JP4503573B2 - Medical X-ray equipment with scout view function - Google Patents

Description

  The present invention relates to an improvement of a medical X-ray imaging apparatus having a scout view function.

  As a recent dental X-ray imaging apparatus, a panoramic X-ray imaging apparatus in which an imaging unit is configured by an electrical imaging element has been widely used. Such an X-ray imaging apparatus generally has a configuration in which an electrical imaging device such as a long and narrow CCD sensor is mounted as an imaging means. The subject is scanned with an X-ray slit beam in accordance with a predetermined imaging trajectory. The transmitted X-rays are tracked by an electric imaging device and acquired as an image signal, and then these image signals are connected and arranged in time series to obtain one panoramic X-ray image.

  In addition, an apparatus that irradiates a subject with an X-ray cone beam and performs partial CT imaging of the subject using an imaging means of a two-dimensional image sensor such as an X-ray image intensifier or a MOS sensor is also popular.

  The following Patent Document 1 and Patent Document 2 disclose an X-ray imaging apparatus that performs panoramic X-ray imaging using the above-described electrical imaging element.

  That is, Japanese Patent Laid-Open No. 11-104127 discloses an X-ray imaging apparatus that performs panoramic imaging using an electrical X-ray image detector such as a CCD sensor formed in a cassette shape that can be replaced with a film cassette. Is disclosed.

  Japanese Patent Laid-Open No. 11-104128 discloses an electrical X-ray image detector such as a CCD sensor formed in a cassette shape that can be mounted on a panoramic X-ray imaging apparatus. An electric X-ray image detector, which is an image sensor in which a plurality of square imaging elements are arranged in a two-dimensional shape so as to be rectangular, is disposed on the inner surface of the X-ray light receiving unit provided in the X-ray receiving unit. It is electrically controlled by a control signal corresponding to the turning of the swivel arm that is a support means for supporting the line detection unit, converts the X-rays into electric signals, and converts the image signals necessary for generating a panoramic X-ray image into digital signals. The output is in the form.

  Patent Document 3 (Japanese Patent Laid-Open No. 7-275240) discloses an elevating body that supports a swivel arm (supporting means for supporting an X-ray generator and an X-ray detector) including an X-ray generator and a film cassette. Discloses a medical X-ray imaging apparatus in which a patient frame including a head holding device that can move up and down with respect to a support column and that holds a patient's head can be moved up and down separately with respect to the lifting body. Has been.

  In Patent Document 4 (Japanese Patent Laid-Open No. 10-225455), an imaging means of a two-dimensional image sensor that irradiates a subject with an X-ray cone beam and includes an electrical imaging element such as an X-ray image intensifier or a MOS sensor. An X-ray imaging apparatus is disclosed that performs partial CT imaging of a subject using the. In this X-ray imaging apparatus, the mode can be further switched between partial CT imaging and panoramic X-ray imaging, but a configuration in which a plurality of imaging units are provided is not disclosed. Also disclosed are a configuration for changing the irradiation field in a direction parallel to the axial direction of the pivot axis of the support arm that supports the X-ray source and the X-ray imaging unit with respect to the imaging means, and a specific configuration related to the shape of the imaging means. Not.

In Patent Document 5 (Japanese Patent Application Laid-Open No. 2004-329293), a subject is irradiated with an X-ray cone beam, and an image pickup unit of a two-dimensional image sensor including an electric image pickup device such as an X-ray image intensifier or a MOS sensor. An X-ray imaging apparatus is disclosed that captures and displays fluoroscopic images of a subject from a plurality of directions and performs CT imaging of the region of interest of the subject by designating the region of interest on the displayed fluoroscopic image. However, a configuration in which a plurality of imaging units are provided, a configuration in which the irradiation field is changed in a direction parallel to the axial direction of the pivot axis of the moving unit with respect to the imaging units, and a specific configuration regarding the shape of the imaging unit are not disclosed.

  In Patent Document 6 (Japanese Patent Laid-Open No. 7-327985), an operation panel is provided on a patient frame provided with a chin rest for holding the patient's head, and a panoramic illustration image is displayed on a display means provided on the operation panel. Although a configuration is disclosed in which an area code is input and linear tomography of the input area is performed, what is displayed is a panoramic illustration, and is not an image obtained as a result of actually shooting a subject. That is, it does not faithfully display the organizational structure of individual subjects.

  In Patent Document 7 (Japanese Patent Application Laid-Open No. 2002-315746), when an X-ray imaging target region is made to coincide with a predetermined position of the subject, a schematic diagram of the subject and a X-ray imaging target region that are modeled and drawn are displayed. And display the relative movement between the subject and the X-ray imaging target area as the movement of the X-ray imaging target area with respect to the schematic diagram of the subject. Although the position setting is performed, what is displayed is a schematic diagram of the subject, and is not an image obtained as a result of actually photographing the subject. That is, it does not faithfully display the organizational structure of individual subjects.

Japanese Patent Laid-Open No. 11-104127 JP-A-11-104128 JP 7-275240 A JP-A-10-225455 JP 2004-329293 A JP-A-7-327985 JP 2002-315746 A

  By the way, although the two-dimensional image sensor can be used as a substitute for the conventional X-ray film due to its shape, there is a problem that the acquisition price increases dramatically according to the size of the light receiving portion. It is practically difficult to use a large size two-dimensional image sensor.

  Further, in tomographic imaging in which a transmission image of a subject is captured and a tomographic image is generated from the captured transmission image, a large size two-dimensional image sensor is used, and an X-ray cone beam corresponding to the size is applied to the subject. If irradiated, there will be a problem of exposure to the subject patient.

  On the other hand, in particular, in cross-sectional image shooting that generates cross-sectional images from a large number of transmission images, it is relatively limited to a small part near the region of interest of the subject and other unnecessary parts are not to be imaged. A configuration in which a narrow X-ray beam is used and an X-ray image is obtained with a two-dimensional image sensor having a size corresponding to the narrow X-ray beam is advantageous in terms of cost and exposure.

  Furthermore, as described above, panoramic X-ray imaging apparatuses in which imaging means are configured by an electrical imaging element have become widespread in recent dental X-ray imaging apparatuses, but in many panoramic X-ray imaging apparatuses, they have been positioned. With respect to the patient's head, the swivel arm, which is a support means provided with an X-ray generation unit and an X-ray detection unit at both ends, does not move up and down. Therefore, if a sensor for CT imaging is added to such a conventional panoramic X-ray imaging apparatus and a three-dimensional expansion can be provided in a range where partial CT imaging can be performed, the conventional panoramic X-ray imaging apparatus is slightly different. A medical X-ray imaging apparatus capable of performing partial CT imaging of an arbitrary part with only a slight improvement is realized.

  The present invention was developed in view of such circumstances, and was developed in particular from the viewpoint of reducing X-ray exposure, effective use of a two-dimensional image sensor, and effective use of a conventional panoramic X-ray imaging apparatus configuration. An object of the present invention is to provide a medical X-ray imaging apparatus having a scout view function.

In order to solve the above problems, the present invention having the following features is proposed.
That is, the first aspect of the present invention proposed in claim 1 is directed to an X-ray generation unit and an X-ray detection unit that are supported by a supporting unit so as to face each other, and a subject that holds the supporting unit by a subject holding unit. includes moving means for relatively moving the medical X-ray imaging apparatus for capturing an X-ray image of the object by operating the moving means, and said supporting means pivotably by said moving means, said support means X-ray detector that includes a first imaging means that extends in a direction parallel to the axial direction of the swivel axis, a second imaging means that is used for X-ray CT imaging, and X-ray generation that irradiates an X-ray beam includes a vessel, said first slit changing the shape of the X-ray beam corresponding to each of the imaging means and the second imaging means, and to said second imaging means, at least said pivot axis axial and the ground in a direction parallel to the And X-ray generation unit that includes a irradiation field changing means for changing the position of the radiation field by lifting the door, and a display unit for displaying the first X-ray image acquired by the first imaging means, the display In order to obtain an operation unit that designates a region of interest on the first X-ray image displayed on the unit, and a second X-ray image that is a CT image of the region of interest designated by the operation unit, A medical X-ray imaging apparatus comprising control means for controlling an irradiation field changing means and controlling the moving means.
Further, in any of claims 1 to 4, in any one of claims 1, the irradiation field changing means includes first and second slits corresponding to the first imaging means and the second imaging means, respectively. A plurality of the second slits, or a first slit and a second slit corresponding to each of the first imaging means and the second imaging means, The second slit is one, and is configured to be controlled so that it can be moved up and down, or the first and second slits correspond to the first imaging unit and the second imaging unit, respectively. The first and second slits are formed by moving two slit plates each having a slit and overlapping the slits formed on the two slit plates. It is characterized by being composed.

  According to a second aspect of the present invention proposed in claim 5, an X-ray generation unit and an X-ray detection unit supported by a support unit so as to face each other, and a subject holding the support unit by a subject holding unit. In a medical X-ray imaging apparatus that includes a moving means that moves relatively, and operates the moving means to capture an X-ray image of a subject, the support means can be turned by the moving means, First imaging means extending in a direction parallel to the axis direction of the pivot axis and second imaging means used for X-ray CT imaging are individually provided, and the second imaging means is at least the axis of the pivot axis. An X-ray detector having an imaging means moving means for moving in a direction parallel to the direction, an X-ray generator for irradiating an X-ray beam, and the first imaging means and the second imaging means, respectively. Correspondingly change the shape of the X-ray beam An X-ray generator provided with an irradiation field changing means for changing an irradiation field at least in a direction parallel to the axial direction of the pivot axis with respect to the second imaging means, and acquired by the first imaging means A display unit that displays a first X-ray image, an operation unit that designates a region of interest on the first X-ray image displayed on the display unit, and a CT image of the region of interest designated by the operation unit And a control means for controlling the imaging means moving means, the irradiation field changing means, and the moving means to obtain the second X-ray image. A medical X-ray imaging apparatus.

Further, in the first to third aspects of the present invention, the medical X-ray imaging apparatus proposed in claim 6 further includes at least one of a panoramic image, a cephalo image, and a linear scan image as the first X-ray image. The medical X-ray imaging apparatus according to claim 7 , wherein when the panoramic image is captured, the moving unit connects the X-ray generation unit and the X-ray detection unit to each other. Move along a trajectory for X-ray imaging.

In the medical X-ray imaging apparatus according to claim 8 , the control of the moving means is two-dimensional two-dimensional control defined on a plane intersecting the axial direction of the pivot axis.

In the medical X-ray imaging apparatus according to claim 9, the movement unit is controlled in two directions defined on a plane intersecting the axial direction of the pivot axis and one direction parallel to the axial direction of the pivot axis. Three-dimensional control.

The medical X-ray imaging apparatus according to claim 10 , wherein the second imaging unit is offset forward or backward in the turning direction of the X-ray detection unit, so that a portion of the designated region of interest is always projected and projected. Projection is performed over the entire region, and X-ray CT imaging of the region of interest is performed.

According to a third aspect of the present invention proposed in claim 11 , an X-ray generation unit and an X-ray detection unit supported by a support unit so as to oppose each other, and a subject holding the support unit by a subject holding unit. includes moving means for relatively moving the medical X-ray imaging apparatus for capturing an X-ray image of the object by operating the moving means, and said supporting means pivotably by said moving means, said support means The first imaging means that extends in a direction parallel to the axial direction of the pivot axis and the second imaging means that is used for X-ray CT imaging have a partial area on a single detection surface of the image sensor. The shape of the X-ray beam corresponding to each of the X-ray detector set together so as to overlap, an X-ray generator for irradiating the X-ray beam, and the first imaging unit and the second imaging unit It has a slit to be changed, the second imaging Relative stage, at least the X-ray generating unit axial and the slit in a direction parallel with the irradiation field changing means for changing the position of the radiation field by elevating the pivot axis, the first imaging means A display unit that displays a first X-ray image that is a panoramic image acquired in Step 1, an operation unit that specifies a region of interest on the first X-ray image displayed on the display unit, and a specification by the operation unit And a control means for controlling the irradiation field changing means and the moving means in order to obtain a second X-ray image which is a CT image of the region of interest. X-ray imaging apparatus.

The medical X-ray imaging apparatus according to claim 12 , wherein the second X-ray image reconstructs three-dimensional CT data of a three-dimensional region obtained by CT imaging, and the three-dimensional regions are orthogonal to each other. It is a tomographic plane image displayed as an X tomographic plane image, a Y tomographic plane image, and a Z tomographic plane image.

In the medical X-ray imaging apparatus according to claim 13 , the display unit that displays the first X-ray image acquired by the first imaging unit includes an X-ray imaging apparatus main body, the vicinity of the X-ray imaging apparatus main body, It is provided in at least one of the control box outside the X-ray room surrounding the imaging apparatus main body and the electronic computer connected to the X-ray imaging apparatus.

The medical X-ray imaging apparatus according to claim 14 , wherein an operation unit that designates a region of interest on the first X-ray image displayed on the display unit is an X-ray imaging apparatus main body, in the vicinity of the X-ray imaging apparatus main body. Further, at least one of a control box outside the X-ray room surrounding the X-ray imaging apparatus main body and an electronic computer connected to the X-ray imaging apparatus is further provided.

The medical X-ray imaging apparatus according to claim 15 displays the second X-ray image on the display unit that displays the first X-ray image.

In the medical X-ray imaging apparatus according to any one of claims 1 to 14 , a desired region of interest is designated on a first X-ray image captured by using an elongated first imaging unit. This first X-ray image is obtained by scanning imaging, and the amount of exposure to the subject is reduced. In addition, since the second X-ray image needs to be captured only in a narrow range around the region of interest, a two-dimensional image sensor having a small light receiving area can be used as the second imaging unit. Therefore, it is advantageous in terms of cost. In addition, since the second imaging means has a small light receiving portion, it suffices to irradiate an X-ray beam in an irradiation field matched to the light receiving portion, so that the amount of exposure to the subject is also reduced.

Further, in the medical X-ray imaging apparatus according to claims 1 and 5 , in addition to the above effect, the second imaging means is used for CT imaging, and at least the second imaging means Irradiation field changing means for changing the position of the irradiation field in a direction parallel to the pivot axis. This is because many conventional panoramic X-ray imaging apparatuses are configured such that a swing arm, which is a support means provided with an X-ray generation unit and an X-ray detection unit at both ends, does not move up and down with respect to a positioned patient's head. Furthermore, if the idea of the present invention is applied and a two-dimensional image sensor for CT imaging and the above-mentioned irradiation field changing means are added, it means that the range in which partial CT imaging can be performed can be expanded to three dimensions. is doing. That is, a medical X-ray imaging apparatus capable of performing partial CT imaging of an arbitrary part is realized by adding a slight improvement according to the present invention to a conventional panoramic X-ray imaging apparatus.

Particularly in the first to fourth aspects, since the irradiation field can be changed in a direction parallel to the axial direction of the pivot axis of the support means with respect to the imaging surface of the second image pickup means, the second image pickup means is turned by the support means. What is necessary is just to comprise by the image sensor which spreads in the direction parallel to the axial direction of an axis | shaft, and does not need to make the structure of a 2nd imaging means mechanically complicated. In this case, the direction of the second imaging means that intersects the axial direction of the pivot axis of the support means can be set to the minimum necessary width in accordance with the size of the region of interest. Image sensor.

In particular, since the position of the second imaging means is mechanically changed in claim 5 , the size of the two-dimensional image sensor constituting the second imaging means can be minimized.

