JP2014144119A - X-ray ct apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus capable of shifting the position of a desired diagnosis object to an imaging region without inflicting suffering on a patient.SOLUTION: The X-ray CT apparatus includes: a gantry having an opening part; a top plate on which a patient is placed and the longitudinal direction of which faces the opening part; a top plate shifting mechanism supporting the top plate so as to be movable in at least a perpendicular direction and its longitudinal direction; a projector set to the gantry and projecting light to the patient; and a projector shifting mechanism supporting the projector so as to be movable in the perpendicular direction and the longitudinal direction of the top plate.

Description

  Embodiments described herein relate generally to an X-ray CT apparatus.

  Generally, an X-ray CT apparatus includes a bed and a gantry. The bed is provided with a top plate on which a patient is placed, and the top plate on which the patient is placed can be taken in and out of an opening provided in a cylindrical shape in the center of the gantry. On the other hand, an X-ray tube and an X-ray detector are supported inside the gantry so as to face each other with the opening interposed therebetween, and rotate around the opening while facing both. During rotation, the X-ray tube emits X-rays to the patient located in the opening, and the X-ray detector detects X-rays transmitted through the patient. The tomographic image is obtained by collecting the detection data for all angles detected in this way and reconstructing them with a computer.

  In the tomographic imaging as described above, in order to reduce the exposure dose of the patient and perform the imaging efficiently, the desired diagnostic region or tomographic imaging start position is between the X-ray tube and the X-ray detector. It is necessary to align the patient before imaging so as to be appropriately positioned within the imaging range.

  In general, in an X-ray CT apparatus, a patient is aligned using a projector. For example, the X-ray CT apparatus includes a projector capable of projecting a cross-shaped light toward a patient inside the opening, and the operator projects the light projected from the projector onto the patient's diagnostic site. The patient is aligned in the horizontal direction by moving the top board so that it hits the target position such as the tomography start position. In addition, the X-ray CT apparatus includes a projector that projects light horizontally on both the left and right sides of the entrance of the opening, and the light projected by the projectors installed on the left and right is applied to the center of the patient's body thickness. Thus, the patient is aligned in the vertical direction.

Japanese Patent Laid-Open No. 7-67869

  However, in order to accurately match the target position of the patient with the light of the projector, it is necessary to repeatedly make fine adjustments such as, for example, returning the top plate to the inside of the opening portion when the top plate is moved too much, and moving it backward when it is returned too much. In the alignment by the conventional projector as described above, there is a possibility that the patient is intoxicated by this fine adjustment, and the patient feels bad, and a burden is imposed on the patient.

  In patent document 1, the projector is installed in the uppermost part of the opening part entrance similarly to the previous example. The projector in Patent Document 1 can change the angle of the light to be projected from the vertical direction to the direction of the patient's foot, and the position of the light projected on the patient can be changed by changing the angle of the light to be projected. It can be freely changed with respect to the body axis direction of the patient. In Patent Document 1, first, the angle of the light to be projected is changed so that the position of the light projected on the patient matches the target position separated from the desired diagnostic site by a predetermined distance. Next, the longitudinal direction of the top board necessary for the patient's desired diagnostic region to move within the imaging range from the angle amount changed to match the position of the light projected onto the patient and the target position Is calculated using a predetermined function. Finally, the direction of the light to be projected is returned to the vertically downward direction, and the top plate on which the patient is placed is moved in the longitudinal direction of the patient by the calculated amount of movement. As a result, in the longitudinal direction of the top plate, accurate positioning can be performed without finely moving the top plate and repeating fine adjustments. However, in patent document 1, it is not assumed about the alignment about the vertical direction of a top plate.

  The problem to be solved by the present invention is to provide an X-ray CT apparatus that can move a patient to a desired position without imposing a burden on the patient.

  In order to solve the above-described problems, an X-ray CT apparatus according to an embodiment includes a gantry having an opening, a top plate on which a patient is placed, and whose longitudinal direction faces the opening, and the top plate. A top plate moving mechanism that supports the top plate so as to be movable at least in the vertical direction and the longitudinal direction thereof, a projector installed in the gantry and capable of projecting light to the patient, and the projector in the vertical direction and the longitudinal direction of the top plate A projector moving mechanism that is movably supported in the direction.

