JP2006122479A - X-ray tomograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray tomograph where unnecessary exposure is suppressed and which is easily operated. <P>SOLUTION: This X-ray tomograph is provided with: a bed mechanism having a top plate movable in the direction of the body axis of a subject in the state of mounting the subject; an X-ray source for irradiating the subject with X-rays; a detector for detecting X-rays having passed through the subject; a gantry where the X-ray source and the detector are arranged so as to rotate oppositely to each other across the subject; a position setting means for setting the optional position of the subject or the top plate, for designating a plurality of areas of the subject; a positional relation detection means for detecting a positional relation between the plurality of areas and the gantry based on a position set by the position setting means; and a scanogram photographing control means for continuously photographing a scanogram image in each of the plurality of areas by moving the top plate while switching irradiation and stop of X-rays from the X-ray source based on the detected positional relation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray tomography apparatus for obtaining a tomogram of a subject.

  In the X-ray tomography apparatus, it is necessary to make a scan plan before actually starting data collection. The scan plan includes setting of an X-ray tube voltage, an X-ray tube current, a slice thickness, a gantry tilt angle, a reconstruction matrix, and a scan range from a scan start position to a scan end position.

  In order to set the imaging conditions in these scan plans, the X-ray exposure is performed while moving the top plate on which the subject is placed in the body axis direction of the subject while the rotation of the X-ray tube and the detector is stopped. It is necessary to capture a scanogram such as an X-ray projection image in an X-ray diagnostic apparatus by detecting incident and transmitted X-rays, and specify an imaging condition including a scan start position and a scan range on the scanogram.

  Here, when it is desired to photograph a plurality of parts of the subject in one diagnosis, it is necessary to photograph all the scanograms of the subject part to be tomographic. In such a case, as a first method, a scanogram imaging range is broadly specified so as to include all parts, and a scanning condition is set with one scanogram, or as a second method, tomography is performed. For each part to be performed, a method has been used in which a series of operations are repeated in which tomographic imaging is performed by setting imaging conditions while imaging a scanogram and referring to the scanogram.

Further, a technique described in Patent Document 1 is also known as a method for setting a scan plan without taking a scanogram.
JP-A-7-1000012

  However, the above method has the following drawbacks. First, the first method has a drawback in that the amount of exposure to a subject increases because scanogram imaging must be performed over a wide range so as to include a plurality of sites. For example, when the first method is used to perform tomographic imaging of the head and thigh of the subject, the scanogram imaging range must be specified so as to include the thigh from the head. For this reason, imaging by X-ray irradiation is also performed on the abdomen and chest that originally do not require imaging. Therefore, according to the first method, unnecessary X-ray exposure to the subject occurs.

  Next, with respect to the second method, a series of operations are repeated in which a scanogram is taken for each region where tomography is to be performed, and the tomography is performed while setting imaging conditions while referring to the scanogram. For this reason, there is a drawback that the throughput of diagnosis is reduced, which is a burden on the operator and the subject.

  Furthermore, in the method of setting a scan plan without taking a scanogram, although a scan range can be set, a scanogram image cannot be obtained, so an X-ray tube voltage, an X-ray tube current, a slice thickness, There is a drawback that it is difficult to appropriately set detailed settings such as a gantry tilt angle and a reconstruction matrix.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an X-ray tomographic imaging apparatus that can be operated easily while suppressing unnecessary exposure.

  In order to solve the above-described problems, an X-ray tomography apparatus according to the present invention includes a bed mechanism having a top plate on which a subject is mounted and movable in the body axis direction of the subject, and X-rays on the subject. An X-ray source for irradiating the X-ray, a detector for detecting X-rays transmitted through the subject, and the X-ray source and the detector rotate opposite to each other across the subject A position setting means for setting an arbitrary position of the subject or the top plate for designating a plurality of areas of the subject, and a position set by the position setting means. And a positional relationship detecting means for detecting a positional relationship between the plurality of regions and the gantry, and the top plate while switching between irradiation and stopping of X-rays from the X-ray source based on the detected positional relationship. By moving the scan for each of the plurality of regions. It is characterized by comprising a scanogram control means for photographing a Noguramu image.

  According to the present invention, it is possible to provide an X-ray tomography apparatus capable of suppressing unnecessary exposure and simultaneously operating easily.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram showing a first embodiment of an X-ray tomography apparatus according to the present invention. The CT apparatus of this embodiment includes a bed mechanism 10, a gantry 20, and a projector 30.