Particularly, in claims 6 and 7 , since at least one of a panoramic image, a cephalo image, and a linear scan image is adopted as the first X-ray image, if applied to the field of dentistry, the dentition of the patient The whole can be the target of expanded display. Thus, the operator can easily specify a specific part such as a tooth decay as a region of interest for CT imaging.

Especially in claim 8, the position control of the support means and the object holding means, since two-dimensional control on a plane that intersects the axial direction of the pivot axis, can be used a known technique such as an X-Y table, and the two-dimensional plane control Becomes easier.

Particularly in claim 9 , since the position control of the support means and the subject holding means is three-dimensional control in two directions on a plane intersecting the axis direction of the pivot axis and one direction parallel to the axis direction of the pivot axis, X- By applying a known technique such as a Y table, an XYZ table obtained by adding the above-described one direction can be used, and three-dimensional spatial control becomes easy.

In particular claim 10, since the configuration of partially projecting the region of interest in the second image pickup means it can CT imaging a larger region of interest than a normal CT imaging.

In particular, in claim 11 , in the X-ray detection unit, the first imaging means extending in a direction parallel to the axial direction of the pivot axis of the support means and the second imaging means used for X-ray CT imaging are images. Since a part of the region is set to overlap the single detection surface of the sensor, the region is shared as a part of the first and second imaging means. Therefore, the manufacturing cost is reduced as compared with the configuration in which the first and second imaging units having the same size are separately provided.

In Claim 12 , the 2nd X-ray image reconfigure | reconstructs the three-dimensional CT data of the three-dimensional area | region obtained by CT imaging | photography, X tomographic plane image, Y tomographic plane orthogonal to each other about the said three-dimensional area | region Since it is a tomographic plane image displayed as an image or a Z tomographic plane image, stereoscopic observation in a three-dimensional space of the region of interest is easy.

According to a thirteenth aspect of the present invention , the display unit for displaying the first X-ray image acquired by the first imaging means has an X-ray imaging apparatus main body, the vicinity of the X-ray imaging apparatus main body, and an X-proof for surrounding the X-ray imaging apparatus main body. Since it is provided in at least one of a control box outside the X-ray room and an electronic computer connected to the X-ray imaging apparatus, the operator leaves the first place where various operations for X-ray imaging are performed. There is no need to check the X-ray image.

According to a fourteenth aspect of the present invention , the operation unit for designating the region of interest on the first X-ray image displayed on the display unit surrounds the X-ray imaging apparatus body, the vicinity of the X-ray imaging apparatus body, and the X-ray imaging apparatus body. Since it is further provided in at least one of the control box outside the X-ray room and the electronic computer connected to the X-ray imaging apparatus, the operator leaves the place where various operations for X-ray imaging are performed. There is no need to specify the area of interest.

According to claim 15, the display unit for displaying the first X-ray image, so and displaying a second X-ray image, the first display and the second X-ray image of the X-ray image A common display unit can be used for display, and there is no need to go to separate display units to check images, and costs can be kept low.

  Hereinafter, an example of a medical X-ray imaging apparatus according to the present invention will be described with reference to the drawings. In each of the embodiments, an X-ray imaging apparatus for dentistry is described. However, the idea of the present invention is that X-ray imaging is performed on a limited part of a patient, such as the ear, nose, throat, and breast, in addition to dentistry. It can be easily applied to an X-ray imaging apparatus.

FIG. 1 is a schematic block diagram for explaining the overall configuration of a medical X-ray imaging apparatus to which the first invention is applied. FIGS. 2 (a) and 2 (b) show the medical X-ray imaging apparatus from the front and side. FIG.
The configuration of the first embodiment will be described below with reference to these drawings.

  The apparatus M moves the X-ray generation unit 12 and the X-ray detection unit 13 supported by the support unit 11a so as to face each other and the support unit 11a relative to the subject o held by the subject holding unit 11c. And a display unit 14 including an electronic computer 16A such as a workstation or a personal computer, an operation unit 15, and a control unit 16 for controlling the apparatus M. The moving unit 11 is operated to operate the subject. o X-ray images are taken.

  The fixing portion 11b holds the support means 11a in a suspended manner by the turning axis A. In addition, the rotating means 11d for rotating the turning axis A by a turning control motor (not shown), the turning axis A of the support means 11a by two-dimensional control by an X-axis control motor (not shown) and a Y-axis control motor (not shown). And an XY table 11e for controlling the position of the support means 11a on the plane intersecting the turning axis A. For this XY table 11e, the configurations shown in FIGS. 13, 14, and 14A described in examples of other configurations of the device M described in detail later can be appropriately adopted.

  The fixing unit 11b functions as an installation unit 11n for installing the support unit 11a on the floor or the ground. The main body (X-ray imaging apparatus main body) M1 of the apparatus M includes at least an X-ray detection unit 13 and an X-ray generation unit. 12, support means 11a, installation means 11n, and subject holding means 11c.

  Although not shown, the support means 11a may be installed on a wall or ceiling. In this case, a member fixed to the wall or ceiling holds the pivot axis A of the support means 11a. The member fixed to is the installation means 11n.

  The display unit 14, the operation unit 15, and the control means 16 may all be provided in the X-ray imaging apparatus main body M1, or may be provided in the electronic computer 16A connected to the X-ray imaging apparatus main body M1, or any other location. May be provided.

  When the display unit 14, the operation unit 15, and the control unit 16 are not provided in the X-ray imaging apparatus main body M1, if one is provided in the vicinity of the X-ray imaging apparatus main body M1, for example, one surgeon is on the X-ray imaging apparatus main body M1 side. When performing both of the above work and the work related to at least one of the display unit 14, the operation unit 15, and the control unit 16, the distance is not separated and the operation is efficient. In the vicinity of the X-ray imaging apparatus main body M1, for example, an X-ray imaging apparatus main body M1 is installed in the same room as the X-ray imaging apparatus main body M1. In this case, the wall surface of the panel 100a of the X-ray room 100 or a location adjacent to the wall surface can be considered.

  In the above two-dimensional control, the support means 11a is two-dimensionally arranged in a plurality of different directions intersecting the axial direction of the turning axis A, preferably in a plurality of different directions on a plane orthogonal to the axial direction of the turning axis A. However, this can be realized by, for example, control for moving the turning axis A in two dimensions. Note that it is desirable to protect the swivel axis A by making it a hollow shaft and passing the cables to the X-ray generation unit 12 and the X-ray detection unit 13 therethrough.

  The subject holding means 11c includes a headrest that holds the head of the patient who is the subject o, a chin rest on which the patient's chin is placed, a chair on which the patient sits, etc., and an elevating means (not shown) provided on the fixed portion 11b. It is connected.

  In the embodiment shown in FIGS. 2A and 2B, the subject holding means 11c includes a chair 11c1 and a headrest 11c2 on which a patient sits. The elevating means includes an elevating control motor (not shown), and controls the position of the subject holding means 11c in a direction parallel to the axial direction of the turning axis A. As each control motor of the moving means 11, it is desirable to use a stepping motor or the like that can control the rotation angle and the rotation speed.

  The moving means 11 includes an XY table 11e, a rotating means 11d, a turning axis A, a connecting portion 11x, and a subject holding means 11c.

  Then, the support unit 11a that supports the X-ray generation unit 12 and the X-ray detection unit 13 so as to face each other is moved by the moving unit 11, so that the X-ray generation unit 12 and the X-ray detection unit 13 are held as a result. The object 11c is moved relative to the subject o.

  The moving means 11 is a general component that performs the function of moving the support means 11a relative to the subject o held by the subject holding means 11c, according to the type of imaging and the structure of the X-ray imaging apparatus. The components can be different. For example, also in this embodiment, when performing later-described linear scan imaging or cephalometric radiography (cephalometric imaging), the rotating means 11d is not necessarily used, and the moving means in this case is an XY table. 11e, the turning axis A, the connecting portion 11x, and the subject holding means 11c. For example, when the position control of at least one of the support unit 11a and the subject holding unit 11c is three-dimensional control described later, the lifting unit (not shown) provided in the above-described fixing unit 11b also constitutes the moving unit. Become an element. With regard to the three-dimensional control, an accommodation frame 11f described later that moves the support means 11a up and down in a direction parallel to the axial direction of the turning axis A according to the description of FIG.

  In FIG. 1, FIG. 2 (a), (b), as above-mentioned, the rotating shaft A of the support means 11a is moved two-dimensionally by the XY table 11e, and the to-be-photographed object holding means 11c raises / lowers by the raising / lowering means. The support means 11a does not have a lifting / lowering means, and the subject holding means 11c is an example that does not move two-dimensionally in a direction intersecting with the axis direction of the turning axis A, but is not limited to this configuration. There are possible combinations.

  There are basically two methods for the moving means 11 to move the support means 11a relative to the subject o held by the subject holding means 11c. One is a method for moving the support means 11a as described above, and the other is a method for moving the subject holding means 11c. In addition, both the support unit 11a and the subject holding unit 11c may be moved.

  That is, since the support unit 11a only needs to move relative to the subject o held by the subject holding unit 11c, in the X-ray imaging, the support unit 11a moves relative to the non-moving subject o held by the non-moving subject holding unit 11c. The moving means 11 for moving the supporting means 11a may be employed, the subject holding means 11c may be moved with respect to the supporting means 11a that does not move, or the subject o held by the subject holding means 11c may be moved. You may employ | adopt the moving means 11 to move. Alternatively, the moving unit 11 that moves both the support unit 11a and the subject holding unit 11c may be employed.

  When the subject holding means 11c is stationary, the subject holding means 11c moves relative to the subject held by the subject holding means by being stationary with respect to the moving support means 11a. Have Therefore, the subject holding means 11c is an element constituting the moving means even if it is stationary.

  In order to move the subject holding means 11c, for example, there is a method of using the same mechanism as the XY table 11e in the subject holding means 11c. In this configuration, the rotating means 11d, the turning axis A, the connecting portion 11x, and the subject holding means 11c using the XY table constitute the moving means 11. As such a configuration, the configuration described in Japanese Patent Application Laid-Open No. 2000-139902 related to the application of the present applicant can be used as appropriate.

  Therefore, for example, without providing the XY table 11e for moving the swivel axis A of the support means 11a in FIGS. 1, 2 (a) and 2 (b), the swivel axis A is fixed in position and the support means. It may be configured such that only the turn of 11a is performed and the subject holding means 11c is moved two-dimensionally by an XY table (not shown). In this case, only the support means 11a may be provided with the lifting means, or only the subject holding means 11c may be provided with the lifting means, and both the support means 11a and the subject holding means 11c are provided with the lifting means. You may do it.

  Japanese Patent Application Laid-Open No. 2000-139902 shows a configuration in which the subject holding means is position-controlled two-dimensionally or three-dimensionally by a holding means position adjusting mechanism. Japanese Patent Laid-Open No. 2000-139902 also shows a configuration in which both the swivel arm corresponding to the support unit of the present case and the subject holding unit are moved, and this configuration can also be used as appropriate.

  The support means 11a can be turned by the moving means 11, and the axial direction of the turning axis A is set in the vertical direction with respect to the floor surface as in the above-described example.

  In any of the embodiments, the direction and the like are described centering on an example in which the axial direction of the turning axis A is set to be perpendicular to the floor surface. However, the axial direction of the turning axis A can be freely set and is horizontal. Any configuration may be adopted, and an arbitrary angle may be set. When the axial direction of the turning axis A of the support means 11a is set to be horizontal with respect to the floor surface, the subject holding means 11c may be configured as a bed on which the patient lies.

  With each configuration described above, the position control of the support means 11a is performed by the above-described two-dimensional control such as control in two directions defined on a plane intersecting the axial direction of the turning axis A. However, any configuration may be used as long as at least one of the support unit 11a and the subject holding unit 11c can be two-dimensionally controlled.

  For example, as shown in FIG. 27, a joint that rotates the other end of the arm A1 whose one end is fixed to the fixed portion 11b so as to be rotatable on a surface intersecting the turning axis A, and one end of the other arm A2. Thus, the arm A2 may be joined so as to be rotatable on a surface intersecting with the turning axis A, and the turning axis A may be joined to the other end of the arm A2 so as to be rotatable. Further, in addition to the above-described position control by the lifting means (not shown), the position control of at least one of the support means 11a and the subject holding means 11c is performed in two directions defined on the plane intersecting the axial direction of the turning axis A. In addition to the above-described two-dimensional control, such as control, a plane that intersects the axis direction of the swivel axis A is further added with one direction that intersects, preferably one direction parallel to the axis direction of the swivel axis A is added. You may make it carry out by dimension control.

  The X-ray generation unit 12 includes an X-ray generator 12a that irradiates the X-ray beam B, and an irradiation field changing unit 12b that changes the shape of the X-ray beam B by a slit, preferably an X-ray cone beam, Irradiation is performed as an X-ray beam B whose shape has been changed.

  An X-ray detector 13a formed in the shape of a cassette is attached to the X-ray detector 13, and an X-ray detector control circuit 13b that drives and controls the X-ray detector 13a is provided. Further, a cassette moving means 13c such as a slide motor for moving the X-ray detector 13a and an exposure field regulating means 13d having a slit for regulating the exposure area of the X-ray beam are further provided. The X-ray detector 13a is formed as a cassette having a housing that can be exchanged with and attached to the X-ray detector 13 in the embodiments of FIGS. 1, 2A, and 2B. The housing is provided with an image sensor 13e on which an X-ray image is projected. As the image sensor 13e, a semiconductor X-ray detection element can be used, and a flat panel having a two-dimensional extension can be formed. More specifically, an image sensor using a MOS sensor, a CMOS sensor, a TFT sensor, a CCD sensor, a MIS sensor, a CdTe (cadmium tellurium) sensor, an X-ray solid-state imaging device, or the like can be used. The image sensor 13e forms a first imaging unit 13f and a second imaging unit 13g, which will be described later. The X-ray detection unit 13 includes a first imaging unit 13f and a second imaging unit 13g by mounting the X-ray detector 13a.

  The X-ray detector 13a is a foundation on which first imaging means 13f and second imaging means 13g described later are provided. The size of the mounting portion of the X-ray detector 13a may be set to the same size and shape as a conventional X-ray film cassette so as to be compatible with the X-ray film cassette. Alternatively, any dimensions and shapes may be used. Therefore, XII (X-ray image intensifier) can be used for the second imaging means 13g. Further, the X-ray detector 13a may be fixed to the X-ray detection unit 13 or may be integrally formed without being attached to and detachable from the X-ray detection unit 13.

  The display unit 14 is composed of a workstation, a personal percomputer, or the like connected to the control means 16 via a communication cable. The workstation or the like includes a video memory 14a for storing image data transmitted from the control means 16. A signal processing unit 14b that executes image processing on image data stored in the video memory 14a, an image reconstruction unit 14c that reconstructs various images, a CRT 14d that displays images and various information, and the like are provided. A liquid crystal display may be used instead of the CRT 14d. Alternatively, the CRT 14d and the liquid crystal display may be made independent of the workstation or the like, and the video memory 14a, the signal processing unit 14b, and the image reconstruction unit 14c may be configured as a part of the control unit 16.

  The operation unit 15 is configured by a keyboard, a mouse, or the like such as a workstation or a personal computer constituting the display unit 14. Of course, instead of the CRT 14d, the display unit 14 using a touch panel type liquid crystal display or the like may be adopted, and the operation unit 15 may also be used.

