JP2007167408A - Medical diagnostic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein, in apparatuses for executing PET (Positron Emission Tomography) examination and an X-ray CT examination by assembling a PET diagnostic apparatus and an X-ray CT apparatus together and using a common bed, a top board mounted with a subject is sent into gantries of the both apparatuses in a cantilevered state, the top board is deflected by the body weight of the subject and it is difficult to capture the same tomographic image by the both apparatuses. <P>SOLUTION: Top board support mechanisms 14 and 15 are provided in the gantries of the both apparatuses respectively, till the top board 2 is sent, wait at the height a little lower than the height of the top board 2 and, whenever the examination cross section of the subject 1 reaches imaging surfaces of the respective gantries, the corresponding top board support mechanism 14 or 15 is raised to the height horizontally supporting the top board respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a medical image diagnostic apparatus including two types of image diagnostic apparatuses that share a single bed.

In recent years, devices that perform PET inspection and X-ray CT inspection in succession by combining a PET (positron emission tomography) diagnostic apparatus and an X-ray CT apparatus and using a common bed have become widespread (for example, patents). Reference 1). Specifically, as shown in FIG. 4 (a), a PET detector 6 is arranged in a circular shape inside, and a PET gantry 5 having a tunnel portion 10 in the center is disposed opposite to and integrated with the PET gantry 5. An X-ray CT gantry 7 having a rotatable X-ray tube 8 and a CT detector 9 and having a tunnel portion 11 at the center is arranged as close as possible. The bed 16 is installed as close as possible to the opposite side. The couch 16 includes a couch base 3 and a top plate 2 that is held on the couch 16 so as to be horizontally movable. A cross section (hereinafter referred to as an inspection cross section) to be imaged perpendicular to the body axis of the subject 1 placed on the top 2 is moved in the tunnel portion 10 of the PET gantry 5 by the horizontal movement of the top 2. After being sent to a position that coincides with the PET imaging surface, that is, the position shown in FIG. 4B, imaging by the PET diagnostic apparatus is performed. Thereafter, the inspection section of the subject 1 is again sent to the position coincident with the CT imaging surface in the tunnel portion 11 of the X-ray CT gantry 7 by the horizontal movement of the top plate 2, that is, the position shown in FIG. After that, imaging by the X-ray CT apparatus is performed. The captured PET image and CT image are subjected to appropriate image processing by an image processing unit (not shown) built in the console 4 and displayed on a monitor device (not shown) to be used for diagnosis. Are often displayed superimposed. In some cases, data obtained by an X-ray CT apparatus is used as absorption correction data when a PET image is created.
Japanese Patent Laid-Open No. 7-20245

  When performing the overlay display of the above-described PET image and CT image, naturally, both images must have the same cross section of the subject 1, and the data obtained by the X-ray CT apparatus is subjected to absorption correction when the PET image is created. Even when used as data, an accurate PET image cannot be obtained unless both images have the same cross section of the subject 1. In this regard, when the top plate 2 is fed into the tunnel portion 10 of the PET gantry 5 by horizontal movement and further into the tunnel portion 11 of the X-ray CT gantry 7, the top plate 2 is moved to one side by the bed base 3. The body is supported only at the end of the head, and deflection occurs due to the weight of the subject 1, but the amount increases as the length of the feeding from the bed base 3 of the top 2 increases. Even if the top 2 is stopped at a position where the inspection cross section of 1 coincides with the respective imaging surfaces in the PET gantry 5 and the X-ray CT gantry 7, the amount of deflection of the top 2 at both stop positions Strictly speaking, the same section of the subject 1 is not imaged due to the difference between the two.

