JP5238893B1 - X-ray CT apparatus, image display apparatus, and image display method - Google Patents

Abstract

A technique capable of displaying a medical image reflecting a periodic movement in a subject is provided.
An X-ray CT apparatus according to an embodiment is an X-ray CT apparatus that scans a subject including a part with a periodic motion with X-rays and acquires detection data. The X-ray CT apparatus includes a reconstruction processing unit, a moving image creation unit, and a display control unit. The reconstruction processing unit creates a plurality of volume data based on the plurality of detection data acquired during one period in the periodic movement. The moving image creating unit creates a moving image showing a periodic movement based on at least a part of the plurality of volume data. The display control unit superimposes the moving image on the image based on the volume data and displays the image on the display unit.
[Selection] Figure 1

Description

  Embodiments described herein relate generally to an X-ray CT apparatus, an image display apparatus, and an image display method.

  An X-ray CT (Computed Tomography) apparatus is an apparatus that scans a subject using X-rays and processes the collected data by a computer, thereby imaging the inside of the subject.

  Specifically, the X-ray CT apparatus emits X-rays to a subject a plurality of times from different directions, detects X-rays transmitted through the subject with an X-ray detector, and generates a plurality of detection data. collect. The collected detection data is A / D converted by the data collection unit and then transmitted to the console device. The console device pre-processes the detection data and creates projection data. Then, the console device performs reconstruction processing based on the projection data, and creates tomographic image data or volume data based on a plurality of tomographic image data. Volume data is a data set representing a three-dimensional distribution of CT values corresponding to a three-dimensional region of a subject.

  The X-ray CT apparatus can perform MPR (Multi Planar Reconstruction) display by rendering the volume data in an arbitrary direction. Hereinafter, a cross-sectional image displayed in MPR by rendering volume data may be referred to as an “MPR image”. The MPR image includes, for example, an axial image showing a cross section orthogonal to the body axis, a sagittal image showing a cross section of the subject along the body axis, and a coronal image showing a cross section of the subject along the body axis. There is. Furthermore, an arbitrary cross-sectional image (oblique image) in the volume data is also included in the MPR image. The plurality of created MPR images can be simultaneously displayed on a display unit or the like.

  In addition, there is an imaging method called CT fluoroscopy (CTF) performed using an X-ray CT apparatus. CT fluoroscopy is an imaging method in which an image relating to a region of interest of a subject is obtained in real time by continuously irradiating the subject with X-rays. In CT fluoroscopy, images are created in real time by reducing the detection data collection rate and reducing the time required for reconstruction processing. CT fluoroscopy is used, for example, for confirming the positional relationship between the tip of a puncture needle and a part from which a specimen is collected during a biopsy, or for confirming the position of a tube when performing a drainage method. The drainage method is a method of draining the body fluid accumulated in the body cavity with a tube or the like.

  Here, when performing a biopsy on a subject while referring to an MPR image based on volume data obtained by CT fluoroscopy, for example, scanning and puncturing may be performed alternately. Specifically, first, an MPR image of the subject is acquired by CT fluoroscopy. A doctor or the like performs puncturing while referring to the MPR image. At this time, for example, in order to confirm the positional relationship between the tip of the puncture needle and the part from which the specimen is collected, CT fluoroscopy is performed again at a stage where puncture is performed to some extent. While referring to the MPR image obtained by another CT fluoroscopy, the doctor or the like further advances the puncture. By repeatedly performing this operation until the biopsy is completed, the biopsy can be reliably performed.

JP 2005-261932 A

  An organ (for example, lung) and a lesioned part inside a subject are accompanied by periodic movement due to the influence of respiration and pulsation. Therefore, when a biopsy is performed on a subject while referring to the MPR image, a part of the MPR image where the sample is collected at the timing when the volume data that is the source of the MPR image is acquired and the current timing when the puncture is performed May be out of position. However, it has been difficult to confirm this shift (periodic movement) with an MPR image.

  The embodiment has been made to solve the above-described problems, and an object thereof is to provide a technique capable of displaying a medical image reflecting a periodic movement in a subject.

  The X-ray CT apparatus according to the embodiment is an X-ray CT apparatus that scans a subject including a region with a periodic motion with X-rays and acquires detection data. The X-ray CT apparatus includes a reconstruction processing unit, a moving image creation unit, and a display control unit. The reconstruction processing unit creates a plurality of volume data based on the plurality of detection data acquired during one period in the periodic movement. The moving image creating unit creates a moving image showing a periodic movement based on at least a part of the plurality of volume data. The display control unit superimposes the moving image on the image based on the volume data and displays the image on the display unit.

  In addition, the X-ray CT apparatus of the embodiment is an X-ray CT apparatus that scans a subject including a part with periodic motion with X-rays and acquires detection data. The X-ray CT apparatus includes a reconstruction processing unit, a trajectory image creation unit, and a display control unit. The reconstruction processing unit creates a plurality of volume data based on the plurality of detection data acquired during one period in the periodic movement. The trajectory image creation unit creates a trajectory image indicating a periodic trajectory based on at least a part of the plurality of volume data. The display control unit superimposes the trajectory image on the image based on the volume data and displays the image on the display unit.

1 is a block diagram of an X-ray CT apparatus according to a first embodiment. It is a figure which shows the image displayed on the display part which concerns on 1st Embodiment. It is a figure which shows the display screen of the display part which concerns on 1st Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 1st Embodiment. It is a block diagram of the process part of the X-ray CT apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 2nd Embodiment. It is a block diagram of the process part of the X-ray CT apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 3rd Embodiment. It is a block diagram of the process part of the X-ray CT apparatus which concerns on the modification 1 of 1st-3rd embodiment. It is a block diagram of the console apparatus of the X-ray CT apparatus which concerns on the modification 2 of 1st-3rd embodiment. It is a block diagram of the X-ray CT apparatus which concerns on 4th Embodiment. It is a figure which shows the image displayed on the display part which concerns on 4th Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 4th Embodiment. It is a block diagram of the process part of the X-ray CT apparatus which concerns on 5th Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 5th Embodiment. It is a block diagram of the process part of the X-ray CT apparatus which concerns on 6th Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 6th Embodiment. It is a block diagram of the console apparatus of the X-ray CT apparatus which concerns on the modification of 4th-6th embodiment. It is a figure which shows the image displayed on the display part which concerns on the modification of 4th-6th embodiment.

(First embodiment)
The configuration of the X-ray CT apparatus 1 according to the first embodiment will be described with reference to FIGS. 1 to 3. Since “image” and “image data” have a one-to-one correspondence, in the present embodiment, they may be regarded as the same. In addition, the “three-dimensional image (three-dimensional moving image)” in the present embodiment includes a so-called “pseudo three-dimensional image” in which three-dimensional image data is displayed two-dimensionally.

<Device configuration>
As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40.

[Mounting device]
The gantry device 10 is an apparatus that irradiates the subject E with X-rays and collects detection data of the X-rays transmitted through the subject E. The gantry device 10 includes an X-ray generator 11, an X-ray detector 12, a rotating body 13, a high voltage generator 14, a gantry driver 15, an X-ray diaphragm 16, a diaphragm driver 17, And a data collection unit 18.

  The X-ray generator 11 includes an X-ray tube that generates X-rays (for example, a vacuum tube that generates a conical or pyramidal beam (not shown)). The generated X-ray is exposed to the subject E. The X-ray detection unit 12 includes a plurality of X-ray detection elements (not shown). The X-ray detection unit 12 detects X-ray intensity distribution data (hereinafter sometimes referred to as “detection data”) indicating the intensity distribution of X-rays transmitted through the subject E with an X-ray detection element, and the detection data is Output as a current signal. As the X-ray detection unit 12, for example, a two-dimensional X-ray detector (plane detector) in which a plurality of detection elements are arranged in two directions (slice direction and channel direction) orthogonal to each other is used. The plurality of X-ray detection elements are provided, for example, in 320 rows along the slice direction. By using a multi-row X-ray detector in this way, it is possible to image a three-dimensional imaging region having a width in the slice direction by one rotation scan (volume scan). The slice direction corresponds to the body axis direction of the subject E, and the channel direction corresponds to the rotation direction of the X-ray generation unit 11.

  The rotating body 13 is a member that supports the X-ray generation unit 11 and the X-ray detection unit 12 so as to face each other with the subject E interposed therebetween. The rotating body 13 has an opening 13a penetrating in the slice direction. In the gantry device 10, the rotating body 13 is arranged so as to rotate in a circular orbit around the subject E.