  The control means 16 includes an X-ray tube control section 16a for controlling the tube voltage and current of the X-ray generator 12a of the X-ray generation section 12, a slit control section 16b for controlling the slit of the irradiation field changing means 12b, and an X-ray Another slit control unit 16c that controls the slit of the exposure field regulating means 13d of the detection unit 13, a type determination unit 16d that determines the type of the image sensor 13e and the X-ray film cassette of the X-ray detector 13a, and a cassette moving unit A cassette moving means controller 16e for driving 13c, an imaging trajectory controller 16f for driving each control motor of the moving means 11, and clock generation for generating control clocks for the X-ray detector control circuit 13b and the imaging trajectory controller 16f Unit 16g, an operation panel 16h for simply displaying information and receiving operation inputs, and a work memory 16i for temporarily storing various variables for control, etc. A frame memory 16j for storing X-ray images taken for each frame, and a CPU16k integrating control means 16.

  FIG. 3 is a principle view for specifically explaining the basic configuration of the X-ray generator 12 described above. In this X-ray generator 12, an irradiation field is provided in front of the irradiation direction of the X-ray generator 12a that irradiates the X-ray beam B from the X-ray tube (tube voltage 90 kV, tube current of about 10 mA) 12g shown in FIG. A slit plate 12c constituting the changing means 12b is arranged, and the slit plate 12c can be slid left and right by a motor 12f1 shown in FIG. 3A (a). The slit plate 12c includes a slit 12d # 1 having a shape extending in a direction parallel to the axial direction of the turning axis A corresponding to the first imaging unit 13f (described later), and a second imaging unit 13g (described later). And two slits 12d # 2 and 12d # 3 having different heights in the direction parallel to the axial direction of the turning axis A are formed, so that the slit plate 12c is used as the optical axis of the X-ray. On the other hand, by sliding in the lateral direction, the spread is restricted to a slit shape, and the irradiation field of the X-ray beam B that becomes the X-ray cone beam CB is changed. In this figure, the X-ray beam B is regulated by the slit 12d # 2, and the X-ray cone beam CB corresponding to the second imaging means 13g is irradiated from the X-ray generator 12a slightly forward and downward. Is shown.

  Similar to the slit 12d # 2, the slit 12d # 3 is used for regulating the X-ray beam B corresponding to the second imaging means 13g, but is provided at a higher position than the slit 12d # 2, as shown in FIG. It is used to irradiate the line cone beam CB forward and slightly upward. The irradiation field changing unit 12b selects the slit 12d # 2 and the slit 12d # 3, so that the X-ray cone beam CB is parallel to the axis direction of the turning axis A with respect to the second imaging unit 13g. The position of the irradiation field is changed and controlled. The shape of the slit plate 12c and the number of slits corresponding to the second imaging means 13g are not particularly limited.

  3A (a) and 3 (b) are diagrams showing a specific structure of the X-ray generator 12. FIG. Inside the X-ray generator 12, the X-ray generator 12a is fixed to the support means 11a. An X-ray beam B is irradiated from an X-ray tube 12g inside the X-ray generator 12a, and a slit 12d # formed in a slit plate 12c provided in an irradiation field changing means 12b provided in front of the X-ray generator 12a. It is restricted to 1, 12d # 2, 12d # 3 and is further irradiated forward. The X-ray beam B that has passed through the slit 12d # 1 becomes an X-ray slit beam NB.

  The irradiation field changing means 12b includes a fixed block 12f2 that is fixed to the X-ray generator 12a and that has a through-hole inside that allows passage of the X-ray beam B from the X-ray generator, and a motor fixed to the fixed block 12f2. 12f1, a drive shaft 12f3 that is a screw shaft that is rotationally driven by a motor 12f1, a driven member 12f4 that is displaced in a direction intersecting the X-ray beam B with respect to the fixed block 12f2 by the drive shaft 12f3, and an X on the front surface of the fixed block 12f2. A roller fixing plate 12f6 fixed at a position not hindering passage of the X-ray beam B from the line generator, four rollers 12f5 provided on the roller fixing plate 12f6, and the rollers 12f5 are guided to be driven member 12f4. And a slit plate 12c that is displaced in a direction intersecting the X-ray beam B together with the driven member 12f4. By driving the driven member 12f4 by f3, the slit plate 12c is displaced in a direction transverse to the X-ray beam B. Any of the slits 12d # 1, 12d # 2, and 12d # 3 can be selected according to the displacement of the slit plate 12c.

The irradiation field of the X-ray beam B is the X-ray cone beam CB or the X-ray slit beam NB corresponding to the slits 12d # 1 to 12d3 selected by the irradiation field changing means 12b, and particularly the slit 12d # 2. , 12d # 3 is selected, the second imaging means 13g described later is displaced in a direction parallel to the axial direction of the turning axis A.

  Note that the direction parallel to the axial direction of the turning axis A is not necessarily a direction that completely coincides with the axial direction of the turning axis A, as in the example of FIGS. 3B (a) and (b). ) And may be changed obliquely as in the example of (b).

  3B (a), 3 (b), 3C (a), and (b) are examples of application of the example of FIG.

  The X-ray beam B that has passed through the slit 12d # 2 shown in FIG. 3B (a) becomes an X-ray cone beam CB and is irradiated to the position of the irradiation field 12d # 2 ′. FIG. 3B (b) shows a state in which the X-ray cone beam CB passing through the slit 12d # 3 is irradiated to the position of the irradiation field 12d # 3 ′ by displacing the slit plate 12c of FIG. 3B (a). The irradiation field 12d # 2 ′ is changed to the position of the irradiation field 12d # 3 ′ on the upper side in the vertical direction in the figure, which is a direction that completely coincides with the axial direction of the turning axis A.

  On the other hand, the X-ray cone beam CB that has passed through the slit 12d # 2 shown in FIG. 3C (a) is irradiated to the position of the irradiation field 12d # 2 ′. FIG. 3B (b) shows a state in which the X-ray cone beam CB passing through the slit 12d # 3 is irradiated to the position of the irradiation field 12d # 3 ′ by displacing the slit plate 12c of FIG. 3B (a). Irradiation field 12d # 2 'is changed to the position of irradiation field 12d # 3' obliquely in the vertical direction in the figure, not in a direction that completely coincides with the axial direction of pivot axis A.

  Such a change can be easily realized by adjusting the displacement amount of the slit plate 12c. In the case of the configuration of FIGS. 3C (a) and (b), for example, a CT image can be acquired by offset scan CT imaging according to the description of FIG. 9 described later. The “direction parallel to the axial direction of the turning axis A” referred to in the present application includes not only a direction completely coincident with the axial direction of the turning axis A but also an oblique direction as described above.

  The above example is an example of changing the position of the irradiation field by displacing a plurality of slits having different heights in the direction parallel to the axial direction of the turning axis A with respect to the X-ray generator 12a. There is also a possibility of this.

31 (a), (b), (c), FIG. 31A, FIG. 31B, and FIG. 31C all show an example of another method in principle, but since it is a modified example of FIG. Description of the points to be performed is omitted. Further, in any of FIGS. 31A, 31B, and 31C, the anti-rotation member and the movement guide member of the X-ray generator 12a can be easily realized by using a well-known mechanism, and are not shown. It is omitted.
FIGS. 31A, 31B, and 31C show a state in which the X-ray beam B from the X-ray generator 12a is irradiated with the X-ray cone beam CB regulated by the slit 12d # 2. .

  FIG. 31A is an example in which the X-ray generator 12a itself rotates to change the irradiation field. Unlike FIG. 3A (a), the support means 11a and the X-ray generator 12a of FIG. 31 (a) are separated, and the rotation members 12f22 and 12f21 are interposed. Here, the X-ray generator 12a has a rotating member 12f22 at the top thereof. At the bottom of the support means 11a, another rotating member 12f21 is provided at a position corresponding to the rotating member 12f22. The rotation member 12f22 and the rotation member 12f21 are joined to each other so as to be rotatable about a common rotation shaft 12f24. The axial direction of the rotating shaft 12f24 is set to a direction orthogonal to the direction parallel to the axial direction of the turning axis A. Therefore, the rotation member 12f22 is rotatable so as to displace the X-ray cone beam CB irradiated by the X-ray generator 12a toward the X-ray detection unit 13 in a direction parallel to the axial direction of the turning axis A. is there. At the top of the X-ray generator 12a, a fan-shaped member 12f23 is provided in a state where the main part of the fan-shape is fixed to the top of the X-ray generator 12a, and the bottom of the support means 11a on the X-ray generator 12 side Is provided with a motor 12f20. The drive shaft of the motor 12f20 is in contact with the arcuate edge of the fan-shaped member 12f23, and rotates the fan-shaped member 12f23. The axial direction of the rotation shaft of the fan-shaped member 12f23 is set in the same direction as the rotation shaft 12f24. Accordingly, when the motor 12f20 is driven, the X-ray generator 12a is rotated, and the X-ray cone beam CB irradiated by the X-ray generator 12a toward the X-ray detection unit 13 is parallel to the axial direction of the turning axis A. Displace in the direction.

  FIG. 31B shows an example in which the irradiation field is changed by moving the X-ray generator 12a itself up and down relative to the slit plate 12c. Unlike FIG. 3A (a), the fixed block 12f2 is fixed to the bottom of the support means 11a on the X-ray generation unit 12 side. Here, the X-ray generator 12a is not directly fixed to the support means 11a, but is moved up and down with respect to the support means 11a by the driven member 12f32 described below.

  The through hole that allows passage of the X-ray beam B from the X-ray generator 12a inside the fixed block 12f2 is set to a dimension that allows the tip of the X-ray generator 12a to move up and down within a certain range. A motor 12f30 is fixed to the bottom of the support means 11a on the X-ray generation unit 12 side with a shaft 12f31, which is a screw shaft, facing downward. On the back surface of the X-ray generator 12a, a driven member 12f32 threaded into the shaft 12f31 is inserted and driven up and down by the shaft 12f31. Accordingly, when the shaft 12f31 is driven, the X-ray generator 12a is moved up and down with respect to the fixed block 12f2 and the slit 12d # 2, and the irradiation field is changed up and down. That is, by driving the motor 12f30, the X-ray cone beam CB irradiated by the X-ray generator 12a toward the X-ray detection unit 13 is displaced in a direction parallel to the axial direction of the turning axis A.

  FIG. 31C is an example in which the irradiation field is changed by moving the slit plate 12c up and down relative to the X-ray generator 12a. Here, the X-ray generator 12a is fixed to the bottom of the support means 11a on the X-ray generator 12 side, and the fixed block 12f2 is fixed to the X-ray generator 12a. A motor 12f40 is fixed to the bottom of the support means 11a on the X-ray generation unit 12 side with a shaft 12f41, which is a screw shaft, facing downward. Unlike FIG. 3A (a), the roller fixing plate 12f6 is separated from the fixing block 12f2, and is configured as a member that moves up and down. On the back surface of the roller fixing plate 12f6, there is provided a driven member 12f42 that is threaded into the shaft 12f41 that is inserted and driven up and down by the shaft 12f31. Therefore, when the shaft 12f41 is driven, the roller fixing plate 12f6, the roller 12f5 fixed to the roller fixing plate 12f6, and the slit plate 12c sandwiched between the upper and lower rollers 12f5 are moved up and down, and the irradiation field is moved up and down. Changed to That is, by driving the motor 12 f 40, the X-ray cone beam CB emitted from the X-ray generator 12 a toward the X-ray detection unit 13 is displaced in a direction parallel to the axial direction of the turning axis A.

  In any of FIGS. 31A, 31B, and 31C, two slits corresponding to the second imaging unit 13g (described later) are not necessary, only 12d # 2 is provided, and 12d # 3 is omitted. it can.

  31A and 31B, a slit 12d # 2 for restricting the X-ray beam B to become an X-ray cone beam CB corresponding to the second imaging means 13g is provided separately from the slit plate 12c of FIG. 3A (a). In this example, the slit plate 12c1 is displaced in a direction parallel to the axial direction of the turning axis A.

  FIG. 31A is a side view for explaining in principle the structure of the X-ray generator 12, and FIG. 31B is a perspective view of a fixed block 12f2 fixed to the X-ray generator 12a and a mechanism provided in the fixed block 12f2. The “front surface” described below is a front surface viewed from the direction of receiving the X-ray beam B from the X-ray generator 12a.

  Here, the X-ray generator 12a is fixed to the support means 11a, and a fixed block 12f2 having a through-hole that allows passage of the X-ray beam B from the X-ray generator 12a is fixed to the X-ray generator 12a. The Roller fixing plates 12f50 and 12f50 are fixed at positions on the front surface of the fixed block 12f2 that do not hinder the passage of the X-ray beam B from the X-ray generator. Among them, a shaft 12f53, which is a screw shaft on which the motor 12f52 rotates, is fixed to the bottom of the lower roller fixing plate 12f50 so as to face downward. The slit plate 12c1 is guided by four rollers 12f56 provided on the two roller fixing plates 12f50 and 12f50, and is displaced in a direction parallel to the axial direction of the turning axis A. The slit plate 12c1 is formed with a slit 12d # 2 for restricting the X-ray beam B to be an X-ray cone beam CB corresponding to the second imaging means 13g, and an opening 12d # 6 that is largely opened for the purpose described later. Has been. The slit plate 12c1 is provided with a driven member 12f55 that is internally threaded, and is driven by a shaft 12f53. Accordingly, when the driven member 12f55 is driven, the slit plate 12c1 is displaced in the vertical direction of the drawing, that is, in a direction parallel to the axial direction of the turning axis A.

  The two roller fixing plates 12f58 and 12f58 are fixed to the front surfaces of the roller fixing plates 12f50 and 12f50 by four pins 12f57 so as not to hinder the movement of the displaced slit plate 12c1. Four rollers 12f5 are provided on the front surfaces of the roller fixing plates 12f58 and 12f58. On the upper part of the upper roller fixing plate 12f58, a shaft 12f3 that is a screw shaft on which the motor 12f1 rotates is fixed sideways. In the slit plate 12c, slits 12d # 1 and 12d # 4 having a shape extending in a direction parallel to the axial direction of the turning axis A corresponding to the first imaging unit 13f are formed.

  The slit 12d # 1 is a slit for panoramic photography or linear scan photography, and 12d # 4 is a slit for cephalometric radiography (cephalometric photography). In addition, the slit plate 12c is formed with an opening 12d # 7 that is largely opened for the purpose described later. A driven member 12f4 threaded inside is provided on the front surface of the slit plate 12c, and is driven by a shaft 12f3. Therefore, when the driven member 12f4 is driven, the slit plate 12c is displaced in a direction crossing the X-ray beam B. At this time, the roller 12f5 guides the displacement of the slit plate 12c.

  Specifically, in the case of X-ray CT imaging, the slit plate 12c1 is displaced by the motor 12f52 so that the slit 12d # 2 comes to a position where the X-ray beam B is regulated. By adjusting the displacement amount, it is possible to adjust the displacement of the slit 12d # 2 in the direction parallel to the axial direction of the turning axis A. For this purpose, the X-ray cone beam CB is irradiated to the second imaging means 13g. Can be changed in a direction parallel to the axial direction of the turning axis A. In this case, the slit plate 12c is displaced by the motor 12f1 so that the opening 12d # 7 is in front of the slit 12d # 2. The opening 12d # 7 is set to such a size that the X-ray cone beam CB that has passed through the slit 12d # 2 is not prevented from passing.

