axis of the third imaging system reaching 23 and the optical axis of the fourth imaging system extending from the fourth X-ray tube 14 to the fourth flat panel detector 24 pass through the coordinate position P corresponding to the reference mark 10. Become.

  Next, a specific detection operation for detecting the presence / absence of a positional shift for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system will be described. FIG. 4 is a flowchart showing a detection operation according to the first embodiment for detecting the presence / absence of a positional shift for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system.

  In this first embodiment, in order to detect the presence / absence of misalignment of the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system, first, the reference mark 10 is placed on the table 19. (Step S11). At this time, the reference mark 10 may be disposed in the vicinity of the isocenter, as long as the reference mark 10 can be photographed by the first photographing system, the second photographing system, the third photographing system, and the fourth photographing system. For this reason, as described above, it is not necessary to accurately place the reference mark 10 with respect to the isocenter with an accuracy of the order of mm. Therefore, the work can be performed efficiently.

  In this state, an image of the reference mark 10 is captured by the first imaging system (step S12). Further, an image of the reference mark 10 is captured by the second imaging system (step S13). Then, using the two-dimensional image of the reference mark 10 photographed by the first photographing system and the two-dimensional image of the reference mark 10 photographed by the second photographing system, the three-dimensional coordinates of the reference mark 10 are calculated (step S14). ).

  Next, an image of the reference mark 10 is captured by the third imaging system (step S15). Then, it is determined whether or not the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the third photographing system match the three-dimensional coordinates of the reference mark 10 calculated in step S14 (step S16). This determination is made by the determination unit 34. When the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the third photographing system and the three-dimensional coordinates of the reference mark 10 computed in step S14 do not match, the first photographing system, the second photographing system, It is determined that a positional shift has occurred in any of the third imaging systems (step S19), and an error is displayed on the display unit or the like.

  On the other hand, when the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the third photographing system and the three-dimensional coordinates of the reference mark 10 calculated in step S14 match (step S16), the fourth An image of the reference mark 10 is taken by the shooting system (step S17). Then, it is determined whether or not the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the fourth photographing system match the three-dimensional coordinates of the reference mark 10 calculated in step S14 (step S18). This determination is made by the determination unit 34. In the case where the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the fourth photographing system and the three-dimensional coordinates of the reference mark 10 computed in step S14 do not match, a positional deviation occurs in the fourth photographing system. (Step S19), an error is displayed on the display unit.

  When the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the fourth photographing system and the three-dimensional coordinates of the reference mark 10 computed in step S14 are matched (step S18), the first photographing system Then, it is determined that no positional deviation has occurred in all of the second imaging system, the third imaging system, and the fourth imaging system (step S20), and a display to that effect is displayed. Thereby, the daily check is completed.

  In the case where the two-dimensional coordinates in the two-dimensional image of the reference mark 10 photographed by the third photographing system or the fourth photographing system and the three-dimensional coordinates of the reference mark 10 calculated in step S14 do not match, the same as in the past. According to the method, the positions of the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system are adjusted.

  Next, another embodiment of the detection operation for detecting the presence / absence of misalignment for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system will be described. FIG. 5 is a flowchart showing a detection operation according to the second embodiment for detecting the presence / absence of a positional shift for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system.

  In the second embodiment, in order to detect the presence / absence of misalignment for the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system, first, as in the case of the first embodiment, The reference mark 10 is placed on the table 19 (step S21). At this time, the reference mark 10 is arranged near the isocenter.

  In this state, the image of the reference mark 10 is sequentially photographed by the first photographing system, the second photographing system, the third photographing system, and the fourth photographing system (steps S22, S23, S24, and S25). Then, a straight line expression connecting the focal point of the first X-ray tube 11 and the reference mark 10, a straight line expression connecting the focal point of the second X-ray tube 12 and the reference mark 10, and the focal point of the third X-ray tube 13 and the reference mark. 10 and a straight line connecting the focal point of the fourth X-ray tube 14 and the reference mark 10 are respectively calculated (step S26).

