JP5893102B2 - X-ray computed tomography system - Google Patents

Description

  The present invention relates to an X-ray computed tomography apparatus equipped with a two-dimensional detector (area detector).

  In recent years, an X-ray computed tomography apparatus capable of so-called CT fluoroscopy has been introduced that immediately reconstructs and displays a tomographic image in parallel with scanning. Attempts have been made to use CT fluoroscopy for catheterization. CT reconstruction has a very large number of processing steps. In the current CT fluoroscopy, for example, the three-stage surface, the fluoroscopic range in the body axis direction combining the three-stage surfaces is only about 6 mm (see FIG. 13). It is possible to widen the slice range of each cross section and expand the perspective range to, for example, 32 mm. Increasing the slice thickness makes the partial volume phenomenon more prominent and obscure the tip of the needle or catheter. Therefore, the X-ray computed tomography apparatus cannot be used for catheterization or the like.

  Recently, an X-ray computed tomography apparatus equipped with an area detector such as 320 columns and having a wide field of view that can cover the heart has appeared. However, the fluoroscopic range in which CT fluoroscopy is possible is still limited by the reconstruction processing speed, and in CT fluoroscopy, many segments are stopped as shown in FIG.

  Therefore, in reality, the X-ray computed tomography apparatus cannot be applied to situations requiring immediateness and a wide field of view such as catheterization. Even if reconstruction technology has been developed and hundreds of cross sections can be reconstructed in real time, it is necessary to continuously expose a wide area, resulting in exposure problems.

JP 2000-83941 A

  An object of the present invention is to enable an X-ray computed tomography apparatus equipped with an area detector to be applied to a situation requiring immediateness and a wide field of view such as catheterization.

An aspect of the present invention includes an X-ray tube, an X-ray detector having a plurality of two-dimensionally arranged X-ray detection elements, a rotation mechanism that rotatably supports the X-ray tube, and the X-ray A high voltage generator for generating a high voltage applied to the X-ray tube to generate X-rays from the tube, and reconstructing multi-slice tomographic image data or volume data based on the output of the X-ray detector A reconstruction processing unit, a three-dimensional image processing unit that generates a pseudo three-dimensional image for setting a fluoroscopic position from the multi-slice tomographic image data or the volume data, a display unit, and the X-ray The tube is continuously rotated, X-rays are repeatedly generated at a plurality of locations on the rotation trajectory of the X-ray tube, and based on data output from the X-ray detector in synchronization with the generation of the X-rays Before mapping to multiple locations Provided is an X-ray computed tomography apparatus comprising: a rotation control unit that controls the rotation mechanism, the high voltage generation unit, and the display unit in order to display a projection image as a moving image on a display unit. To do.

  According to the present invention, an X-ray computed tomography apparatus equipped with an area detector can be applied to situations requiring immediateness and a wide field of view such as catheterization.

