JP2020005760A - X-ray ct apparatus - Google Patents

Abstract

To reduce a burden on a subject in an examination executing a plurality of scans related to a plurality of scanning types.SOLUTION: An X-ray CT apparatus includes an X-ray generation unit, an X-ray detection unit, a setting unit, and an execution unit. The X-ray generation unit generates an X-ray irradiated onto a subject. The X-ray detection unit includes a plurality of detection elements for detecting an X-ray, and a plurality of detection element arrays in a row direction, which consist of a plurality of detection elements arranged in a channel direction. The setting unit selects and sets two ro more scanning types from a table showing a plurality of scanning types consisting of combinations of scan modes and collection modes. The execution unit controls the X-ray generation unit and the X-ray detection unit after setting scan parameters related to the two or more scanning types respectively, and executes two or more scans related to the two or more scanning types respectively.SELECTED DRAWING: Figure 6

Description

  Embodiments of the present invention relate to an X-ray CT (Computed Tomography) apparatus.

  There is a medical image diagnostic apparatus that generates medical image data in which a body tissue of a subject is imaged. Examples of the medical image diagnostic apparatus include an X-ray CT (Computed Tomography) apparatus and an MRI (Magnetic Resonance Imaging) apparatus. The X-ray CT apparatus converts three-dimensional image data based on two-dimensional image data or volume data of an axial tomographic image of an object based on X-rays detected by an X-ray detector by irradiating the object with X-rays. Generate as image data.

  In the X-ray CT apparatus, there is a case where an inspection is performed in which two CT scans related to two scan types are performed by combining two acquisition modes with one scan mode. In this case, after setting the scan mode, the first acquisition mode, and the scan parameters (including scano imaging), respectively, and executing the first scan, the scan mode, the second acquisition mode, and the scan parameters (scanogram imaging) are performed. ), And the second scan is executed.

JP 2016-140660 A

  The problem to be solved by the present invention is to reduce the burden on a subject in an inspection for performing a plurality of scans relating to a plurality of scan types.

  The X-ray CT apparatus according to the embodiment has an X-ray generation unit, an X-ray detection unit, a setting unit, and an execution unit. The X-ray generation unit generates X-rays for irradiating the subject. The X-ray detection unit includes a plurality of detection elements that detect X-rays, and includes a plurality of detection element rows including a plurality of detection elements arranged in a channel direction in the column direction. The setting unit selects and sets two or more scan types from a plurality of scan types stored in the storage unit and configured by a combination of the scan mode and the acquisition mode. After setting scan parameters for two or more scan types, the execution unit controls the X-ray generation unit and the X-ray detection unit to execute two or more scans for two or more scan types, respectively. I do.

FIG. 1 is a schematic diagram illustrating a configuration of an X-ray CT apparatus according to an embodiment. FIG. 2 is a diagram showing a configuration example of a pixel arrangement of an X-ray detector provided in the X-ray CT apparatus according to the embodiment. FIG. 3 is a diagram illustrating an example of use of a detectable area of an X-ray detector according to an acquisition mode in the X-ray CT apparatus according to the embodiment. FIG. 4 is a diagram showing the concept of an element group formed by grouping a plurality of detection elements constituting an X-ray detector by a fixed number in the X-ray CT apparatus according to the embodiment. FIG. 5 is a block diagram showing an addition unit that performs addition in element group units in the X-ray CT apparatus according to the embodiment. FIG. 6 is a block diagram showing functions of the X-ray CT apparatus according to the embodiment. FIG. 7 is a view showing an example of a scan type table in the X-ray CT apparatus according to the embodiment. FIG. 8 is an exemplary flowchart showing the operation of the X-ray CT apparatus according to the embodiment; FIG. 9 is a flowchart illustrating an operation in a first example of a plurality of scan types in the X-ray CT apparatus according to the embodiment. FIG. 10 is a flowchart illustrating an operation in a second example of a plurality of scan types in the X-ray CT apparatus according to the embodiment. FIG. 11 is a view showing, as a flowchart, an operation in a third example of a plurality of scan types in the X-ray CT apparatus according to the embodiment. FIG. 12 is an exemplary flowchart showing an operation in a fourth example of a plurality of scan types in the X-ray CT apparatus according to the embodiment.

  Hereinafter, an embodiment of an X-ray CT apparatus will be described in detail with reference to the drawings.