  The bed mechanism 10 is configured to place the subject OBJ on the top plate 11 and move it in the body axis direction and the vertical direction.

  Moreover, the gantry 20 has the entrance / exit 21 in the front surface and the rear surface, and the opening part of the entrance / exit 21 is expanded in the taper shape. The top plate 11 on which the subject OBJ is placed through the doorway 21 carries in and out the subject OBJ. In addition, a slice plane SLS is installed at a position about half the thickness of the gantry 20 from the entrance / exit 21, and the target slice portion of the subject OBJ is aligned with the slice plane SLS, and the X-ray source 22 and the detection unit 23. Is scanned by rotating inside the gantry 20. The gantry 20 is installed so as to be movable in the body axis direction of the subject by a rail mechanism (not shown).

  The projector 30 is attached to the gantry 20 so as to irradiate laser light in a predetermined direction, and the subject OBJ is irradiated by irradiating laser light from the projector 30 while moving the top plate 11 in the body axis direction of the subject OBJ. Any position in the body axis direction can be irradiated. In addition, a projector that irradiates the slice surface SLS has been conventionally used to align the position of the subject and the gantry 20. It is preferable that the projector 30 in the present invention is configured to be shared therewith.

  Next, the control mechanism of the CT apparatus of FIG. 1 will be described with reference to FIG. The operation console 1 includes an input device 2 for inputting instructions and information from an operator, a central processing device 3 for executing image reconstruction processing, a photographing sequence, and the like, a bed signal mechanism 10, a gantry 20 and a projector. 30 has a control interface 4 for outputting to 30, a data collection buffer 5 for collecting data acquired by the gantry 20, a monitor 6 for displaying images and the like, and a storage device 7 for storing various data and programs. Yes.

  The bed mechanism 10 has a bed mechanism controller 12. The couch mechanism controller 12 exchanges information for controlling the operation console 1 and the couch mechanism 10 via the control interface 4, thereby enabling the couch mechanism 10 to be remotely operated from the operation console 1.

  The gantry 20 also has an X-ray system controller 24 that exchanges control information for X-ray scanning with the operation console 1. Thus, remote operation from the operation console 1 is possible. Data obtained by scanning with X-ray radiation from the gantry 20 is sent from the data collection unit 25 to the data collection buffer 5.

  Next, the functional configuration representing the function for specifying the scanogram range of the central processing unit 3 will be described with reference to FIG. The central processing unit 3 has a positional relationship detection function 3a, a scanogram imaging control function 3b, a memory 3c, a tomography condition setting function 3d, and a tomography control function 3e.

  The positional relationship detection function 3a detects from which position on the top plate the laser light is radiated, based on the position information of the top plate 11 based on information input from the input device, and the start / end position of scanogram imaging. This is a function for storing information in the memory 3c.

  The scanogram imaging control function 3 b is a function for controlling the bed mechanism 10 and the gantry 20 via the control interface 4 at the time of scanogram imaging.

  The tomography condition setting function 3d is a function for setting various conditions for performing tomography in accordance with an operator's input and the like, and storing them in the memory 3c as tomography conditions. This is sometimes a function for controlling the bed mechanism 10 and the gantry 20 via the control interface 4.

  Next, the operation of the X-ray tomography apparatus according to this embodiment will be described with reference to FIGS.

  First, FIG. 4 shows an outline of a series of operations from the start to the end in the X-ray tomography apparatus according to the present embodiment. FIG. 4 shows a case where a plurality of scanogram imaging ranges are set as an example.

  First, in step S100, the operator sets an arbitrary number of scanogram imaging ranges and sequentially stores them in the apparatus. Next, in step S200, the operator captures a scanogram according to the stored scanogram capturing setting range. When there are a plurality of set scanogram setting ranges, scanogram images corresponding to them are continuously taken. As a result, the operator obtains a scanogram image of only a nearby region where a tomographic image of the subject OBJ is to be obtained. In step S300, various conditions for tomography are set with reference to the obtained scanogram image. In step S400, tomography is performed under the set conditions. Diagnosis is performed using the tomographic image thus obtained. Hereinafter, the operation of the apparatus according to these operations will be described in detail for each step.

  First, the operation of this apparatus in setting the scanogram imaging range in step S100 in FIG. 4 will be described with reference to FIG.