  In the case of panoramic photography or linear scan photography, the slit plate 12c is displaced by the motor 12f1 so that the slit 12d # 1 is positioned to regulate the X-ray beam B. X-ray beam B passes through slit 12d # 1 and becomes X-ray slit beam NB. The slit plate 12c1 is displaced by the motor 12f52 so that the opening 12d # 6 is behind the slit 12d # 1 so that the passage of the X-ray slit beam NB that has passed through the slit 12d # 1 is not hindered. The opening 12d # 6 is set to a size that does not hinder the passage of the X-ray slit beam NB that has passed through the slit 12d # 1.

  In the case of cephalometric radiography (cephalometric imaging), the operation is the same except that the slit 12d # 1 is replaced with 12d # 4 during panoramic imaging or linear scan imaging, and therefore detailed description is avoided. .

  FIG. 31C is an application diagram of FIG. 31B. In the embodiment of FIG. 31C, only the slit 12d # 2 of the embodiment of FIG. 31B is replaced with the slit 12d # 5 and the opening 12d # 7 is replaced with the slit 12d # 8, and the other description is omitted.

  The embodiment of FIG. 31C is characterized in that, in the case of X-ray CT imaging, the slit 12d # 5 and the slit 12d # 8 overlap to change the irradiation field in cooperation. The vertical width of the slit 12d # 5 is set to the same length as the vertical width of the slit 12d # 2, and the horizontal width of the slit 12d # 5 is set longer than the horizontal width of the slit 12d # 2. On the other hand, the vertical width of the slit 12d # 8 is set longer than the vertical width of the slit 12d # 2, and the horizontal width of the slit 12d # 8 is set to the same length as the horizontal width of the slit 12d # 2. . By adjusting the displacement amount of the slit plate 12c and the slit plate 12c1, the irradiation field can be controlled two-dimensionally up and down and left and right.

  4A and 4B are perspective views showing two basic configurations of the X-ray detection unit 13 described above.

  The X-ray detection unit 13 includes a base 130a that is the basis of the X-ray detection unit 13, a movable unit 130b or 130c that functions as a sensor holder that displaces the inside of the base 130a in a direction substantially parallel to the turning direction of the X-ray detection unit 13. The X-ray detector 13a is mounted on the movable part 130b or 130c, and includes a first imaging unit 13f and a second imaging unit 13g.

  Of the two X-ray detectors 13a in FIG. 4A, in the X-ray detector 13a shown in the upper side of the figure, the first imaging means 13f that extends in a direction parallel to the axial direction of the pivot axis A of the support means. And a second imaging means 13g that is two-dimensionally spread with respect to the first imaging means 13f used for X-ray CT imaging, and a single detection of the image sensor 13e provided in the X-ray detector 13a. Areas are set so that some areas overlap on the surface.

  In the X-ray detector 13a shown in the upper side of FIG. 4A, the region is set so that the first imaging unit 13f and the second imaging unit 13g partially overlap on the detection surface of the image sensor 13e. On the other hand, in the X-ray detector 13a shown in the lower part of FIG. 4A, they are independently provided. In any case, the X-ray detector control circuit 13b constitutes an imaging means moving means 13i that changes the position of the region setting of the second imaging means 13g in a direction parallel to the axial direction of the turning axis A of the support means 11a. And has a function of changing the setting of the area of the second imaging means 13g non-mechanically by an electronic or software method.

  However, since the irradiation field of the X-ray beam B is regulated by the slit 12d # 1, slit 12d # 2, and slit 12d # 3 of the irradiation field changing means 12b to be the X-ray cone beam CB and switched, the image sensor The entire surface of 13e may always be an effective area.

  By the way, in the case of the example of FIG. 4A, since the first imaging unit 13f and the second imaging unit 13g are set on the same image sensor 13e, the first imaging surface and the second imaging unit are set. It can also be considered as a surface.

  FIG. 4A shows two movable parts 130b and 130c. Of these, the movable part 130b shown in the upper part of the figure will be described first. The base portion 130a is provided with a guide portion 13h1 for guiding a guided portion 13h2 provided in the movable portion 130b, and the movable portion 130b is driven to be displaced by a cassette moving means 13c including, for example, a motor and a roller. The movable part 130b is provided with a receiving part 13j for mounting the X-ray detector 13a, in which there is an X shown in the upper part of the figure of the two X-ray detectors 13a in FIG. A line detector 13a is attached. An exposure field restricting means 13d is provided at a position in front of the X-ray detector 13a when the X-ray detector 13a is mounted on the movable portion 130b. The exposure field restricting means 13d is made of a flat plate-like member, and a secondary slit 13l having a size substantially matching the dimensions of the first image pickup means 13f and the second image pickup means 13g is opened, and the first image pickup means 13f, While allowing the second imaging means 13g to irradiate the X-ray beam, other unnecessary X-ray beams are blocked.

  Of the two movable parts in FIG. 4A, the movable part 130c shown in the lower part is a modified example of the movable part 130b. Of the two X-ray detectors 13a in FIG. This is for mounting the X-ray detector 13a shown in the lower part of the figure. The difference from the movable part 130b substantially matches the size of each imaging unit in accordance with the X-ray detector 13a in which the first imaging unit 13f and the second imaging unit 13g are independently set in the region. The point is that two secondary slits 13l and 13l are opened. The movable unit 130c displaces each imaging unit so that the X-ray beam is irradiated according to the selection of the first imaging unit 13f and the second imaging unit 13g of the mounted X-ray detector 13a. Let

  In the example of FIG. 4A, the first imaging unit 13f and the second imaging unit 13g are rectangular and rectangular. However, the first imaging unit is not particularly limited to this shape, and the first elongated imaging unit is not limited to this shape. The second imaging means 13g only needs to be two-dimensionally spread with respect to the means 13f. The fact that the second imaging means 13g has a two-dimensional expansion with respect to the elongated first imaging means 13f means that the second imaging means 13g is wider than the elongated first imaging means 13f. It is a wide shape.

FIGS. 26A and 26B show examples of different shapes of the first imaging unit 13f and the second imaging unit 13g, respectively. The example of FIG. 26A is an example in which the first image pickup unit 13f and the second image pickup unit 13g are rectangular and rectangular as in the example of FIG. 4, but for example, the shape as shown in FIG. But it is optional. The first image pickup means 13f in the example of FIG. 26B has a rounded shape at the four corners of the rectangle, and the second image pickup means 13g has a round shape at the four corners.

  Here, the dimension of the maximum vertical width of the first imaging means 13f is W1f, the dimension of the maximum vertical width of the second imaging means 13g is W1g, and the dimension of the horizontal maximum width of the first imaging means 13f is If W2f and the dimension of the horizontal maximum width of the second imaging means 13g are W2g, they can be set to have a relationship of W1f> W1g and W2f <W2g. These vertical and horizontal dimensions can also be set from a ratio, and may be set to have a relationship of W1f / W2f> W1g / W2g. For example, if W2f is 1, W1f may be set at a ratio of 3-30, and if W2g is 1, W1g may be set at a ratio of 0.3-2.

  More specifically, W1f is set to about 150 mm or about 150 mm ± 30 mm suitable for panorama, and W2f is set to about 10 mm or about 10 mm ± 5 mm suitable for capturing a panoramic tom clearly and without waste. 120mm or 120mm ± 30mm, suitable for CT imaging only around the teeth or ear stapes, W2g is also 120mm, suitable for imaging only several teeth or ears around the stapes Alternatively, it may be set to about 120 mm ± 30 mm.

  Further, W1g may be set to about 70 mm or 70 mm ± 20 mm, and W2g may be set to about 70 mm or 70 mm ± 20 mm. Even with a detection surface of 70 mm square or 70 mm ± 20 mm square, one tooth and its left and right teeth can be accommodated within the CT imaging range, and each tooth can be imaged from the crown to the apex. Therefore, it is within a practical size range, and the cost can be kept low.

  Next, the basic operation of the apparatus M will be described. The present invention provides a medical X-ray imaging apparatus that designates a specific region of interest R as a subject o and acquires a CT image of the region of interest R. For this purpose, the control means 16 of the apparatus M includes: In summary, the first X-ray image obtained by scanning and photographing the subject o over a wide range with the first imaging unit 13f is displayed on the display unit 14, and is displayed on the display unit 14 by the operation of the operation unit 15. In order to designate the region of interest R on the first X-ray image and obtain a second X-ray image that is a CT image of the designated region of interest R, position control of the irradiation field changing means 12b, The position control of the image pickup means 13g and the position control of the support means 11a and / or the subject holding means 11c, that is, the control of the moving means 11 as a whole, are performed, and the CT image is controlled as a second X-ray image. Perform basic operations.

  FIG. 5 is a flowchart showing a control procedure by the control means 16 for performing the basic operation. If this flowchart is followed, the control means 16 will perform the arrangement | positioning step which arrange | positions the to-be-photographed object o to a reference | standard position first (step 101). That is, when a predetermined operation is accepted by the keyboard of the operation unit 15 or the operation panel 16h, the subject holding unit 11c holding the subject o is moved up and down to position the subject o at the reference position.

  Then, by operating the keyboard of the operation unit 15 or the operation panel 16h, the panorama mode is selected as the imaging type of the first X-ray image, and when the imaging command is received (step 102), the X-ray beam (X-ray) Panorama shooting is selected as the locus of the slit beam NB) (step 103), the support means 11a is positioned on a plane intersecting the pivot axis of the optical system (step 104), and the slit 12d # of the irradiation field changing means 12b is selected. 1 is selected (step 105), and the first X-ray image is scanned and imaged using the first imaging means 13f (step 106), and the preliminary imaging steps (steps 102 to 106) are executed.

  FIG. 6 is a plan view showing the trajectories of the X-ray generation unit 12 and the X-ray detection unit 13 during scanning photographing of the subject o. In the present embodiment, when panoramic X-ray imaging is performed, the support unit 11a is moved (turned) along the path for panoramic X-ray imaging by the moving unit 11 with respect to the subject holding unit 11c that fixes and holds the subject o. .

  Here, the two-dimensional movement of the turning axis A is performed by the XY table 11e as described above, and the rotation axis A is rotated by the rotating means 11d. By the rotation of the turning axis A, the support means 11a turns. Panorama shooting is performed by a total motion of the two-dimensional movement of the turning axis A by the XY table 11e and the turning of the supporting means 11a by the rotating means 11d.

  That is, in order to keep the projection magnification constant, in synchronization with the rotation of the support means 11a, the swivel axis A is also near the tooth at the back right so as to keep the distance from the dentition as constant as possible as shown by the dotted line in the center of the figure. A1 is moved from A1 in the vicinity of the center of the front tooth, and from A2 to A3 in the vicinity of the left back tooth. The X-ray generator 12, more specifically the X-ray generator 12 a, moves the X-ray beam (X-ray slit beam) with the teeth on the right back of the dentition from the lingual side toward the cheek side according to the rotation of the support means 11 a. NB) is irradiated at position P1, X2 beam (X-ray slit beam NB) is irradiated with the teeth near the center of the front teeth facing the lips from the lingual side, and the left tooth of the dentition is cheeked from the lingual side The X-ray detector 13 moves in a counterclockwise direction as viewed from the top of the figure along a trajectory that sequentially passes through the position P3 that irradiates the X-ray beam (X-ray slit beam NB) toward the side. The first imaging means 13f synchronizes with the X-ray generator 12a at the position P1 and the X-ray generator 12a at the position P2 that receives the X-ray beam (X-ray slit beam NB) from the X-ray generator 12a at the position P1. From the X-ray generator 12a at position PP2 and position P3 that receives the X-ray beam (X-ray slit beam NB) Along a trajectory passing through the X-ray beam (X-ray slit beam NB) a receiving position PP3 when viewed from the top in FIG moves counterclockwise. In the illustrated example, the X-ray generation unit 12 and the X-ray detection unit 13 are moving counterclockwise, but may be clockwise.

The orbit during panoramic X-ray imaging is specifically described in Japanese Patent Publication No. 2-18092, which is filed by the applicant of the present invention. In this Japanese Patent Publication No. 2-18092, the movement trajectory of the rotation center of the X-ray bundle is configured to draw a substantially triangular envelope trajectory that is a right and left object with a vertex protruding toward the front tooth portion of the dental arch as a boundary. A panoramic X-ray imaging apparatus is disclosed. For example, such a trajectory at the time of panoramic X-ray imaging can be employed.
FIG. 28 shows how the locus of the X-ray beam (X-ray slit beam NB) irradiated from the X-ray generator 12a toward the first imaging means 13f draws the envelope EN.

  FIG. 7 is a schematic enlarged view for explaining the state of the subject o during scanning photographing. In this figure, the extension line of the pivot axis A passes through the central portion of the patient's dental arch, which is depicted as a specific subject o ′ in the subject o. The X-ray beam B is regulated by the slit 12d # 1 of the slit plate 12c to become an X-ray slit beam NB, and an elongated transmission image of the dentition is projected on the first imaging means 13f. In addition, FIG. 7, FIG. 10, FIG. 18, FIG. 19, FIG. 24, and FIG. 25 are all schematic explanatory diagrams, and the dental arch o ′ is drawn larger than the actual one. For emphasis and simplification.

  When imaging of the first X-ray image is thus completed, the acquired image data is processed and reconstructed (step 107), a panoramic image is displayed on the display unit 14 (step 108), and the mouse operation of the operation unit 15 is performed. The region of interest R is designated on the panoramic image by the interlocking cursor, and the type of the second X-ray image is selected (step 109). The region of interest designation step (steps 107 to 109) is executed.

  An X-ray image including a panoramic image, a cephalometric image described later, a linear scan image, and other necessary information may be displayed on the display unit 14 including a workstation or a personal percomputer. As a display unit on the apparatus main body side for a personal computer or a personal computer, for example, the apparatus main body side display unit 16ds may be provided on the operation panel 16h of the X-ray imaging apparatus main body M1 shown in FIG. Further, it may be displayed on both the display unit 14 and the apparatus main body side display unit 16ds. Of course, the apparatus main body side display unit 16ds is also an example of the display unit.

  Furthermore, the panoramic image displayed on the display unit 14 may be displayed in an enlarged or reduced manner, and when a part that cannot be fit on the screen of the display part is generated as a result of the enlargement, only the part that fits on the screen is displayed. Then, the portion displayed by scrolling the screen may be changed. If the contrast of the displayed panoramic image is adjusted, the panoramic image can be visually recognized even better.

  The apparatus main body side display unit 16ds may be provided anywhere on the apparatus main body side. However, for example, if the apparatus main body side display unit 16ds is provided on the support means 11a or the fixing unit 11b, the space occupied by the apparatus main body side display unit 16ds itself can be saved. is there.

  The operation unit 15 for designating the region of interest R is easy to operate if it is provided on the apparatus main body side, like the apparatus main body side display unit 16ds. The operation unit 15 may be provided anywhere on the apparatus main body side, but the vicinity of the apparatus main body side display unit 16ds is particularly convenient and convenient. In addition, when the apparatus main body side display unit 16ds is provided on the support means 11a or the fixing unit 11b, it is particularly convenient to provide the operation unit 15 at the same location.

  Even when a panoramic image is displayed on the apparatus main body side display unit 16ds, the region of interest R is designated on the panoramic image by the operation of the operation unit 15, but the operation means of the operation unit 15 is a keyboard or a palm. In addition to a mouse that is held and operated, it is convenient because it does not require a large installation space even if a touch pen or a mouse that is generally used for notebook computers and touches with a finger on the membrane sheet is used. . As described above, the display unit 14 and the operation unit 15 may be combined using a touch panel type liquid crystal display or the like.

