JP6440928B2 - X-ray CT apparatus, image display apparatus - Google Patents

Description

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

  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. And a console apparatus performs the reconstruction process based on projection data, and produces CT image data.

  By the way, when an X-ray CT apparatus scans an object having a motion such as the heart, there is a possibility that a CT image obtained by the influence of the motion is blurred (motion artifacts may occur). In order to reduce the influence of this movement, for example, there is a technique called electrocardiographic synchronization reconstruction. In the ECG synchronization reconstruction, an X-ray scan is performed in a state where the heart or the like is moving, and ECG waveform data is acquired by an electrocardiograph in parallel with the X-ray scan. And there exists a method of specifying the detection data acquired at the timing with little influence of movement in the electrocardiogram waveform data among the acquired detection data, and reconstructing only the detection data. In this way, the X-ray CT apparatus creates CT image data by reconstructing only detection data acquired at a timing with little influence of motion. That is, a CT image based on this CT image data is an image in which motion artifacts and the like are reduced.

  Further, the X-ray CT apparatus can display on the display unit a screen for confirming and processing detection data acquired by the X-ray scan (hereinafter also referred to as “raw data page”). On the raw data page, it is possible to display a CT image based on the detection data (projection data), process the detection data (for example, re-execute the reconstruction process), and the like.

JP 2006-158444 A

  Here, when observing a CT image based on detection data obtained by electrocardiographic synchronization reconstruction, an operator may want to confirm an electrocardiographic waveform image corresponding to the CT image. For this purpose, the CT image and the electrocardiographic waveform image need to be associated with each other.

  In addition, the surgeon may want to perform a reconstruction process on the detection data acquired at a timing different from the detection data that is the basis of the CT image on the raw data page and observe a new CT image. is there. For this purpose, it is convenient to specify the detection data based on the electrocardiographic waveform data corresponding to the electrocardiographic waveform image.

  The embodiment has been made to solve the above-described problems, and can easily associate a CT image (CT image data) with a corresponding electrocardiographic image (electrocardiographic waveform image data). An object is to provide an X-ray CT apparatus and an image display apparatus that can easily display ECG waveform data corresponding to an ECG waveform image.

The X-ray CT apparatus of the embodiment performs X-ray scanning on a subject and acquires detection data. The X-ray CT apparatus includes a setting unit, a specifying unit, a reconstruction processing unit, a storage unit, a control unit, and a display control unit. The setting unit sets a desired range for the electrocardiographic waveform data of the subject obtained in parallel with the X-ray scan. The specifying unit specifies detection data acquired at a timing included in a desired range from the detection data. The reconstruction processing unit reconstructs projection data based on the identified detection data, and creates CT image data. The controller, on the basis of the signal to start the reconstruction process, based on the desired range set electrocardiographic waveform data, detection data are electrocardiographic waveform image data, and specific based on the electrocardiogram waveform data CT The image data is associated and stored in the storage unit. The display control unit, based-out of the stored electrocardiographic complex image data, is displayed together electrocardiographic waveform and CT images based on the stored CT image data for selecting the electrocardiographic waveform data to the display unit When an electrocardiographic waveform image is selected, electrocardiographic waveform data in which a desired range corresponding to the selected electrocardiographic waveform image is set is displayed on the display unit.

1 is a block diagram of an X-ray CT apparatus according to an embodiment. It is a figure which supplements description of the setting part which concerns on embodiment. It is a figure which supplements description of the change part which concerns on embodiment. It is a figure which supplements description of the change part which concerns on embodiment. It is a figure which supplements description of the specific part which concerns on embodiment. It is a figure which supplements description of the specific part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on embodiment. It is a figure which supplements description of the specific part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment. It is a figure which supplements description of the specific part which concerns on embodiment. It is a figure which shows the display screen of the display part which concerns on embodiment.

(Embodiment)
The configuration of the X-ray CT apparatus 1 according to the embodiment will be described with reference to FIGS. 1 to 6.

<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. In addition to the X-ray CT apparatus 1, an electrocardiograph 50 is provided.

[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. That is, the X-ray generator 11 emits X-rays 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. That is, the X-ray detection unit 12 detects X-rays that have passed through the subject E and outputs detection data. 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 generator 11 and the X-ray detector 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 collecting unit 18 transmits the detection data converted into the digital signal to the console device 40 (image processing unit 44 (described later)).

[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 setting unit 42, a specifying unit 43, an image processing unit 44, a control unit 45, a display control unit 46, an input unit 47, a storage unit 48, and a display unit. 49.

  The scan control unit 41 controls various operations related to X-ray scanning. For example, the scan control unit 41 controls the gantry driving unit 15 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.

  In the present embodiment, the electrocardiographic waveform data of the subject E is acquired by the electrocardiograph 50 in parallel with the X-ray scan by the X-ray CT apparatus 1. That is, the time axis of the X-ray scan and the time axis of the electrocardiographic waveform data are synchronized. The detection data acquired by the X-ray scan and the electrocardiographic waveform data are associated on the same time axis and stored in the storage unit 48 or the like.

  The setting unit 42 sets a desired range R for the electrocardiographic waveform data of the subject E obtained in parallel with the X-ray scan.