  The scanogram imaging range is set by the operator operating the projector 30 via the input device 2 and sequentially storing desired imaging positions in the central processing unit 3. Hereinafter, this operation will be specifically described for each step.

  First, as step S110, the operator operates the input device 2 to start irradiation with laser light from the projector 30. The projector 30 irradiates one point of the top plate 11, and the operator can grasp the irradiation position of the laser beam by visual observation.

  Next, in step S120, the operator adjusts the laser beam to irradiate the scanogram imaging start position, which is one end of the area where scanogram imaging is desired, while observing the irradiation point on the top board. Adjustment of the irradiation position of the laser light is performed by moving the top plate 11 by the operator operating the input device 2. In addition, the movement of the gantry 20 in the direction of the subject axis may be combined. The positions of the top plate 11 and the gantry 20 are controlled by the central processing unit 3 based on information input from the input device 2.

  In step S130, the operator confirms the irradiation point on the subject OBJ and determines whether to determine the irradiation point as the scanogram start position. If the operator determines that the irradiation point is correctly at the desired position, the operator inputs a decision to the input device 2 and proceeds to step S140. If not, the process returns to step S120 for further adjustment.

  Through such a process, one of the scanogram imaging start positions is determined in step S140. The determined position information is stored in a memory 3c built in the central processing unit 3. The processing of the central processing unit 3 at this time will be described in detail with reference to FIG.

  In step S141, the positional relationship detection function 3a of the central processing unit 3 receives the position information of the top board 11 and the gantry 20 stored in the memory 3c in response to an input of position determination by the operator to the input device 2. read out.

  In step S142, the positional relationship detection function 3a detects the position in the subject axis direction of the irradiation point irradiated by the projector 30 from the read information on the position of the top plate 11 and the gantry 20. The form of information to be detected is, for example, one-dimensional coordinate information based on an arbitrary point (for example, slice plane SLS) of the gantry 20.

  In step S143, the detected position information is added with information on the number of scanograms and information about the scanogram imaging start position or end position, and is stored in the memory 3c.

  Similarly, in step S150 to step S170, the scanogram imaging end position is determined. In step S180, it is determined whether another scanogram imaging range is set. When the setting is further continued, the process returns to step S110, and an operation for setting a new scanogram imaging range is performed.

  In this way, the start position of the first scanogram shooting range, the end position of the first scanogram shooting range, the start position of the shooting range of the second scanogram, and the end position of the shooting range of the second scanogram As described above, the position information of the scanogram is sequentially set in the memory 3c. For example, when it is desired to take a scanogram of a region surrounded by a dotted line as shown in FIG. 7, the laser beam irradiation points are respectively moved on the top plate lines corresponding to the positions a, b, c and d in the figure, The decision will be entered.

  Here, in this embodiment, the start position and the end position of the area where the scanogram is to be photographed are set. However, the present invention is not limited to this, and various setting methods are possible. For example, as in the conventional case, the setting is performed by setting one wide range so as to include the entire region of the subject to be scanned for scanograms, and then specifying a position where scanogram shooting is not required. You may go.

  Next, the operation of the present apparatus in the scanogram imaging shown in step S200 of FIG. 4 will be described with reference to FIG.

  Scanogram imaging can be performed by fixing the rotation of the X-ray source 22 and the detection unit 23 and by imaging while moving the top plate 11. In the present embodiment, when the set scanogram imaging range reaches the X-ray irradiation area of the gantry, X-rays are emitted from the X-ray source 22 to perform scanogram imaging. Hereinafter, this operation will be described in detail for each step.

  First, the operator operates the input device 2 to input an instruction to start scanogram imaging. Here, as step S210, the scanogram imaging control function 3b of the central processing unit 3 is activated, and the couch mechanism controller 12 is driven to move the top board 11. Here, as an example, it is assumed that the top plate 11 and the gantry 20 are positioned as shown in FIG. In this case, the top plate 11 moves in the direction of arrow A in FIG.

  Next, as step S220, the start position of the scanogram imaging range approaches the slice plane SLS of the gantry, and at the same time, scanogram imaging in the first scanogram imaging range is started. More specifically, the scanogram imaging control function 3b constantly monitors the position of the top board 11, and when the top board 11 comes to the scanogram imaging start position stored in the memory 3c, the X-ray controller 21 Send a shooting start signal. Accordingly, X-ray irradiation starts from the X-ray source 22 toward the subject. The top plate 11 continues to move in the direction of the arrow A as it is and takes a scanogram image of a nearby region where a tomographic image of the subject is to be obtained.