  Thereafter, it is determined whether or not each calculated straight line converges to one point (step S27). This determination is executed by the determination unit 34. As shown in FIG. 3, when each calculated straight line converges to a coordinate position P corresponding to the position of the reference mark 10, the first photographing system, the second photographing system, the third photographing system, and the fourth photographing system. It is determined that no positional deviation has occurred in all of the above (step S29), and a display to that effect is displayed. Thereby, the daily check is completed.

  On the other hand, if the calculated straight lines do not converge to one point, it is determined that a positional deviation has occurred in any of the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system. (Step S28), an error is displayed on the display unit or the like.

  In the above-described embodiment, the first imaging system including the first X-ray tube 11 and the first flat panel detector 21, the second imaging system including the second X-ray tube 12 and the second flat panel detector 22, and the third X-ray. There are four imaging systems, a third imaging system comprising a tube 13 and a third flat panel detector 23 and a fourth imaging system comprising a fourth X-ray tube 14 and a fourth flat panel detector 24. There should be at least three systems. That is, a configuration in which three or more imaging systems having an X-ray tube and a flat panel detector are provided and two imaging systems used for X-ray fluoroscopy can be selected from these three or more imaging systems. If it is.

  In the above-described embodiment, the first power supply unit 28 selectively supplies the tube voltage and the tube current necessary for irradiating the X-ray to the first X-ray tube 11 or the second X-ray tube 12. In addition, a configuration is adopted in which the second power supply unit 29 selectively supplies the tube voltage and the tube current necessary for irradiating the X-rays to the third X-ray tube 13 or the fourth X-ray tube 14. By adopting such a configuration, the number of power supply units can be halved, and the manufacturing cost of the apparatus can be reduced. However, a power supply unit may be provided for each of the first X-ray tube 11, the second X-ray tube 12, the third X-ray tube 13, and the fourth X-ray tube 14. When such a configuration is adopted, X-ray fluoroscopy is performed by selecting any two imaging systems from the first imaging system, the second imaging system, the third imaging system, and the fourth imaging system. It becomes possible.

  Further, in the above-described embodiment, a flat panel detector is used as the X-ray detector functioning as the radiation detector according to the present invention, but X-ray detection such as an image intensifier (II) is used. Or other radiation detectors may be used.

DESCRIPTION OF SYMBOLS 10 Reference mark 11 1st X-ray tube 12 2nd X-ray tube 13 3rd X-ray tube 14 4th X-ray tube 19 Table 21 1st flat panel detector 22 2nd flat panel detector 23 3rd flat panel detector 24 4th flat panel detector 28 First power supply unit 29 Second power supply unit 30 Control unit 31 Image processing unit 34 Determination unit

Claims (3)

The marker that moves with the body movement of the subject by acquiring an image including the marker placed in the body of the subject or an image including the specific part of the subject from two different directions, or A radioscopic apparatus for detecting the position of the specific part,
With three or more imaging systems having a radiation irradiation unit and a radiation detector that detects radiation irradiated from the radiation irradiation unit and transmitted through the subject,
A radioscopy apparatus comprising: a determination unit configured to determine whether or not coordinate positions of reference marks captured by the three or more imaging systems match each other. The radiographic apparatus according to claim 1,
The determination unit photographs the reference mark by two of the three or more photographing systems to calculate a three-dimensional coordinate of the reference mark, and the reference of the three or more photographing systems. Radiographic fluoroscopy in which the reference mark is imaged by an imaging system other than the imaging system in which the mark is imaged, the two-dimensional coordinates of the reference mark are calculated, and whether the three-dimensional coordinates and the two-dimensional coordinates match apparatus. The radiographic apparatus according to claim 1,
The determination unit shoots the reference mark by the three or more imaging systems , respectively calculates a straight line connecting the focal point of the radiation irradiation unit and the captured reference mark in the three or more imaging systems , A radioscopic apparatus that determines whether or not each straight line after computation converges to one point.

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