The electrocardiographic waveform data is data indicating the state of electrical activity of the heart. FIG. 2 is a schematic diagram showing electrocardiographic waveform data of the subject E as a graph G. In FIG. 2, the vertical axis represents voltage, and the horizontal axis represents time (t). By referring to the graph G, the surgeon can confirm that the R waves r _k (k = 1 to n) are detected at regular intervals with the movement of the heart of the subject E (in FIG. 2, Only the R waves r _{1 to} r ₃ are shown). Further, the surgeon can confirm that a wave Ar indicating an arrhythmia is detected between the R wave r ₂ and the R wave r ₃ .

  The desired range R is a range corresponding to the time phase of the electrocardiogram waveform data (hereinafter sometimes referred to as “timing”), and is a range for specifying detection data used for creating a CT image (CT image data). It is. The desired range R is a range indicating a timing at which the influence of movement of the heart or the like is small. The X-ray CT apparatus 1 according to the present embodiment can create a CT image with less influence of motion based on detection data acquired at a timing included in a desired range R (details will be described later).

The desired range R can be set manually. In this case, the display control unit 46 causes the display unit 49 to display the graph G indicating the electrocardiographic waveform data shown in FIG. The surgeon designates an arbitrary region in the graph G (region corresponding to the desired range R) via the input unit 47 or the like. FIG. 2 shows an example in which a region where there is no influence of arrhythmia (a partial region between R wave r ₁ and R wave r ₂ ) is designated. The setting unit 42 sets an arbitrary region designated by the input unit 47 or the like as the desired range R for the electrocardiographic waveform data. The designation of an arbitrary area by the input unit 47 can be directly written in the graph G by using a marker or the like, for example. Alternatively, the R wave interval is divided into a plurality of regions (for example, 1 to 100) in advance, and an arbitrary region is designated by inputting a numerical value (for example, 50 to 90) corresponding to the region through the input unit 47. May be.

The desired range R can also be set automatically. For example, when there is an abnormality in the motion of the heart, the interval between R waves may vary. A CT image based on detection data obtained in a state where there is an abnormality in the motion of the heart is highly likely to be affected by motion artifacts. Therefore, general intervals S between R waves are classified in advance in the X-ray CT apparatus 1 by age, body type, etc., and registered as a part of the expert plan. Setting unit 42 compares the distance S that has been registered, the spacing S'R-wave adjacent the acquired electrocardiographic waveform data (interval between R-wave r _k-1 and R-wave r _k). When the interval S and the interval S ′ are substantially equal, the heart motion is likely to be normal. In this case, the setting unit 42 sets the region in the interval S ′ as the desired range R. The expert plan is an inspection plan including various conditions in a series of operations in the X-ray CT apparatus 1 such as a scan condition for performing an X-ray scan. The X-ray CT apparatus 1 performs X-ray scanning and reconstruction processing based on a preset expert plan, and creates a CT image.

The ratio of the desired range R in the interval S ′ can be arbitrarily set. For example, a range to be set as a desired range R in the expert plan is stored in advance. When the setting unit 42 determines that the interval S and the interval S ′ are equal, the setting unit 42 sets the desired range R by applying the stored range to be set to the electrocardiographic waveform data. Also good. For example, "out between R-wave r _{k-1 to R-wave} r _k, the area corresponding from R-wave r _k 75%" as a range to be set and is stored in the expert plan. In this case, setting unit 42, among the regions in interval S', it sets the area corresponding from R-wave r _k to 75% as the desired range R.

  Note that the setting unit 42 may set the exclusion range R ′ for a region affected by arrhythmia by the same method as that for setting the desired range R (see FIG. 2). By observing the electrocardiogram waveform image in which the exclusion range R ′ is set, the surgeon confirms that the detection data acquired at the timing included in the exclusion range R ′ is not used for creating the CT image data. Yes (details below). Desirably, the desired range R and the excluded range R ′ can be identified when displayed as an electrocardiographic waveform image H (described later). In this case, the setting unit 42 performs setting so that the marker indicating the desired range R and the marker indicating the exclusion range R ′ have different forms and colors.

  The setting unit 42 in the present embodiment includes a changing unit 42a. The changing unit 42a changes the set desired range R to the electrocardiographic waveform data in which the desired range R displayed on the display unit 49 is set, and sets a new range NR.

3A and 3B are schematic diagrams showing electrocardiographic waveform data (graph G) displayed on the display unit 49 by the display control unit 46. FIG. In electrocardiographic waveform data shown in FIG. 3A, the desired range R between the R-wave r ₁ and R-wave r ₂ it is set.

The surgeon makes a new region different from the region corresponding to the desired range R in the electrocardiogram waveform data via the input unit 47 or the like (region corresponding to the new range NR). Is specified (see FIG. 3B). FIG. 3B shows an example in which a part of the region between the R wave r _{2 and the} R wave r _{3 that} is not affected by the arrhythmic wave Ar is specified. The changing unit 42a changes a desired range R for the electrocardiogram waveform data, and sets a new region designated by the input unit 47 or the like as a new range NR. Designation of a new area by the input unit 47 can be performed using a marker or the like as described above.

  The specifying unit 43 specifies detection data acquired at a timing included in a desired range R among detection data obtained by X-ray scanning. Further, the specifying unit 43 specifies the detection data acquired at the timing included in the new range NR.