  The high voltage generator 14 applies a high voltage to the X-ray generator 11. The X-ray generator 11 generates X-rays based on the high voltage. The gantry driving unit 15 drives the rotating body 13 to rotate. The X-ray diaphragm section 16 has a slit (opening) having a predetermined width, and by changing the width of the slit, the fan angle (expansion angle in the channel direction) of X-rays exposed from the X-ray generation section 11 and X Adjust the cone angle of the line (the spread angle in the slice direction). The diaphragm drive unit 17 drives the X-ray diaphragm unit 16 so that the X-rays generated by the X-ray generation unit 11 have a predetermined shape.

  A data collection unit 18 (DAS: Data Acquisition System) collects detection data from the X-ray detection unit 12 (each X-ray detection element). The data collection unit 18 converts the collected detection data (current signal) into a voltage signal, periodically integrates and amplifies the voltage signal, and converts the voltage signal into a digital signal. Then, the data collection unit 18 transmits the detection data converted into the digital signal to the console device 40 (processing unit 42 (described later)). When performing CT fluoroscopy, it is desirable that the reconstruction processing unit 42b (described later) performs reconstruction processing in a short time based on the detection data collected by the data collection unit 18 and obtains a CT image in real time. Therefore, the data collection unit 18 shortens the collection rate of the detection data.

[Bed equipment]
The couch device 30 is a device for placing and moving the subject E to be imaged. The couch device 30 includes a couch 31 and a couch driving unit 32. The couch 31 includes a couch top 33 for placing the subject E and a base 34 that supports the couch top 33. The couch top 33 can be moved by the couch driving unit 32 in the body axis direction of the subject E and in the direction perpendicular to the body axis direction. That is, the bed driving unit 32 can insert and remove the bed top plate 33 on which the subject E is placed with respect to the opening 13 a of the rotating body 13. The base 34 can move the bed top 33 in the vertical direction (a direction perpendicular to the body axis direction of the subject E) by the bed driving unit 32.

[Console device]
The console device 40 is used for operation input to the X-ray CT apparatus 1. The console device 40 has a function of reconstructing CT image data (tomographic image data and volume data) representing the internal form of the subject E from the detection data collected by the gantry device 10. The console device 40 includes a scan control unit 41, a processing unit 42, a display control unit 43, a storage unit 44, a display unit 45, an input unit 46, and a control unit 47.

  The scan control unit 41 controls various operations related to X-ray scanning. For example, the scan control unit 41 controls the high voltage generation unit 14 to apply a high voltage to the X-ray generation unit 11. The scan control unit 41 controls the gantry driving unit 15 so as to rotationally drive the rotating body 13. The scan control unit 41 controls the aperture driving unit 17 to operate the X-ray aperture unit 16. The scan control unit 41 controls the bed driving unit 32 to move the bed 31.

  The processing unit 42 performs various processes on the detection data transmitted from the gantry device 10 (data collection unit 18). The processing unit 42 includes a preprocessing unit 42a, a reconstruction processing unit 42b, a moving image creation unit 42c, and an MPR processing unit 42d.

  The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction on the detection data detected by the gantry device 10 (X-ray detection unit 12) to create projection data. To do.

  The reconstruction processing unit 42b creates CT image data (tomographic image data and volume data) based on the projection data (detection data) created by the preprocessing unit 42a. For reconstruction of tomographic image data, any method such as a two-dimensional Fourier transform method, a convolution / back projection method, or the like can be employed. Volume data is created by interpolating a plurality of reconstructed tomographic image data. For the reconstruction of volume data, for example, an arbitrary method such as a cone beam reconstruction method, a multi-slice reconstruction method, an enlargement reconstruction method, or the like can be adopted. As described above, a wide range of volume data can be reconstructed by volume scanning using a multi-row X-ray detector. In addition, when performing CT fluoroscopy, since the collection rate of detection data is shortened, the reconstruction time by the reconstruction processing unit 42b is shortened. Therefore, real-time CT image data corresponding to scanning can be created.

  In addition, the reconstruction processing unit 42b in the present embodiment creates a plurality of volume data based on a plurality of detection data (projection data) acquired during one period in the periodic movement of the subject E. The “periodic movement” refers to a movement of a part of the subject E that is periodically repeated with breathing and pulsation. For example, expansion / contraction of the lung accompanying breathing is an example of periodic movement. In addition, the “periodic movement” includes a movement of a part caused by the movement (for example, movement of a lesioned part of the lung accompanying movement of the lung due to respiration).

  As a specific example, a case will be described in which the first to nth detection data is acquired by performing n rotation scans (first to nth scans) during one period. In this case, the reconstruction processing unit 42b creates a plurality of tomographic image data based on the first detection data detected in the first scan. Further, the reconstruction processing unit 42b creates first volume data by performing interpolation processing on a plurality of tomographic image data. The reconstruction processing unit 42b repeats this process up to the nth detection data, thereby creating n volume data (first to nth volume data).

  Note that one period of the periodic movement can be measured by a sensor or the like provided in the X-ray CT apparatus 1 (or another detection apparatus). For example, when obtaining one cycle of respiration, a respiration sensor including a laser measuring instrument or the like is used. The respiration sensor irradiates the abdomen of the subject E with laser light and measures the movement of the abdomen. As the subject E breaths, the abdomen moves periodically. Therefore, the respiration sensor can calculate one period of the periodic movement based on the measurement result. Then, the X-ray CT apparatus 1 (scan control unit 41) starts the X-ray scan in accordance with the timing at which one cycle starts, and ends the X-ray scan at the timing at which one cycle ends. It is possible to acquire a plurality of detection data (data that is the basis of projection data).

  The moving image creating unit 42c creates a moving image showing the periodic movement of the subject E based on at least a part of the plurality of volume data. For example, it is assumed that the reconstruction processing unit 42b creates the first to nth volume data (a plurality of volume data) based on the first to nth detection data acquired during one period. At this time, the moving image creation unit 42c can create one moving image by configuring the first to nth volume data in time series. Alternatively, the moving image creation unit 42c can create one moving image using only a part of the volume data created by the reconstruction processing unit 42b (for example, the first to (n-1) th detection data). It is. In the present embodiment, the moving image creation unit 42c creates a three-dimensional moving image obtained by configuring a plurality of volume data in time series as a moving image.

  The MPR processing unit 42d displays an MPR by rendering a three-dimensional image based on the volume data in an arbitrary direction (that is, the MPR processing unit 42d creates an MPR image). For example, the MPR processing unit 42d creates an MPR image by rendering an image (details will be described later) on which a three-dimensional moving image is superimposed by the display control unit 43 in an arbitrary direction. The MPR processing unit 42d can create an axial image, a sagittal image, a coronal image, or an oblique image, which is an arbitrary cross-sectional image, as an MPR image.

  The display control unit 43 performs various controls related to image display. For example, the display control unit 43 causes the display unit 45 to display a moving image superimposed on the image based on the volume data.

  The “image based on volume data” on which the moving image is superimposed is, for example, an image based on the m-th volume data obtained by the m-th scan performed at a timing different from a series of scans (first to n-th scans). is there. As an image based on such mth volume data, for example, there is an image obtained based on a scan performed during puncturing. By superimposing a moving image based on a series of scans performed before puncture on an image based on a scan during puncture, the movement of the part to be punctured (part with periodic movement) is grasped during puncture. be able to.

  Alternatively, the “image based on volume data” may be based on a part of volume data among volume data (first to nth volume data) from which a moving image is generated. That is, when the first to nth volume data is acquired based on a series of scans, the moving image creation unit 42c creates a moving image based on the first to n-1th volume data. The display control unit 43 can also superimpose the moving image on the image based on the nth volume data. Thus, an image obtained by superimposing a moving image based on other volume data (first to n-1th volume data) on an image based on a part of volume data (nth volume data) is, for example, This is a reference for a puncture plan for determining a puncture route. That is, according to the image, it is possible to grasp in advance the periodic movement of the part to be punctured. Therefore, it is possible to make a puncture plan reflecting the movement by referring to the image.

  The first to n-th volume data and the m-th volume data are assumed to have the same number of tomographic image data and the number of pixels of the image. In addition, the imaging conditions (imaging position, rotation speed of the rotating body 13 and the like) of the first to nth scan and the mth scan are also equal. That is, the first to nth volume data and the mth volume data are in the same coordinate system.

  In the present embodiment, the display control unit 43 superimposes the 3D moving image created by the moving image creating unit 42c on the 3D image based on the volume data (for example, the mth volume data). The MPR processing unit 42d creates an MPR image obtained by rendering a three-dimensional image on which a three-dimensional moving image is superimposed in an arbitrary direction. The display control unit 43 causes the display unit 45 to display the MPR image. The display control unit 43 may cause the display unit 45 to display a 3D image (pseudo 3D image) on which the 3D moving image is superimposed as it is.

  2 and 3 are examples of MPR images. In FIG. 2 and FIG. 3, the moving image portion is indicated by a solid line and the other portions are indicated by broken lines in order to facilitate understanding of the portion displayed as a moving image.