1 is a perspective view of an X-ray CT apparatus in Embodiment 1. FIG. 1 is a cross-sectional view of an X-ray CT apparatus in Embodiment 1. FIG. FIG. 3 is a block diagram according to the first embodiment. FIG. 3 is an enlarged view of a projector and a projector moving mechanism in Embodiment 1. FIG. 3 is a perspective view of a projector movable range in the first embodiment. FIG. 3 is an enlarged view of an operation unit in the first embodiment. FIG. 7 is a schematic diagram of an operation unit in a modification of the first embodiment. FIG. 3 is a flowchart in Example 1. 1 is a cross-sectional view of an X-ray CT apparatus in an initial state of a flow according to Embodiment 1. FIG. Sectional drawing of the X-ray CT apparatus in S1 of the flow of Example 1. FIG. Sectional drawing of the X-ray CT apparatus in S2 of the flow of Example 1. FIG. Sectional drawing of the X-ray CT apparatus in S4 of the flow of Example 1. FIG. Sectional drawing of the X-ray CT apparatus in S5 of the flow of Example 1. FIG. The perspective view of the projector movable range in Example 2. FIG. Sectional drawing of the X-ray CT apparatus in the initial state of the flow of Example 2. FIG. Sectional drawing of the X-ray CT apparatus in S1 of the flow of Example 2. FIG. Sectional drawing of the X-ray CT apparatus in S2 of the flow of Example 2. FIG. Sectional drawing of the X-ray CT apparatus in S4 of the flow of Example 2. FIG. Sectional drawing of the X-ray CT apparatus in S5 of the flow of Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1
FIG. 1 is a perspective view of the X-ray CT apparatus according to the first embodiment. The X-ray CT apparatus in the present embodiment includes a gantry 1, a bed 2, a top plate 3, an operation unit 5, and an upper projector 25.

  The couch 2 can be moved so that the top plate 3 can move in the x direction, the reverse direction of the x direction, the y direction, the reverse direction of the y direction, the z direction, and the reverse direction of the z direction in FIG. Support.

  The top 3 is put in and out of the opening 4 according to an instruction from the operation unit 5. As shown in FIG. 1, there is a peripheral portion 24 around the opening 4, and an upper projector for aligning the patient's body axis in the opening 4 in the lateral direction above the peripheral portion 24. 25 is installed. The light projected from the upper projector 25 is projected in the direction opposite to the y direction, and the operator aligns the patient's midline with this light to align the patient's body axis in the lateral direction.

  Details of the operation unit 5 will be described later. In the following drawings, it is assumed that a coordinate system that can be expressed by x, y, and z in FIG. 1 is shared.

  FIG. 2 is a cross-sectional view of the X-ray CT apparatus according to the first embodiment in a cross section passing through the center of the opening 4 and parallel to the yz plane. The gantry 1 has an X-ray tube 12, an X-ray detector 13, and a data collection device (not shown) inside itself. The X-ray tube 12 emits X-rays to the patient P in the opening 4 while rotating around the opening 4. The X-ray detector 13 rotates around the opening 4 while facing the X-ray tube 12 and detects X-rays transmitted through the patient P. The data collection device collects detection data for all angles detected while rotating in this way. A tomogram is generated by reconstructing the detection data collected by the data collection device by a computer. Note that tomographic imaging is performed in a state where the diagnosis target region 15 of the patient P is within the imaging range 14 between the X-ray tube 12 and the X-ray detector 13 as shown in FIG. 2, for example.

  FIG. 3 is a block diagram according to the first embodiment.

  As shown in FIG. 3, the X-ray CT apparatus according to the first embodiment includes the gantry 1, the bed 2, the top plate 3, the operation unit 5, the X-ray tube 12, and the X-ray detector described with reference to FIGS. 1 and 2. 13. In addition to the image generation unit (not shown), the projector 6, the projector movement mechanism 7, the top board movement mechanism 8, and the movement amount calculation unit 9 are provided.

  The projector 6 projects light in accordance with instructions from the operation unit 5 described later.