On the apparatus main body side display unit 16ds, not only a panoramic image but also an image acquired by linear scan imaging described later may be displayed as the first X-ray image IM1, or a head X-ray standard photography imaging described later may be displayed. You may display the cephalo image acquired by (cephalometric photography).
In any case, it can be configured that the region of interest R is designated on the displayed image, the movement control of the support means 11a is performed, and CT imaging of the region of interest R is performed, as in the case of the panoramic image. is there.
The apparatus main body side display unit 16ds may display a second X-ray image IM2 such as a CT image.

  FIG. 8 is an example of a panoramic image (first X-ray image IM1) for explaining a method of specifying the region of interest R. The region of interest R may be specified by a cursor that moves on the CRT 14d of the display unit 14 in accordance with the operation of the operation unit 15. As the cursor, any of an arrow-shaped cursor, a cross-shaped cursor, and a rectangular cursor that displays a region of interest frame may be used, or a cursor combining them may be used. As the arrow cursor, an arrow pointer known in a personal computer or the like can be used. The cursor or pointer does not necessarily have an arrow shape, and may be an arbitrary shape. The first X-ray image IM1 may be displayed on the display unit 14 or may be displayed on the apparatus main body side display unit 16ds. Of course, you may display on both the display part 14 and the apparatus main body side display part 16ds.

  The illustrated cursors ca and cb are examples of cross-shaped cursors. In this case, for example, each of the cursors ca and cb is operated with a mouse or the like, pressed and held, and moved on the screen to designate the region of interest R. By holding and moving the intersections of the cursors ca and cb, these two cursors may be moved simultaneously.

  The illustrated cursor R ′ is an example of a rectangular cursor. Assuming two diagonal lines connecting the four vertices of the quadrangle indicated by the cursor R ′, even if the region of interest R is designated by the position where the two diagonals intersect or its vicinity designate the center of the region of interest R. Alternatively, the cursor R ′ may be displayed so that the size of the cursor R ′ matches the size of the region of interest R.

  The cursors ca, cb and the cursor R ′ may be displayed at the same time. Assuming two diagonal lines connecting the four vertices of the quadrangle indicated by the cursor R ′, the position where the two diagonal lines intersect with each other, the cursor ca, You may display so that the intersection of cb may correspond.

  Since the coordinate information of the three-dimensional position of the panoramic tomography can be grasped in advance, such a cursor can explicitly specify the coordinates with respect to two coordinate axes in which the three-dimensional position of the region of interest R is orthogonal on the panoramic image. Further, with respect to one coordinate axis in the thickness direction of the panoramic image, the coordinates near the center of the dentition thickness may be automatically designated based on the size of the dentition image.

  Although the offset scan will be described later, the normal CT mode or the offset scan CT mode is selected as the imaging type of the second X-ray image by operating the keyboard of the operation unit 15 or the operation panel 16h. When the command is received (step 110), the position of the designated region of interest R is calculated (step 111), then the type of the second X-ray image is determined (step 112), and the second X-ray is obtained. If the type of image is normal CT imaging, normal CT imaging is selected as the locus of the X-ray beam (X-ray cone beam CB) (step 113), and the support means 11a is moved to rotate the optical system. On the other hand, if the type of the second X-ray image is offset scan CT imaging, the X-ray beam (X The offset scan CT imaging is selected as the locus of the cone beam CB (step 115), the support means 11a is moved and positioned on the plane intersecting the pivot axis of the optical system (step 116), and the X-ray detector 13a is selected. Is slid forward or backward in the turning direction so that the second X-ray imaging means 13g is offset with respect to the X-ray generator 12 and the region of interest R (step 117), and then the region of interest R If the position of the region of interest R is higher than the reference position, the slit 12d # 3 of the irradiation field changing means 12b is selected (step 119), and the second imaging means 13g If the region is raised (step 120) and positioned in a direction parallel to the pivot axis of the optical system, while the region of interest R is lower than the reference position, the irradiation field changing means The 2b slit 12d # 2 is selected (step 121), the region of the second imaging means 13g is lowered (step 122), and the photographing position adjusting step (steps 110 to 110) is positioned parallel to the pivot axis of the optical system. 122).

  At this time, in addition to raising and lowering the area of the second image pickup means 13g, by controlling the raising and lowering of the support means 11a and the subject holding means 11c, the adaptive range for the position of the region of interest R can be further expanded. Can do. As for the raising and lowering of the support means 11a and the subject holding means 11c, the raising and lowering means for the subject holding means 11c (not shown) provided in the fixing portion 11b according to the explanation of FIG. 1, and the support means according to the explanation of FIG. A storage frame 11f, which will be described later, for moving the 11a up and down can be used.

  Then, based on the positioning in the imaging position adjustment step, the moving unit 11 is driven, and the second imaging unit 13g causes the entire region of interest R or a transmission image including a portion of a ratio of ½ or more to be given at predetermined angles. (Step 123), the acquired transmission image is subjected to image processing, and a CT image of the desired cross section of the region of interest R is reconstructed (step 124). The main imaging steps (steps 123 and 124) are executed.

  In the selection of the above-described imaging type, at least a panorama mode and a CT mode can be selected, and a normal CT mode and an offset scan CT mode can be selected as the CT mode. However, the linear scan mode or the like may be selected, and when the region of interest R is designated on the CRT 14d on which the panoramic image is displayed while the panoramic mode is selected, the CT is automatically performed. A mode may be selected.

  In the linear scan imaging, as shown in FIG. 30A, the X-ray generator 12a and the first imaging unit 13f are moved in the same direction while the subject is sandwiched between the X-ray generator 12a and the first imaging unit 13f. In this case, the transmission image of the region of interest of the subject is acquired by the X-ray slit beam NB. Synchronous movement of the X-ray generator 12a and the first imaging means 13f in the same direction can be easily realized by an XY table described later. Therefore, when the linear scan mode is selected, a transmission image (linear scan image), which is the first X-ray image, is acquired by linear scan imaging and displayed on the CRT 14d as imaging by the first imaging unit 13f. A region of interest R is designated on the transparent image of the subject as in the case of the panoramic image, and CT imaging is performed by the second imaging unit 13g to obtain a CT image as the second image. Good.

In addition, as imaging by the first imaging means 13f, cephalo ( head X-ray standard photography ) may be performed. For example, as shown in FIG. 30B, the head X-ray standard photography (cephalometric imaging) includes a first imaging means 13f and an X-ray generator that are long enough to image the human head as the subject o. 12a, with the human head facing sideways sandwiched between the first imaging means 13f from the front of the head to the rear or the reverse direction, from the top of the head to the lower or the reverse direction, It is imaging | photography which moves so that the whole head can be image | photographed and acquires the transparent image of a head.

  In the illustrated example, the X-ray generator 12a is fixed, and a slit 12d # 4 having a length that can irradiate the X-ray slit beam NB with a length that can sufficiently image a human head is provided with the first imaging means 13f. Move the camera in sync with and shoot. For this type of imaging, the configuration of Japanese Patent Application Laid-Open No. 2003-245277 according to the application of the applicant of the present application can be appropriately employed.

  For example, the above-mentioned slit 12d # 4 is added to the slit plate 12c shown in FIGS. 3 and 3A (a) and (b), and the apparatus M is used for cephalometric radiography (cephalometric imaging) with a well-known configuration. By providing a long horizontal arm and providing the above-mentioned first imaging means 13f in the second X-ray detection section at the tip of the arm so as to be able to move synchronously, the above imaging can be performed. Therefore, when the cephalometric radiography (cephalometric imaging) mode is selected, a transmission image (cephalometric image) that is the first X-ray image is acquired by cephalometric radiography (cephalometric imaging). The region of interest R is designated in the same manner as in the case of the panoramic image on the transmission image (cephalo image) of the subject displayed on the CRT 14d, and CT imaging is performed by the second imaging unit 13g, and the second image is displayed. A certain CT image may be acquired.

  Regarding the designation of the region of interest R, for example, a plurality of linear scan images taken from different angles are displayed, the region of interest R is designated on one linear scan image, and the region of interest R is designated also on another linear scan image. Then, since coordinate information of the three-dimensional position of the region of interest is obtained, CT imaging of the region of interest R can be performed from the coordinate information.

  When the region of interest R is specified on the cephalometric image, the right and left sides of the dental arch o ′ are displayed so as to overlap with each other. Is specified separately from the operation unit 15. The human head as the subject o is fixed to the second X-ray detection unit described above, and the three-dimensional position of the dental arch o ′ is also grasped. In this case, for example, if a means for positioning the front teeth at a specific fixed position is provided, the three-dimensional position of the dental arch o ′ can be grasped more accurately. In addition, since the coordinate information of the three-dimensional position of the region of interest R is obtained from the general shape of the dental arch o ′, CT imaging of the region of interest R can be performed. The dental arch shape may be measured individually in advance.

  FIG. 9 is a plan view showing the locus of an X-ray beam for CT imaging (X-ray cone beam CB). FIG. 9A shows a trajectory for normal CT imaging, and FIG. 9B shows a trajectory for offset scan CT imaging. During normal CT imaging, the X-ray generator 12a and the second imaging means 13g are aligned with the center of the region of interest R by moving the turning axis A of the support means 11a by the XY table 11e. In the state where the turning axis A is the turning axis of the optical system, the turning means 11d rotates the turning axis A of the supporting means 11a, and the supporting means is turned. The entire region of interest R is always projected onto the second X-ray imaging means 13g.

  On the other hand, at the time of offset scan CT imaging, the X-ray generator 12a and the second imaging means 13g each use the turning axis A aligned with the center of the region of interest R as the turning axis of the optical system, and the X-ray generator. In a state where the second X-ray imaging unit 13g is offset forward or backward in the turning direction of the X-ray detection unit 13 with respect to the region 12a and the region of interest R, the region of interest R rotates at least one turn synchronously. A portion with a ratio of 1/2 or more is always projected onto the second X-ray imaging means 13g. As described above, in the offset scan CT imaging, the second imaging unit 13g is offset forward or backward in the turning direction of the X-ray detection unit 13, so that a part of the designated region of interest R is always projected and projected. Projection is performed over the entire region R, and X-ray CT imaging of the region of interest R is performed. The offset of the second imaging means 13g is, for example, a structure in which the connecting portion 11x according to the description of FIG. 1 is a support means moving table, and the entire support means 11a is moved on a plane intersecting the turning axis A. This can be realized by driving the movable portion 130b by the imaging means moving means 13i according to the description of FIGS. 4 (a) and 4 (b). The locus for offset scan CT imaging can be variously modified.

  Here, the term “region of interest” means a region of interest that falls within a range that can be imaged by CT imaging and that is to be reconstructed. On the other hand, the term “region of interest” is used for a region that is pathologically interested.

  According to such a definition, the sizes of the “region of interest” and the “region of interest” may match, but may not match. The “region of interest” is large, and the “region of interest” may be a part of the “region of interest” that is particularly desired to be photographed, or the “region of interest” is small and there is room in the “region of interest”. In some cases, it will be completely accommodated.

9A (a) and 9 (b) are a side view of the X-ray cone beam CB and the region of interest R as seen from a direction orthogonal to the turning axis A, and a plan view as seen from a direction parallel to the turning axis A, respectively. FIG. 9A (c) is a cross-sectional view taken along the turning axis A of the region of interest R obtained by CT imaging. The cross section orthogonal to the irradiation direction of the X-ray cone beam CB is square, and the upper and lower sides of the square are perpendicular to the direction parallel to the turning axis A when viewed from the irradiation direction of the X-ray cone beam CB. In some cases, as shown in FIGS. 9A (a) and (b), the region of interest R is defined by the extent (solid angle) of the X-ray cone beam CB, and strictly speaking, it is not a cylindrical shape, It has a hexagonal cross section with conical portions above and below. Therefore, if the region designated by the cursor R ′ in the designation of the region of interest by the panoramic image of FIG. 8 is made to correspond to, for example, the double hatched region inside the region of interest R shown in FIG. 9A (c), CT imaging is performed to ensure that the region is included.
Strictly as described above, unless otherwise required, in the application, the X-ray cone beam CB in the region of interest R is shown in a cylindrical shape.

  FIG. 10 is a schematic enlarged view for explaining a state of the region of interest R during transmission image capturing. This figure shows the state at the time of normal CT imaging, and the extension line of the turning axis A passes through the center of the cylindrical body of the region of interest R. The X-ray beam B is regulated by the slit 12d # 3 of the slit plate 12c to become an X-ray cone beam CB, and a transmission image including the entire region of interest R is projected on the second imaging means 13g. Note that the X-ray generation unit 12 and the X-ray detection unit 13 move synchronously along a turning trajectory having the turning axis A as the turning axis of the optical system.

  7 and 10 are examples in which the first imaging unit 13f is set on the same imaging plane as the second imaging unit 13g as shown in FIG. As in b), the first imaging means 13f and the second imaging means 13g may be provided as separate imaging surfaces.

  FIG. 11 is an example of a CT image that is the second X-ray image IM2 displayed on the display unit 14 after the transmission image capturing of the region of interest R is completed. Here, the X, Y, and Z directions are orthogonal to each other. The Z direction may be set to coincide with the turning axis A, but is not limited thereto, and an arbitrary angle can be set. The X, Y, and Z planes are planes orthogonal to the X, Y, and Z directions, respectively, and these planes are applied as cross sections of the region of interest R, and a tomographic plane image in each cross section is displayed. Has been. The region of interest R can be arbitrarily rotated and moved with respect to this orthogonal cross section, and the corresponding tomographic plane image is reconstructed from the transmission image captured in the main imaging step accordingly. It has become.

  FIG. 11A is a diagram for more specifically explaining the display of the tomographic plane image of FIG. 11, and the region of interest R in this figure is a part of the dentition different from the region of interest R of FIG. In this figure, IX, IY, and IZ are the tomographic plane image on the X plane, the tomographic plane image on the Y plane, and the tomographic plane on the Z plane of the region of interest R displayed on the screen 14s of the display unit 14, respectively. It is a surface image.

  cx, cy, and cz are X cursors that are projection lines of the X, Y, and Z planes from which the X tomographic plane image IX, the Y tomographic plane image IY, and the Z tomographic plane image IZ are cut out to the other planes. , Y cursor and Z cursor.

  The X cursor cx is displayed on the Y tomographic plane image IY and the Z tomographic plane image IZ as a projection line of the X plane from which the X tomographic plane image IX is cut out. The Y cursor cy is displayed as a Y plane projection line from which the Y tomographic plane image IY is cut out in the X tomographic plane image IX and the Z tomographic plane image IZ. The Z cursor cz is displayed on the X tomographic plane image IX and the Y tomographic plane image IY as a Z plane projection line from which the Z tomographic plane image IZ is cut out.

  That is, the X cursor cx displayed in the Y tomographic plane image IY and the Z tomographic plane image IZ is the position of the X plane, the Y cursor cy displayed in the X tomographic plane image IX and the Z tomographic plane image IZ is the position of the Y plane, The Z cursor cz displayed in the X tomographic plane image IX and the Y tomographic plane image IY indicates the position of the Z plane.

  P is an arbitrary point in the region of interest R. Here, paying attention to this point P, each tomographic plane image including this point P is displayed.

  In these drawings, a Z tomographic plane image IZ, a Y tomographic plane image IY, and an X tomographic plane image IX including an arbitrary point P are arranged and displayed as in a normal plan view, front view, and side view, Since the tomographic image obtained by viewing any one point from the top, front, and side is displayed in comparison, the relative relationship between the three X, Y, and Z tomographic images is intuitive. Easy to understand.