  In order to eliminate such inconvenience, a bed 17 as shown in FIG. 5 is considered. That is, the subject 1 is placed on the top 12 supported by the bed base 13 only at one end, and wheels (not shown) attached to the bottom of the bed base 13 and rails laid on the floor (shown) The bed base 13 moves in a direction approaching the PET gantry 5, and the inspection cross section of the subject 1 is positioned on the PET imaging surface in the tunnel portion 10 of the PET gantry 5 and the X-ray CT gantry 7. When the CT imaging surface position in the tunnel portion 11 is reached, the operation stops and imaging of the PET image and CT image is performed. In this case, as shown in FIG. 5, the top 12 is always deflected by a certain amount due to the weight of the subject 1, and the amount of deflection in the examination section of the subject 1 is the same at both the PET imaging surface position and the CT imaging surface position. Although it is possible to take an image of the same cross section of the subject 1 at both imaging surface positions, it is difficult to accurately stop because the entire bed 17 is moved by this method, and the entire top plate 12 is only at one end. The top plate 12 is likely to vibrate because of the structure that is supported by and moves together with the bed base 13 that supports it. Further, there is a problem that the mechanism for movement becomes large and complicated. 5 are the same as those in FIG. 4 and the description thereof will be omitted.

  In order to solve the above problems, the invention of claim 1 is provided with two sets of imaging means for collecting and imaging image information of the subject from a direction orthogonal to the body axis of the subject, A medical device sharing a set of couches configured to include a couch for placing an examiner and a couch base for holding the couch so that it can move horizontally, and transferring the subject to each imaging position of the 2 imaging units In the diagnostic imaging apparatus, a medical apparatus provided with a set of top plate support mechanisms that are arranged corresponding to the imaging positions farther from the bed among the imaging positions and horizontally support the top plate together with the bed base. An image diagnostic apparatus is provided.

  In order to solve the above problem, the invention of claim 2 is provided with two sets of imaging means for collecting and imaging image information of the subject from a direction orthogonal to the body axis of the subject, A medical device sharing a set of couches configured to include a couch for placing an examiner and a couch base for holding the couch so that it can move horizontally, and transferring the subject to each imaging position of the 2 imaging units In the diagnostic imaging apparatus, there is provided a medical diagnostic imaging apparatus provided with two types of top plate support mechanisms which are arranged corresponding to the respective imaging positions and horizontally support the top plate together with the bed base.

  In order to solve the above problems, the top plate support mechanism holds the top plate from below so that the top plate can be moved horizontally, and holds the top plate support portion so that the top plate can move up and down. Top plate support unit holding means, vertical drive means for driving the top plate support unit held by the top plate support unit holding unit in the vertical direction, and until the top plate reaches directly above the top plate support unit Maintains the top plate support portion at a height that does not contact the top plate, and the top plate support portion is a height at which the top plate is horizontally supported after the top plate has reached the top of the top plate support portion. The medical image diagnostic apparatus according to claim 1 or 2, further comprising a top plate support mechanism control means for controlling the vertical drive means so as to be raised.

  According to the present invention, in an apparatus for performing PET inspection and X-ray CT inspection in succession using a common bed by combining a PET diagnostic apparatus and an X-ray CT apparatus, the positions of the captured images of both apparatuses due to the deflection of the top plate Therefore, it is possible to properly display the overlay of the PET image and the CT image, and use the data obtained by the X-ray CT apparatus as the absorption correction data when creating the PET image. A PET image can be obtained.

  In addition, the present invention can accurately stop the subject at the imaging position and generate vibration of the top plate as compared with the conventionally proposed method described in the section “Problems to be Solved by the Invention”. It is difficult to achieve and can be realized with a small and simple structure.

  The embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a diagram showing an example of the stop position of the top board 2 and the arrangement of the top board support mechanisms 14 and 15 for imaging at two imaging positions, and FIG. 2 shows the PET gantry 5 as an example. It is a perspective view which shows the example of arrangement | positioning of the top-plate support mechanism. FIG. 3 is a diagram schematically showing a configuration example of the top plate support mechanisms 14 and 15. In these drawings, the parts and the like denoted by the same reference numerals as those in FIG. 4 are the same as those in FIG.