  For example, FIG. 2 shows an MPR image (coronal image CI) obtained by rendering a three-dimensional image on which a three-dimensional moving image is superimposed in the coronal direction. FIG. 2 is an example showing a periodic movement of the lung L. FIG. In the coronal image CI, the upper and lower sides of the diaphragm D due to respiration and the accompanying periodic change in the volume of the lung L are reproduced as a moving image (in FIG. 2, an image in which the volume of the lung L is maximum (right Image), the smallest image (left image), and the middle image (middle image)).

  Alternatively, as shown in FIG. 3, the display control unit 43 combines not only the coronal image CI but also an MPR image (axial image AI) rendered in the axial direction and an MPR image (sagittal image SI) rendered in the sagittal direction. It is also possible to display on the display screens 45a to 45c of the display unit 45. Thus, by displaying the MPR images in the three orthogonal cross sections, it becomes possible to observe the periodic movement of the subject E from different directions. Note that an axial image AI, a sagittal image SI, and a coronal image CI in FIG. 3 indicate images at a certain point in one cycle.

  The storage unit 44 is configured by a semiconductor storage device such as a RAM or a ROM. The storage unit 44 stores detection data, projection data, CT image data after reconstruction processing, a created moving image, and the like.

  The display unit 45 includes an arbitrary display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube) display.

  As shown in FIG. 3, viewing boxes Va to Vc corresponding to the MPR images are displayed on the display unit 45. The viewing boxes Va to Vc are icons that schematically indicate which section of the volume data corresponds to the displayed MPR image. In FIG. 3, a viewing box Va corresponding to the axial image AI is displayed on the display screen 45a. A viewing box Vb corresponding to the sagittal image SI is displayed on the display screen 45b. A viewing box Vc corresponding to the coronal image CI is displayed on the display screen 45c. In each viewing box, a region indicated by a broken line indicates a cross-sectional position of the volume data. Dashed arrows in each viewing box indicate the direction of rendering. Control related to the display of the viewing box is performed by the display control unit 43.

  The input unit 46 is used as an input device that performs various operations on the console device 40. The input unit 46 includes, for example, a keyboard, a mouse, a trackball, a joystick, and the like. Further, a GUI (Graphical User Interface) displayed on the display unit 45 can be used as the input unit 46.

  The control unit 47 performs overall control of the X-ray CT apparatus 1 by controlling operations of the gantry device 10, the couch device 30, and the console device 40. For example, the control unit 47 controls the scan control unit 41 to cause the gantry device 10 to perform a preliminary scan and a main scan and collect detection data. In addition, the control unit 47 controls the processing unit 42 to perform various processing (preprocessing, reconstruction processing, moving image creation processing, MPR processing, etc.) on the detected data.

<CT fluoroscopy>
Here, an example of CT fluoroscopy will be described. Hereinafter, a biopsy using CT fluoroscopy will be described.

  First, the scan control unit 41 starts an X-ray scan in a state where the bed top 33 on which the subject E is placed is inserted into the opening 13a (first scan). The X-ray scan is started based on, for example, an instruction input from a switch (not shown) provided in the gantry device 10 or a hand switch (not shown) connected to the X-ray CT apparatus 1. Note that the input unit 46 may also function as a switch.

  When the first scan is completed, based on an instruction input from a switch or the like, the scan control unit 41 controls the bed driving unit 32 and temporarily extracts the bed top plate 33 from the opening 13a. The surgeon punctures the site of interest while referring to the image based on the volume data obtained in the first scan. As described above, when the puncture is performed, the X-ray scan is stopped, and the subject E is extracted from the opening 13a, whereby the exposure dose can be reduced. Furthermore, compared with the case where the subject E is disposed in the opening 13a, a wide treatment space can be secured.

  After the puncture has progressed to some extent, the operator may wish to confirm the state of the puncture needle (such as whether the puncture needle has advanced in a certain direction of interest). At this time, the scan control unit 41 controls the bed driving unit 32 to insert the bed top plate 33 into the opening 13a again. Then, the scan control unit 41 starts an X-ray scan (second scan). That is, the scan control unit 41 controls the bed driving unit 32 so that the bed top plate 33 is extracted from the opening 13a between the timing of the first scan and the timing of the second scan.

  The scan control unit 41 repeats the insertion / extraction operation of the bed top plate 33 with respect to the opening 13a based on an instruction input from an operator or the like until the biopsy is completed.

  In addition, it is also possible to puncture with the bed top plate 33 inserted into the opening 13a (the bed top plate 33 is not inserted or removed). Also in this case, the exposure dose can be reduced by stopping the X-ray exposure between the first scan and the second scan.

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a moving image showing a periodic movement accompanying breathing is created. In addition, the volume data (first to nth volume data) that is the source of the moving image and the volume data (mth volume data) that is the source of the image on which the moving image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S10). In the present embodiment, scans of n rotations are performed during one cycle, and a plurality of detection data (first to nth detection data) corresponding to each scan is acquired. The detection data detected by the X-ray detection unit 12 is collected by the data collection unit 18 and sent to the preprocessing unit 42a.

  The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S10, and creates a plurality of projection data (first to nth projection data) (S11). ). The plurality of created projection data is sent to the reconstruction processing unit 42 b based on the control of the control unit 47.

  The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S11 (S12). The plurality of created volume data is sent to the moving image creation unit 42 c based on the control of the control unit 47.

  The moving image creating unit 42c creates a three-dimensional moving image based on the first to nth volume data created in S12 (S13). The created three-dimensional moving image is a moving image indicating a periodic movement (for example, expansion / contraction of the lungs) accompanying respiration. The three-dimensional moving image created in S13 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs an X-ray scan at a timing different from the scan timing in S10, and creates corresponding m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S14). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The detection data detected by the X-ray detection unit 12 is collected by the data collection unit 18 and sent to the preprocessing unit 42a. The imaging conditions for the first to nth scans and the mth scan are the same.

  The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing on the acquired m-th detection data to create projection data (m-th projection data) (S15). The created projection data is sent to the reconstruction processing unit 42b based on the control of the control unit 47.

  The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S15. Further, the reconstruction processing unit 42b creates m-th volume data by performing interpolation processing on a plurality of tomographic image data (S16).

  The display control unit 43 superimposes the three-dimensional moving image created in S13 on the three-dimensional image based on the m-th volume data created in S16 (S17).

  The MPR processing unit 42d creates an MPR image by rendering the three-dimensional image on which the three-dimensional moving image is superimposed in S17 in an arbitrary direction (S18). The created MPR image is displayed on the display unit 45 by the display control unit 43 (S19). For example, as shown in FIG. 3, the display control unit 43 displays MPR images (axial image AI, sagittal image SI, coronal image CI) having three orthogonal cross sections.

  With the MPR image displayed in S19, the surgeon can easily recognize the periodic movement of the lung accompanying breathing in the image. By referring to this image, for example, the drainage tube can be punctured and body fluid accumulated in the lungs can be discharged while grasping the movement of the lungs.

  Note that the scan control unit 41, the processing unit 42, the display control unit 43, and the control unit 47 are not illustrated in a process such as a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), or an ASIC (Application Specific Integrated Circuit). It may be configured by a device and a storage device (not shown) such as a ROM (Read Only Memory), a RAM (Random Access Memory), or an HDD (Hard Disc Drive). The storage device stores a scan control program for executing the functions of the scan control unit 41. In addition, the storage device stores a processing program for executing the function of the processing unit 42. The storage device stores a display control program for executing the function of the display control unit 43. The storage device stores a control program for executing the function of the control unit 47. A processing device such as a CPU executes the functions of each unit by executing each program stored in the storage device.

  In the present embodiment, the configuration of the X-ray CT apparatus 1 has been described. However, the configuration that achieves the action in the present embodiment is not limited to the X-ray CT apparatus 1. For example, the detection data acquired by the X-ray CT apparatus is transmitted to an apparatus different from the X-ray CT apparatus (for example, an image display apparatus such as an image viewer), and the same processing is performed in the apparatus, whereby the embodiment The same function can be realized. In this case, it is desirable that a processing unit 42, a display control unit 43, and a display unit 45 are provided in the image display device.

<Action and effect>
The operation and effect of this embodiment will be described.

  The X-ray CT apparatus 1 of the present embodiment is an X-ray CT apparatus that scans a subject E with periodic movement with X-rays and acquires detection data. The X-ray CT apparatus 1 includes a reconstruction processing unit 42b, a moving image creation unit 42c, and a display control unit 43. The reconstruction processing unit 42b creates a plurality of volume data based on a plurality of detection data acquired during one period in the periodic movement. The moving image creation unit 42c creates a moving image showing the periodic movement of the subject based on at least a part of the plurality of volume data. The display control unit 43 causes the display unit 45 to display a moving image superimposed on the image based on the volume data.