  FIG. 11B (a) is a conceptual diagram showing cutout of a tomographic plane image in the present invention, and (b) is a conceptual diagram of display by the cutout. If three-dimensional CT data is obtained for each point constituting the region of interest R in FIG. 11B (a), when the xyz coordinate system is set for the region of interest R as shown in the figure, the xyz coordinate system The voxel value V (x, y, z) of the point (x, y, z) is determined.

  Here, to cut out an X tomographic plane image with respect to a plane perpendicular to the X direction, that is, the X plane, an x coordinate (x = xm) is determined, and a voxel value V on the X tomographic plane having the x coordinate is determined. (Xm, y, z) may be arranged in a two-dimensional plane. The X tomographic plane image thus obtained is described as X (y, z) xm.

  In this way, X (y, z) x0, X (y, z) x1,..., X (y, z) xm, X (y, z) xm + 1, X (y, z) xm + 2, X ( y, z) xm + 3,..., X (y, z) xn is obtained. X (y, z) x0... X (y, z) xn may all be obtained in advance, or may be obtained every time the x coordinate is determined.

  Similarly, a Y plane image, Y (z, x) y0, Y (z, x) y1,..., Y (z, x) ym with respect to a plane perpendicular to the Y direction, that is, the Y plane. Y (z, x) ym + 1, Y (z, x) ym + 2, Y (z, x) ym + 3,..., Y (z, x) yn, and a plane perpendicular to the Z direction, that is, Z tomographic image, Z (x, y) z0, Z (x, y) z1,..., Z (x, y) zm, Z (x, y) zm + 1, Z (x, y) zm + 2, Z (x, y) zm + 3,..., Z (x, y) zn are obtained.

  11B (b) shows an outline of a screen in which an X, Y, Z tomographic plane image including an arbitrary point P in the region of interest R is cut out and displayed together with the X cursor cx, Y cursor cy, Z cursor cz. A specific example is shown in FIG. 11A.

  For example, in the Y tomographic plane image IY of FIG. 11A, when the Z cursor cz is operated with a mouse or the like, pressed and held, and moved downward, the Z cursor cz of the X tomographic plane image IX is also moved accordingly. The image processing is performed so that the Z tomographic plane image IZ cut in the Z plane defined by the Z cursor cz is displayed in synchronization. Such display while moving the cursor is also possible for the Y tomographic plane image IY and the X tomographic plane image IX.

  In addition, on the screen in which the array is displayed, the X cursor cx indicating the position of the X tomographic plane, the Y cursor cy indicating the position of the Y tomographic plane, and the Z cursor cz indicating the position of the Z tomographic plane can be selected with the mouse. Since the tomographic plane image corresponding to the moved cursor is displayed in accordance with the movement, it is easy to find the optimum tomographic plane image desired by the operator.

  The second X-ray image IM2 may be displayed on the display unit 14 or may be displayed on the apparatus main body side display unit 16ds. Of course, you may display on both the display part 14 and the apparatus main body side display part 16ds.

Also, instead of one by one moves the cursor as described above, Z sectional image IZ, Y sectional image IY, X cursor cx you are orthogonal each X sectional image IX and a Y cursor cy, Z cursor By holding and moving the intersection of cz and X cursor cx, Y cursor cy and Z cursor cz (corresponding to symbol P in the figure), these two cursors are moved at the same time. You may make it each display the tomographic plane image cut out beforehand about two corresponding tomographic planes. In this case, since the display of the two tomographic plane images changes at the same time, the usability is improved.

  The setting of the region of interest R on the panoramic image need not be limited to one place at a time, and a plurality of places may be designated. In this case, it is possible to configure such that CT imaging at a plurality of designated locations is continuously performed in a desired order. Further, the setting of the region of interest R and CT imaging may be linked. That is, as described above, in the configuration in which the CT mode is automatically selected when the region of interest R is designated on the CRT 14d on which the panoramic image is displayed, not only the CT mode but also the CT mode is selected. You may make it progress to execution of imaging | photography.

  The region of interest R is not necessarily specified in a state where the patient who is the subject o is fixed to the subject holding means 11c after the panoramic photographing is completed. That is, as long as the reproducibility of the subject holding state is maintained, the patient is once released from the subject holding means, and at another opportunity, the patient is again fixed to the subject holding means 11c at the same position as when panoramic photography is completed, and the video memory The panoramic image recorded in 14a may be called to specify the region of interest R as described above. In this case, identification information is set for each patient, the subject holding state is detected by a detecting means such as a potentiometer, and stored in a separate storage unit in association with the identification information. The subject holding state associated with the identification information may be called, or the subject holding unit 11c may be automatically driven to reproduce the subject holding state.

  FIG. 12 is an external view for specifically explaining another configuration of the apparatus M. FIG. According to this configuration, the apparatus M includes the X-ray imaging apparatus main body M1 and the electronic computer 16A as in the apparatus M of FIG. 2. The X-ray imaging apparatus main body M1 includes the X-ray generation unit 12 and the X-ray detection unit 13. And moving means 11 for moving.

  The main body M1 (X-ray imaging apparatus main body M1) of the apparatus M in FIG. 12 is surrounded by a rectangular parallelepiped X-ray chamber 100 composed of a panel 100a made of a material that blocks X-rays. A part of the panel 100a is provided with an entrance / exit door 100b made of a material that shields X-rays. The panel 100a may be composed of six peripheral four sides, a floor and a ceiling, may be composed of five peripheral four sides and a ceiling, or may be composed of only four peripheral sides. With the configuration of six sheets, X-rays can be shielded more efficiently when the X-ray imaging apparatus main body M1 is completely surrounded. However, it is not always necessary to form the periphery in a quadrangle, and it may be composed of three or more arbitrary polygons, or the whole may be composed of a panel 100a having an arbitrary shape such as a cylinder or a sphere. Needless to say, the X-ray chamber 100 can be used not only for the apparatus M shown in FIG. 12 but also for the apparatus M shown in FIGS.

  In addition to an operation panel 16h that receives operation inputs, the apparatus M includes a control box 150 that includes a deadman-type emission switch (X-ray imaging start switch) 151 that is operated by being held by a hand. In the illustrated example, it is provided on the outer wall surface of the X-ray imaging apparatus body 100 around the X-ray imaging apparatus main body M1.

  The control box 150 is easy to operate if it is provided approximately at the eye level of the operator's eyes on the panel 100a of the X-ray room 100. However, the position of the control box 150 may be outside the X-ray room 100. There is no need to be in contact with the wall. For example, a dedicated stand or pole may be raised outside the X-ray chamber 100 at a location separated from the panel 100a and provided at the tip of the stand. The surgeon performs X-ray irradiation by operating the emission switch 151 from outside the X-ray room 100.

In addition, the control box 150 may be provided in a place away from the X-ray imaging apparatus body M1 without installing the X-ray room 100. For example, if the control box 150 is provided in a room or the like where the X-ray imaging apparatus main body M1 is not installed, there is no possibility that the operator will be adversely affected by X-rays generated by the X-ray imaging apparatus main body M1, Safer.

  Then, as shown in FIG. 12A, the control box 150 includes a lamp 154 that lights up the X-ray irradiation state, a lamp 155 that lights up that the support means 11a is set at the imaging start position, and the power switch is on. A lamp 156 is provided for lighting up the display.

  The moving unit 11 includes a support unit 11a to which the X-ray generation unit 12 and the X-ray detection unit 13 are fixed, a storage frame 11f that suspends and supports the support unit 11a by a swing axis A, and the storage frame 11f. And a main body frame 11b which is a fixed portion with respect to. Note that a hollow shaft is used as the turning shaft A, and the cables to the X-ray generation unit 12 and the X-ray detection unit 13 are disposed and protected therein, thereby improving the aesthetics of the apparatus. The housing frame 11f is guided up and down by the main body frame 11b, and moves the support means 11a up and down in a direction parallel to the axial direction of the turning axis A.

As will be described later, as shown in FIGS. 13 and 14 (a), the housing frame 11f allows the X- axis table 11g to which the turning axis A is fixed to be two-dimensionally controlled by the Y-axis control motor 11h and the X-axis control motor 11i. An XY table 11e that controls the position by two-dimensional control on a plane that intersects the turning axis A is built in the upper part, and an operation panel 16h that includes an indicator lamp and an operation switch is provided on the side surface as shown in FIG. The control means 16 having the configuration described in FIG. 1 is stored inside. The main body frame 11b is attached with subject holding means 11c for positioning the subject o.

  The main body frame 11b functions as an installation means 11n for installing the support means 11a on the floor or the ground via the housing frame 11f. The main body (X-ray imaging apparatus main body) M1 of the apparatus M includes at least the X-ray detection unit 13, The X-ray generator 12 includes a support unit 11a, an installation unit 11n, and a subject holding unit 11c.

  Similar to the apparatus M in FIG. 2, the apparatus main body side display unit 16ds may be provided on the operation panel 16h of the X-ray imaging apparatus main body M1 to display necessary information including an X-ray image. 14 and the apparatus main body side display unit 16ds may be displayed.

  The apparatus main body side display unit 16ds may be provided anywhere on the apparatus main body side. For example, if the apparatus main body side display unit 16ds is provided on at least one of the support unit 11a, the housing frame 11f, or the fixing unit 11b, the apparatus main body side display unit 16ds itself occupies. Convenient because it saves space.

  The operation unit 15 for designating the region of interest R is easy to operate if it is provided on the apparatus main body side, like the apparatus main body side display unit 16ds. The operation unit 15 may be provided anywhere on the apparatus main body side, but the vicinity of the apparatus main body side display unit 16ds is easy to operate and is particularly convenient.

  When the apparatus main body side display portion 16ds is provided in at least one of the support means 11a, the housing frame 11f, or the fixing portion 11b, it is particularly convenient to provide the operation portion 15 in the same place. The place where the operation unit 15 is provided is arbitrary, but can also be provided in the control box 150 as described later.

  In the example of FIGS. 12 and 12A, the control box 150 is also provided with a control box side display section 16ds ′. The control box side display unit 16ds ′ is an example of the display unit 14 like the apparatus main body side display unit 16ds, and can display a first X-ray image IM1 such as a panoramic image in order to designate the region of interest R. In addition to the X-ray image, other necessary information may be displayed. Of course, the second X-ray image 2 such as a CT image may be displayed.

  The surgeon moves the cursor or pointer on the first X-ray image IM1 displayed on the control box side display unit 16ds ′ by operating the touch pen 152 or the membrane type mouse 153, for example, to thereby display the region of interest R. specify. In this case, the touch pen 152 or the membrane type mouse 153 constitutes the operation unit 15.

  The membrane-type mouse 153 has a well-known configuration in a notebook personal computer, and includes a membrane-type finger operation unit 154, a left click button 155, and a right click button 156. The surface of the finger operation unit 154 is touched with a finger. In this way, the cursor and pointer move on the control box side display section 16ds ′. The left click button 155 and the right click button 156 are interested when the cursor or pointer moves to a desired position on the first X-ray image IM1 such as a panoramic image displayed on the control box side display section 16ds ′. It can be used for a determination command and other commands when designating the region R as a region.

  The touch pen 152 or the membrane-type mouse 153 is one example of configuring the operation unit 15, but is not limited thereto. For example, as shown in FIG. 12A, on the control box side display section 16ds', an upper designation key (key to move up) 157 for moving the cursor and pointer up, down, left and right, a lower designation key (move down) (Key) 158, left designation key (key moved to the left) 159, and right designation key (key moved to the right) 160 may be arranged in a cross. Although not shown, a numeric keypad may be provided so that the area can be code-inputted.

  The region of interest region R may be specified by turning on the emission switch 151 without using the mouse 153. In this case, the emission switch 151 also constitutes the operation unit 15.

  The control box 150 may be provided with a switch (not shown) for switching between the CT mode and the panoramic imaging mode, but the setting of the region of interest R and the CT imaging may be linked. That is, the CT mode may be automatically selected when the region of interest R is designated.

  A chin rest on which the patient puts his / her chin is provided at the center of the subject holding means 11c. The chin rest can be moved up and down or tilted and positioned according to the patient's body shape. By configuring the chin rest to be movable in this way, for example, adjusting the tilt of the irradiation line with respect to the horizontal plane for each imaging part such as the upper jaw and the lower jaw can be achieved by adjusting the upper jaw joint and the lower jaw tip located below. As described above, it is also possible to adjust so that the site separated vertically is positioned in the center of the irradiation field.

  Here, the structure of the moving means 11 and the accommodation frame 11f is further demonstrated. The support means 11a moves relative to the main body frame 11b together with the housing frame 11f in accordance with the patient's physique. Accordingly, the X-ray generation unit 12 and the X-ray detection unit 13 provided integrally with the support unit 11a move with respect to the subject holding unit 11c together with the housing frame 11f.

  However, the housing frame 11f and the support means 11a may be separated from each other so that each moves independently with respect to the main body frame 11b. Further, the X-ray generation unit 12 and the X-ray detection unit 13 may move with respect to the housing frame 11f or the subject holding unit 11c. In the above-mentioned Patent Document 3 relating to the application of the present applicant, the X-ray generation unit 12 is compared with an example in which the housing frame 11f and the support unit 11a are separated from each other, or with respect to the housing frame 11f or the subject holding unit 11c. Discloses an example configured to move.

  In Patent Document 3, the portion corresponding to the housing frame 11f described above is referred to as a “patient frame” and the portion corresponding to the support means 11a is referred to as a “lifting body”. In addition, for example, the inclination of the irradiation line with respect to the horizontal plane is adjusted for each imaging region, so that the irradiation field can be successfully applied to a region separated vertically, such as a temporomandibular joint located above and a lower jaw tip located below. It is to adjust so that it is located in the center.

  A configuration in which the subject holding means 11c can be moved up and down or tilted, a configuration in which the housing frame 11f and the support means 11a are separated, and an X-ray generation unit 12 and an X-ray detection unit with respect to the housing frame 11f or the subject holding unit 11c. A more fine adjustment may be made by combining with the configuration in which the 13 moves.

  The X-ray generator 12 is based on the basic configuration shown in FIG. 2, and the X-ray generator 12a having a fixed anode and the X-ray beam B emitted from the X-ray tube 12a are converted into the first imaging means 13f. A slit 12d # 1 for restricting as an X-ray slit beam NB corresponding to the above, and a rectangular slit 12d # 2 for restricting as an X-ray wide-area beam for CT imaging corresponding to the second imaging means 13g, that is, an X-ray cone beam CB. , 12d # 3 and the like, and can selectively irradiate either the X-ray slit beam NB or the X-ray wide-area beam (X-ray cone beam CB). As the target structure, those shown in FIG. 3 and FIG. 3A (a) can be adopted as appropriate.

  FIG. 13 is a horizontal cross-sectional view seen from above for explaining the internal structure of the upper portion of the housing frame 11f holding the support means 11a. This figure shows the structure of the XY table 11e, and the Y-axis table 11j is moved in parallel with the Y-axis by rotating the rotating shaft connected to the Y-axis control motor 11h fixed to the receiving frame 11f. The X-axis table 11g is moved in parallel with the X-axis by rotating the rotating shaft connected to the X-axis control motor 11i fixed to the Y-axis table 11j.

FIG. 14 is a vertical cross-sectional view of the connecting portion between the upper portion of the housing frame 11f and the support means 11a as viewed from the side. The support means 11a is rotatably connected to the turning axis A by a ball bearing 11k, and the support means 11a rotates with respect to the turning axis A by driving by a turning control motor 11m fixed to the X-axis table 11g. It has become.
The turning control motor 11m is a specific example of the rotating means 11d.