  FIG. 4 is a front view of the projector 6 and the projector moving mechanism 7. For example, as shown in FIG. 4, the projector moving mechanism 7 includes two rails 7 a and 7 b that are perpendicular to each other. The rail 7a supports the projector 6 so as to be movable in the z direction and the direction opposite to the z direction. On the other hand, the rail 7b supports the rail 7a so as to be movable in the y direction and the direction opposite to the y direction. The length of the rail 7a in the direction of arrow C is L1, and the length of the rail 7b in the direction of arrow D is L2. The projector moving mechanism 7 moves the projector 6 via a driving mechanism such as a motor (not shown) based on an operation instruction such as a pulse signal received from the operation unit 5 described later. For example, when the movement amount of the projector moving mechanism 7 is set so that the projector 6 moves 0.05 mm with one pulse signal, when the projector moving mechanism 7 receives 1000 pulse signals from the operation unit 5 described later, The projector 6 moves by 50 mm.

  FIG. 5 is a movable range (projector movable range 17) of the projector 6 according to the first embodiment. The projector 6 and the projector moving mechanism 7 are installed inside the gantry 1 so that light can be projected onto a patient in a space surrounded by the peripheral portion 24. The light projected by the projector 6 is parallel to the x direction, and the projector 6 can freely move in the projector movable range 17 by operating the projector moving mechanism 7 in accordance with an instruction from the operation unit 5 described later. . The projector movable range 17 has lengths L1 in the z direction and L2 in the y direction, and corresponds to the lengths of the rail 7a and the rail 7b of the projector moving mechanism 7.

  The light emitted from the projector 6 is projected onto the patient surrounded by the peripheral portion 24 through the transparent member 10 as shown in FIG. 5, for example. The transparent member 10 is provided in a range where the projector movable range 17 is projected onto the peripheral portion 24.

  The couchtop moving mechanism 8 is provided on the couch 2, and in accordance with instructions from the operation unit 5 described later, the x direction, the reverse direction of the x direction, the y direction, the reverse direction of the y direction, and the z direction in FIG. The top plate 3 is moved in the direction opposite to the z direction. The top plate moving mechanism 8 moves the top plate 3 through a driving mechanism such as a motor (not shown) based on the pulse signal received from the operation unit 5. For example, when the operation of the top plate moving mechanism 8 is set so that the top plate 3 moves 0.05 mm with one pulse signal, when the top plate moving mechanism 8 receives 1000 pulse signals from the operation unit 5, The top 3 moves by 50 mm. In the first embodiment, the amount of movement with respect to one pulse signal is the same for the top 3 and the projector 6.

  The operation unit 5 corresponds to a button corresponding to a manual operation of the top 3 and the projector 6 by the operator, a button corresponding to ON / OFF of the projector 6, and an automatic operation of the top 3 and the projector 6 based on a predetermined setting. Operation items such as buttons and operation means are provided.

  FIG. 6 shows the operation unit 5 in the first embodiment. In FIG. 6, when the operator presses the button 5a and the button 5b, the top 3 moves in the y direction and the direction opposite to the y direction. When the operator depresses the buttons 5c and 5d, the top 3 moves in the z direction and the direction opposite to the z direction. When any of the buttons 5a, 5b, 5c, and 5d is pressed while pressing 5e, the operation unit 5 increases the frequency of the pulse signal in the direction corresponding to the pressed button. As a result, the movement in the direction corresponding to the pressed button is accelerated. Further, when the operator presses the right half of the button 5m, the top 3 moves in the x direction, and when the left half of the button 5e is pressed, the top 3 moves in the direction opposite to the x direction.

  On the other hand, when the operator presses the button 5f and the button 5g in FIG. 6, the projector 6 moves in the direction opposite to the y direction and the y direction via the projector moving mechanism 7. When the operator presses the button 5h and the button 5i, the projector 6 moves in the direction opposite to the z direction and the z direction via the projector moving mechanism 7. As described above, the operator can manually operate the movement of the top 3 and the projector 6. In addition, the movement amount of the top plate 3 and the projector 6 in Example 1 is determined by the time for which the operator presses the button. For example, when the button 5d is pressed for 1 second and 1000 pulse signals are set to be transmitted to the top plate moving mechanism 8, when the operator presses the button 5d for 2 seconds, the 2000 pulse top plate moving mechanism 8 is displayed. The top plate 3 moves 100 mm in the direction opposite to the z direction. In Example 1, it is assumed that the number of pulses sent to the top board moving mechanism 8 by pressing each button is the same.