  In step S230, the end position of the scanogram imaging range of the subject passes through the gantry slice plane SLS, and at the same time, X-ray irradiation from the X-ray source 22 is stopped, and scanogram imaging in the first scanogram imaging range is performed. finish. The scanogram imaging control function 3b monitors the position of the top plate 11 even during scanogram imaging. When the top board 11 reaches the scanogram imaging end position stored in the memory 3c, the X-ray system controller 21 terminates imaging. Send a signal. Accordingly, X-ray irradiation is stopped from the X-ray source 22 toward the subject.

  In step S240, the scanogram shooting control function 3b determines whether another scanogram shooting range is set in addition to the scanogram shooting range after shooting. If another scanogram imaging range is set, the scanogram imaging control function 3b continues to move the top plate 11 in the direction of arrow A, and returns to step S220, so that the scanograms of other set areas are set. It will move to control for photography. If no other setting has been made, the process moves to step S250, the movement of the top plate 11 is stopped, and the process ends.

  Next, the operation of the present apparatus in setting the imaging conditions for tomographic imaging shown in step S300 of FIG. 4 will be described. When scanning of the scanogram image is completed, the tomography condition setting function 3d is activated, and the captured scanogram images are displayed on the monitor 6 as a list as shown in FIG. When the operator refers to these scanogram images in a list and inputs a plurality of imaging conditions such as a tomographic imaging position one after another, the tomography condition setting function 3d sequentially stores the input imaging conditions in the memory 3c. Imaging conditions to be set include an X-ray tube voltage, an X-ray tube current, a slice thickness, a gantry tilt angle, a reconstruction matrix, and the like in addition to a tomographic image capturing position such as a scan start position and a scan end position.

  Next, the operation of this apparatus in tomography shown in step S400 of FIG. 4 will be described.

  When the operator inputs tomography start using the input device 2, the tomography control function 3e is activated in step S400. The tomography control function 3e sequentially reads out the imaging conditions stored in the memory 3c, and sequentially performs tomographic imaging at each set position according to the set imaging conditions.

  The tomographic image data obtained by the data collecting unit 24 in this way is subjected to predetermined image processing by the central processing control device 3 via the image data collecting buffer under the control of the tomographic imaging control function 3e. And displayed on the monitor 6 or stored in the storage device 7.

  As described above, according to the present embodiment, it is possible to provide an X-ray tomographic imaging apparatus that can suppress unnecessary exposure and can be easily operated.

  In the present embodiment, since the position detection mechanism is provided, the minimum necessary scanogram imaging range can be accurately set according to the region where the tomographic image of the subject is to be obtained. For this reason, it is not necessary to perform X-ray irradiation for photographing an unnecessary scanogram. Therefore, according to the present embodiment, unnecessary exposure of the subject can be reduced.

  In this embodiment, since the plurality of scanogram imaging ranges are stored in the memory one after another by the positional relationship detection function, the scanogram imaging ranges corresponding to the plurality of areas can be set independently. Therefore, even when the areas of the subject for which tomographic images are to be taken are separated from each other, it is not necessary to set the scanogram imaging range so as to include all of the plurality of areas as in the past, and the minimum necessary for each area. A limited scanogram shooting range may be set. As a result, it is not necessary to perform X-ray irradiation for imaging an unnecessary scanogram, and according to this embodiment, unnecessary exposure of the subject can be reduced.

  In addition, when the areas where the tomographic image of the subject is to be obtained are separated from each other, the operation procedure from scanogram setting to tomographic imaging is taken for each area where one tomographic image is to be obtained as in the past. The same operation, such as setting the scanogram imaging range and tomographic conditions, can be performed simultaneously on all areas, greatly reducing the burden on the operator and the subject. Can be made.

  Furthermore, according to the present embodiment, since a conventionally used projector can be used together as means for designating a scanogram imaging range, it can be realized without greatly changing the hardware configuration of a conventionally used apparatus.

(Second Embodiment)
Compared with the first embodiment described above, the present embodiment is provided with a projector support means for rotatably supporting the projector 30 as means for recognizing the position of the scanogram imaging range, and the top plate 11 and the gantry 20 are moved. The feature is that an arbitrary position of the subject OBJ can be irradiated. In the description of the present embodiment, the method for acquiring the irradiation position of the laser beam when using a rotating projector is mainly described, and the description of the same parts as those in the first embodiment is omitted.