  More specifically, the housing frame 11f includes a housing 11f1 and a beam 11f2 to which the housing is fixed. A Y-axis control motor 11h is fixed to the beam 11f2, and a screw is attached to the Y-axis control motor 11h. A Y drive shaft 11hy, which is an axis, is provided, and when the Y drive shaft 11hy rotates, the driven member 11ji threaded inside fixed to the Y axis table 11j is displaced in the y direction shown in the figure. Since the wheel 11y2 is provided on the Y-axis table 11j and the rail 11y1 for guiding the wheel 11y2 is provided on the beam 11f2, if the Y-axis control motor 11h is driven to rotate, the Y-axis table 11j becomes the rail 11y1. Move smoothly along.

  On the other hand, an X-axis control motor 11i is fixed to the Y-axis table 11j. The X-axis control motor 11i is provided with an X drive shaft 11ix that is a screw shaft. When the X drive shaft 11ix rotates, the X-axis table 11g A driven member 11gx threaded into the fixed interior is displaced in the x direction shown in the figure. Since the X-axis table 11g is provided with wheels 11x2, and the Y-axis table 11j is provided with rails 11x1 for guiding the wheels 11x2, if the X-axis control motor 11i is driven to rotate, the X-axis table 11g It moves smoothly along the rail 11x1.

  In the example of FIG. 14, a turning control motor 11m, which is a rotating means, is fixed to the X-axis table 11g, and a rotational force is transmitted to the rotating shaft A by a roller. Here, since the ball bearing 11k is interposed between the X table and the rotary shaft A, the rotational force of the turning control motor 11m is transmitted to the rotary shaft A with very little frictional resistance.

  FIG. 14A is an embodiment in which a turning control motor 11m is provided inside the supporting means 11a, unlike the embodiment of FIG. 14, and the rotational force is transmitted to the turning shaft A by a pulley and a belt. Is the same.

  For the XY table 11e, the techniques described in Japanese Patent Application Laid-Open Nos. 11-104123, 11-104124, and 11-104125, which are filed by the present applicant, can be applied as appropriate.

  Next, an embodiment of the second invention will be described with reference to the drawings. In the second embodiment, the configuration of the X-ray detection unit 13A is different from that of the first embodiment, but the other configuration is the same.

  FIG. 15 is a schematic block diagram for explaining the overall configuration of the apparatus M2 as the second embodiment. In this figure, the constituent elements other than the X-ray detection unit 13A are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  The X-ray detector 13A is equipped with an X-ray detector 13a, and is provided with an X-ray detector control circuit 13b for driving and controlling the X-ray detector 13a.

  16A and 16B are perspective views showing the basic configuration of the X-ray detection unit 13A and its modification. In any configuration, the X-ray detector 13a includes a first imaging unit 13f that extends in a direction parallel to the axial direction of the pivot axis A of the support unit, and a first imaging unit 13f used for X-ray CT imaging. The second imaging means 13g that is two-dimensionally widened is provided, but of the two X-ray detectors 13a in FIG. Only the image pickup means 13g can move up and down mechanically in the direction parallel to the axial direction of the turning axis A of the support means 11a by the image pickup means moving means 13i, whereas the two X-ray detections in FIG. In the modified configuration shown in the lower part of the figure, the first imaging means 13f and the second imaging means 13g are simultaneously provided in the X-ray detector 13a by the imaging means moving means 13i. You can also move horizontally There.

  Of the two X-ray detectors 13a shown in FIG. 16, the movable part 130d shown in the upper part of the figure to which the X-ray detector 13a shown in the upper part of the figure is attached is the movable part 130c shown in FIG. Since the structure is the same, the description will be omitted, but the X-ray shown in the lower part of the figure of the two X-ray detectors 13a in FIG. 16 for mounting the above-described modified configuration of the X-ray detector 13A. The movable portion 130e shown in the lower part of the figure, to which the detector 13a is attached, has an opening dimension of the secondary slit 13l that increases in accordance with the horizontal movement of the first imaging means 13f and the second imaging means 13g. Is different.

Here, FIG. 29A shows a specific structure of the X-ray detector 13a shown in the upper part of the figure among the two X-ray detectors 13a shown in FIG. . The X-ray detector 13a basically includes a substrate 13a1, a first imaging unit 13f, a second imaging unit 13g, and a second imaging unit 13a1, which are formed as a cassette that can be attached to and detached from the movable unit 130d that functions as a sensor holder. The image pickup means 13g is made up of an image pickup means moving means 13i for raising and lowering the position of the image pickup means 13g in the substrate 13a1, and the first image pickup means 13f is provided at substantially the center of the substrate 13a1, and the second image pickup means 13g is provided on the side thereof. It has been.

  The substrate 13a1 is provided with a rectangular opening 13a2 at the center, and the second imaging means 13g is formed in a size and shape that can move up and down in the opening 13a2. And the protrusion part 13g1 is provided in the left-right side surface of the 2nd imaging means 13g, and the ditch | groove 13a3 is drilled corresponding to the said protrusion part 13g1 in opening 13a2. For this reason, the protrusion 13g1 fits into the groove 13a3 and is guided up and down in a direction parallel to the axial direction of the rotation axis A.

  The second imaging means 13g is provided with a hole 13g2 threaded in the upper and lower sides, and an imaging means moving means 13i composed of a ball screw extending vertically passes through the hole 13g2 in a state of meshing with the threading. is doing. The imaging means moving means 13i is fixed to the edge of the opening 13a2 so as to be rotatable up and down, and is rotated by a motor 13i1 to raise and lower the second imaging means 13g.

  As shown in FIG. 29B, the specific structure of the X-ray detector 13a shown in the lower part of the figure among the two X-ray detectors 13a shown in FIG. It differs from the X-ray detector 13a shown in FIG.

  That is, the X-ray detector 13a shown in FIG. 29A is provided with the first imaging means 13f and the second imaging means 13g which is moved up and down by the imaging means moving means 13i on the substrate 13a1. The X-ray detector 13a shown in FIG. 29B is provided with a large opening 13a5 in the center of the substrate 13a1, and another substrate 13a4 is displaced in the same direction as the turning direction of the X-ray detection unit 13 inside the opening 13a5. To do. The substrate 13a4 is provided with a first imaging means 13f and a second imaging means 13g. The lifting mechanism of the second imaging means 13g is the same as that shown in FIG.

  Here, the substrate 13a1 is provided with a rectangular opening 13a5 at the center, and the substrate 13a4 is formed in a size and shape that can move horizontally within the opening 13a5. And the protrusion part 13a6 is provided in the up-and-down side surface of the board | substrate 13a4, and the ditch | groove 13a7 is drilled in the opening 13a5 corresponding to the said protrusion part 13a6. For this reason, the protruding portion 13g6 fits into the concave groove 13a7 and is displaced and guided in substantially the same direction as the turning direction of the X-ray detection portion 13.

  The board 13a4 is provided with a hole 13a8 threaded on the inside so as to penetrate left and right, and a board moving means 13x made of a ball screw extending to the left and right passes through the hole 13a8 in a state of meshing with the threading. The substrate moving means 13x is fixed to the edge of the opening 13a5 so as to be rotatable left and right, and is rotationally driven by a motor 13x1 to displace the second imaging means 13g.

  Next, the basic operation of the device M2 will be described. The control means 16 of the apparatus M2 is the same as the control of the apparatus M. In summary, the first X-ray image acquired by scanning and photographing the subject o over a wide range by the first imaging means 13f is displayed on the display unit 14. By operating the operation unit 15, the region of interest R is designated on the first X-ray image displayed on the display unit 14, and a second X-ray image that is a CT image of the designated region of interest R is acquired. Therefore, the position control of the irradiation field changing means 12b, the position control of the second imaging means 13g, the position control of the support means 11a and / or the subject holding means 11c, that is, the control of the moving means 11 as a whole is performed. As a second X-ray image, a basic operation for controlling imaging of a CT image is performed.

  FIG. 17 is a flowchart showing a control procedure by the control means 16 for performing the basic operation. According to this flowchart, as in the apparatus M of the first embodiment, the control unit 16 first executes an arrangement step (step 201) for arranging the subject o at the reference position, and uses the first photographing unit 13f. A preliminary photographing step (steps 202 to 206) for scanning and photographing the object o is executed.

  FIG. 18 is a schematic partial enlarged view for explaining a state during scanning photographing of the subject o. In this figure, the extension line of the pivot axis A passes through the central portion of the patient's dentition depicted as the subject o. The X-ray beam B is regulated by the slit 12c # 1 of the slit plate 12c to become an X-ray slit beam NB, and an elongated transmission image of the dentition is projected on the first imaging means 13f. Note that the trajectories of the X-ray generator 12 and the X-ray detector 13A at this time are the same as those in the first embodiment. Steps 201 to 207 are the same as steps 101 to 107 shown in FIG.

  Next, a panoramic image is displayed on the display unit 14 (step 208), and the region of interest R is specified for the subject o and the second X-ray image type is selected by operating the cursor on the display screen of the operation unit 15 (step 208). Steps 209) to be received are executed (steps 207 to 209).

  Thereafter, when an imaging command for the second X-ray image is received from the keyboard of the operation unit 15 or the operation panel 16h (step 210), the position of the designated region of interest R is calculated (step 211), and the second If the type of the X-ray image is determined (step 212) and the type of the second X-ray image is normal CT imaging, the normal CT imaging is used as the locus of the X-ray beam (X-ray cone beam CB). Select (step 213), move the support means 11a and position it on a plane intersecting the turning axis of the optical system (step 214), slide the X-ray detector 13a forward or backward in the turning direction, and The second X imaging unit is positioned so that the generation unit 12, the region of interest R, and the second imaging unit 13g are in series (step 215), while the type of the second X-ray image is the offset scan. In the case of CT imaging, offset scanning CT imaging is selected as the trajectory of the X-ray beam (X-ray cone beam CB) (step 216), and the support means 11a is moved so as to be on the plane intersecting the pivot axis of the optical system. (Step 217), the X-ray detector 13a is slid forward or backward in the turning direction by a distance different from that in the case of normal CT imaging, and the second X-ray imaging means is connected to the X-ray generation unit 12. The position of the region of interest R is offset (step 218), and then the position of the region of interest R is determined (step 219). If the region of interest R is higher than the reference position, the irradiation field is changed. The slit 12d # 3 of the means 12b is selected (step 220), and the second image pickup means 13g is mechanically raised parallel to the optical axis of the optical system so as to be parallel to the optical axis of the optical system. On the other hand, if the position of the region of interest R is lower than the reference position, the slit 12d # 2 of the irradiation field changing unit 12b is selected (step 222), and the second imaging unit 13g is turned by the optical system. The imaging position adjustment step (steps 210 to 223) is executed by mechanically lowering the axis parallel to the axis and positioning it in the direction parallel to the turning axis of the optical system (step 223).

  Next, similarly to the apparatus M of the first embodiment, based on the positioning in the imaging position adjustment step, a transmission image of the region of interest R is imaged for each predetermined turning angle (step 224), and CT for a desired cross section of the region of interest R is performed. An image is reconstructed (step 225), and a main photographing step (steps 224 and 225) is executed.

  FIG. 19 is a schematic partially enlarged view for explaining a state of the region of interest R during transmission image capturing. This figure corresponds to the state at the time of normal CT imaging, and the extension line of the turning axis A passes through the center of the cylindrical body of the region of interest R. Further, the X-ray beam B is regulated by the slit 12c # 3 of the slit plate 12c, becomes an X-ray cone beam CB, and a transmission image including the entire cylindrical body of the region of interest R is mechanically processed by the imaging unit moving unit 13i. Is projected onto the second image pickup means 13g aligned with. Here, the trajectories of the X-ray generator 12 and the X-ray detector 13A are the same as those in the first embodiment.

[Reference example]
Next, reference examples will be described with reference to the drawings. In this reference example , the configuration of the X-ray generation unit 12A and the configuration of the X-ray detection unit 13B are different from those of the first embodiment, but the other parts are configured in common.

Figure 20 is a schematic block diagram illustrating the overall configuration of the apparatus M3. In this figure, the same reference numerals as those of the apparatus M described as the first embodiment are assigned to the same components as those of the first embodiment except for the X-ray generation unit 12A and the X-ray detection unit 13B, and the description thereof is omitted. To do.

  The X-ray generator 12A includes an X-ray generator 12a that irradiates the X-ray beam B, and an irradiation field changing unit 12b that controls the shape of the X-ray beam B using a slit.

  An X-ray detector 13a is mounted on the X-ray detector 13B, and an X-ray detector control circuit 13b for driving and controlling the X-ray detector 13a is provided.

  FIG. 21 is a principle view for more specifically explaining the basic configuration of the X-ray generator 12A. In this example, a slit plate 12c constituting the irradiation field changing means 12b is arranged in front of the irradiation direction of the X-ray generator 12a that irradiates the X-ray beam B from the X-ray tube 12g, and this slit plate 12c is not shown. The actuator can slide left and right. The slit plate 12c is formed with a slit 12d # 1 having a shape corresponding to the first imaging means 13f and a slit 12d # 2 corresponding to the second imaging means 13g. On the other hand, the spread of the X-ray beam B is regulated by sliding in the lateral direction. In the figure, the X-ray beam B is regulated by the slit 12d # 2, and the X-ray cone beam CB corresponding to the second imaging means 13g is irradiated from the X-ray generator 12A. .

  FIG. 22 is a perspective view showing a basic configuration of the X-ray detection unit 13B. As shown in this figure, the X-ray detector 13a basically includes a substrate 13a1, a first image pickup means 13f, and a second image pickup formed as a cassette that can be attached to and detached from a movable portion 130d that functions as a sensor holder. It consists of means 13g. The X-ray detector 13a includes a first imaging unit 13f extending in a direction parallel to the axial direction of the pivot axis of the support unit, and a second imaging unit 13g having a two-dimensional extension used for X-ray CT imaging. Are configured as a single image sensor 13e. The image sensor 13e may be formed as a single image pickup surface or may be formed by bringing a plurality of image pickup surfaces into close contact, but the latter is advantageous in terms of cost. Further, the shape in which the first image pickup means 13f and the second image pickup means 13g are connected is not particularly limited.

  The movable part 130f to which the X-ray detector 13a shown in FIG. 22 is attached has the same structure as the movable part 130b in FIG.

  Next, the basic operation of the device M3 will be described. The control means 16 of the apparatus M3 is substantially the same as the control of the apparatus M. In summary, the first X-ray image obtained by scanning and photographing the subject o over a wide range by the first imaging means 13f is displayed on the display unit 14. Then, by operating the operation unit 15, the region of interest R is designated on the first X-ray image displayed on the display unit 14, and a second X-ray image that is a CT image of the designated region of interest R is acquired. Therefore, the position control of the irradiation field changing unit 12b and the position control of the support unit 11a and / or the subject holding unit 11c, that is, the control of the moving unit 11 as a whole are performed, and the CT image is obtained as the second X-ray image. Basic operation to control shooting.

  FIG. 23 is a flowchart showing a control procedure by the control means 17 for performing the basic operation. According to this flowchart, as in the apparatus M of the first embodiment, the control unit 17 executes an arrangement step (step 301) in which the subject o is arranged at the reference position, and performs scanning imaging using the first imaging unit 13f. A preliminary photographing step (steps 302 to 306) is performed.