  With the button 5j in FIG. 6, it is possible to operate whether or not the light from the projector 6 is projected. For example, when the operator presses the button 5j when the projector 6 is not projecting light, the projector 6 projects light. On the other hand, if the operator presses the button 5j when the projector 6 is not projecting light, the projector 6 turns off the light.

  The button 5k in FIG. 6 is used when the top 3 and the projector 6 are automatically operated based on a calculation result by a movement amount calculation unit 9 described later. When the operator presses the button 5k, the projector 6 moves from a position before the button 5k is pressed to a predetermined origin position. At this time, the top plate 3 moves in the same direction by the same movement amount as the projector 6 moves to the origin position. These movements are performed based on transmission of a pulse signal, as in the case of the manual operation.

  In the first embodiment, the operation means of the operation unit 5 is assumed to be a button type, but a lever type using a lever 18 as shown in FIG. 7 may be used. In this case, the frequency of the pulse signal to be transmitted is increased when the lever 18 is tilted deep, and the frequency of the pulse signal to be transmitted is decreased when the lever 18 is tilted shallow. The frequency should be adjustable. In the lever-type operation unit 5, it is also possible to move the projector 6 or the top plate 3 in an oblique direction corresponding to the direction in which the lever 18 is tilted by tilting the lever 18 in the diagonal direction. For example, when the lever 18 in FIG. 7 is an operation means for moving the top 3 and the direction of the arrow A corresponds to the movement in the y direction and the direction of the arrow C in the z direction, the direction of the arrow B When the lever 18 is tilted, the operation unit 5 simultaneously transmits a pulse signal for moving the top plate 3 in the y direction and a pulse signal for moving the top plate 3 in the z direction to the top plate moving mechanism 8. As a result, the top 3 moves in a direction having a y-direction component and a z-direction component, that is, in an oblique direction. By making the operation unit 5 a lever type as described above, the operator can more intuitively operate the movement of the projector 6 or the top 3.

  The movement amount calculation unit 9 calculates the number of pulse signals transmitted from the operation unit 5 to the projector moving mechanism 7 in order to move the projector 6 by manual operation. For example, by manual operation, first, 4000 pulse signals corresponding to the z direction, then 2000 pulse signals corresponding to the reverse direction of the y direction, and finally pulse signals corresponding to the reverse direction of the z direction ( When 1000 operation signals are transmitted to the projector moving mechanism 7, the movement amount calculation unit 9 causes the operation unit 5 to output 4000 pulse signals corresponding to the z direction. It is calculated that -1000 (= 3000) pulses and 2000 pulse signals corresponding to the direction opposite to the y direction have been transmitted. When an automatic operation is instructed by the operator pressing the button 5 k of the operation unit 5, the movement amount calculation unit 9 moves the projector movement mechanism 7 and the top plate movement mechanism 8 via the operation unit 5 in the z direction. 3000 pulse signals corresponding to the reverse direction and 2000 pulse signals corresponding to the y direction are transmitted. The projector moving mechanism 7 and the top plate moving mechanism 8 move the projector 6 and the top plate 3 based on the received pulse signal. As a result, the projector 6 moves from the position before pressing the button 5k to the predetermined origin position as described above, and at this time, the top 3 is moved in the same direction by the same amount of movement as the projector 6 moves to the origin position. Move to.

  In the first embodiment, when a predetermined operation is performed after the top 3 is moved by the above-described auto operation, the diagnosis target region 15 is located in the imaging range 14 as shown in FIG. . Details of these will be described with reference to FIGS. 8, 9, 10, 11, 12, and 13.

  FIG. 8 is a flowchart in the first embodiment. FIG. 9 shows a first embodiment in a cross section parallel to the yz plane through the center of the opening 4 in an initial state in which no operation is performed after the patient P lies on the top 3. It is sectional drawing of X-ray CT apparatus. As shown in FIG. 9, the cross-shaped light (projection light 11) projected from the projector 6 in the initial state is L3 in the z direction from the center line M of the imaging range, and the reverse of the y direction from the top of the opening 4. Projected to a position (origin position O) separated by L4 in the direction. This origin position O corresponds to the position of the projector 6 when the rail 7a is at the midpoint position in the longitudinal direction of the rail 7b and the projector 6 is at the right end of the rail 7a in FIG. 4, for example. In the first embodiment, the target position 16 in FIGS. 9 and 10 is the center of the diagnosis target region 15 projected on the side of the patient P.