  4A and 4B are schematic diagrams showing the correspondence between the electrocardiogram waveform data and the detection data (the upper part shows the electrocardiogram waveform data, the lower part shows the detection data, and the horizontal axis shows time (t)).

  As described above, the time axis of the X-ray scan and the time axis of the electrocardiogram waveform data are synchronized. Therefore, when the desired range R is set in the electrocardiogram waveform data, the specifying unit 43 can specify the detection data D acquired at the time (timing) included in the desired range R (see FIG. 4A). ). Further, when a new range NR is set by the changing unit 42a in the electrocardiogram waveform data, the specifying unit 43 may specify the detection data D ′ acquired at the time (timing) included in the new range NR. Yes (see FIG. 4B).

  The image processing unit 44 performs various processes on the detection data transmitted from the gantry device 10 (data collection unit 18). In the present embodiment, the image processing unit 44 performs various processes on the detection data D (detection data D ′) specified by the specifying unit 43. The image processing unit 44 includes a preprocessing unit 44a, a reconstruction processing unit 44b, and a rendering processing unit 44c.

  The preprocessing unit 44a performs preprocessing 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 44b creates CT image data (two-dimensional tomographic image data and three-dimensional volume data) based on the projection data created by the preprocessing unit 44a. 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 expansion 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.

  The rendering processor 44c performs a rendering process on the volume data created by the reconstruction processor 44b. For example, the rendering processing unit 44c displays the MPR by rendering the volume data created by the reconstruction processing unit 44b in an arbitrary direction. That is, the rendering processing unit 44c creates an MPR image (MPR image data).

  The control unit 45 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 45 controls the image processing unit 44 to perform various processing (preprocessing, reconstruction processing, MPR processing, etc.) on the detected data. Alternatively, the control unit 45 performs various controls related to image display. For example, the control unit 45 causes the display unit 49 to display a CT image based on the image data stored in the storage unit 48.

  Further, the control unit 45 in the present embodiment, based on the signal for starting the reconstruction process, the electrocardiographic waveform data in which the desired range R is set, the electrocardiographic waveform image data based on the electrocardiographic waveform data, and the identification The CT image data based on the detected data D is associated and stored in the storage unit 48 or the like.

  For example, when a surgeon inputs an instruction to start the reconstruction process via the input unit 47 or the like, the control unit 45 causes the reconstruction processing unit 44b to control the reconstruction unit 44b based on the instruction input. This is an instruction signal that causes the reconstruction processing to be executed. Alternatively, when the reconstruction process is automatically started based on the expert plan, the signal for starting the reconstruction process is an instruction signal for the control unit 45 to cause the reconstruction processing unit 44b to perform the reconstruction process based on the expert plan. It is.

  The control unit 45 acquires electrocardiographic waveform data in which the desired range R is set by the setting unit 42 based on a signal for starting the reconstruction process. The electrocardiographic waveform data in which the desired range R is set is data including electrocardiographic waveform data and information indicating the desired range R. The electrocardiographic waveform data may include information indicating the exclusion range R ′.

  Further, the control unit 45 acquires electrocardiographic waveform data in which the desired range R is set by the setting unit 42 as electrocardiographic waveform image data based on a signal for starting the reconstruction process. Specifically, the control unit 45 captures the electrocardiographic waveform data in which the desired range R is set as an image, and acquires it as electrocardiographic waveform image data. That is, the electrocardiographic waveform image data in the present embodiment is integral image data including the electrocardiographic waveform data and information indicating the desired range R. The electrocardiographic waveform image data may include information indicating the exclusion range R ′.

  Based on the electrocardiographic waveform data in which the desired range R is set, the acquired electrocardiographic waveform image data, and the detection data specified by the specifying unit 43, the control unit 45 performs the image processing unit 44 (the preprocessing unit 44a and the re-processing unit 44a). The CT image data created by the configuration processing unit 44b) is associated with and stored in the storage unit 48. The CT image data is created based on a signal for starting the reconstruction process. In the present embodiment, for a plurality of CT image data, one image data indicating the entire electrocardiographic waveform data in which a desired range R is set is stored as electrocardiographic waveform image data.

  On the other hand, when the desired range R is changed, the control unit 45, based on the signal for starting the reconstruction process, the electrocardiogram waveform data in which the new range NR is set, and the electrocardiogram based on the electrocardiogram waveform data. The shape image data and the CT image data based on the specified detection data D ′ are associated and stored in the storage unit 48 or the like. The electrocardiographic waveform data in which the new range NR is set is data including electrocardiographic waveform data and information indicating the new range NR. The electrocardiographic waveform image data in this case is integral image data including the electrocardiographic waveform data and information indicating a new range NR. The detection data D ′ is detection data acquired at a timing specified by the specifying unit 43 and included in the new range NR.

  As described above, the control unit 45 uses the signal (reconfiguration processing request) for starting the reconstruction process as a trigger, and the electrocardiographic waveform data in which the desired range R (new range NR) is set, the electrocardiographic waveform data. The correlation between the electrocardiographic waveform image data based on the CT data and the CT image data based on the detection data specified by the specifying unit 43 is automatically executed. Therefore, since it is not necessary for the surgeon to instruct the association every time, the operation in the X-ray CT apparatus 1 is simplified. The electrocardiographic waveform data, the electrocardiographic waveform image data, and the CT image data are also associated with the patient ID of the subject E. Therefore, by inputting the patient ID, the X-ray CT apparatus 1 (control unit 45) can read the corresponding electrocardiographic waveform data, electrocardiographic waveform image data, and CT image data.