  Specifically, the moving image creation unit 42c in the X-ray CT apparatus 1 of the present embodiment creates a three-dimensional moving image based on at least a part of a plurality of volume data as a moving image. The display control unit 43 causes the display unit 45 to display a three-dimensional moving image superimposed on the three-dimensional image based on the volume data.

  As described above, the moving image creating unit 42c creates a moving image (three-dimensional moving image) indicating the movement of the subject E based on at least a part of the plurality of volume data reconstructed by the reconstruction processing unit 42b. Then, the display control unit 43 superimposes a moving image (three-dimensional moving image) on the image (three-dimensional image) based on the volume data and causes the display unit 45 to display the superimposed image. Therefore, it is possible to easily recognize the actual movement of the part with periodic movement in the image. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject. Such a medical image can be used, for example, as an aid to a procedure performed while checking the image, such as a biopsy or a drainage method.

  In addition, the X-ray CT apparatus 1 according to the present embodiment includes an MPR processing unit 42d. The MPR processing unit 42d creates an MPR image showing a predetermined cross section in the three-dimensional image based on the volume data. The display control unit 43 displays the MPR image on the display unit 45.

  In this way, by performing MPR display of a three-dimensional image on which a three-dimensional moving image is superimposed, it is possible to recognize a periodic movement in the subject in an arbitrary cross section. Further, when a plurality of MPR images from different directions are displayed, it becomes easier to understand the periodic movement of the subject. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

  Further, the configuration of the present embodiment can be applied to an image display apparatus. Such an image display apparatus includes a display unit 45, a reconstruction processing unit 42b, a moving image creation unit 42c, and a display control unit 43. The reconstruction processing unit 42b creates a plurality of volume data based on a plurality of detection data acquired by scanning the subject E including a part with a periodic motion with X-rays for one period. The moving image creating unit 42c creates a moving image showing the periodic movement of the subject E based on at least a part of the plurality of volume data. The display control unit 43 causes the display unit 45 to display a moving image superimposed on the image based on the volume data.

  The configuration of the present embodiment can also be realized as an image display method. In this image display method, the reconstruction processing unit 42b has a plurality of volumes based on a plurality of detection data acquired by scanning the subject E including a region with a periodic motion with X-rays for one cycle. Creating data. In addition, the moving image creation unit 42c includes a step of creating a moving image showing the periodic movement of the subject E based on at least a part of the plurality of volume data. Further, the display control unit 43 includes a step of superimposing a moving image on an image based on the volume data and causing the display unit 45 to display the image.

  Even in such an image display apparatus or image display method, the moving image creation unit 42c shows the movement of the subject E based on at least a part of the plurality of volume data reconstructed by the reconstruction processing unit 42b. Create a video. Then, the display control unit 43 causes the display unit 45 to display a moving image superimposed on the image based on the volume data. Therefore, it is possible to easily recognize the actual movement of the part with periodic movement in the image. That is, according to the image display apparatus and the image display method of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Second Embodiment)
Next, the configuration of the X-ray CT apparatus 1 according to the second embodiment will be described with reference to FIGS. 5 and 6. In the second embodiment, the moving image creation unit 42c creates a two-dimensional moving image (MPR moving image) from a three-dimensional moving image based on a plurality of volume data (for example, first to nth volume data). A configuration in which the display control unit 43 superimposes and displays an MPR moving image on a two-dimensional image based on volume data (for example, m-th volume data) will be described. Note that a detailed description of the same configuration as in the first embodiment may be omitted.

<Device configuration>
FIG. 5 shows only the configuration of the processing unit 42 in the X-ray CT apparatus 1 of the present embodiment. Other configurations are the same as those of the first embodiment.

  The moving image creation unit 42c in the present embodiment includes an MPR moving image creation unit 42e. Similar to the first embodiment, the moving image creation unit 42c creates a three-dimensional moving image based on at least a part of a plurality of volume data.

  The MPR moving image creating unit 42e creates an MPR moving image showing a predetermined cross section in the three-dimensional moving image. For example, the MPR moving image creating unit 42e creates a two-dimensional moving image (that is, an MPR moving image) in a predetermined cross section by rendering a three-dimensional moving image based on the first to nth volume data in an arbitrary direction. To do.

  The MPR processing unit 42d in this embodiment displays the MPR by rendering the volume data created by the reconstruction processing unit 42b in an arbitrary direction (that is, the MPR processing unit 42d displays the MPR image (two-dimensional image). create). For example, the MPR processing unit 42d creates an MPR image by rendering m-th volume data different from the first to n-th volume data, which is a source of a three-dimensional moving image, in an arbitrary direction.

  The display control unit 43 superimposes the MPR moving image created by the MPR moving image creating unit 42e on the two-dimensional image (MPR image) based on the volume data (for example, the mth volume data) and displays the superimposed image on the display unit 45. Let Note that, when the MPR moving image is superimposed on the MPR image based on the mth volume data, the direction for rendering the three-dimensional moving image based on the first to nth volume data and the direction for rendering the mth volume data. Is preferably equal.

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a moving image showing a periodic movement accompanying breathing is created. In addition, the volume data (first to nth volume data) that is the source of the moving image and the volume data (mth volume data) that is the source of the image on which the moving image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E and acquires the detection data (S20). In the present embodiment, as in the first embodiment, the X-ray detection unit 12 acquires first to nth detection data. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S20, and creates a plurality of projection data (first to nth projection data) (S21). ). The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S21 (S22). The moving image creating unit 42c creates a three-dimensional moving image based on the first to nth volume data created in S22 (S23).

  Then, the MPR moving image creating unit 42e creates an MPR moving image by rendering the three-dimensional moving image created in S23 from an arbitrary direction (S24). The created MPR moving image is a two-dimensional moving image showing periodic movement (for example, expansion / contraction of the lungs) accompanying respiration. The MPR moving image created in S24 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs X-ray scanning at a timing different from the scanning timing in S20, and creates m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S25). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the acquired mth detection data, and creates projection data (mth projection data) (S26). The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S26. Further, the reconstruction processing unit 42b creates m-th volume data by interpolating a plurality of tomographic image data (S27).

  Then, the MPR processing unit 42d creates an MPR image by rendering the m-th volume data created in S27 from the same direction as that rendered in S24 (S28). That is, the MPR moving image created in S24 and the MPR image created in S28 show cross sections in the same direction.

  The display control unit 43 causes the display unit 45 to display a two-dimensional image obtained by superimposing the MPR moving image created in S24 on the MPR image created in S28 (S29).

<Action and effect>
The operation and effect of this embodiment will be described.

  The moving image creation unit 42c in the X-ray CT apparatus 1 of the present embodiment creates a three-dimensional moving image based on at least a part of a plurality of volume data. The moving image creation unit 42c has an MPR moving image creation unit 42e. The MPR moving image creating unit 42e creates an MPR moving image showing a predetermined cross section in the three-dimensional moving image. The display control unit 43 causes the display unit 45 to display the MPR moving image superimposed on the two-dimensional image based on the volume data.

  As described above, when an MPR moving image is created in advance from a three-dimensional moving image and displayed on a corresponding MPR image (an image showing a cross-section in the same direction as the MPR moving image), the actual part with periodic movement is actually displayed. Can be easily recognized in a two-dimensional image. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Third embodiment)
Next, the configuration of the X-ray CT apparatus 1 according to the third embodiment will be described with reference to FIGS. In the third embodiment, the moving image creation unit 42c creates a moving image based on MPR image data in each of a plurality of volume data (for example, first to nth volume data). A configuration in which the display control unit 43 superimposes and displays a moving image on a two-dimensional image based on volume data (for example, m-th volume data) will be described. Note that the detailed description of the same configuration or the like as in the first embodiment or the second embodiment may be omitted.

<Device configuration>
FIG. 7 shows only the configuration of the processing unit 42 in the X-ray CT apparatus 1 of the present embodiment. Other configurations are the same as those in the first embodiment or the second embodiment.

  The moving image creation unit 42c has an MPR data creation unit 42f. The MPR data creation unit 42f creates a plurality of MPR image data indicating a predetermined section in each of the plurality of volume data. For example, the MPR data creation unit 42f creates the first to nth MPR image data corresponding to the first to nth volume data by rendering each of the first to nth volume data from the same direction. .

  The moving image creation unit 42c creates a two-dimensional moving image based on the plurality of MPR image data created by the MPR data creation unit 42f. For example, the moving image creation unit 42c creates a moving image by configuring the first to nth MPR image data in time series.

  Similar to the second embodiment, the MPR processing unit 42d renders the MPR image (two-dimensional image) by rendering the volume data (for example, the m-th volume data) created by the reconstruction processing unit 42b in an arbitrary direction. create).