  The data collection method using the X-ray CT apparatus includes a rotation / rotation (RR) method in which the X-ray source and the X-ray detector rotate as a unit around the subject, and a ring-shaped method. There are various systems such as a fixed / rotation (SR) system in which a large number of detection elements are arrayed and only an X-ray tube rotates around the subject. The present invention can be applied to any method. Hereinafter, the X-ray CT apparatus according to the embodiment will be described taking as an example a case where a third-generation rotation / rotation method, which is currently dominant, is adopted.

  FIG. 1 is a schematic diagram illustrating a configuration of an X-ray CT apparatus according to the embodiment.

  FIG. 1 shows an X-ray CT apparatus 1 according to the embodiment. The X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40. The gantry device 10 and the bed device 30 are installed in an examination room. The gantry device 10 collects X-ray detection data on a subject (for example, a patient) P placed on the bed device 30. On the other hand, the console device 40 is installed in a control room adjacent to the examination room, generates projection data in multiple directions based on the detection data in multiple directions, and reconstructs a CT image based on the projection data in multiple directions. indicate.

  The gantry device 10 includes an X-ray tube 11, an X-ray detector 12, a data acquisition circuit (DAS: Data Acquisition System) 13, a rotating frame 14, an X-ray high-voltage device 15, a control device 16, a wedge 17, and a collimator 18. Prepare.

  The X-ray tube 11 is provided on a rotating frame 14. The X-ray tube 11 is a vacuum tube that irradiates thermoelectrons from a cathode (filament) to an anode (target) by applying a high voltage from an X-ray high voltage device 15. In the embodiment, a single-tube X-ray CT apparatus and a so-called multi-tube X-ray CT apparatus in which a plurality of pairs of an X-ray tube and an X-ray detector are mounted on a rotating ring are also used. Applicable.

  Note that the X-ray source that generates X-rays is not limited to the X-ray tube 11. For example, instead of the X-ray tube 11, a focus coil for converging an electron beam generated from an electron gun, a deflection coil for electromagnetic deflection, and a target for generating an X-ray by colliding with a deflected electron beam surrounding a half circumference of the patient P X-rays may be generated by a fifth generation method including a ring. The X-ray tube 11 is an example of an X-ray generator.

  The X-ray detector 12 is provided on the rotating frame 14 so as to face the X-ray tube 11. The X-ray detector 12 detects X-rays emitted from the X-ray tube 11 and outputs detection data corresponding to the X-ray dose to the DAS 13 as an electric signal. In the X-ray detector 12, for example, a plurality of detection element rows including a plurality of detection elements are arranged in the channel direction along one arc in the channel direction around the focal point of the X-ray tube in the row direction (slice direction, row direction). Having a structure.

  The X-ray detector 12 is, for example, an indirect conversion type detector having a grid, a scintillator array, and a photosensor array. The scintillator array has a plurality of scintillators, and the scintillator has a scintillator crystal that outputs light having a photon amount corresponding to an incident X-ray dose. The grid has an X-ray shielding plate disposed on the surface of the scintillator array on the X-ray incident side and having a function of absorbing scattered X-rays. The optical sensor array has a function of converting an electric signal according to the amount of light from the scintillator, and includes, for example, an optical sensor such as a photodiode.

  Note that the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electric signal. The X-ray detector 12 is an example of an X-ray detector.

  FIG. 2 is a diagram illustrating a configuration example of a pixel arrangement of the X-ray detector 12.

  The X-ray detector 12 shown in FIG. 2 has m (m: a positive integer) in the channel direction, that is, n (n: a positive integer) detection element rows in the column direction. That is, it is arranged in n columns. Note that the number (m) of the detection elements constituting the detection element row shown in FIG. 2 is for convenience. Therefore, the number of the detection elements constituting the detection element row is not limited to the case shown in FIG. The same applies to the number (n) of detection element arrays arranged in the channel direction.

  FIG. 3 is a diagram illustrating a usage example of the detectable area of the X-ray detector 12 according to the acquisition mode. FIG. 3A is a diagram illustrating an example of use of the detectable area U of the X-ray detector 12 in the high definition mode “HR”. FIG. 3B is a diagram illustrating an example of use of the detectable area U in the standard resolution mode “NR” of the X-ray detector 12. FIG. 3C is a diagram illustrating an example of use of the detectable area U in the low noise mode “LN” of the X-ray detector 12.