  The display control unit 46 performs various controls related to image display. For example, the display unit 49 is controlled to display a CT image based on the CT image data created by the reconstruction processing unit 44b. In addition, the display control unit 46 can display one piece of information or an image in each display area by setting one screen (display screen) of the display unit 49 as one page and providing a plurality of display areas in one page. . The raw data page RP described below is an example.

In the present embodiment, the display control unit 46 causes the display unit 49 to display an ECG waveform image based on the stored ECG waveform image data and a CT image based on the stored CT image data. 5A to 5E are screens showing examples of the raw data page RP. The raw data page RP has display areas P _{1 to} P ₃ . Note that the raw data page RP shown in FIGS. 5A to 5E shows only a part of the display area necessary for explaining the present embodiment.

Displayed on the display area P ₃ "Recon" is a soft key F for instructing the execution of the reconstruction process. When the soft key F is selected by the input unit 47 or the like, the reconstruction processing unit 44b performs a reconstruction process (re-execution of the reconstruction process) based on the set reconstruction process condition. The reconstruction processing condition can be displayed on a raw data page RP (for example, display area P ₃ ) by displaying a reconstruction processing condition setting screen, and specific processing conditions can be set on the screen.

For example, when the patient ID of the subject E is input, the control unit 45 causes the electrocardiographic waveform data in which a desired range R corresponding to the patient ID is set, and the electrocardiographic waveform image data based on the electrocardiographic waveform data. And CT image data by the specified detection data is read. The display control unit 46 displays the CT image (tomographic image) I _k (k = 1 to n) based on the read CT image data and the read electrocardiographic waveform image in the display area P ₁ of the raw data page RP. ECG waveform images H based on the data are displayed side by side (see FIG. 5A). Is this way, by displaying the electrocardiographic waveform image H associated with the CT image I _k on one screen, the operator was created on the basis of what electrocardiographic waveform CT image being displayed Can be easily understood. For example, the surgeon who sees the electrocardiogram waveform image H in FIG. 5A displays the detection data obtained at the timing between the R wave r ₁ and the R wave r ₂ when the CT image I _k is displayed in a predetermined range R. It can be confirmed that it was created based on this.

Here, when the surgeon selects the electrocardiographic waveform image H displayed on the display unit 49 by the input unit 47 or the like, the display control unit 46 selects the desired range R corresponding to the selected electrocardiographic waveform image H. There displays the electrocardiographic waveform data set in the display area P ₂ of the display unit 49 (see FIG. 5B). Thus, by displaying the electrocardiogram waveform data on the display unit 49, the surgeon can execute an input operation (edit) on the electrocardiogram waveform data.

For example, when observing a CT image at the timing between the R wave r _{2 and the} R wave r ₃ , the surgeon desires to set the electrocardiogram waveform data in the display area P ₂ via the input unit 47 or the like. Range R is deleted, and a new region (region corresponding to the new range NR) is designated (see FIG. 5C). The changing unit 42a sets the designated area as a new range NR. The specifying unit 43 specifies the detection data D ′ acquired at the timing included in the new range NR among the detection data stored in the storage unit 48 or the like.

  Thereafter, the reconstruction process is re-executed by the X-ray CT apparatus 1. That is, when the surgeon selects the soft key F via the input unit 47 or the like, the control unit 45 causes the reconstruction processing unit 44b to execute a reconstruction process using the detection data D ′ based on the instruction input (reconstruction). Rerun configuration process).

  In this case, the control unit 45, based on the signal for starting the reconstruction process, the electrocardiographic waveform data in which the new range NR is set, the electrocardiographic waveform image data based on the electrocardiographic waveform data, and the specified new CT image data based on detection data acquired at a timing included in a wide range NR is stored in association with each other.

The display control unit 46, after the re-execution of the reconstruction process is completed, instead of the electrocardiographic waveform image H and CT image I _k, the electrocardiographic waveform image new range NR is set H'and the detection data The CT image I _k ′ (k = 1 to n) based on D ′ may be displayed in the display area P ₁ of the display unit 49 (see FIG. 5D).

Further, the display control unit 46 causes the display unit 49 to display in parallel the CT image I _k based on the detection data corresponding to the desired range R and the CT image I _k ′ based on the detection data corresponding to the new range NR. Is also possible (see FIG. 5E). Thus, by displaying CT images in parallel, it is possible to easily compare CT images based on detection data acquired at different timings. The CT image I _k in the present embodiment is an example of a “first CT image”. Further, the CT image I _k ′ in the present embodiment is an example of a “second CT image”.

  The input unit 47 is used as an input device that performs various operations on the console device 40. The input unit 47 is composed of, for example, a keyboard, a mouse, a trackball, a joystick, and the like. As the input unit 47, a GUI (Graphical User Interface) displayed on the display unit 49 can be used.

  The storage unit 48 is configured by a semiconductor storage device such as a RAM or a ROM. The storage unit 48 stores detection data, projection data, or CT image data after reconstruction processing. In the present embodiment, as described above, the storage unit 48 stores CT image data and electrocardiographic waveform image data in association with each other.

  The display unit 49 includes an arbitrary display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube) display. For example, the reconstructed CT image is displayed on the display unit 49.