  The display control unit 43 causes the display unit 45 to display the moving image created by the moving image creation unit 42c on the two-dimensional image (MPR image) based on the volume data (for example, the mth volume data). When the moving image is superimposed on the MPR image based on the mth volume data, it is desirable that the direction in which the first to nth volume data is rendered is equal to the direction in which the mth volume data is rendered.

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a moving image showing a periodic movement accompanying breathing is created. In addition, the volume data (first to nth volume data) that is the source of the moving image and the volume data (mth volume data) that is the source of the image on which the moving image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E and acquires the detection data (S30). In the present embodiment, as in the first embodiment and the second embodiment, the X-ray detection unit 12 acquires first to nth detection data. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S30, and creates a plurality of projection data (first to nth projection data) (S31). ). The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S31 (S32).

  Then, the MPR data creation unit 42f creates the first to nth MPR image data corresponding to the first to nth volume data by rendering each of the first to nth volume data from the same direction. (S33). The moving image creation unit 42c creates a moving image based on the first to nth MPR image data created in S33 (S34). The created moving image is a two-dimensional moving image showing periodic movement (for example, expansion / contraction of the lungs) accompanying respiration. The MPR moving image created in S34 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs X-ray scanning at a timing different from the scanning timing in S30, and creates m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E and acquires the detection data (S35). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing on the acquired m-th detection data to create projection data (m-th projection data) (S36). The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S36. In addition, the reconstruction processing unit 42b creates m-th volume data by performing interpolation processing on a plurality of tomographic image data (S37).

  Then, the MPR processing unit 42d creates an MPR image by rendering the m-th volume data from the same direction as that rendered in S33 (S38). That is, the MPR image data created in S33 (an image based on the MPR image data) and the MPR image created in S38 show cross sections in the same direction.

  The display control unit 43 causes the display unit 45 to display a two-dimensional image obtained by superimposing the moving image created in S34 on the MPR image created in S38 (S39).

<Action and effect>
The operation and effect of this embodiment will be described.

  The moving image creation unit 42c in the X-ray CT apparatus 1 of the present embodiment has an MPR data creation unit 42f. The MPR data creation unit 42f creates a plurality of MPR image data indicating a predetermined section in each of the plurality of volume data. The moving image creation unit 42c creates a moving image based on a plurality of MPR image data. The display control unit 43 causes the display unit 45 to display a moving image superimposed on the two-dimensional image based on the volume data.

  As described above, when a moving image is created from a plurality of MPR image data and displayed on a corresponding two-dimensional image (MPR image; an image showing a cross section in the same direction), the actual part of the region with periodic movement is displayed. The movement can be easily recognized in the two-dimensional image. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Modification 1 according to the first to third embodiments)
In the above embodiment, an example in which a moving image is created using a plurality of entire volume data has been described. According to this example, it is possible to confirm the entire region with periodic movement.
On the other hand, there is a case where it is desired to observe only a part of a part with periodic movement. For example, when puncturing a lung lesion, the lesion moves as the lung moves due to respiration. At this time, there is a case where it is desired to confirm only the movement of the lesion. In this modification, an X-ray CT apparatus capable of displaying the movement of a part of a part (for example, a lesioned part) accompanied with a periodic movement will be described.

  FIG. 9 is a block diagram showing a configuration of the processing unit 42 in the X-ray CT apparatus 1 of the present modification. The processing unit 42 in the X-ray CT apparatus 1 includes an extraction unit 42g. The extracting unit 42g extracts data corresponding to a part of a part accompanied by a periodic motion in the plurality of volume data reconstructed by the reconstruction processing unit 42b. Specifically, the extraction unit 42g performs image processing on each volume data, and specifies an area corresponding to the part in each volume data. Then, the extraction unit 42g extracts volume data corresponding to the area. As the image processing, a region growing method, threshold processing for the gradation value of each voxel, or the like can be used.

  Based on the volume data extracted by the extraction unit 42g, the moving image creation unit 42c performs the moving image creation process according to any one of the first to third embodiments, thereby moving the moving image based on the extracted volume data. Can be created. The display control unit 43 causes the display unit 45 to display a moving image based on the extracted volume data by superimposing it on a three-dimensional image or MPR image. Although FIG. 9 is described based on the configuration of the first embodiment, in the configurations of the second embodiment and the third embodiment, an extraction unit 42g can be provided.

(Modification 2 according to the first to third embodiments)
When an image based on volume data and a moving image are displayed in an overlapping manner, it is desirable that the images are displayed in a state where they can be distinguished from each other. In this modification, an X-ray CT apparatus capable of changing the display mode of images and moving images based on volume data will be described.

  FIG. 10 is a block diagram showing a configuration of the console device 40 of the X-ray CT apparatus 1 according to this modification. The display control unit 43 in the X-ray CT apparatus 1 includes a changing unit 43a. The changing unit 43a changes the image display mode based on the volume data and the moving image display mode. Specifically, the changing unit 43a changes at least one of the color, transparency, and CT value of the image (moving image). For example, the changing unit 43a changes the image based on the volume data so as to be a gray scale, and changes the moving image to be a color. In this way, when displaying with a different color, it becomes easy to recognize a part with periodic movement in the image. Alternatively, the changing unit 43a increases the transparency of the image based on the volume data and decreases the transparency of the moving image. As described above, when the moving image is displayed with low transparency, it is possible to highlight and display a portion accompanied by a periodic motion. Although FIG. 10 is described based on the configuration of the first embodiment, it is also possible to provide a changing unit 43a in the configurations of the second embodiment and the third embodiment.

(Fourth embodiment)
Next, the configuration of the X-ray CT apparatus 1 according to the fourth embodiment will be described with reference to FIGS. 11 to 13. In the fourth embodiment, a configuration will be described in which the display control unit 43 superimposes and displays a trajectory image indicating a trajectory of a periodic movement in a subject on an image based on volume data. The “trajectory” in the present embodiment refers to an area that indicates a range (including a part) in which a part that accompanies periodic movement moves. Note that detailed description of the same configurations and the like as in the first to third embodiments may be omitted.

<Device configuration>
FIG. 11 is a block diagram showing a configuration of the X-ray CT apparatus 1 according to the present embodiment.

  The processing unit 42 in the X-ray CT apparatus 1 of this embodiment includes a preprocessing unit 42a, a reconstruction processing unit 42b, a trajectory image creation unit 42h, and an MPR processing unit 42d. Since the pre-processing unit 42a and the reconstruction processing unit 42b have the same configuration as that of the first to third embodiments, detailed description thereof is omitted.

  The trajectory image creation unit 42h creates a trajectory image indicating a trajectory of a periodic movement in the subject E based on at least a part of the plurality of volume data created by the reconstruction processing unit 42b. In the present embodiment, the trajectory image creation unit 42h includes a specifying unit 42i.

  The specifying unit 42i specifies the position of a part with periodic movement in each of the plurality of volume data. For example, it is assumed that the reconstruction processing unit 42b creates the first to nth volume data based on the first to nth detection data acquired during one period. The specifying unit 42i performs image processing such as a region growing method on each volume data, and specifies a three-dimensional position (coordinate value) of a part (for example, a lesioned part) accompanied by periodic movement.

  The trajectory image creation unit 42h creates a three-dimensional trajectory image indicating a trajectory of a part with periodic motion by connecting a plurality of three-dimensional positions specified by the specification unit 42i. Note that the specifying unit 42i specifies the three-dimensional position of the part with periodic movement based on a part of the first to nth volume data (for example, every other volume data). The trajectory image creation unit 42h can also obtain a rough trajectory image by connecting the specified positions.

  The MPR processing unit 42d in the present embodiment creates an MPR image by rendering a three-dimensional image (details will be described later) on which a three-dimensional trajectory image is superimposed by the display control unit 43 in an arbitrary direction.

  The display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the image based on the volume data. For example, the display control unit 43 superimposes the three-dimensional trajectory image created by the trajectory image creation unit 42h on the three-dimensional image based on the mth volume data. The MPR processing unit 42d creates an MPR image obtained by rendering a three-dimensional image on which a three-dimensional trajectory image is superimposed in an arbitrary direction. The display control unit 43 causes the display unit 45 to display the MPR image. Note that the display control unit 43 may display the three-dimensional image (pseudo three-dimensional image) on which the three-dimensional trajectory image is superimposed on the display unit 45 as it is.

  FIG. 12 is an example of an MPR image on which a trajectory image is superimposed. Here, an MPR image (coronal image CI) obtained by rendering a three-dimensional image on which a three-dimensional trajectory image is superimposed in the coronal direction is shown. In the coronal image CI, a moving range of the lesion P (part with periodic movement) is displayed as a trajectory image T. In FIG. 12, in order to facilitate understanding of the locus portion, the locus image T is indicated by a solid line, and other portions are indicated by broken lines. The MPR processing unit 42d can also create three MPR images in which a three-dimensional image on which a three-dimensional trajectory image is superimposed is rendered in each of an axial direction, a sagittal direction, and a coronal direction.