It is a figure which shows the structure of the X-ray computed tomography apparatus which concerns on embodiment of this invention. It is a figure which shows the external appearance of the X-ray computed tomography apparatus of FIG. It is a flowchart which shows the operation | movement procedure of this embodiment. It is a figure which shows an example of the perspective angle setting screen of process S12 of FIG. It is a figure which shows the other example of the perspective angle setting screen of process S12 of FIG. It is a figure which shows the relationship between rotation of a X-ray tube, and a fluoroscopic angle in this embodiment. It is a figure which shows the relationship between fluoroscopy and a scan in this embodiment. It is a figure which shows the irradiation range at the time of fluoroscopy of process S15 of FIG. It is a figure which shows the see-through | perspective position of process S15 of FIG. In this embodiment, it is a figure which shows perspective angle difference (alpha) in stereoscopy. In this embodiment, it is a figure which shows the example of the perspective position of a stereo perspective and orthogonal biplane perspective. In this embodiment, it is a figure which shows the example of the perspective position of orthogonal biplane perspective. It is a figure which shows the viewing angle at the time of CT fluoroscopy at the time of using the conventional 3 row detector. It is a figure which shows the viewing angle at the time of CT fluoroscopy at the time of using the conventional multi-row detector.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The X-ray computed tomography apparatus includes a rotation / rotation method in which an X-ray tube and an X-ray detector are rotated as one body, and a large number of X-ray detectors are arranged on a ring. Various methods such as a fixed / fixed method in which only the tube rotates around the subject, a fixed / fixed method in which a plurality of X-ray tubes are arranged on the ring, and a plurality of X-ray detectors are similarly arranged on the ring. Although there are methods, the present invention is more effective when applied to a rotation / rotation method and a fixed / rotation method. Also, a single tube type in which a pair of X-ray tubes and X-ray detectors are mounted on a rotating frame, and a so-called multi-tube type in which a plurality of pairs of X-ray tubes and X-ray detectors are mounted on a rotating frame However, the present invention can be applied to any type. In addition, the mechanism for converting incident X-rays into electric charge includes an indirect conversion type in which X-rays are converted into light by a phosphor such as a scintillator and the light is further converted into electric charge by a photoelectric conversion element such as a photodiode, and an X-ray semiconductor. The generation of electron-hole pairs in the electrode and the transfer to the electrode, that is, the direct conversion type utilizing a photoconductive phenomenon, is the mainstream. Any of these methods may be adopted as the X-ray detection element.

  FIG. 1 shows the configuration of an X-ray computed tomography apparatus according to this embodiment. FIG. 2 shows its appearance. The gantry 100 includes an X-ray tube 101 and an X-ray detector 103.

The radiation window of the X-ray tube 101 is equipped with a collimator 113. The collimator 113 arbitrarily adjusts the cone angle in the range from the maximum cone angle of the X-ray according to the width of the X-ray detector 103 with respect to the Z axis to the minimum cone angle of one row (one segment) of the X-ray detector 103. It has a structure to change.

The X-ray detector 103 is an area detector (also referred to as a two-dimensional array detector) having a wide visual field in the Z-axis direction equipped with, for example, 320 columns (320 segments).

  The X-ray tube 101 and the X-ray detector 103 are mounted on an annular frame 102 supported so as to be rotatable about a rotation axis Z. The X-ray detector 103 faces the X-ray tube 101 with the subject placed on the top plate 138 of the bed 137 sandwiched between the imaging region 5 opened in the center of the gantry 100. The frame 102 can be rotated at a high speed of, for example, 0.25 seconds / rotation by driving the rotating unit 107. The rotation angle of the frame 102 is detected by a rotation angle detector 111 realized by a rotary encoder. A tube voltage is applied to the X-ray tube 101 from the high voltage generator 109 via the slip ring 108, and a filament current is supplied. The high voltage generator 109 may be mounted on the frame 102 together with the capacitor. X-rays are generated from the X-ray tube 101 by applying a tube voltage and supplying a filament current. The X-ray detector 103 detects X-rays that have passed through the subject.

  The gantry 100 is supported by the tilt mechanism 127 so as to be tiltable. Thereby, the rotation axis Z of the frame 102, that is, the rotation axis Z of the X-ray tube 101 and the X-ray detector 103 can be tilted back and forth at an arbitrary angle from the horizontal position.

  A data acquisition circuit 104 generally called a DAS (data acquisition system) converts a signal output from the X-ray detector 103 for each channel into a voltage signal, amplifies it, and further converts it into a digital signal. This data (raw data) is sent to the preprocessing device 106 accommodated in the console 115 via the non-contact data transmission device 105, where it is subjected to correction processing such as sensitivity correction, and is in a stage immediately before the reconstruction processing. It is stored in the storage device 112 as so-called projection data.