  The scan control unit 41, the setting unit 42, the specifying unit 43, the image processing unit 44, the control unit 45, and the display control unit 46 are, for example, a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), or an ASIC (Application). A processing device (not shown) such as a specific integrated circuit (ROM) and a storage device (not shown) such as a read only memory (ROM), a random access memory (RAM), or an HDD (hard disc drive) are included. The storage device stores a control program for executing the function of each unit. A processing device such as a CPU executes the functions of each unit by executing each program stored in the storage device.

[Electrocardiograph]
The electrocardiograph 50 is connected to the subject E and detects a weak electrical signal generated by the heartbeat of the subject E. The electrocardiograph 50 outputs the time change of the detected electrical signal as electrocardiographic waveform data.

<Operation>
Next, the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, an example will be described in which the X-ray CT apparatus 1 executes an electrocardiogram synchronization reconstruction process based on a certain expert plan.

  When starting the X-ray scan, the operator selects an expert plan suitable for the subject E (S10). In the expert plan, conditions for setting a desired range R in the electrocardiographic waveform data are determined together with the scanning conditions and the reconstruction processing conditions.

  The X-ray CT apparatus 1 starts an X-ray scan for the subject E based on the expert plan selected in S10 (S11). The electrocardiograph 50 acquires electrocardiographic waveform data in parallel with the X-ray scan in S11 (S12).

  The setting unit 42 sets a desired range R for the electrocardiographic waveform data obtained in S12 based on the expert plan selected in S10 (S13).

  The specifying unit 43 specifies the detection data D acquired at the timing included in the predetermined range R set in S13 (S14).

  The reconstruction processing unit 44b reconstructs the projection data based on the detection data D identified in S14 based on the expert plan selected in S10, and creates CT image data (S15).

  Based on the signal for starting the reconstruction process in S15, the control unit 45 generates the electrocardiographic waveform data in which the desired range R is set in S13, the electrocardiographic waveform image data based on the electrocardiographic waveform data, and in S15 The obtained CT image data is associated and stored in the storage unit 48 (S16).

After the end of the X-ray scan, the display control unit 46 displays the raw data page RP on the display unit 49 based on an instruction input from the operator. When the surgeon inputs the patient ID or the like of the subject E, the display control unit 46 reads out the electrocardiographic waveform data, CT image data, and electrocardiographic waveform image data corresponding to the input patient ID from the storage unit 48. Then, the display control unit 46 displays side by side on the display unit 49 electrocardiographic waveform image H based on the CT image I _k and electrocardiographic waveform image data based on the CT image data read out (S17. See Fig. 5A).

  When the electrocardiographic waveform image H is selected, the display control unit 46 displays the electrocardiographic waveform data corresponding to the electrocardiographic waveform image H on the display unit 49 (S18, see FIG. 5B).

  The surgeon changes the desired range R in the electrocardiographic waveform data displayed in S18 via the input unit 47 or the like. Based on this change, the changing unit 42a sets a new range NR (S19, see FIG. 5C).

  The specifying unit 43 specifies the detection data D ′ acquired at the timing included in the new range NR set in S19 (S20).

  When the surgeon selects the soft key F via the input unit 47 or the like, the control unit 45 causes the reconstruction processing unit 44b to execute a reconstruction process using the detection data D ′ (re-execution of the reconstruction process). The reconstruction processing unit 44b reconstructs the projection data based on the detection data D ′ specified in S20, and creates CT image data (S21, re-execution of the reconstruction process).

  Based on the signal for starting the reconstruction process, the control unit 45 generates the electrocardiographic waveform data in which the new range NR is set in S19, the electrocardiographic waveform image data based on the electrocardiographic waveform data, and the step S21. The CT image data is associated and stored in the storage unit 48 (S22).

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 1, the electrocardiographic waveform data acquired by the electrocardiograph 50, and the like are transmitted to an apparatus different from the X-ray CT apparatus 1 (for example, an image display apparatus such as an image viewer). Then, by performing the same processing in the apparatus, the same function as that of the above embodiment can be realized. In this case, it is desirable that at least a setting unit 42, a specifying unit 43, a reconstruction processing unit 44b, a control unit 45, a display control unit 46, and a display unit 49 are provided in the image display device. The control unit 45 provided in the image display device, based on at least a signal for starting reconstruction processing, electrocardiographic waveform data in which a desired range R is set, electrocardiographic waveform image data based on the electrocardiographic waveform data, and What is necessary is just to have the function to associate and memorize CT image data based on the specified detection data. The display control unit 46, at least along the CT image I _k based on the CT image data heart is wave-shaped image H and the storage based on the stored electrocardiographic waveform image data to the display unit 49 to display, and the electrocardiographic waveform When the image H is selected, it is only necessary to have a function of causing the display unit 49 to display ECG waveform data in which a desired range R corresponding to the selected ECG waveform image H is set. Further, the storage unit 48 may be in the image display apparatus or in the X-ray CT apparatus 1. Alternatively, an external server or the like may function as the storage unit 48.