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a trajectory image indicating the trajectory of the lesioned part P with periodic motion is created. Further, the volume data (first to nth volume data) that is the origin of the trajectory image and the volume data (mth volume data) that is the origin of the image on which the trajectory image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S40). In the present embodiment, as in the first to third embodiments, the X-ray detection unit 12 acquires the first to nth detection data. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S40, and creates a plurality of projection data (first to nth projection data) (S41). ). The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S41 (S42).

Then, the specifying unit 42i specifies the position (P _{1 to} P _n ) of the lesioned part P with periodic movement in each of the first to nth volume data created in S42 (S43). Path image creation unit 42h, by connecting the position _P 1 to P _n identified by the identifying unit 42i, to create a three-dimensional trajectory image (S44). The created trajectory image is a three-dimensional image showing the trajectory of the movement of the lesioned part P. The trajectory image created in S44 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs an X-ray scan at a timing different from the scan timing in S40 to create m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detector 12 detects X-rays that have passed through the subject E, and acquires the detection data (S45). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing on the acquired m-th detection data to create projection data (m-th projection data) (S46). The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S46. Further, the reconstruction processing unit 42b creates m-th volume data by interpolating a plurality of tomographic image data (S47).

  The display control unit 43 superimposes the three-dimensional trajectory image created in S44 on the three-dimensional image based on the m-th volume data created in S47 (S48).

  The MPR processing unit 42d creates an MPR image by rendering the 3D image on which the 3D moving image is superimposed in an arbitrary direction in S48. The created MPR image is displayed on the display unit 45 by the display control unit 43 (S49).

  From the MPR image displayed in S49, the surgeon can easily recognize the locus of the lesioned part P with periodic movement in the image. By referring to this image, for example, when puncturing the lesion P, the movement of the lesion P can be predicted based on the trajectory shown in the image. Therefore, the accuracy of puncture can be improved.

<Action and effect>
The operation and effect of this embodiment will be described.

  The X-ray CT apparatus 1 according to the present embodiment is an X-ray CT apparatus that scans a subject E including a part with a periodic motion with X-rays and acquires detection data. The X-ray CT apparatus 1 includes a reconstruction processing unit 42b, a trajectory image creation unit 42h, and a display control unit 43. The reconstruction processing unit 42b creates a plurality of volume data based on a plurality of detection data acquired during one period in the periodic movement. The trajectory image creation unit 42h creates a trajectory image indicating a periodic trajectory based on at least a part of the plurality of volume data. The display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the image based on the volume data.

  Specifically, the trajectory image creation unit 42h in the X-ray CT apparatus 1 of the present embodiment includes a specifying unit 42i. The specifying unit 42i specifies the position of a part with periodic movement in each of the plurality of volume data. The trajectory image creation unit 42h creates a three-dimensional trajectory image based on the position of the identified part. The display control unit 43 causes the display unit 45 to display a three-dimensional trajectory image superimposed on the three-dimensional image based on the volume data.

  As described above, the trajectory image creation unit 42h creates a trajectory image indicating a trajectory of a part with periodic movement based on at least a part of the plurality of volume data reconstructed by the reconstruction processing unit 42b. Then, the display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the image based on the volume data. Therefore, it is possible to easily recognize in the image the range in which the region with periodic movement actually moves. That is, according to the X-ray CT apparatus of the present embodiment, a medical image reflecting the periodic movement of the subject can be displayed.

  In addition, the X-ray CT apparatus 1 according to the present embodiment includes an MPR processing unit 42d. The MPR processing unit 42d creates an MPR image showing a predetermined cross section in the three-dimensional image based on the volume data. The display control unit 43 displays the MPR image on the display unit 45.

  As described above, by displaying the three-dimensional image on which the three-dimensional trajectory image is superimposed by MPR display, it is possible to recognize a range in which a part with periodic movement in an arbitrary direction actually moves. In addition, when a plurality of MPR images from different directions are displayed, it becomes easier to understand the range in which the region with periodic movement actually moves. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

  Further, the configuration of the present embodiment can be applied to an image display apparatus. Such an image display device includes a display unit 45, a reconstruction processing unit 42b, a trajectory image creation unit 42h, and a display control unit 43. The reconstruction processing unit 42b creates a plurality of volume data based on a plurality of detection data acquired by scanning the subject E including a part with a periodic motion with X-rays for one period. The trajectory image creation unit 42h creates a trajectory image indicating a periodic trajectory based on at least a part of the plurality of volume data. The display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the image based on the volume data.

  The configuration of the present embodiment can also be realized as an image display method. In this image display method, the reconstruction processing unit 42b has a plurality of volumes based on a plurality of detection data acquired by scanning the subject E including a region with a periodic motion with X-rays for one cycle. Creating data. The trajectory image creation unit 42h includes a step of creating a trajectory image indicating a periodic motion trajectory based on at least a part of the plurality of volume data. In addition, the display control unit 43 includes a step of superimposing the trajectory image on the image based on the volume data and causing the display unit 45 to display the image.

  Even in such an image display device or image display method, the trajectory image creation unit 42h is accompanied by a periodic movement based on at least a part of the plurality of volume data reconstructed by the reconstruction processing unit 42b. A trajectory image showing the trajectory of the part is created. Then, the display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the image based on the volume data. Therefore, it is possible to easily recognize in the image the range in which the region with periodic movement actually moves. That is, according to the image display apparatus and the image display method of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Fifth embodiment)
Next, the configuration of the X-ray CT apparatus 1 according to the fifth embodiment will be described with reference to FIGS. 14 and 15. In the fifth embodiment, the display control unit 43 superimposes and displays the two-dimensional trajectory image based on the first to nth volume data on the two-dimensional image (MPR image) based on the volume data (mth volume data). A configuration to be described will be described. Note that detailed description of the same configurations and the like as in the first to fourth embodiments may be omitted.

<Device configuration>
In FIG. 14, only the structure of the process part 42 in the X-ray CT apparatus 1 of this embodiment is shown. Other configurations are the same as those in the first to fourth embodiments.

  The trajectory image creation unit 42h in the present embodiment includes a specifying unit 42i. Since the specifying unit 42i has the same configuration as that of the fourth embodiment, detailed description thereof is omitted.

  The trajectory image creation unit 42h creates a three-dimensional image showing the trajectory based on the position of the part with the periodic motion specified by the specification unit 42i, and a two-dimensional image obtained by viewing the three-dimensional image from a predetermined direction. Is created as a trajectory image. For example, it is assumed that the specifying unit 42i performs predetermined image processing on a plurality of volume data and specifies a three-dimensional position (coordinate value) of a part (for example, a lesioned part) that accompanies periodic movement. . The trajectory image creation unit 42h first creates a three-dimensional trajectory image by connecting a plurality of positions specified by the specifying unit 42i. Then, the trajectory image creation unit 42h creates a two-dimensional trajectory image viewed from the direction by rendering the three-dimensional trajectory image from a predetermined direction.

  The MPR processing unit 42d in this embodiment displays the MPR by rendering the volume data created by the reconstruction processing unit 42b in an arbitrary direction (that is, the MPR processing unit 42d displays the MPR image (two-dimensional image). create). For example, the MPR processing unit 42d creates an MPR image by rendering m-th volume data different from the first to n-th volume data, which is a source of a three-dimensional trajectory image, in an arbitrary direction.

  The display control unit 43 causes the display unit 45 to display a two-dimensional trajectory image superimposed on the two-dimensional image obtained by rendering the volume data. For example, the display control unit 43 superimposes the two-dimensional trajectory image created by the trajectory image creation unit 42h on the two-dimensional image obtained by rendering the mth volume data. The display control unit 43 causes the display unit 45 to display a two-dimensional image (MPR image) on which the trajectory image is superimposed. Note that, when a two-dimensional trajectory image is superimposed on a two-dimensional image based on the m-th volume data, it is desirable that the direction in which the three-dimensional trajectory image is rendered and the direction in which the m-th volume data is rendered are equal. .

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a trajectory image indicating the trajectory of the lesioned part P with periodic motion is created. Further, the volume data (first to nth volume data) that is the origin of the trajectory image and the volume data (mth volume data) that is the origin of the image on which the trajectory image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E and acquires the detection data (S50). In the present embodiment, as in the first to fourth embodiments, the X-ray detection unit 12 acquires the first to nth detection data. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S50, and creates a plurality of projection data (first to nth projection data) (S51). ). The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S51 (S52).