  In an X-ray detector including a plurality of detection element arrays composed of m-channel (illustrated in FIG. 2) detection elements, the addition number (bundling number) s of detection data is changed according to the acquisition mode. The addition number s is determined by an addition number component i (i is a positive integer) in the channel direction and an addition number component j (j is a positive integer) in the column direction (s = i × j). FIG. 3A shows a usage example of the detectable area U when the number of additions s is one (i × j = 1 × 1) in the high-definition mode “HR”. FIG. 3B shows a usage example of the detectable area U when the number of additions s is 4 (i × j = 2 × 2) in the standard resolution mode “NR”. FIG. 3C shows a usage example of the detectable area U when the number of additions s is 16 (i × j = 4 × 4) in the low noise mode “LN”.

  As shown in FIG. 3A, the detectable area U of the X-ray detector 12 includes a first area (detection area) V for performing the high-definition mode, and another second area (non-detection area). are categorized. The detection area V includes r pixels corresponding to r detection element rows. Each detection element row in the detection area V includes m pixels corresponding to the m-channel detection elements. On the other hand, the non-detection area includes nr pixels corresponding to nr detection element columns. Each detection element row in the non-detection area includes m pixels corresponding to m channels. r is a positive integer and r <n. In the case of the high-definition mode, the detection data of m × r detection elements included in the r detection element rows are not added, and are output as the detection data of m × r pixels. That is, according to FIG. 3A, a high-resolution reconstructed image can be generated in the detection area V.

  As shown in FIGS. 3B and 3C, in the case of the standard resolution mode and the low noise mode, m × n detection elements included in all (or a part) of the detection element rows constituting the detectable area U are used. In the detection data of the elements (shown in FIG. 2), detection data of adjacent s (i × j) detection elements are added (bundled). The detectable area U includes n / j pixels corresponding to n detection element rows. Each detection element row in the detection area V includes m / i pixels corresponding to the m-channel detection elements. As a result, detection data of m × n / s pixels is output. FIG. 3B shows a case where the number of additions s of the detection data is four. A plurality of detection elements corresponding to a plurality of detection data to be added are defined as four detection elements adjacent in the channel direction and the column direction. Here is an example. That is, according to FIG. 3B, the noise can be reduced by lowering the resolution as compared with the case of the high definition mode shown in FIG. 3A.

  FIG. 3C shows a case where the number of additions s of the detection data is 16, and a plurality of detection elements corresponding to a plurality of detection data to be added are defined as 16 detection elements adjacent in the channel direction and the column direction. Here is an example. That is, according to FIG. 3C, the noise can be reduced by lowering the resolution as compared with the case of the standard resolution mode shown in FIG. 3B.

  Returning to the description of FIG. 1, the DAS 13 is provided on the rotating frame 14. The DAS 13 performs an amplification process on an electric signal output from each X-ray detection element of the X-ray detector 12 under the control of the control device 16, and converts the electric signal into a digital signal under the control of the control device 16. An A / D (Analog to Digital) converter that converts the signal into a signal, and generates detection data after amplification and digital conversion. The detection data generated by the DAS 13 is transferred to the console device 40.

  Here, the detection data generated by the DAS 13 is transmitted from a transmitter provided on the rotating frame 14 to a non-rotating part of the gantry device 10, for example, a receiver provided on a fixed unit (not shown) by non-contact data transmission. , To the console device 40. The method of transmitting the detection data from the rotating frame 14 to the non-rotating portion of the gantry device 10 is not limited to the above-described optical communication, and any method may be adopted as long as it is a non-contact type data transmission. Further, a fixing portion (not shown) is a frame that rotatably supports the rotating frame 14.

  FIG. 4 is a diagram showing the concept of an element group formed by grouping a plurality of detection elements constituting the X-ray detector 12 by a fixed number. FIG. 5 is a block diagram illustrating an addition unit that performs addition in units of element groups.

  FIG. 4 shows a k-th (k: positive integer) k-th element group Gk in the detection area V among a plurality of element groups formed in the detection area U shown in FIG. Each element group corresponds to a plurality of detection elements constituting the X-ray detector 12, for example, 16 detection elements D including four detection elements in the channel direction and four detection elements in the column direction. In addition, each element group is not limited to the case including 16 detection elements, and may be, for example, 4 or 32. Further, the shape of each element group determined by the number of detection elements in the channel direction and the column direction may not be square.