  In this embodiment, as shown in FIG. 10, the projector 30 is attached to the gantry 20 via the projector support means 32 so as to irradiate the top plate 11 or the subject OBJ with laser light. The projector support means 32 supports the projector 30 so as to be rotatable with respect to the gantry 20. By the rotation, the projector 30 can irradiate various parts of the top board 11 and the subject OBJ. Further, the projector 30 and the position detection mechanism 32 may be attached to the ceiling in addition to being attached to the gantry 20. In addition, any configuration that can irradiate the subject OBJ and the top board 11 with laser light may be used.

  In addition, a projector for aligning the position of the subject and the gantry or bed mechanism has been conventionally used, but the projector 30 in the present invention may be configured to be shared therewith. Further, a plurality of light projectors 30 may be provided. In this case, a plurality of positions of the subject OBJ and the bed mechanism 10 can be irradiated simultaneously. Further, in the present embodiment, the irradiation position of the laser beam is made free by the projector support means 32 rotatably supporting the projector. However, the present invention is not limited to this, and the irradiation direction of the laser beam is controlled by an optical method. Etc.

  In the present embodiment, the projector support means 32 emits a laser beam from the projector 30 based on the control information given from the central processing unit 3, or moves the irradiation position of the laser beam by rotating the projector 30. To do. The operation of the projector support means 32 is performed based on an input to the input device 2 by the operator.

  Furthermore, in the present embodiment, the positional relationship detection function 3a detects which position on the top plate the laser beam irradiates from the irradiation angle of the laser beam based on information input from the input device, and scanogram This is a function for storing in the memory 3c as position information of the start / end of shooting.

  In addition, among the operations of the X-ray tomography apparatus according to the present embodiment, the operations of the apparatus in setting the scanogram imaging range will be described with reference to FIG.

  First, as step S110, the operator operates the input device 2 to start driving the projector 30. When the projector 30 is driven, laser light is emitted from the projector 30. The projector 30 irradiates one point of the top plate 11, and the operator can grasp the irradiation position of the laser beam by visual observation.

  Next, in step S120, the operator adjusts the laser beam to irradiate the scanogram imaging start position, which is one end of the area where scanogram imaging is desired, while observing the irradiation point on the top board. Adjustment of the irradiation position of the laser light is performed by rotating the projector 30 when the operator operates the input device 2. In addition to this, the movement of the top plate 11 and the gantry 20 in the direction of the subject axis may be combined. The positions of the projector 30, the top plate 11, and the gantry 20 are controlled by the central processing unit 3 based on information input from the input device 2.

  In step S130, the operator confirms the irradiation point on the top plate 11, and determines whether to determine the irradiation point as the scanogram start position. If the operator determines that the irradiation point is correctly at the desired position, the operator inputs a decision to the input device 2 and proceeds to step S140. If not, the process returns to step S120 for further adjustment.

Through such a process, one of the scanogram imaging start positions is determined in step S140. The determined position information is stored in a memory 3c built in the central processing unit 3. The processing of the central processing unit 3 at this time will be described in detail with reference to FIG.

  In step S141, the positional relationship detection function 3a of the central processing unit 3 is triggered by the position input to the input device 2 by the operator, and the positions of the top board 11, the gantry 20 and the projector 30 stored in the memory 3c. Read information.

  In step S142, the positional relationship detection function 3a detects the position of the irradiation point irradiated by the projector 30 in the subject axis direction from the read information on the positions of the projector 30, the top plate 11, and the gantry 20. The form of information to be detected is, for example, one-dimensional coordinate information based on an arbitrary point (for example, slice plane SLS) of the gantry 20.

  In step S143, the detected position information is added with information on the number of scanograms and information about the scanogram imaging start position or end position, and is stored in the memory 3c.

  Similarly, in step S150 to step S170, the scanogram imaging end position is determined. In step S180, it is determined whether another scanogram imaging range is set. When the setting is further continued, the process returns to step S110, and an operation for setting a new scanogram imaging range is performed.

  In the present embodiment, the projector 30 rotates to irradiate an arbitrary position on the top plate 11, but is not limited thereto. For example, as shown in FIG. 11, a rail 35 may be provided on the ceiling, and the rail 35 may be irradiated with an arbitrary position on the top plate 11 by moving the light projector 30. In this way, even if the scanogram imaging range is set based on the laser light directly irradiated on the subject OBJ on the top plate 11, the laser light is viewed from a direction perpendicular to the body axis of the subject OBJ. Irradiated. Therefore, when the object OBJ is irradiated with laser light and when the top plate is irradiated with laser light to indicate the same position, the irradiation angle of the laser light is the same, so the object OBJ is directly irradiated with laser light. By doing so, the shooting range can be set precisely.