  The storage device 112 includes a reconstruction device 114, a three-dimensional image processing unit 128, a monitor 116, a stereo monitor 117, a glasses-type stereo monitor 118, an operation unit 115, a foot switch 119, a projection condition setting support unit 121, and a fluoroscopy control unit 120. , Connected to the system controller 110 via a data / control bus. The reconstruction device 114 reconstructs the volume data based on the projection data stored in the storage device 112 under the cone beam image reconstruction method. A Feldkamp method is generally used as the cone beam image reconstruction method. The Feldkamp method is an approximate reconstruction method based on the fan beam convolution and back projection method. The convolution process assumes that the cone angle is relatively small and regards the data as fan projection data. Done. However, the back projection process is performed along an actual ray corresponding to the inclined cone angle.

  The three-dimensional image processing unit 128 generates a two-dimensional image that can be displayed on the two-dimensional screen from the volume data by volume rendering processing. In the volume rendering process, transparency and color are defined in stages according to pixel values and the like, and a target portion is selectively extracted. Actually, the pixel values of the points on the ray are sequentially added while applying a predetermined coefficient, and the addition result is used as the pixel value of the projection plane. The coefficient is determined by the transparency with respect to the pixel value, the distance from the line-of-sight direction (the distance from the projection plane to the point), the shadow condition, and the like. By this volume rendering process, for example, a pseudo three-dimensional image can be created so that the inside can be seen through.

  As described above, in this embodiment, the monitor 116, the stereo monitor 117, and the glasses-type stereo monitor 118 are provided as display units. The monitor 116 and the stereo monitor 117 are installed in the photographing room together with the gantry 100. The glasses-type stereo monitor 118 is attached to a surgeon performing catheterization, for example. A three-dimensional image and a projected image are displayed on the monitor 116. The stereo monitor 117 and the glasses-type stereo monitor 118 have a right-eye monitor unit (or right-eye display area) and a left-eye monitor unit (or left-eye display area), respectively. And used. The surgeon visually recognizes the right-eye monitor unit and the left-eye monitor unit of the stereo monitor 117 or the glasses-type stereo monitor 118 with the left and right eyes, respectively, thereby realizing stereoscopic viewing and recognizing the target three-dimensional structure.

  The operation unit 115 is provided for an operator to mainly perform a switching operation between a normal CT scan mode and a fluoroscopic mode and a condition setting operation for each mode. The normal CT scan mode is a mode for executing a general volume scan, and is not a new function, and thus detailed description thereof is omitted. The fluoroscopic mode is a mode for realizing a fluoroscopic function approximate to X-ray fluoroscopy using an X-ray diagnostic apparatus using an X-ray computed tomography apparatus, and the fluoroscopic mode will be described in detail below.

  The fluoroscopy condition setting support unit 121 provides a setting screen for easily and easily setting the fluoroscopy conditions by the operator. The provided setting screen will be described later. The foot switch 119 is a foot-operated switch that can be disposed at an arbitrary position on the floor near the gantry 100 or the bed 137. In the fluoroscopic mode, the subject is irradiated with X-rays during a period in which the foot switch 119 is stepped on and the on state is continued, and live fluoroscopy is executed. That is, in the fluoroscopic mode, every time the X-ray tube 101 is rotated, two to three images, and a set number of images more than that, are taken. When the X-ray tube 101 rotates continuously, images at each imaging angle are repeatedly generated at a period equivalent to the time for which the X-ray tube 101 rotates once, for example, 0.4 seconds. By displaying the repeatedly generated image immediately, it is possible to provide a moving image that can confirm the dynamic displacement of the subject to be photographed although the frame rate is relatively low. The fluoroscopic control unit 120 controls each unit in order to execute the CT fluoroscopic operation.