  In S <b> 1, the operator manually operates the operation unit 5 to place the top 3 so that the target position 16 is located in the region where the projection light 11 can be projected, as shown in FIG. 10. Move. The projectable area of the projection light 11 is a three-dimensional space in which the projector movable range 17 in FIG. 5 is projected into the area surrounded by the peripheral portion 24. As a result of the above-described manual operation by the operator, the position of the target position 16 at the time of completion of S1 is a position away from the origin position O of the projection light 11 by L5 in the z direction and L6 in the direction opposite to the y direction. Here, since there is no intention of accurately aligning the position of the top plate 3 with the movement of the top plate 3 here, it is determined by the operator whether or not the target position 16 is within the region where the projection light 11 can be projected. Rough things such as visual inspection may be used.

  In S <b> 2, the operator moves the position of the projector 6 by a manual operation via the operation unit 5 so that the projection light 11 is projected at the target position 16 in FIG. 10. As a result, as shown in FIG. 11, the projection light 11 moves from the origin position O to a position separated by L5 in the z direction and by L6 in the opposite direction of the y direction. The projector 6 is moved in the direction opposite to the z direction and the y direction based on the pulse signal transmitted from the operation unit 5 to the projector moving mechanism 7 as described above.

  As shown in S <b> 3, the movement amount calculation unit 9 calculates the pulse signal transmitted from the operation unit 5 to the projector movement mechanism 7 in each direction. The calculation method at this time is as described above.

  In S4, first, the operator presses a button 5k provided on the operation unit 5. When the button 5k is pressed, the movement amount calculation unit 9 moves the projector 6 and the top plate 3 so that the movement amount is the same in the opposite direction to the movement direction and movement amount of the projector 6 in S2. Moving. In other words, the same number of pulse signals that are opposite in polarity to the pulse signal transmitted to the projector moving mechanism 7 for moving the projector 6 in S3 are transmitted to the projector moving mechanism 7 and the top plate moving mechanism 8. As a result, as shown in FIG. 12, at the end of S2, the projection located at a position separated by L3 + L5 in the z direction from the center line M of the imaging range and L4 + L6 in the direction opposite to the y direction from the top of the opening 4 The light 11 moves from the center line M of the imaging range to the origin position O of the projector 6 that is L3 in the z direction and L4 away from the upper part of the opening 4 in the direction opposite to the y direction. As shown in FIG. 12, the top plate 3 also moves L5 in the direction opposite to the z direction and L6 in the y direction.

  When S4 is completed, the operator presses a not-shown top-plate feed button on the operation unit 5. When the operator depresses the top board feed button, as shown in S5, the operation unit 5 sends a pulse signal for moving the top board 3 in a direction opposite to the z direction by a predetermined distance (L3). To give. As a result, the top 3 moves to a position where the target position 16 coincides with the center line M of the imaging range as shown in FIG.

  In S6, scanning by the X-ray CT apparatus is started, and a tomographic image of the patient P is taken.

  In the first embodiment, it is assumed that the diagnostic target region 15 can be imaged only by rotating the X-ray tube 12 and the X-ray detector 13 once as shown in FIG. When it is necessary to move the top 3 in the direction opposite to the z direction while rotating the tube 12 and the X-ray detector 13, the target position 16 is the diagnosis start position.

  In the first embodiment, the specification is such that the projection light 11 is projected only on one side of the patient. However, the projector 6 projects the projection light 11 on the other side of the patient. Two sets of the projector moving mechanism 7 may be installed. In that case, it is preferable to install two sets of operation units 5 as shown in FIG.

  As described above, the X-ray CT apparatus according to the first embodiment is placed on the top 3 because it is not necessary to finely move the top 3 in order to move the target position 16 of the patient to a position desired by the operator. It is possible to reduce the burden on the patient such that the patient who has been injured may get drunk.

  As one modification, the movement of the top 3 and the projector 6 in S4 may be divided into a movement step in the y direction and a movement step in the direction opposite to the z direction. In this case, the operation unit is provided with a button for moving step in the y direction and a button for moving step in the opposite direction of the z direction, and each button is pressed to move to the corresponding direction. The top plate 3 and the projector 6 are moved. Alternatively, only one movement step may be performed, and the movement in the remaining direction may be left to manual operation. These specifications make it possible to sufficiently handle the sudden demands of the operator.