Then, the specifying unit 42i specifies the position (P _{1 to} P _n ) of the lesioned part P with periodic movement in each of the first to nth volume data created in S52 (S53). Path image creation unit 42h, by connecting the position P ₁ to P _n identified by the identifying unit 42i, to create a three-dimensional image showing the trajectory. Then, the trajectory image creation unit 42h creates a two-dimensional trajectory image by rendering the three-dimensional image in a predetermined direction (S54). The created trajectory image is a two-dimensional image showing the trajectory of the lesion P. The trajectory image created in S54 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs an X-ray scan at a timing different from the scan timing in S50 to create m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S55). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing on the acquired m-th detection data to create projection data (m-th projection data) (S56). The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S56. Further, the reconstruction processing unit 42b creates m-th volume data by interpolating a plurality of tomographic image data (S57).

  Then, the MPR processing unit 42d creates an MPR image by rendering the m-th volume data from the same direction as that rendered in S54 (S58). That is, the trajectory image created in S54 and the MPR image created in S58 show images in the same direction.

  The display control unit 43 causes the display unit 45 to display the two-dimensional trajectory image created in S54 on the MPR image based on the m-th volume data created in S58 (S59).

<Action and effect>
The operation and effect of this embodiment will be described.

  The trajectory image creation unit 42h in the X-ray CT apparatus 1 of the present embodiment includes a specifying unit 42i. The specifying unit 42i specifies the position of a part with periodic movement in each of the plurality of volume data. The trajectory image creation unit 42h creates a three-dimensional image showing the trajectory based on the position of the identified part, and creates a two-dimensional image obtained by viewing the three-dimensional image from a predetermined direction as a trajectory image. The display control unit 43 causes the display unit 45 to display a two-dimensional trajectory image superimposed on the two-dimensional image based on the volume data.

  As described above, the trajectory image creation unit 42h creates a three-dimensional trajectory image indicating a periodic motion trajectory in the subject E based on the three-dimensional position of the part specified by the specifying unit 42i. Further, the trajectory image creation unit 42h creates a two-dimensional trajectory image from the three-dimensional trajectory image. Then, the display control unit 43 causes the display unit 45 to display the two-dimensional trajectory image superimposed on the two-dimensional image based on the volume data. Therefore, it is possible to easily recognize in the two-dimensional image the range in which the region with periodic movement actually moves. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Sixth embodiment)
Next, the configuration of the X-ray CT apparatus 1 according to the sixth embodiment will be described with reference to FIGS. 16 and 17. In the sixth embodiment, the trajectory image creation unit 42h creates a two-dimensional trajectory image based on MPR image data in each of a plurality of volume data (for example, first to nth volume data). A configuration in which the display control unit 43 superimposes and displays a two-dimensional trajectory image on a two-dimensional image based on volume data (for example, m-th volume data) will be described. Note that detailed description of the same configurations and the like as in the first to fifth embodiments may be omitted.

<Device configuration>
FIG. 16 shows only the configuration of the processing unit 42 in the X-ray CT apparatus 1 of the present embodiment. Other configurations are the same as those in the first to fifth embodiments.

  The trajectory image creation unit 42h in the present embodiment includes an MPR data creation unit 42f and a specification unit 42i. Since the MPR data creation unit 42f has the same configuration as that of the third embodiment, detailed description thereof is omitted.

  The specifying unit 42i in the present embodiment specifies the position of a part with periodic movement in each of the plurality of MPR image data created by the MPR data creating unit 42f. For example, it is assumed that the MPR data creating unit 42f creates first to nth MPR image data indicating a predetermined cross section in each of the first to nth volume data. The specifying unit 42i performs image processing such as a region growing method and edge detection on each of the first to n-th MPR image data, and a two-dimensional position (for example, a lesioned part) with a periodic motion ( Specify the coordinate value.

  The trajectory image creation unit 42h creates a two-dimensional trajectory image indicating the trajectory based on the position of the part specified by the specifying unit 42i. For example, it is assumed that the specifying unit 42i specifies a two-dimensional position (coordinate value) of a part (for example, a lesioned part) accompanied with a periodic motion in each of the first to nth MPR image data. The trajectory image creation unit 42h creates a two-dimensional trajectory image by connecting a plurality of positions specified by the specifying unit 42i.

  The display control unit 43 causes the display unit 45 to display a two-dimensional trajectory image superimposed on the two-dimensional image obtained by rendering the volume data. For example, the display control unit 43 superimposes the two-dimensional trajectory image created by the trajectory image creation unit 42h on the two-dimensional image obtained by rendering the m-th volume data. The display control unit 43 causes the display unit 45 to display a two-dimensional image on which the trajectory image is superimposed. When a two-dimensional trajectory image is superimposed on a two-dimensional image based on the mth volume data, the direction in which the first to nth volume data is rendered is equal to the direction in which the mth volume data is rendered. Is desirable.

<Operation>
Next, an example of the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, a case will be described in which a trajectory image indicating the trajectory of the lesioned part P with periodic motion is created. Further, the volume data (first to nth volume data) that is the origin of the trajectory image and the volume data (mth volume data) that is the origin of the image on which the trajectory image is superimposed are detected at different timings. Based on data.

  First, the X-ray CT apparatus 1 performs a plurality of X-ray scans (first to nth scans) with one cycle of respiration, and outputs a corresponding plurality of volume data (first to nth volume data). create.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S60). In the present embodiment, as in the first to fourth embodiments, the X-ray detection unit 12 acquires the first to nth detection data. The preprocessing unit 42a performs preprocessing such as logarithmic conversion processing on the first to nth detection data acquired in S60, and creates a plurality of projection data (first to nth projection data) (S61). ). The reconstruction processing unit 42b creates a plurality of corresponding volume data (first to nth volume data) based on the first to nth projection data created in S61 (S62).

Then, the MPR data creation unit 42f creates the first to nth MPR image data corresponding to the first to nth volume data by rendering each of the first to nth volume data from the same direction. (S63). The specifying unit 42i specifies the position (P _{1 to} P _n ) of the lesioned part P with periodic movement in each of the _{first to n-} th MPR image data created in S63 (S64). Path image creation unit 42h, by connecting the position _P 1 to P _n identified by the identifying unit 42i, to create a two-dimensional image showing the trajectory (S65). The created trajectory image is a two-dimensional image showing the trajectory of the lesion P. The trajectory image created in S65 is stored in the storage unit 44.

  Next, the X-ray CT apparatus 1 performs an X-ray scan at a timing different from the scan timing in S60, and creates m-th volume data.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S66). Here, scanning for one rotation is performed, and detection data (m-th detection data) corresponding to the scan is acquired. The pre-processing unit 42a performs pre-processing such as logarithmic conversion processing on the acquired m-th detection data to create projection data (m-th projection data) (S67). The reconstruction processing unit 42b creates a plurality of tomographic image data based on the mth projection data created in S67. Further, the reconstruction processing unit 42b creates m-th volume data by interpolating a plurality of tomographic image data (S68).

  Then, the MPR processing unit 42d creates an MPR image by rendering the m-th volume data from the same direction as that rendered in S68 (S69). That is, the trajectory image created in S65 and the MPR image created in S69 show images in the same direction.

  The display control unit 43 causes the display unit 45 to display the two-dimensional trajectory image created in S65 superimposed on the MPR image created in S69 (S70).

<Action and effect>
The operation and effect of this embodiment will be described.

  The trajectory image creation unit 42h in the X-ray CT apparatus 1 of the present embodiment includes an MPR data creation unit 42f and a specification unit 42i. The MPR data creation unit 42f creates a plurality of MPR image data indicating a predetermined section in each of the plurality of volume data. The specifying unit 42i specifies the position of a part with periodic movement in each of the plurality of MPR image data. The trajectory image creation unit 42h creates a two-dimensional trajectory image based on the position of the identified part. The display control unit 43 causes the display unit 45 to display a two-dimensional trajectory image superimposed on the two-dimensional image based on the volume data.

  In this way, the trajectory image creation unit 42h creates a two-dimensional trajectory image indicating a periodic motion trajectory in the subject E based on the two-dimensional position of the part specified by the specifying unit 42i. Then, the display control unit 43 causes the display unit 45 to display the trajectory image superimposed on the two-dimensional image based on the volume data. Therefore, it is possible to easily recognize in the two-dimensional image the range in which the region with periodic movement actually moves. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

(Modifications According to Fourth to Sixth Embodiments)
When an image based on volume data and a trajectory image are displayed in an overlapping manner, it is desirable that they are displayed in a state where they can be distinguished from each other. In this modification, an X-ray CT apparatus capable of changing the display mode of an image based on volume data and a trajectory image will be described.