  The perspective mode has a stereo perspective format, a biplane format, and a combined format combining these stereo perspective and biplane. These types have different perspective angles. In the fluoroscopic mode according to the present embodiment, the X-ray tube 101 and the X-ray detector 103 continuously rotate around the subject along with the frame 102. During the period in which the rotation is continued and the foot switch 119 is shifted to the ON state, the X-ray tube 101 has at least two locations (hereinafter referred to as fluoroscopic positions or Each time it passes through (the fluoroscopic angle), pulsed X-rays are repeatedly generated. A projection image is generated based on data output from the X-ray detector 103 in synchronism with the generation of the X-ray, and is instantaneously displayed as a moving image on the monitors 116, 117, and 118 assigned in advance to the respective fluoroscopic positions. Is displayed. When the stereo perspective format is selected, the two perspective angles are limited to any angular difference in the range of 5-10 °. This angle difference corresponds to binocular parallax, and stereoscopic viewing is possible by viewing the two fluoroscopic images with the left and right eyes, respectively. When the biplane format is selected, there is no limit on the difference between the two perspective angles, but it is typically initialized to 90 °. When the combine format is selected, the perspective positions are set at three locations. The two fluoroscopic positions are set to any angular difference in the range of 5-10 ° and function as a stereo fluoroscopic format. One of the two fluoroscopic positions and the other one fluoroscopic position are typically Is set to an angle difference of 90 ° and functions as a biplane format.

  FIG. 3 shows an operation procedure of the fluoroscopic mode under the control of the fluoroscopic control unit 120 according to the present embodiment. First, a normal CT scan, here a volume scan, is executed (S11). Volume data is reconstructed by the reconstruction device 114 based on the projection data collected by the volume scan. A pseudo 3D image is generated from the volume data by the 3D image processing unit 128. A pseudo 3D image is displayed by the fluoroscopy condition setting support unit 121, and a fluoroscopic position (Z position) is set for the pseudo 3D image (S12). The gantry 100 is moved to the set position.

  Further, a perspective condition setting support screen including a pseudo three-dimensional image is configured. The main perspective conditions are selection of a stereo perspective format, a biplane format, and a combine format, and designation of a perspective angle. A line representing the rotation axis Z of the X-ray tube 101 is superimposed and displayed on the pseudo three-dimensional image. Further, a plurality of candidate lines having a perspective angle are superimposed on each other in a plane perpendicular to the line. The candidate line is a line segment that connects the center of the detector with the viewpoint that is irradiated with X-rays in the rotation trajectory. When a candidate line for which it is determined that the region to be operated is easy to see from a plurality of candidate lines is designated, a translucent cone beam model representing the field of view around the candidate line is displayed. After confirming that the fluoroscopic target part is included in the cone beam model, the designated candidate line is determined, and the fluoroscopic angle is set. When the stereo perspective format is selected, only candidate lines whose angle difference from the determined perspective angle is in the range of 5 to 10 ° are displayed. This means that the difference in perspective angle is substantially limited, and the range of this angle difference corresponds to the range of binocular parallax that enables stereoscopic viewing (see FIG. 10). In the stereo perspective format, two perspective angles are set.

  Two perspective angles are also set in the biplane format, but there is no limitation on the angle difference, and two arbitrary perspective angles can be set. In the biplane format, when one perspective angle is set, two candidate lines before and after that have an angle difference of 90 ° with respect to the perspective angle are initially displayed (see FIG. 12). Typically, two perspective angles having an angle difference of 90 ° are set. In the combine format, the procedure for setting the perspective angle in the stereo perspective format and the biplane format is repeated. However, one perspective angle is commonly set between two perspective angles set under the stereo perspective format and two perspective angles set under the biplane format (see FIG. 11). .