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

The X-ray CT apparatus 1 of the present embodiment performs an X-ray scan on the subject E and acquires detection data. The X-ray CT apparatus 1 includes a setting unit 42, a specifying unit 43, a reconstruction processing unit 44b, a control unit 45, and a display control unit 46. The setting unit 42 sets a desired range R for the electrocardiographic waveform data of the subject E obtained in parallel with the X-ray scan. The specifying unit 43 specifies the detection data D acquired at the timing included in the desired range R among the detection data. The reconstruction processing unit 44b reconstructs projection data based on the specified detection data D, and creates CT image data. Based on the signal for starting the reconstruction process, the control unit 45 applies the ECG waveform data in which the desired range R is set, the ECG waveform image data based on the ECG waveform data, and the specified detection data D. The associated CT image data is stored in association with each other. The display control unit 46, together CT image I _k based on the CT image data heart is wave-shaped image H and the storage based on the stored electrocardiographic waveform image data to the display unit 49 to display, and the electrocardiographic waveform image H Is selected, the electrocardiographic waveform data in which a desired range R corresponding to the selected electrocardiographic waveform image H is set is displayed on the display unit 49.

  As described above, the control unit 45 automatically stores the electrocardiographic waveform data, the electrocardiographic waveform image data, and the CT image data based on the signal for starting the reconstruction process. Therefore, the electrocardiographic waveform data, the electrocardiographic waveform image data, and the CT image data can be associated with each other and stored without requiring the association instruction each time. Further, when an electrocardiographic waveform image based on the electrocardiographic waveform image data is selected, the display control unit 46 can display the corresponding electrocardiographic waveform data on the display unit 49. That is, according to the X-ray CT apparatus 1 of the present embodiment, a CT image (CT image data) and a corresponding electrocardiographic waveform image (electrocardiographic waveform image data) can be easily associated, and the electrocardiographic waveform. ECG waveform data corresponding to the image can be easily displayed. Therefore, the operation in the X-ray CT apparatus 1 becomes simple.

  In addition, the setting unit 42 in the present embodiment includes a changing unit 42a. The changing unit 42a changes the set desired range R to the electrocardiographic waveform data in which the desired range R displayed on the display unit 49 is set, and sets a new range NR. The specifying unit 43 specifies the detection data D ′ acquired at the timing included in the new range NR. Based on the signal for starting the reconstruction process, the control unit 45 sets the ECG waveform data in which the new range NR is set, the ECG waveform image data based on the ECG waveform data, and the specified new range NR. The CT image data based on the detection data D ′ acquired at the timing included in FIG.

Thus, the changing unit 42a can arbitrarily change the desired range R with respect to the electrocardiographic waveform data. Then, the specifying unit 43 specifies the detection data D ′ acquired at the timing included in the changed range (new range NR). Therefore, according to the X-ray CT apparatus 1 in the present embodiment, a CT image at an arbitrary timing can be obtained based on the electrocardiographic waveform data. For example, in a state where the region between the R wave r _{1 and the} R wave r ₂ is set as the desired range R, it is based on detection data between other R waves (for example, between the R wave r _{2 and the} R wave r ₃ ). There may be cases where it is desired to confirm the CT image. Even in such a case, based on the instruction input via the input unit 47 or the like, the changing unit 42a changes the desired range R and sets a new range NR between the R wave r _{2 and the} R wave r _3. Can be set. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, a CT image in the changed range (new range NR) can be easily confirmed. In addition, according to the X-ray CT apparatus 1 of the present embodiment, the electrocardiographic waveform data, the electrocardiogram, in which a new range NR is set based on the reconstruction processing request, even if the operator does not give an association instruction each time. Shape image data and CT image data can be stored in association with each other.

In addition, the display control unit 46 in the present embodiment is based on the first CT image (CT image I _k ) based on the detection data D corresponding to the desired range R and the detection data D ′ corresponding to the new range NR. The second CT image (CT image I _k ′) is displayed in parallel on the display unit 49.

  In this way, the display control unit 46 displays in parallel CT images based on detection data in different ranges (desired range R, new range NR) set for one ECG waveform data. That is, according to the X-ray CT apparatus 1 in the present embodiment, it is possible to easily compare CT images based on detection data obtained at different timings in one electrocardiographic waveform data.

Further, the configuration of the present embodiment can be applied to an image display apparatus. Such an image display device includes a setting unit 42, a specifying unit 43, a reconstruction processing unit 44b, a control unit 45, a display unit 49, and a display control unit 46. The setting unit 42 sets a desired range R for the electrocardiographic waveform data of the subject E obtained in parallel with the X-ray scan for the subject E. The specifying unit 43 specifies the detection data D acquired at the timing included in the desired range R among the detection data acquired by the X-ray scan. The reconstruction processing unit 44b reconstructs projection data based on the specified detection data D, and creates CT image data. Based on the signal for starting the reconstruction process, the control unit 45 applies the ECG waveform data in which the desired range R is set, the ECG waveform image data based on the ECG waveform data, and the specified detection data D. The associated CT image data is stored in association with each other. The display control unit 46, together CT image I _k based on the CT image data heart is wave-shaped image H and the storage based on the stored electrocardiographic waveform image data to the display unit 49 to display, and the electrocardiographic waveform image H Is selected, the electrocardiographic waveform data in which a desired range R corresponding to the selected electrocardiographic waveform image H is set is displayed on the display unit 49.