(Example 2)
As in the first embodiment, the X-ray CT apparatus in the second embodiment includes a gantry 1, a bed 2, a top plate 3, an operation unit 5, an upper projector 25, an X-ray tube 12, an X-ray detector 13, and an image generation (not shown). Unit, projector 6, projector moving mechanism 7, top plate moving mechanism 8, movement amount calculating unit 9, opening 4, and peripheral part 24. In addition, about the structure of each part or each mechanism, it shall function similarly to Example 1. FIG.

  FIG. 14 is a perspective view of the projector movable range 17 in the second embodiment. The projector movable range 17 in the second embodiment is different from that in the first embodiment, and the patient in the opening 4 can irradiate light from the projector 6 as shown in FIG. The light projected by the projector 6 is parallel to the x direction as in the first embodiment, and the projector 6 moves in the projector movable range 17 by operating the projector moving mechanism 7 in accordance with an instruction from the operation unit 5. Can move freely. On the other hand, if the projector 6 and the projector moving mechanism 7 enter the imaging range 14 as shown in FIG. 2, the projector 6 and the projector moving mechanism 7 may interfere with the imaging of the tomographic image. It is desirable that it is provided in a range that does not enter the area. Alternatively, it is desirable to have a mechanism that can avoid the projector 6 and the projector moving mechanism 7 from the imaging range 14 when capturing a tomographic image. As in the first embodiment, the projector movable range 17 has a length L1 in the z direction and a length L2 in the y direction, and corresponds to the lengths of the rail 7a and the rail 7b of the projector moving mechanism 7 in FIG. To do.

  The light emitted from the projector 6 is projected onto the patient surrounded by the peripheral portion 24 through the transparent member 10 as shown in FIG. 5, for example. Note that the transparent member 10 is provided in a range in which the projector movable range 17 is projected into the opening 4 as in the first embodiment.

  The flow of the second embodiment will also be described with reference to FIG.

  FIG. 15 shows the X of the present embodiment in a section parallel to the yz plane through the center of the opening 4 in an initial state in which no operation is performed after the patient P lies on the top 3. It is sectional drawing of a line CT apparatus. As shown in FIG. 16, the projection light 11 projected from the projector 6 in the initial state is separated from the center line M of the photographing range by L7 in the z direction and by L8 from the upper part of the opening 4 in the direction opposite to the y direction. Projected to the original position (origin position O). This origin position O corresponds to the position of the projector 6 when the rail 7a is at the midpoint position in the longitudinal direction of the rail 7b and the projector 6 is at the right end of the rail 7a in FIG. 4, for example. In this embodiment, the target position 16 in FIGS. 15 and 16 is the center of the diagnostic target region 15 projected on the side of the patient P.

  In S <b> 1, the operator manually operates the operation unit 5 to move the top 3 so that the target position 16 is located in the area where the projection light 11 can be projected as shown in FIG. 16. Move. The area where the projection light 11 can be projected is a three-dimensional space in which the projector movable range 17 in FIG. 14 is projected into the opening 4. As a result of the above-described manual operation by the operator, the position of the target position 16 when S1 is completed is a position away from the origin position O of the projection light 11 by L9 in the z direction and L10 in the direction opposite to the y direction. Here, since there is no intention of accurately aligning the position of the top plate 3 with the movement of the top plate 3 here, it is determined by the operator whether or not the target position 16 is within the region where the projection light 11 can be projected. Rough things such as visual inspection may be used.

  In S <b> 2, the operator moves the position of the projector 6 by a manual operation via the operation unit 5 so that the projection light 11 is projected at the target position 16 in FIG. 16. As a result, as shown in FIG. 17, the projection light 11 moves from the origin position O to a position separated by L9 in the z direction and L10 in the direction opposite to the y direction. The projector 6 is moved in the direction opposite to the z direction and the y direction based on the pulse signal transmitted from the operation unit 5 to the projector moving mechanism 7 as described above.

  As shown in S <b> 3, the movement amount calculation unit 9 calculates the pulse signal transmitted from the operation unit 5 to the projector movement mechanism 7 in each direction. The calculation method at this time is as described above.