  FIG. 4 shows another simple fluoroscopy condition setting support screen by the fluoroscopy condition setting support unit 121. In this case, no volume scan is required. A perspective line 201 representing the first perspective angle and a perspective line 202 representing the second perspective angle are superimposed on the rotational trajectory model 200 of the X-ray tube 101. The perspective line is a line segment connecting the center of the detector from the viewpoint irradiated with X-rays in the rotation trajectory. The perspective lines 201 and 202 are dragged with the pointer 203 and rotated to an arbitrary angle, and determined at a desired angle. The same screen is obtained by dividing the first perspective angle numerical value display column 204, the second perspective angle numerical value display column 205, the numerical value display column 206 of the perspective angle difference therebetween, and dividing the perspective angle difference by the rotational angular velocity. A time difference display field 207 and a stereoscopic on / off setting field 208 are displayed. These values are related to the rotation operation of the perspective lines 201 and 202. Further, by inputting numerical values of the first and second perspective angles, rotation of the perspective lines 201 and 202 is related to the input values. When stereoscopic vision (stereoscopic perspective) is set to ON, the first perspective angle is set so that the angle difference between the first and second perspective angles is within a range of 5 to 10 °. The input range of the perspective angle of 2 is limited. When stereoscopic vision (stereoscopic perspective) is set to OFF, the restriction on the angle difference between the first perspective angle and the second perspective angle is released as described in the biplane format.

  FIG. 5 shows still another fluoroscopy condition setting support screen by the fluoroscopy condition setting support unit 121. In this case, all or some of the plurality of projection images 211 having different view angles collected by the volume scan are displayed as thumbnails. When a fluoroscopic image 211 that is determined to be easy to see the region to be operated from a plurality of projection images 211 is designated, a viewpoint mark 213 corresponding to the designated fluoroscopic image 211 is specified in the rotation trajectory model 212 of the X-ray tube 101. Are superimposed. The designated fluoroscopic image 211 is slightly enlarged or displayed with high luminance. When the viewpoint mark 213 is dragged with the pointer 203 and moved on the rotational trajectory model 212 to an arbitrary angle, the perspective image 211 corresponding to the viewpoint mark 213 is slightly enlarged or displayed with high luminance. The desired perspective angle is determined while confirming with the projection image.

  After the fluoroscopic angle is set as described above, the gantry 100 or the top board 138 is moved to the fluoroscopic position (S13). After the above preparation is completed, the start of fluoroscopy is instructed (S14). The rotating frame 102 is continuously rotated with the X-ray tube 101 and the X-ray detector 103. This continuous rotation of the rotating frame 102 is continued until a fluoroscopic end instruction (S19) is given. When the foot switch 119 is turned on during the continuous rotation period of the rotating frame 102, a pulse X-ray is irradiated from the X-ray tube 101 to the subject 2 or 3 times per rotation while the on state is maintained. (S15). As shown in FIGS. 6 and 9, the irradiation point is a viewpoint according to the set perspective angle. As shown in FIG. 8, the maximum fan angle and the maximum cone angle corresponding to the sensitivity region of the X-ray detector 103 are applied to the X-ray detector 103 so that the entire sensitivity region where the detection elements of the X-ray detector 103 are arranged is irradiated. Irradiated with.

  The projection image corresponding to the first perspective angle is displayed, for example, as a right-eye image on a pre-assigned screen (right-eye screen) of the stereo monitor 117 or the glasses-type stereo monitor 118. The projection image corresponding to the second perspective angle is immediately displayed on the screen (left-eye screen) assigned in advance in the stereo monitor 117 or the glasses-type stereo monitor 118, for example, as a left-eye image. Each of the right-eye screen and the right-eye screen is displayed as a moving image at a frame rate equivalent to the reciprocal of one rotation time.

  When the biplane format is selected, the projection image corresponding to the first perspective angle is displayed on one screen of the stereo monitor 117 or the glasses-type stereo monitor 118, and the projection image corresponding to the second perspective angle is It is displayed on the other screen or monitor 116. When the combine format is selected, the projected images for the left and right eyes are displayed on the respective screens of the stereo monitor 117 or the glasses-type stereo monitor 118, and the projected image having a perspective angle of 90 ° left is displayed on the monitor 116. Is done.