  As described above, also in the external device of the X-ray CT apparatus 1, the control unit 45 automatically stores the electrocardiographic waveform data, the electrocardiographic waveform image data, and the CT image data based on the signal for starting the reconstruction process. Let Therefore, the electrocardiographic waveform data, the electrocardiographic waveform image data, and the CT image data can be associated with each other and stored without requiring the association instruction each time. Further, when an electrocardiographic waveform image based on the electrocardiographic waveform image data is selected, the display control unit 46 can display the corresponding electrocardiographic waveform data on the display unit 49. That is, according to the image display device of the present embodiment, the CT image (CT image data) and the corresponding electrocardiographic waveform image (electrocardiographic waveform image data) can be easily associated, and the electrocardiographic waveform image. ECG waveform data corresponding to can be easily displayed.

  Instead of the reconstruction method described in the above embodiment, a segment reconstruction method can be applied. The segment reconstruction method is a kind of electrocardiogram synchronization reconstruction, and acquires detection data in a predetermined cardiac phase range over a plurality of heartbeats while rotating the rotator 13, and reconstruction based on the plurality of detection data By performing processing, CT image data is created. Hereinafter, the segment may be referred to as a desired range.

  FIG. 7 shows the correspondence between the electrocardiographic waveform data and the detection data when the segment reconstruction method is applied. The time axis of the X-ray scan and the time axis of the electrocardiographic waveform data are synchronized. Reference G indicates a graph of electrocardiographic waveform data.

Graph G shows 5 heartbeats sandwiched between R waves r ₁ and r ₆ (the number of heartbeats is arbitrary). In each heartbeat, the cardiac phase is expressed as a percentage value. In this example, the range of α (%) to β (%) is used as the range of the cardiac phase that is the target of the segment reconstruction method. The range is arbitrarily set. The range in the heartbeat between the R wave r _q and the R wave r _{q + 1} is indicated by a symbol R _q (q = 1 to 5). In this example, a plurality of ranges R _{1 to} R ₅ are desired ranges.

Processing for setting a desired range is executed by the setting unit 42. As an example of this setting process, when the expert plan includes “the range of the cardiac time phase subject to the segment reconstruction method = α (%) to β (%)” in advance, the setting unit 42 includes a plurality of settings. A plurality of ranges R _q corresponding to time phases α (%) to β (%) in the heartbeat can be set as desired ranges.

A symbol D _q indicates detection data acquired in the corresponding range R _q (q = 1 to 5). The detection data D _q corresponding to each range R _q is specified by the specifying unit 43. The preprocessing unit 44a creates projection data by performing predetermined preprocessing on each detection data _Dq specified by the specifying unit 43. The reconstruction processing unit 44b creates CT image data by reconstructing a projection data group based on a plurality of detection data _Dq . This CT image data represents the shape of the heart in the target cardiac time phase.

The display control unit 46 causes the display unit 49 to display an electrocardiogram waveform image based on the electrocardiogram image data and a CT image based on the created CT image data. As an example of the display mode, there is a raw data page similar to the above embodiment. FIG. 8 shows a display example of the raw data page RP. A plurality of CT images I _k and an electrocardiographic waveform image H ₁ corresponding to the patient ID are displayed on the display unit 49 as in the above embodiment.

In this process, a CT image based on electrocardiographic waveform data in which a plurality of desired ranges _Rq corresponding to the patient ID are set, electrocardiographic waveform image data based on the corresponding electrocardiographic waveform data, and identified detection data This is done by the controller 45 reading out the data. Each read data is subjected to reconstruction processing by the reconstruction processing unit 44b.

The reconstruction processing unit 44b executes the reconstruction process based on preset reconstruction process conditions. As for the reconstruction processing conditions, it is possible to display a reconstruction processing condition setting screen on the raw data page RP (for example, the display area P ₃ ) and set specific processing conditions on the screen. Reconstruction process is started in response to the soft key F which has been displayed in the display area P ₃ is selected by such input unit 47.

Also, if the operator selects electrocardiographic waveform image H ₁ displayed on the display unit 49 by such input unit 47, a plurality of desired range R _q in which the display control unit 46 corresponds to the ECG waveform image H ₁ It may be displayed and integrated electrocardiographic waveform data to the display area P ₂ of the display unit 49 (see FIG. 8).

  Further, an input operation for the purpose of editing may be directly executed on the electrocardiographic waveform data displayed on the display unit 49.

In this way, the surgeon can directly edit the electrocardiographic waveform data displayed in the display area P ₂ in addition to the reconstruction processing condition setting screen displayed in P _3. Operation becomes possible.

Electrocardiographic waveform image H ₁ is composed of electrocardiographic waveform data including a desired range R _q of the set predetermined number. Electrocardiographic waveform image H ₁ corresponds to the electrocardiographic waveform data for each time phase each in the desired range R _q, and the detection data of the X-ray for each time phase. By selecting the electrocardiographic waveform image H _1, so that the CT image data obtained by reconstructing the detected data specified based on the electrocardiogram waveform data are displayed.

In the segment reconstruction method, it is possible to exclude the inappropriate range from the plurality of ranges R _q indicating each cardiac time phase and perform the reconstruction process. An example is shown below.

The display control unit 46 displays a CT image I _k (k = 1 to n) based on the read detection data and a heart based on the read electrocardiographic waveform image data on the display area P ₁ of the raw data page RP. and displays side by side and electrocardiogram image H _1.