  FIG. 18 is a block diagram showing a configuration of the console device 40 of the X-ray CT apparatus 1 according to this modification. The display control unit 43 in the X-ray CT apparatus 1 includes a changing unit 43a. The changing unit 43a changes the display mode of the image based on the volume data and the display mode of the trajectory image. Specifically, the changing unit 43a changes at least one of the color, transparency, and CT value of the image (trajectory image). For example, the changing unit 43a changes the image based on the volume data so as to be a gray scale, and changes the trajectory image to be a color. In this way, when displaying with a different color, it becomes easy to recognize a part with periodic movement in the image. Alternatively, the changing unit 43a increases the transparency of the image based on the volume data and decreases the transparency of the trajectory image. When displaying the trajectory image with low transparency, it is possible to highlight and display a region with periodic movement. Although FIG. 18 is described based on the configuration of the fourth embodiment, it is also possible to provide a changing unit 43a in the configurations of the fifth and sixth embodiments.

Furthermore, the changing unit 43a can also change the display mode of the trajectory image so that only a part of the superimposed trajectory image is displayed. FIG. 19 shows an MPR image (coronal image CI) obtained by rendering a three-dimensional image on which a three-dimensional trajectory image is superimposed in the coronal direction. It is assumed that the changing unit 43a changes the display mode of the trajectory image so that only the position where the moving amount is the largest in the periodic movement of the lesioned part P is displayed. As a result, the display control unit 43 displays only the trajectory images (T ₁ and T _n ) at the position where the movement amount is the largest in the periodic movement of the lesioned part P. Thus, the periodic movement of the subject can be roughly grasped by displaying only a part of the trajectory image. In addition, when the periodic movement is complicated, there is a possibility that the entire image becomes difficult to see by superimposing the trajectory image on the MPR image or the like. Even in such a case, by displaying only a part of the trajectory image, it is possible to grasp a part with periodic movement while maintaining the visibility of the image.

<Effects common to the embodiments>
According to the X-ray CT apparatus of at least one embodiment described above, a moving image or a trajectory image (2D or 3D) is superimposed and displayed on an image (2D or 3D) based on volume data. Can do. Therefore, it is possible to easily recognize the actual movement and trajectory of the part with periodic movement in the image. That is, according to the X-ray CT apparatus of the present embodiment, it is possible to display a medical image that reflects the periodic movement of the subject.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These 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 their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 10 Base apparatus 11 X-ray generation part 12 X-ray detection part 13 Rotating body 14 High voltage generation part 15 Base drive part 16 X-ray aperture part 17 Aperture drive part 18 Data collection part 30 Bed apparatus 32 Sleeper drive part 33 bed table 34 base 40 console device 41 scan control unit 42 processing unit 42a pre-processing unit 42b reconstruction processing unit 42c moving image creation unit 42d MPR processing unit 43 display control unit 44 storage unit 45 display unit 46 input unit 47 control Part

Claims (20)

An X-ray CT apparatus that scans a subject including a region with periodic movement with X-rays and acquires detection data,
A reconstruction processing unit that creates a plurality of volume data based on a plurality of the detection data acquired during one period in the periodic movement;
A moving image creating unit that creates a moving image showing the periodic movement based on at least a part of the plurality of volume data;
A display control unit that superimposes the moving image on an image based on volume data and displays the image on a display unit;
An X-ray CT apparatus comprising: In the plurality of volume data, an extractor that extracts data corresponding to a part of the part with the periodic movement,
The X-ray CT apparatus according to claim 1, wherein the moving image creating unit creates a moving image based on the extracted data as the moving image. The moving image creating unit creates a three-dimensional moving image based on at least a part of the plurality of volume data as the moving image,
The X-ray CT apparatus according to claim 1, wherein the display control unit superimposes the three-dimensional moving image on a three-dimensional image based on the volume data and displays the superimposed image on the display unit. An MPR processing unit for creating an MPR image showing a predetermined cross section in the three-dimensional image based on the volume data;
The X-ray CT apparatus according to claim 3, wherein the display control unit displays the MPR image on the display unit. The moving image creating unit creates a three-dimensional moving image based on at least a part of the plurality of volume data;
As the moving image, an MPR moving image creating unit that creates an MPR moving image showing a predetermined cross section in the three-dimensional moving image,
The X-ray CT apparatus according to claim 1, wherein the display control unit superimposes the MPR moving image on a two-dimensional image based on the volume data and displays the MPR moving image on the display unit. The moving image creation unit
An MPR data creation unit for creating a plurality of MPR image data indicating a predetermined cross section in each of the plurality of volume data;
Creating the moving image based on the plurality of MPR image data;
The X-ray CT apparatus according to claim 1, wherein the display control unit superimposes the moving image on a two-dimensional image based on the volume data and displays the superimposed image on the display unit.   The X-ray CT according to claim 1, wherein the display control unit includes a changing unit that changes a display mode of the image based on the volume data and a display mode of the moving image. apparatus.   The X-ray CT apparatus according to claim 7, wherein the display mode changed by the changing unit is at least one of color, transparency, and CT value. A display unit;
A reconstruction processing unit that creates a plurality of volume data based on a plurality of detection data acquired by scanning a subject including a region with a periodic movement with X-rays for one period;
A moving image creating unit that creates a moving image showing the periodic movement based on at least a part of the plurality of volume data;
A display control unit that superimposes the moving image on an image based on volume data and displays the image on a display unit;
An image display device comprising: A step of creating a plurality of volume data by a reconstruction processing unit based on a plurality of detection data acquired by scanning a subject including a region with periodic movement with X-rays for one cycle;
A moving image data creating unit creating a moving image showing the periodic movement based on at least a part of the plurality of volume data;
A step of causing the display control unit to superimpose the moving image on an image based on the volume data and to display the image on the display unit;
An image display method characterized by comprising: An X-ray CT apparatus that scans a subject including a region with periodic movement with X-rays and acquires detection data,
A reconstruction processing unit that creates a plurality of volume data based on a plurality of the detection data acquired during one period in the periodic movement;
A trajectory image creation unit that creates a trajectory image indicating the trajectory of the periodic movement based on at least a part of the plurality of volume data;
A display control unit that superimposes the locus image on an image based on volume data and displays the image on a display unit;
An X-ray CT apparatus comprising: The trajectory image creation unit
In each of the plurality of volume data, it has a specifying unit that specifies the position of the part with the periodic movement,
Based on the position of the identified part, create a three-dimensional trajectory image,
The X-ray CT apparatus according to claim 11, wherein the display control unit superimposes the three-dimensional trajectory image on the three-dimensional image based on the volume data and causes the display unit to display the superimposed image. An MPR processing unit for creating an MPR image showing a predetermined cross section in the three-dimensional image based on the volume data;
The X-ray CT apparatus according to claim 12, wherein the display control unit displays the MPR image on the display unit. The trajectory image creation unit
In each of the plurality of volume data, it has a specifying unit that specifies the position of the part with the periodic movement,
Based on the identified position of the part, create a three-dimensional image showing the trajectory, create a two-dimensional image of the three-dimensional image viewed from a predetermined direction as the trajectory image,
The X-ray CT apparatus according to claim 11, wherein the display control unit superimposes the two-dimensional trajectory image on the two-dimensional image based on the volume data and causes the display unit to display the superimposed image. The trajectory image creation unit
An MPR data creation unit for creating a plurality of MPR image data indicating a predetermined cross section in each of the plurality of volume data;
In each of the plurality of MPR image data, a specifying unit that specifies the position of the part with the periodic movement;
Have
Based on the position of the identified part, create a two-dimensional trajectory image,
The X-ray CT apparatus according to claim 11, wherein the display control unit superimposes the two-dimensional trajectory image on the two-dimensional image based on the volume data and causes the display unit to display the superimposed image.   The X-ray CT according to claim 11, wherein the display control unit includes a changing unit that changes a display mode of the image based on the volume data and a display mode of the trajectory image. apparatus.   17. The X-ray CT apparatus according to claim 16, wherein the display mode changed by the changing unit is at least one of color, transparency, and CT value.   The X-ray CT apparatus according to claim 16 or 17, wherein the changing unit changes a display mode of the trajectory image so as to display only a part of the trajectory image to be superimposed. A display unit;
A reconstruction processing unit that creates a plurality of volume data based on a plurality of detection data acquired by scanning a subject including a region with a periodic movement with X-rays for one period;
A trajectory image creation unit that creates a trajectory image indicating the trajectory of the periodic movement based on at least a part of the plurality of volume data;
A display control unit that superimposes the trajectory image on an image based on volume data and displays the image on the display unit;
An image display device comprising: A step of creating a plurality of volume data by a reconstruction processing unit based on a plurality of detection data acquired by scanning a subject including a region with periodic movement with X-rays for one cycle;
A trajectory image creating unit creating a trajectory image indicating the trajectory of the periodic movement based on at least a part of the plurality of volume data;
A step of causing the display control unit to superimpose the trajectory image on the image based on the volume data and to display the image on the display unit;
An image display method characterized by comprising:

Images