  When a gantry tilt instruction is input during the fluoroscopic period, as shown in FIG. 6, the gantry 100 is tilted in the indicated direction while the fluoroscopic operation is continued. Further, when a volume scan instruction is input during the fluoroscopic period, as shown in FIG. 7, continuous X-rays are irradiated with the maximum fan angle and the maximum cone angle only during one rotation or designated rotation from the start of the volume scan. The

Volume data is reconstructed by the reconstruction device 114 based on the projection data collected by the volume scan, and a pseudo 3D image is generated from the volume data by the 3D image processing unit 128 and displayed on the monitor 116. . At the same time, the projection data of the viewpoint corresponding to the first and second perspective angles in between is displayed as a projection image, and the fluoroscopic operation is continued. In practice, volume data reconstruction processing and three-dimensional image processing require a longer processing time than projection image display (perspective), and are not immediate.

  During the fluoroscopic period, when a change (re-setting) of the fluoroscopic position is instructed as in step S12 (S17), the process returns to step S13, and the gantry 100 is moved to that position.

  The above fluoroscopic operations are repeated until the objective is achieved, that is, until the catheterization is completed (S18), and then the fluoroscopic operation is completed (S19). Finally, a volume scan is executed and the projections acquired thereby Volume data is reconstructed by the reconstruction device 114 based on the data, and a pseudo three-dimensional image is generated from the volume data by the three-dimensional image processing unit 128 and displayed on the monitor 116. Thereby, the result of catheterization is confirmed (S20).

The operation assuming specific measures is as follows.
(Liver cancer TAE (embolization)
(1) A simple CT is imaged and an area to be seen through is determined by ADCT Volume Scan (16 cm) equipped with a wide-field area detector.
(2) Using the planar fluoroscopy function, bring the catheter to the SMA (upper mesenteric artery) and take a CTAP (portal angiography) with Volume Scan.
(3) Take the catheter to the common hepatic artery by plane fluoroscopy and take a CTA by Volume Scan.
(4) A three-dimensional image of the blood vessel is created from the CTA, and the nutritional blood vessel to the tumor is identified.
(5) While confirming the three-dimensional image, the microcatheter is operated and taken to the tumor blood vessels.
(6) Check for tumor staining by CTA.
(7) Insert the embolus into the tumor while confirming with planar fluoroscopy.
(8) Confirm that the embolus has spread to the tumor by CTA.

  In the procedure (5), the position where the branching portion of the blood vessel is known from the created three-dimensional image is displayed. At that position, the gantry rotation position and tilt are performed (it can also be done automatically) and confirmed by plane perspective.

While rotating the gantry, the image is taken in stereo → stereoscopically, and the catheter is operated and guided to an appropriate blood vessel while confirming the actual microcatheter state and the blood vessel running state with the three-dimensional image of the CTA. The normal three-section perspective cannot be obtained even if it is used because the range is insufficient.

  In the present embodiment, since it can be stereoscopically viewed only twice during one rotation, there is an effect that the operation is smooth and the exposure can be reduced. If necessary, the display position is changed and the operation is repeated (at this time, the three-dimensional display of the CTA is also interlocked).

(Needle biopsy (lung field))
(1) A simple CT is imaged and the range to be seen through with ADCT Volume Scan (16 cm) is determined.
(2) Create a three-dimensional image and examine a needle guide that does not damage the bronchi or blood vessels until reaching the tumor.
(3) A display angle that allows easy understanding of major blood vessels and bronchi is calculated along the guide.
(4) Rotate and tilt the pedestal so that the angle is the same, and confirm it with a plan perspective.
(5) Stereo imaging while rotating the gantry, stereoscopic viewing, and advance the biopsy needle to the target tumor while confirming the position of the surrounding blood vessels and bronchi.
(6) If necessary, change the display position and repeat this operation.

  As described above, according to the present embodiment, it is possible to obtain a wide range of three-dimensional CT fluoroscopic images taking advantage of the advantages of ADCT with a minimum exposure amount, and performing puncture and catheter operation while performing fusion with a three-dimensional Volume image. Improvement of accuracy and shortening of operation time can be expected. Furthermore, it is not necessary to reconstruct hundreds of images in real time and perform MPR, which can be realized at low cost.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  The present invention can be used in the field of X-ray computed tomography apparatuses equipped with an area detector.