Thus, by displaying the CT image I _k and electrocardiographic waveform image H ₁ associated on the same screen, whether the operator was created in response to any cardiac phase CT image being displayed Easy to grasp.

For example, the surgeon who has seen the electrocardiogram waveform H ₁ in FIG. 8 displays which segment of the cardiac phase the CT image I _k has as the plurality of predetermined ranges R _q are displayed as the electrocardiogram waveform image H _1. It can be grasped whether it was created based on.

If the CT image I _k is disturbed by motion artifacts or the like, an arrhythmic wave Ar may be included in a part of the segment used for reconstruction as shown in FIG.

If such a CT image I _k is disturbed, the surgeon can confirm a part of the range R _q by checking the electrocardiogram waveform image H ₂ displayed in the display area P ₁ of FIG. Here, it can be grasped that R ₂ ) has an arrhythmia wave Ar, and it can be easily grasped that the CT image I _k is an image reconstructed using the range R ₂ including the arrhythmia.

If the arrhythmia is confirmed in a range R _q performing reconstruction, based on the electrocardiographic waveform data displayed in the reconstruction process condition setting screen and the display area P ₂ is displayed in the display area P ₃ in FIG. 10, a plurality The CT image may be reconstructed by reselecting the ranges R ₁ , R ₃ , and R ₄ excluding the desired range R ₂ including the arrhythmia from the desired range R _q . In this case, the changing unit 42a, based on an instruction input through the input unit 47 or the like, reset the desired range R _q being subjected to treatment.

Furthermore, the specifying unit 43 specifies again the detection data _Dq in the desired cardiac phase based on the reset desired range _Rq .

A plurality of detection data D _q specified by the specifying unit 43 is subjected to reconstruction by the reconstruction processor 44b, a new CT image I _k that avoids desired range R ₂ according to the arrhythmia on the display unit 49 _'is Is displayed.

  According to this example, the amount of exposure to the patient can be reduced by using the segment reconstruction method, and at the time of CT image reconstruction, the image quality can be reduced by motion artifacts of the CT image due to arrhythmia. Can be avoided.

  The number of segments required to construct a CT image by the segment reconstruction method is configured to use three of the five segments in this example, but is not limited to this, and an arbitrary number of segments can be applied. It is.

  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 13a Opening part 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 unit 33 Sleeper top plate 34 Base 40 Console device 41 Scan control unit 42 Setting unit 42a Change unit 43 Identification unit 44 Image processing unit 44a Preprocessing unit 44b Reconfiguration processing unit 44c Rendering processing unit 45 Control unit 46 Display control unit 47 Input unit 48 Storage unit 49 Display unit 50 ECG

Claims (4)

An X-ray CT apparatus that performs X-ray scanning on a subject and acquires detection data,
A setting unit for setting a desired range for the electrocardiographic waveform data of the subject obtained in parallel with the X-ray scan;
Of the detection data, a specifying unit that specifies detection data acquired at a timing included in the desired range;
A reconstruction processing unit that reconstructs projection data based on the identified detection data and creates CT image data;
A storage unit;
Based on the signal for starting the reconstruction process, the ECG waveform data in which the desired range is set, the ECG waveform image data based on the ECG waveform data, and the CT based on the identified detection data A control unit for associating and storing image data in the storage unit;
Based-out stored in the electrocardiographic waveform image data, it is displayed together electrocardiographic waveform image and said stored CT CT image based on the image data for selecting the electrocardiographic waveform data to the display unit, and When the electrocardiographic waveform image is selected, a display control unit that causes the display unit to display the electrocardiographic waveform data in which the desired range corresponding to the selected electrocardiographic waveform image is set;
An X-ray CT apparatus comprising: The setting unit
For the electrocardiographic waveform data in which the desired range displayed on the display unit is set, the set desired range is changed, and a change unit for setting a new range is provided,
The specifying unit specifies detection data acquired at a timing included in the new range,
The control unit, based on a signal for starting the reconstruction process, the electrocardiographic waveform data in which the new range is set, electrocardiographic waveform image data based on the electrocardiographic waveform data, and the specified new The X-ray CT apparatus according to claim 1, wherein the CT image data based on the detection data acquired at a timing included in a range is associated and stored in the storage unit.   The display control unit displays in parallel on the display unit a first CT image based on the detection data corresponding to the desired range and a second CT image based on the detection data corresponding to the new range. The X-ray CT apparatus according to claim 2. A setting unit that sets a desired range for the electrocardiographic waveform data of the subject obtained in parallel with the X-ray scan of the subject;
Among the detection data acquired by the X-ray scan, a specifying unit that specifies detection data acquired at a timing included in the desired range;
A reconstruction processing unit that reconstructs projection data based on the identified detection data and creates CT image data;
A storage unit;
Based on the signal for starting the reconstruction process, the ECG waveform data in which the desired range is set, the ECG waveform image data based on the ECG waveform data, and the CT based on the identified detection data A control unit for associating and storing image data in the storage unit;
A display unit;
Based-out stored in the electrocardiographic waveform image data, a CT image based on the CT image data heart is wave-shaped images and storing for selecting the electrocardiographic waveform data is displayed together on the display unit, When the electrocardiographic waveform image is selected, a display control unit that displays the electrocardiographic waveform data in which the desired range corresponding to the selected electrocardiographic waveform image is set on the display unit;
An image display device comprising:

Images