  Predetermined positions where the operator (not shown) can easily get on and off the subject 1 such as a position where the amount of feeding from the bed base 3 is minimized as shown in FIG. (Hereinafter referred to as the initial position) and the subject 1 is placed thereon. Next, after determining the inspection cross section of the subject 1, the operator measures the distance from the inspection cross section to the PET imaging surface in the tunnel portion 10 of the PET gantry 5, and the operation panel (not shown) of the console 4. Thus, the information is input and stored in the bed control unit 40 configured by, for example, a microcomputer. The couch controller 40 recognizes this distance as a moving distance from the initial position of the top 2 to the PET imaging position. The distance between the PET imaging surface and the CT imaging surface is stored in advance in the bed control unit 40 as a constant determined when the apparatus is installed.

  The operator operates the operation panel to control the top / bottom drive mechanism (not shown) by the bed control unit 40 to adjust the height of the top plate 2, and then operates the operation panel to perform the bed control unit 40. A top plate horizontal drive mechanism (not shown) is controlled to start horizontal movement of the top plate 2 for moving the subject 1 into the tunnel portion 10. The couch controller 40 can move the top plate 2 up and down by the top plate up / down drive mechanism, can read the top plate height by the top plate height detection mechanism (not shown), and the top plate horizontal drive mechanism. The plate 2 can be moved horizontally, and the horizontal movement distance can be read by a top plate horizontal movement detection mechanism (not shown). However, the configurations of the top / bottom drive mechanism, the top / bottom horizontal drive mechanism, the top / bottom height detection mechanism, and the horizontal movement amount detection mechanism are not particularly related to the present invention, and thus further description thereof is omitted.

  When the top plate 2 starts to move horizontally, the bed control unit 40 is constituted by, for example, a microcomputer or the like, and the support mechanism control units 28 and 38 for controlling the operation of the top plate support mechanism 14 or 15 are provided with the roller 20 or Slightly lower than the height at which the top plate 2 becomes horizontal when the roller 30 supports the top plate 2 from below (hereinafter referred to as horizontal support height), and the height at which the top plate 2 is directly above and does not come into contact with the roller 30 Then, a signal instructing the start of vertical movement is transmitted. The horizontal support height is set by the bed control unit 40, for example, as the height of the back surface obtained by subtracting the thickness of the top plate 2 from the height of the top plate 2 at the start of horizontal movement, and the standby height is lower by a certain amount. Both heights are automatically calculated.

  Here, since the top plate support mechanisms 14 and 15 have the same configuration, a configuration example of the top plate support mechanism 14 will be described with reference to the upper part of FIG. A rectangular tubular support rod 21 having a cylindrical roller 20 that supports the top plate 2 from below so as to be horizontally movable is fixed to the upper end, and is inserted into a rectangular tubular support tube 22 fixed to the bottom surface of the PET gantry 5. It is held by a bearing or the like (not shown) so as to be slidable in the vertical direction. A notch having an appropriate length is provided on one side surface of the support cylinder 22 downward from the upper end portion, and a rack 23 attached to one side surface of the support bar 21 is exposed to the outside from the support cylinder 22 through the notch. ing. Then, the rotation of the motor 25 is transmitted to the rack 23 via the gear 29 attached coaxially with the rotating shaft and the pinion 24 meshing with the gear 29, thereby moving the support bar 21 and the roller 20 upward or downward. It is configured as follows. The bearing (not shown) and the motor 25 that support the pinion 24 are both fixed to a frame (not shown) fixed to the bottom surface of the PET gantry 5. Further, a rotary encoder 26 is attached to the pinion 24 so as to be coaxial with the rotating shaft thereof, and outputs information related to the height of the roller 20 to the support mechanism control unit 28.

  When the support mechanism control units 28 and 38 receive from the bed control unit 40 a signal for instructing the standby height and the start of vertical movement to that height, the current heights of the rollers 20 and 30 are output from the outputs of the rotary encoders 26 and 36, respectively. , The motors 27 and 37 are instructed to raise the rollers 20 and 30 if the height is lower than the standby height and to lower the rollers 20 and 30 if the height is higher. Then, when the heights of the rollers 20 and 30 reach the standby heights, the driving of the motors 25 and 35 is stopped and the brakes 51 and 61 are operated by the brake driving units 52 and 62 to rotate the gears 29 and 39, respectively. Is forcibly stopped, and this state is continued until an instruction to move to the horizontal support height is received. Note that the time for the rollers 20 and 30 to reach the standby height after the support mechanism control units 28 and 38 receive the standby height and a signal for instructing the start of the vertical movement to the height from the bed control unit 40 is horizontal. The moving tip is configured to be sufficiently shorter than the time from the initial position to the top of the roller 20.