  FIG. 24 is a schematic partial enlarged view for explaining a state during scanning photographing of the subject o. In this figure, the extension line of the pivot axis A passes through the central portion of the patient's dentition depicted as the subject o. The X-ray beam B is regulated by the slit 12d # 1 of the slit plate 12c to become an X-ray slit beam NB, and an elongated transmission image of the dentition is projected on the first imaging means 13f. The trajectories of the X-ray generation unit 12A and the X-ray detection unit 13B are the same as those in the first embodiment.

  Next, the panoramic image is displayed on the display unit 14 (step 308), and the region of interest R is specified for the subject o and the second X-ray image type is selected by operating the cursor on the display screen of the operation unit 15 (step 308). The region of interest designation step (steps 307 to 309) for receiving step 309) is executed. Steps 301 to 307 are the same as steps 101 to 107 shown in FIG.

  Thereafter, when an imaging command for the second X-ray image is received from the keyboard of the operation unit 15 or the operation panel 16 (step 310), the position of the designated region of interest R is calculated (step 311). If the type of the second X-ray image is determined (step 312) and the type of the second X-ray image is normal CT imaging, normal CT imaging is performed as the locus of the X-ray beam (X-ray cone beam CB). (Step 313), the support means 11a is moved and positioned on the plane intersecting the pivot axis of the optical system (step 314), while the type of the second X-ray image is offset scan CT imaging. For example, offset scanning CT imaging is selected as the trajectory of the X-ray beam (X-ray cone beam CB) (step 315), and the support means 11a is moved so as to intersect the rotation axis of the optical system. (Step 316), and the X-ray detector 13a is slid forward or backward in the turning direction so as to be offset with respect to the X-ray generator 12 and the region of interest R (step 317). The position of the region of interest R is determined (step 318), and if the position of the region of interest R is higher than the reference position, the slit 12d # 2 of the irradiation field changing unit 12b is selected (step 319), and the support unit 11a is turned on. The ascending / descending and / or subject holding means 11c is lowered and positioned in a direction parallel to the pivot axis of the optical system (step 320). On the other hand, if the position of the region of interest R is lower than the reference position, the slit 12d # 2 of the irradiation field changing unit 12b is selected (step 321), and the support unit 11a is lowered and / or the subject holding unit 11c is raised to optically. It is positioned in a direction parallel to the turning axis of the system (step 322), and an imaging position adjustment step is executed (steps 310 to 322).

  Thereafter, similarly to the apparatus M of the first embodiment, based on the positioning in the imaging position adjustment step, a transmission image is taken at every predetermined turning angle (step 323), and a CT image for a desired cross section of the region of interest R is reconstructed. (Step 324) The main photographing step (Steps 323 and 324) is executed.

  FIG. 25 is a schematic partially enlarged view for explaining a state of the region of interest R during transmission image capturing. In this figure, the state at the time of normal CT imaging is shown, and the extension line of the turning axis A passes through the center of the cylindrical body of the region of interest R. Further, the X-ray beam B is regulated by the slit 12d # 2 of the slit plate 12c to become an X-ray cone beam CB, and a transmission image including the entire cylindrical body of the region of interest R is positioned in the second imaging unit. 13g is projected. The trajectories of the X-ray generation unit 12A and the X-ray detection unit 13B are the same as those in the first embodiment.

  In the above, an example of CT imaging has been described as imaging of the second X-ray image, but planar tomography can be performed in addition to CT imaging. Although not shown, planar tomography is a well-known imaging, for example, an X-ray generation unit 12 and an X-ray detection unit with a specific plane tomography that is a region of interest existing in a direction orthogonal to the dental arch o ′. The detection surfaces of the thirteen image sensors 13e are made to face each other, a moving center axis is set at the center of the plane tomography, and the images are moved in opposite directions while maintaining the facing state. The movement may be linear movement or arc movement. In this embodiment, using the turning of the support means 11a, the turning axis A is used as the movement center axis, and the X-ray generation unit 12 and the detection surface of the image sensor 13e of the X-ray detection unit 13 are moved in an arc. An X-ray image (planar tomographic image) of the planar tomography can be obtained. The detection surface of the image sensor 13e can use the second imaging means 13g.

  In this case, a rotation mechanism (not shown) is interposed between the image sensor 13e and the support means 11a so that the detection surface of the image sensor 13e is kept parallel to the plane slice. The planar tomographic image that is the X-ray image of the specific tomography is also an example of the second X-ray image. By specifying the region of interest on the displayed first X-ray image, This is one example where coordinates of a three-dimensional position can be specified.

The schematic block diagram explaining the whole structure of the medical X-ray imaging apparatus to which 1st invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a medical X-ray imaging apparatus to which 1st invention is applied, (a) is the external view seen from the front, (b) is the external view seen from the side. The principle figure explaining the basic composition of a X-ray generation part. It is a figure which shows the specific structure of an X-ray generation part, (a) is sectional drawing, (b) is a fragmentary perspective view. The figure which shows the example by which the irradiation field of a X-ray cone beam is changed correspondingly when the slit plate of an X-ray generation part is displaced from (a) to (b). The figure which shows the other example by which the irradiation field of a X-ray cone beam is changed correspondingly when the slit board of an X-ray generation part is displaced from (a) to (b). It is a figure explaining two kinds of basic composition of an X-ray detection part, (a) is a perspective view and (b) is a sectional view. The flowchart explaining the control procedure of the basic operation | movement of a medical X-ray imaging apparatus. The top view explaining the track | orbit of an X-ray generation part and an X-ray detection part. The typical enlarged view explaining the state at the time of the 1st X-ray image imaging | photography. A panoramic image that explains how to specify a region of interest. It is a top view explaining the locus | trajectory of an X-ray beam (X-ray cone beam), (a) shows normal CT imaging, (b) shows offset scan CT imaging. (A), (b) is the top view which respectively looked at the X-ray cone beam and the region of interest from the direction orthogonal to the turning axis and the direction parallel to the turning axis, and (c) is a CT image. It is sectional drawing cut | disconnected along the turning axis | shaft of the region of interest R. The typical enlarged view explaining the state at the time of 2nd X-ray image imaging | photography. An example of a CT image of a region of interest. The figure which demonstrates the example of the CT image of FIG. 11 more concretely. (A) is a conceptual diagram which shows the cutout of a tomographic plane image, (b) is a conceptual diagram of the display by the cutout. The perspective view explaining the whole structure of the medical X-ray imaging apparatus to which 2nd invention is applied. The front view of the control box of the medical X-ray imaging apparatus shown in FIG. The horizontal sectional view seen from the upper direction explaining the internal structure of the accommodating frame which suspends and hold | maintains a support means. The longitudinal cross-sectional view which looked at the example of the connection part of an accommodation frame and a support means from the side. The longitudinal cross-sectional view which looked at the other example of the connection part of an accommodation frame and a support means from the side. The schematic block diagram explaining the whole structure of the medical X-ray imaging apparatus to which 2nd invention is applied. The perspective view explaining the basic composition of an X-ray detection part, and its deformation | transformation, respectively. The flowchart explaining the control procedure of the basic operation | movement of a medical X-ray imaging apparatus. The typical enlarged view explaining the state at the time of the 1st X-ray image imaging | photography. The typical enlarged view explaining the state at the time of 2nd X-ray image imaging | photography. The schematic block diagram explaining the whole structure of the medical X-ray imaging in a reference example . The principle figure explaining the basic composition of a X-ray generation part. The perspective view explaining the basic composition of an X-ray detection part. The flowchart explaining the control procedure of the basic operation | movement of a medical X-ray imaging apparatus. The typical enlarged view explaining the state at the time of the 1st X-ray image imaging | photography. The typical enlarged view explaining the state at the time of 2nd X-ray image imaging | photography. (A), (b) is a figure explaining the example of a respectively different shape of a 1st imaging means and a 2nd imaging means. The fragmentary perspective view which shows another Example of the two-dimensional movement control of a support means. The top view explaining the envelope which the locus | trajectory of a X-ray beam (X-ray slit beam) draws. (A), (b) is a perspective view which shows the example from which each X-ray detector which concerns on 2nd invention differs. It is a top view which shows 1st X-ray image imaging | photography, (a) is a case where a linear scan is performed, (b) is a case where head X-ray standard photography (cephalometric imaging) is performed. (A), (b), (c) is a respectively different principle figure of the modification of the X-ray generation part shown to Fig.3A (a). It is sectional drawing of the further different modification of the X-ray generation part shown to FIG. 3A. It is sectional drawing of the further different modification of the X-ray generation part shown to FIG. 3A. It is sectional drawing of the further different modification of the X-ray generation part shown to FIG. 3A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Moving means 11a Support means 11c Subject holding means 12 X-ray generator 12a X-ray generator 12b Irradiation field changing means 13 X-ray detector 13a X-ray detector 13f First imaging means 13g Second imaging means 13i Imaging means Moving unit 14 Display unit 15 Operation unit 16 Control unit 16A Computer 100 X-ray proof room 150 Control box A Swing axis B X-ray beam CB X-ray cone beam IM1 First X-ray image IM2 Second X-ray image M, M2, M3 Medical X-ray equipment NB X-ray slit beam R Region of interest o Subject M1 X-ray equipment body

Claims (15)

An X-ray generation unit and an X-ray detection unit supported opposite to each other by a supporting unit, and a moving unit that moves the supporting unit relative to a subject held by the subject holding unit, and operates the moving unit. in medical X-ray imaging apparatus for capturing an X-ray image of the object Te,
The support means is pivotable by the moving means;
An X-ray detector provided with a first imaging means extending in a direction parallel to the axial direction of the pivot axis of the support means, and a second imaging means used for X-ray CT imaging,
An X-ray generator for irradiating the X-ray beam; and a slit for changing the shape of the X-ray beam corresponding to each of the first imaging means and the second imaging means, and the second imaging and to means, and X-ray generator which includes an irradiation field changing means for changing the position of the radiation field by elevating the slit in a direction parallel to the axial direction of at least the pivot axis,
A display unit for displaying a first X-ray image acquired by the first imaging means;
An operation unit for designating a region of interest on the first X-ray image displayed on the display unit;
In order to acquire a second X-ray image that is a CT image of a region of interest designated by the operation unit, the image processing apparatus includes a control unit that controls the irradiation field changing unit and the moving unit. A medical X-ray imaging apparatus characterized by the above. In claim 1,
The irradiation field changing means has first and second slits corresponding to each of the first imaging means and the second imaging means, and a plurality of the second slits are configured. Medical X-ray equipment. In claim 1,
The irradiation field changing means has first and second slits corresponding to each of the first imaging means and the second imaging means, and the number of the second slits is one. A medical X-ray imaging apparatus configured to be controlled to be movable up and down. In claim 1,
The irradiation field changing means has first and second slits corresponding to each of the first imaging means and the second imaging means,
These first and second slits are configured by moving two slit plates each formed with a slit and overlapping the slits formed in the two slit plates. Medical X-ray imaging device. An X-ray generation unit and an X-ray detection unit supported opposite to each other by a supporting unit, and a moving unit that moves the supporting unit relative to a subject held by the subject holding unit, and operates the moving unit. In a medical X-ray imaging apparatus that captures an X-ray image of a subject,
The support means is pivotable by the moving means;
First imaging means extending in a direction parallel to the axial direction of the pivot axis of the support means and second imaging means used for X-ray CT imaging are individually provided, and the second imaging means is at least the An X-ray detector comprising an imaging means moving means for moving in a direction parallel to the axial direction of the pivot axis;
An X-ray generator for irradiating an X-ray beam, a shape of the X-ray beam is changed corresponding to each of the first imaging unit and the second imaging unit, and with respect to the second imaging unit, An X-ray generator comprising irradiation field changing means for changing the irradiation field at least in a direction parallel to the axial direction of the pivot axis;
A display unit for displaying a first X-ray image acquired by the first imaging means;
An operation unit for designating a region of interest on the first X-ray image displayed on the display unit;
In order to obtain a second X-ray image that is a CT image of the region of interest designated by the operation unit, the control of the imaging means moving means, the control of the irradiation field changing means, and the control of the moving means, And a medical X-ray imaging apparatus. Wherein a first X-ray image, the panoramic image, cephalometric image, the linear scanned image of the medical X-ray imaging apparatus according to any one of claims 1 to 4, characterized by capturing at least one. The medical device according to claim 6 , wherein the moving unit moves the X-ray generation unit and the X-ray detection unit along a panoramic X-ray imaging trajectory when imaging a panoramic image. X-ray imaging device. The medical X-ray according to any one of claims 1 to 7 , wherein the control of the moving means is two-dimensional two-dimensional control defined on a plane intersecting with the axial direction of the pivot axis. Shooting device. 2. The control of the moving means is three-dimensional control in two directions defined on a plane intersecting with the axial direction of the pivot axis and one direction parallel to the axial direction of the pivot axis. 8. A medical X-ray imaging apparatus according to any one of 1 to 7 . By offsetting the second imaging means forward or backward in the turning direction of the X-ray detection unit, the entire region of interest is projected while always projecting a part of the designated region of interest, and the X of the region of interest is medical X-ray imaging apparatus according to claim 1, characterized in that the line CT imaging 9. An X-ray generation unit and an X-ray detection unit supported opposite to each other by a supporting unit, and a moving unit that moves the supporting unit relative to a subject held by the subject holding unit, and operates the moving unit. in medical X-ray imaging apparatus for capturing an X-ray image of the object Te,
The support means is pivotable by the moving means;
A first imaging means extending in a direction parallel to the axial direction of the pivot axis of the support means and a second imaging means used for X-ray CT imaging are partially on a single detection surface of the image sensor. An X-ray detector set together so that the regions of
An X-ray generator for irradiating the X-ray beam; and a slit for changing the shape of the X-ray beam corresponding to each of the first imaging means and the second imaging means, and the second imaging and to means, and X-ray generator which includes an irradiation field changing means for changing the position of the radiation field by elevating the slit in a direction parallel to the axial direction of at least the pivot axis,
A display unit for displaying a first X-ray image which is a panoramic image acquired by the first imaging means;
An operation unit for designating a region of interest on the first X-ray image displayed on the display unit;
In order to acquire a second X-ray image that is a CT image of a region of interest designated by the operation unit, the image processing apparatus includes a control unit that controls the irradiation field changing unit and the moving unit. A medical X-ray imaging apparatus characterized by the above. The second X-ray image reconstructs three-dimensional CT data of a three-dimensional region obtained by CT imaging, and an X tomographic plane image, a Y tomographic plane image, and a Z tomographic plane orthogonal to each other for the three-dimensional region. The medical X-ray imaging apparatus according to claim 11 , wherein the medical X-ray imaging apparatus is a tomographic plane image displayed as a plane image. The display unit for displaying the first X-ray image acquired by the first imaging means is an X-ray imaging apparatus main body, the vicinity of the X-ray imaging apparatus main body, and the outside of the X-ray room surrounding the X-ray imaging apparatus main body. medical X-ray imaging apparatus according to any one of the control box, from claim 1, characterized in that provided on at least any one or more of the computer which is connected to the X-ray imaging apparatus 12. An operation unit for designating a region of interest on the first X-ray image displayed on the display unit includes an X-ray imaging apparatus main body, the vicinity of the X-ray imaging apparatus main body, and an X-ray protection apparatus surrounding the X-ray imaging apparatus main body. The medical X-ray imaging apparatus according to claim 13 , further provided in at least one of a control box outside the room and an electronic computer connected to the X-ray imaging apparatus. The medical X-ray imaging apparatus according to any one of claims 1 to 14 , wherein the second X-ray image is displayed on the display unit that displays the first X-ray image.

Images