  DESCRIPTION OF SYMBOLS 101 ... X-ray tube, 102 ... Rotating frame, 103 ... Two-dimensional X-ray detector, 109 ... High voltage generation part, 114 ... Reconstruction process part, 116, 117, 118 ... Monitor, 120 ... Perspective control part, 121 ... Perspective condition setting support unit.

Claims (9)

An X-ray tube;
An X-ray detector having a plurality of X-ray detection elements arranged two-dimensionally;
A rotation mechanism for rotatably supporting the X-ray tube;
A high voltage generator for generating a high voltage applied to the X-ray tube to generate X-rays from the X-ray tube;
A reconstruction processing unit for reconstructing multi-slice tomographic image data or volume data based on the output of the X-ray detector;
A three-dimensional image processing unit that generates a pseudo three-dimensional image for setting a fluoroscopic position from the multi-slice tomographic image data or the volume data;
A display unit;
The X-ray tube is continuously rotated, X-rays are repeatedly generated at a plurality of locations on the rotation trajectory of the X-ray tube, and the data output from the X-ray detector is synchronized with the generation of the X-rays. And a fluoroscopic control unit for controlling the rotation mechanism, the high voltage generation unit, and the display unit in order to display a projected image as a moving image on the display unit respectively associated with the plurality of locations. X-ray computed tomography apparatus.   A plurality of X-ray tubes arranged on the ring;
  A plurality of X-ray detectors having a plurality of X-ray detection elements arranged two-dimensionally;
  A high voltage generator for generating a high voltage applied to the X-ray tube to generate X-rays from the X-ray tube;
  A reconstruction processing unit for reconstructing multi-slice tomographic image data or volume data based on the output of the X-ray detector;
  A three-dimensional image processing unit that generates a pseudo three-dimensional image for setting a fluoroscopic position from the multi-slice tomographic image data or the volume data;
  A display unit;
X-rays are repeatedly generated at a plurality of locations of the X-ray tube, and projected onto the display units respectively associated with the plurality of locations based on data output from the X-ray detector in synchronization with the generation of the X-rays An X-ray computed tomography apparatus comprising: a high-voltage generation unit and a fluoroscopy control unit that controls the display unit to display an image as a moving image. 3. The X-ray computed tomography apparatus according to claim 1, wherein the plurality of locations have any angle difference in a range of 5 to 10 degrees. The X-ray computed tomography apparatus according to claim 3, wherein the projected image is displayed on the display unit so as to be viewed in stereo.   A tilt mechanism for tilting the rotation axes of the X-ray tube and the X-ray detector is further provided, and the fluoroscopic control unit is in parallel with the continuous rotation, generation of the X-rays, and display of the projection image. The X-ray computed tomography apparatus according to claim 1, wherein the tilt mechanism is controlled to tilt the rotation shaft in accordance with an operator instruction.   The fluoroscopic control unit is configured to change the high voltage in order to displace a plurality of locations on the rotation trajectory of the X-ray tube according to an operator instruction in parallel with the continuous rotation, generation of the X-rays, and display of the projection image. The X-ray computed tomography apparatus according to claim 1, wherein the generator is controlled. According to claim 1 or 2, further comprising a three-dimensional image processing unit for generating a plurality of two-dimensional image and the viewpoint of each of the plurality of locations from the tomographic image data or volume data multislice the reconstructed X-ray computed tomography apparatus.   The fluoroscopic control unit executes the control related to the high voltage generation unit and the display unit when a predetermined switch is turned on during a period in which the X-ray tube is continuously rotated. The X-ray computed tomography apparatus according to claim 1.   The X-ray computed tomography apparatus according to claim 1, wherein the display unit updates each projection image at a frame rate equivalent to a reciprocal of one rotation time.