  The top plate 2 that has horizontally moved into the tunnel unit 10 with the subject 1 placed on it reaches the upper part of the roller 20 at the standby height, and the PET from the initial position stored in the bed control unit 40 before the horizontal movement is started. When the movement of the moving distance to the imaging position is finished, that is, when the examination cross section reaches the PET imaging surface, the bed control unit 40 temporarily stops. Thereafter, a signal for instructing the horizontal support height and start of raising is transmitted from the bed control unit 40 to the support mechanism control unit 28 of the top plate support mechanism 14, and the support mechanism control unit 28 raises the roller 20 from the standby height to the horizontal support height. After that, the driving of the motor 25 is stopped, the brake 51 is operated by the brake driving unit 52, the rotation of the gear 29 is forcibly stopped, and the state is kept until the next movement instruction to the standby height is received. continue. As a result, even if the top plate 2 is bent by the weight of the subject 1, it is pushed up and supported in a horizontal state, resulting in the state shown in FIG. At this time, the roller 30 of the top plate support mechanism 15 is still at the standby height. In this state, PET imaging is performed, and the obtained image is subjected to appropriate image processing by an image processing unit (not shown) built in the console 4 and displayed on a monitor device (not shown). It is stored in a storage device (not shown).

  Thereafter, the couch controller 40 starts the horizontal movement of the table 2 again, sends the subject 1 into the tunnel part 11 of the X-ray CT gantry 7, and stores the PET imaging surface and the CT imaging surface stored in advance as constants. Is stopped when the distance is moved, i.e., when the inspection cross section reaches the CT imaging surface. Then, a signal for instructing the horizontal support height and starting to rise to the height is transmitted from the bed control unit 40 to the support mechanism control unit 38 of the top plate support mechanism 15, and the support mechanism control unit 38 moves the roller 30 to the horizontal support height. After being raised, the driving of the motor 35 is stopped, the brake 61 is operated by the brake driving unit 62 to forcibly stop the rotation of the gear 39, and the state is kept until the next movement instruction to the standby height is received. Continue. As a result, even if the top plate 2 is bent by the weight of the subject 1, it is pushed up and supported in a horizontal state, and the state shown in FIG. In this state, CT imaging is performed, and the obtained image is subjected to appropriate image processing by an image processing unit built in the console 4 and displayed on the monitor device and stored in the image storage device. After the CT imaging is completed, the bed control unit 40 horizontally moves the table 2 in the opposite direction to that before, stops at the initial position shown in FIG.

  In the above embodiment, the distance from the examination cross section when the top plate 2 is at the initial position to the PET imaging surface is measured and stored in the bed control unit 40 as the moving distance from the initial position of the top plate 2 to the PET imaging position. However, the fixed surface such as the end surface of the bed base 3 opposite to the gantry is used as a reference surface, and the distance from the reference surface to the PET imaging surface is stored in advance as a constant. The distance to the examination cross section at the initial position is measured and input from the operation panel of the console 4, the difference between the two is calculated by the bed control unit 40, and the moving distance from the initial position of the top 2 to the PET imaging position It is good.

  In the above embodiment, the bed control unit 40 notifies the support mechanism control unit 28 or 38 after the inspection cross section reaches the PET imaging surface or the CT imaging surface, and the table 2 stops the horizontal movement. The motor drive unit 27 or 37 is instructed to raise 20 or 30 to the horizontal support height, but the roller 20 is moved horizontally after the tip of the top plate 2 passes just above the roller 20 and stops. An instruction to raise to the support height may be issued, and an instruction may be given to raise the roller 30 to the horizontal support height after the tip of the top plate 2 passes just above the roller 30 and stops.

  In the above embodiment, the well-known rack and pinion method is used to convert the rotational drive of the motor 25 or 35 into the vertical movement of the support rod 21 or 31, but other well-known methods such as a ball screw method may be used. Good.