  As described above, according to the present embodiment, it is possible to provide an X-ray tomographic imaging apparatus that can suppress unnecessary exposure and can be easily operated.

  In the present embodiment, since the position detection mechanism is provided, the minimum necessary scanogram imaging range can be accurately set according to the region where the tomographic image of the subject is to be obtained. For this reason, it is not necessary to perform X-ray irradiation for photographing an unnecessary scanogram. Therefore, according to the present embodiment, unnecessary exposure of the subject can be reduced.

  In this embodiment, since the plurality of scanogram imaging ranges are stored in the memory one after another by the positional relationship detection function, the scanogram imaging ranges corresponding to the plurality of areas can be set independently. Therefore, even when the areas of the subject for which tomographic images are to be taken are separated from each other, it is not necessary to set the scanogram imaging range so as to include all of the plurality of areas as in the past, and the minimum necessary for each area. A limited scanogram shooting range may be set. As a result, it is not necessary to perform X-ray irradiation for imaging an unnecessary scanogram, and according to this embodiment, unnecessary exposure of the subject can be reduced.

  In addition, when the areas where the tomographic image of the subject is to be obtained are separated from each other, the operation procedure from scanogram setting to tomographic imaging is taken for each area where one tomographic image is to be obtained as in the past. The same operation, such as setting the scanogram imaging range and tomographic conditions, can be performed simultaneously on all areas, greatly reducing the burden on the operator and the subject. Can be made.

  Furthermore, according to the present embodiment, the irradiation position of the laser beam can be changed without moving the top plate 11 on which the subject OBJ is placed or the heavy gantry 20, so the irradiation position of the laser beam can be easily changed with less power. It can be changed. Therefore, the burden on the operator and the subject can be reduced.

(Third embodiment)
Next, a third embodiment of the X-ray tomography apparatus according to the present invention will be described with reference to the drawings.

  The present embodiment is characterized in that a position detection mechanism by reflection of laser light is provided in the gantry as means for recognizing the position of the scanogram imaging range, compared to the first embodiment. In the present embodiment, an operator attaches a mark such as a tape for designating a scanogram imaging range to the top plate, and scanogram imaging is performed while detecting the mark by a position detection mechanism. In the description of the present embodiment, the description will focus on the position detection mechanism, and a description of the same parts as those in the first embodiment will be omitted.

  FIG. 12 is a block diagram showing a second embodiment of the X-ray tomography apparatus according to the present invention. The CT apparatus of this embodiment includes a bed mechanism 10, a gantry 20, a projector 30, and a light receiver 34.

  The projector 30, the light receiver 34, and the gantry 20 are attached to the projector 30. The projector 30 irradiates laser light in one fixed direction and irradiates the side of the top plate 11. The light receiver 34 detects the laser beam reflected by the side of the top plate 11 and detects the level difference and color of the portion where the laser beam is reflected. In FIG. 12, the projector 30 and the light receiver 34 are attached to the upper part near the entrance of the gantry 20. However, the present invention is not limited to this. Alternatively, it may be provided at a plurality of positions.

  The functional configuration of the central processing unit 3 of this embodiment can be shown by using FIG. Here, the positional relationship detection function 3a that is different in function from the first embodiment will be described. The positional relationship detection function 3a receives information on the unevenness and color of the laser irradiation point from the light receiver 34, and determines whether there is a predetermined mark and whether the mark is the start point or end point of the scanogram imaging range. When it is determined that there is a mark, it is detected which position on the top plate the detected mark is. The detected position information is stored in the memory 3c as start / end position information of scanogram imaging. Here, the positional relationship detection function 3a determines that there is a mark at the laser irradiation point based on the color information different from the top plate 11, and determines whether the mark is the start point or the end point of the scanogram imaging range. For example, red color information is determined as the start point, and blue color information is determined as the end point. In this way, the scanogram shooting range can be specified with the red tape and the blue tape.

  Also, the mark detection method is not limited to color information. You may perform by detecting the thickness of a tape using the information of the unevenness | corrugation from the surface of the top plate 11. FIG. Further, whether the start point or the end point is determined using the color information, it may be determined simply in the order of detection. If it is inserted into the gantry from the end of the top plate, it is detected in the order of the start point, end point, start point, end point,...