  In S4, first, the operator presses a button 5k provided on the operation unit 5. When the button 5k is pressed, the movement amount calculation unit 9 moves the projector 6 and the top plate 3 so that the movement amount is the same in the opposite direction to the movement direction and movement amount of the projector 6 in S2. Moving. In other words, the same number of pulse signals that are opposite in polarity to the pulse signal transmitted to the projector moving mechanism 7 for moving the projector 6 in S3 are transmitted to the projector moving mechanism 7 and the top plate moving mechanism 8. As a result, as shown in FIG. 18, at the end of S2, the projection is located at a position away from the center line M of the imaging range by L7 + L9 in the z direction and L8 + L10 from the upper part of the opening 4 in the opposite direction of the y direction. The light 11 moves from the center line M of the imaging range to the origin position O of the projector 6 which is separated by L7 in the z direction and L8 away from the upper part of the opening 4 in the direction opposite to the y direction. As shown in FIG. 18, the top plate 3 also moves L9 in the direction opposite to the z direction and L10 in the y direction.

  When S4 is completed, the operator presses a not-shown top-plate feed button on the operation unit 5. When the operator depresses the top board feed button, as shown in S5, the operation unit 5 sends a pulse signal for moving the top board 3 in a direction opposite to the z direction by a predetermined distance (L7). To give. As a result, the top 3 moves to a position where the target position 16 coincides with the center line M of the imaging range as shown in FIG.

  In S6, scanning by the X-ray CT apparatus is started, and a tomographic image of the patient P is taken.

  As described above, the X-ray CT apparatus according to the second embodiment is placed on the top 3 because it is not necessary to move the top 3 in order to move the target position 16 of the patient to a position desired by the operator. It is possible to reduce the burden on the patient such that the patient who has been injured may get drunk.

  As mentioned above, although embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Gantry 2 ... Bed 3 ... Top plate 4 ... Opening part 5 ... Operation part 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5m ... button 6 ... projector 7 ... projector movement mechanism 8 ... top plate movement mechanism 9 ... movement amount calculation unit 10 ... transparent member 11 ... projection light 12 ... X X-ray detector 13 ... X-ray detector 14 ... imaging range 15 ... diagnostic region 16 ... target position 17 ... projector movable range 18 ... lever 24 ... peripheral portion 25 ...・ Upper floodlight

Claims (8)

A gantry having an opening;
A top plate on which the patient is placed and whose longitudinal direction faces the opening;
A top plate moving mechanism for movably supporting the top plate;
A projector installed in the gantry and capable of projecting light to the patient;
A projector moving mechanism for movably supporting the projector;
X-ray CT apparatus provided with The projector movement mechanism moves the projector from a predetermined origin position so that the light projected by the projector hits a target position in the patient, and then moves the projector to the predetermined origin position.
2. The X-ray CT apparatus according to claim 1, wherein the top plate moving mechanism moves the top plate in the same moving direction and moving amount as the projector moving mechanism moves the projector to the predetermined origin position. . A peripheral portion provided around the entrance on the bed side of the opening,
The X-ray CT apparatus according to claim 1, wherein light emitted from the projector can be projected into a space surrounded by the peripheral portion.   The X-ray CT apparatus according to claim 1, wherein light emitted from the projector can be projected into a space surrounded by the opening.   The X-ray CT apparatus according to claim 1, wherein the projector projects light in a short direction of the top plate. The projector is installed inside the gantry,
The X-ray CT apparatus according to claim 1, wherein a part of the wall surface of the gantry is made of a transparent member so that the light projected by the projector is not shielded by the wall surface of the gantry. First operating means for controlling movement of the top plate and the projector by the top plate moving mechanism and the projector moving mechanism;
A movement amount calculation unit that calculates a movement amount necessary for moving the projector from the movement of the projector by the first operation means to the predetermined origin position for each corresponding movement direction;
A second operation for sending an instruction to the projector moving mechanism and the top plate moving mechanism so as to move the projector and the top plate by a moving amount based on the calculation result in a moving direction based on the calculation result of the movement amount calculating unit. Means,
An X-ray CT apparatus according to claim 1, comprising: The top plate moving mechanism supports the top plate so as to be movable in the vertical direction and the longitudinal direction of the top plate,
The X-ray CT apparatus according to claim 1, wherein the projector moving mechanism supports the projector so as to be movable in a vertical direction and a longitudinal direction of the top plate.

Images