  In the above-described embodiment, the PET gantry 5 is disposed at a position close to the bed 16 and the X-ray CT gantry 7 is disposed at a far position. However, both gantry may be reversed.

  In the above embodiment, the top plate support mechanisms 14 and 15 are provided corresponding to the PET imaging surface and the CT imaging surface, respectively. However, the top plate support mechanism 14 corresponding to the PET imaging surface located on the side closer to the bed 16 is provided. Except for this, substantially the same effect can be obtained with only the top plate support mechanism 15 corresponding to the CT imaging surface located on the side far from the bed 16. However, in order to obtain a tomographic image of the same surface with higher accuracy for the PET image and the CT image, it is preferable to provide the top plate support mechanisms 14 and 15 corresponding to the PET imaging surface and the CT imaging surface, respectively. Since the level is obtained with higher accuracy, it is more effective.

  In the above embodiment, the two imaging apparatuses that collect and image the image information of the subject from the direction orthogonal to the body axis of the subject are the PET diagnostic apparatus and the X-ray CT apparatus, but the MRI diagnostic apparatus, Any combination of two imaging devices that collect and image the subject's image information from a direction orthogonal to the subject's body axis, such as a scintillation camera and a C-arm circulatory X-ray inspection device, may be used. .

  The present invention relates to a medical image diagnostic apparatus including two types of image diagnostic apparatuses that share a single bed.

It is a figure for demonstrating the Example of this invention. It is a figure for demonstrating the Example of this invention. It is a figure for demonstrating the Example of this invention. It is a figure for demonstrating operation | movement of the top plate at the time of a test | inspection. It is a figure for demonstrating a prior art.

Explanation of symbols

1: Subject 2: Top plate 3: Bed base 4: Console 5: PET gantry 6: PET detector 7: X-ray CT gantry 8: X-ray tube 9: CT detector 10: Tunnel portion 11 : Tunnel portion 12: Top plate 13: Bed base 14: Top plate support mechanism 15: Top plate support mechanism 16: Bed 17: Bed 20: Roller 21: Support rod 22: Support cylinder 23: Rack 24: Pinion 25: Motor 26 : Rotary encoder 27: Motor drive unit 28: Support mechanism control unit 29: Gear 30: Roller 31: Support rod 32: Support cylinder 33: Rack 34: Pinion 35: Motor 36: Rotary encoder 37: Motor drive unit 38: Support mechanism Control unit 39: gear 40: bed control unit

Claims (3)

Two types of imaging means for collecting and capturing image information of the subject from a direction orthogonal to the body axis of the subject are arranged in parallel, and the top plate on which the subject is placed and the top plate are moved horizontally. In a medical diagnostic imaging apparatus that is configured by a bed base that can be held and transfers the subject to each imaging position of the two types of imaging means, and that is shared with one set of bed, the imaging position is far from the bed A medical image diagnostic apparatus comprising a top plate support mechanism for horizontally supporting the top plate at the imaging position of the other side. Two types of imaging means for collecting and capturing image information of the subject from a direction orthogonal to the body axis of the subject are arranged in parallel, and the top plate on which the subject is placed and the top plate are moved horizontally. In the medical diagnostic imaging apparatus that is configured by a bed base that can be held and transfers the subject to each imaging position of the two types of imaging means, the horizontal plate is horizontally positioned at each imaging position. A medical image diagnostic apparatus characterized in that a two-type top plate support mechanism for supporting the medical image is provided. The top plate support mechanism includes a top plate support portion that supports the top plate from below so as to be horizontally movable, a top plate support portion holding means that holds the top plate support portion so as to be vertically movable, and the top plate support portion holding means. A vertical driving means for driving the top plate support portion held by the top and bottom in a vertical direction, and a height at which the top plate support portion does not contact the top plate until the top plate reaches directly above the top plate support portion. And the top plate support mechanism for controlling the vertical drive means to raise the top plate support portion to a height at which the top plate is horizontally supported after the top plate reaches directly above the top plate support portion. 3. The medical image diagnostic apparatus according to claim 1, further comprising a control unit.

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