  Next, the operation of the X-ray tomography apparatus according to this embodiment will be described with reference to FIG.

  In this embodiment, the scanogram shooting range is set by the operator attaching a tape or the like to the top plate 11. Scanogram imaging is performed by detecting that the mark has reached the vicinity of the gantry 20 as the top plate 11 moves, and starting and interrupting X-ray irradiation according to the detection. Hereinafter, this operation will be specifically described for each step.

  First, in step T1, the operator marks the top plate 11. The operator puts marks so as to sandwich a desired scanogram imaging range while directly looking at the subject OBJ placed on the top board 11. In this embodiment, as shown in FIG. 12, the marking is performed by attaching a colored tape to the top plate 11, and the scanogram imaging range starts according to the direction in which the top plate 11 is introduced into the gantry 20. A red tape shall be applied at the position and a blue tape shall be applied at the end position.

  Next, as step T2, when the operator operates the input device 2, the central processing unit 3 performs control for scanogram imaging, and the top 11 moves so that the subject OBJ is introduced into the gantry 20. At the same time, the projector 30 starts irradiating the fixed point with the gantry as a reference, and the light receiver 34 starts transmitting the reflected light information to the positional relationship detection function 3a. The positional relationship detection function 3a monitors reflected light information.

  In step T3, the light receiver 34 detects a mark. When the mark approaches the laser irradiation point as the top plate 11 moves, the color information of the laser reflected light transmitted to the positional relationship detection function 3a changes. Thereby, the positional relationship detection function 3a recognizes the mark.

  Next, in step T4, it is determined whether the mark detected by the positional relationship detection function 3a represents the start point or the end point of the scanogram imaging range. In the present embodiment, if the color information of the reflected light is red, it is determined as the start point, and if it is blue, it is determined as the end point. If the detected mark is the start point, the process proceeds to step T5, and if it is the end point, the process proceeds to step T6. Information on the start point and end point is stored in the memory 3c.

  When the process proceeds to step T5, the scanogram imaging control function 3b is activated, the X-ray irradiation is started simultaneously with the mark reaching the slice surface SLS, and the scanogram imaging is started as the top plate 11 moves. Thereafter, the process proceeds to step T3 in order to detect the end position of the scanogram imaging range.

  In step T6, the scanogram imaging control function 3b stops the X-ray irradiation at the same time when the mark reaches the slice surface SLS, and the scanogram imaging in that range is completed. The top plate 11 continues to move.

  If no other scanogram imaging range is set in step T7, the top 11 moves to a predetermined range after the movement of the predetermined range, and the movement stops and the scanogram imaging ends. Further, when the photographing range is set, the operations from step T3 to step T6 are repeated.

  As described above, according to the present embodiment, it is possible to provide an X-ray tomographic imaging apparatus that can suppress unnecessary exposure and can be easily operated.

  In the present embodiment, since the position detection mechanism is provided, the minimum necessary scanogram imaging range can be accurately set according to the region where the tomographic image of the subject is to be obtained, and therefore X-rays for imaging unnecessary scanograms. Irradiation is not necessary. Therefore, according to the present embodiment, unnecessary exposure of the subject can be reduced.

  In the present embodiment, the plurality of scanogram imaging ranges are sequentially captured by the positional relationship detection function 3a, so that the scanogram imaging ranges corresponding to the plurality of regions of the subject can be set independently. . Therefore, even when a plurality of areas of the subject are separated from each other, it is not necessary to set a scanogram imaging range so as to include all of the plurality of areas as in the past, and the minimum scanogram necessary for each area What is necessary is just to set an imaging range. As a result, it is not necessary to perform X-ray irradiation for imaging an unnecessary scanogram, and according to this embodiment, unnecessary exposure of the subject can be reduced.

  In addition, when the areas where the tomographic image of the subject is to be obtained are separated from each other, the procedure from scanogram setting to tomographic imaging should be taken every time one tomographic image is obtained as in the past. The same operation such as setting the scanogram imaging range and tomography conditions can be performed simultaneously on all areas without having to perform the cumbersome operation of repeating, greatly reducing the burden on the operator and the subject. be able to.

  Furthermore, in this embodiment, since it can set by sticking a tape directly to the test object vicinity, a several area | region can be set simply and correctly. As a result, the burden on the operator and the subject can be greatly reduced.

The figure which shows an example of the apparatus structure of 1st Embodiment which concerns on this invention. The figure which shows the structure of 1st Embodiment which concerns on this invention. The figure which shows the function structure of the central processing unit of FIG. The flowchart which shows the outline | summary of operation | movement in 1st Embodiment. 5 is a flowchart showing in detail an operation in a step of setting a scanogram imaging range in FIG. 4. 5 is a flowchart showing in detail the operation of the central processing unit in the step of determining the scanogram imaging position in FIG. The figure which shows an example of the scanogram imaging | photography range in 1st Embodiment. The flowchart which shows the operation | movement in the step which performs the scanogram imaging | photography of FIG. 4 in detail. FIG. 5 is a diagram illustrating an example of an image displayed for setting tomographic image capturing conditions according to the first embodiment. The figure which shows an example of the apparatus structure of 2nd Embodiment which concerns on this invention. The figure which shows an example of the apparatus structure of 2nd Embodiment which concerns on this invention. The figure which shows an example of the apparatus structure of 3rd Embodiment which concerns on this invention. The flowchart which shows operation | movement in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Operation console 2 Input device 3 Central processing unit 4 Control interface 5 Image data collection buffer 6 Monitor 7 Storage device 10 Bed mechanism 11 Top plate 12 Bed mechanism controller 20 Gantry 21 Entrance / exit 22 X-ray source 23 Detector 24 X-ray system controller 25 Data collection unit 30 Projector 32 Projector support means 34 Light receiver 35 Rail

Claims (7)

A bed mechanism having a top plate on which the subject is placed and movable in the body axis direction of the subject;
An X-ray source for irradiating the subject with X-rays;
A detector for detecting X-rays transmitted through the subject;
A gantry in which the X-ray source and the detector are arranged so as to rotate opposite to each other with the subject interposed therebetween;
Position setting means for setting an arbitrary position of the subject or the top plate for designating a plurality of regions of the subject;
A positional relationship detection unit that detects a positional relationship between the plurality of regions and the gantry based on the position set by the position setting unit;
Scanogram imaging control means for imaging a scanogram image for each of the plurality of areas by moving the top plate while switching between irradiation and stopping of X-rays from the X-ray source based on the detected positional relationship; An X-ray tomographic imaging apparatus comprising: The position setting means includes
A projector for setting the arbitrary position by irradiating a laser beam in a predetermined direction with respect to the gantry provided on the gantry or the ceiling;
The positional relationship detecting means includes
The X-ray tomography apparatus according to claim 1, wherein the positional relationship is detected by specifying the arbitrary position based on positional information of the top plate or the gantry. The position setting means includes
Including a projector that irradiates a laser beam to an arbitrary position of the subject or the top plate by being provided on the gantry or the ceiling so as to move or rotate
The positional relationship detecting means includes
The X-ray tomography apparatus according to claim 1, wherein the positional relationship is detected by specifying the arbitrary position based on position information of the projector. The position setting means includes
A projector that emits laser light in a predetermined direction with respect to the gantry;
Receiving a laser beam from the projector reflected from the top plate or the subject, and including a light receiver for acquiring information on the shape or color of the top plate or the subject,
The positional relationship detecting means includes
The positional relationship is detected by specifying the position of the mark on the top plate or the subject based on the information on the shape or color acquired by the light receiver and the position information on the top plate. The X-ray tomography apparatus according to claim 1. An input means for performing an input for operating at least one of the movement and rotation of the projector and the movement of the top plate, and an input for determining that the position irradiated with the laser light is a desired position;
The position setting means receives a plurality of movement inputs and determination inputs from the input means in succession, and controls the positional relation detection means to detect a plurality of the positional relations in succession. The X-ray tomographic imaging apparatus according to claim 2, wherein the X-ray tomographic imaging apparatus is characterized. The position setting means includes
4. The X-ray tomographic imaging according to claim 3, wherein the positional relationship detecting means is controlled so as to detect the positional relationship of the plurality of regions as the top plate moves in the scanogram imaging. apparatus. Display means for displaying the plurality of scanogram images;
With reference to the displayed scanogram image, tomography condition setting means for continuously setting imaging conditions for each of a plurality of tomographic images in the plurality of regions;
2. A tomographic imaging unit for obtaining a tomographic image of the subject by driving the X-ray source and the detector while rotating based on the imaging conditions. 2. The X-ray tomography apparatus according to 2.

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