  FIG. 5 shows the adding unit A. The adder A includes 16 switchers (for example, switches) 51k connected to each of the 16 detection elements belonging to the k-th element group Gk, an integration circuit 52k belonging to the k-th element group Gk, and a k-th element. A switching control circuit 53k belonging to the element group Gk. That is, one integration circuit 52k and one switching control circuit 53k are provided for each element group.

  Further, the switching control circuit 53k is connected to each of the 16 switches 51k belonging to the k-th element group Gk via a signal line. The 16 switches 51k of the adding unit A are provided in the X-ray detector 12, and the integrating circuit 52k and the switching control circuit 53k of the adding unit A are provided in the DAS 13. In this case, However, the present invention is not limited to this. Further, the DAS 13 includes an A / D (Analog to digital) conversion circuit 181 connected to the integration circuits belonging to all the element groups including the k-th element group Gk at a stage subsequent to the integration circuit 52k.

  The integration circuit 52k reads out electric signals from the 16 detection elements belonging to the k-th element group Gk via the 16 switches 51k, and integrates the electric signals over a predetermined period. The predetermined period is set according to the period of one view.

  The switching control circuit 53k controls connection and disconnection of the 16 switches 51k belonging to the k-th element group Gk according to the control of the control device 16. Specifically, the switching control circuit 53k establishes a connection between the 16 switches 51k belonging to the k-th element group Gk and the integration circuit 52k, a connection for the high definition mode and a connection for the standard resolution mode. The 16 switches 51k are individually controlled to switch between the connection and the connection for the low noise node.

  When the collection mode is the high-definition mode (addition number s = 1), the switching control circuit 53k opens and closes the 16 switches 51k belonging to the k-th element group Gk at different timings, so that the integration circuit 52k Electrical signals are read from the 16 detection elements belonging to the k-th element group Gk at different timings. That is, when the acquisition mode is the high-definition mode, the switching control circuit 53k controls the sixteen switching units 51k so as to read out sixteen electrical signals from the sixteen detection elements belonging to the k-th element group Gk.

  When the acquisition mode is the standard resolution mode (addition number s = 4), the switching control circuit 53k classifies the 16 detection elements belonging to the k-th element group Gk into four sets. Then, (1) the switching control circuit 53k opens and closes all of the four switches 51k corresponding to the four detection elements belonging to each set substantially simultaneously, whereby the integration circuit 52k includes four switching elements belonging to each set. (2) The switching control circuit 53k opens and closes the switching devices 51k belonging to different sets at different timings, so that the integration circuit 52k performs different timings from the four different sets. To read out the electric signals. That is, when the acquisition mode is the standard resolution mode, the switching control circuit 53k controls the sixteen switching devices 51k so as to read four electrical signals from the sixteen detection elements belonging to the k-th element group Gk.

  When the collection mode is the low noise mode (addition number s = 16), the switching control circuit 53k opens and closes all of the sixteen switches 51k belonging to the k-th element group Gk almost simultaneously, whereby the integration circuit 52k , The electrical signals are read from the sixteenth detection elements belonging to the k-th element group Gk substantially simultaneously. That is, when the acquisition mode is the low noise mode, the switching control circuit 53k controls the 16 switches 51k so as to read out one electric signal from the 16 detection elements belonging to the k-th element group Gk.

  As shown in FIG. 5, the A / D converter 181 performs A / D conversion on the integrated signals from the plurality of integration circuits, and generates pure raw data before preprocessing such as logarithmic conversion processing. By performing pre-processing on the pure raw data, raw data before the reconstruction processing is generated. The number of the plurality of integrating circuits connected to the A / D converter 181 may be any number. Typically, one A / D converter 181 is connected to a predetermined number of integrating circuits. However, embodiments are not limited to this. One A / D converter 181 may be connected to one integration circuit.

  Returning to the description of FIG. 1, the rotating frame 14 is a rotating unit that supports the X-ray tube 11 and the X-ray detector 12 in opposition. The rotating frame 14 is an annular frame that rotates the X-ray tube 11 and the X-ray detector 12 integrally under the control of the control device 16 described later. The case where the rotating frame 14 further includes and supports the DAS 13 and the X-ray high-voltage device 15 in addition to the X-ray tube 11 and the X-ray detector 12 will be described. At least one of them may be supported by a fixed frame (not shown), which is a fixed portion that rotatably supports the rotating frame 14.

  As described above, the X-ray CT apparatus 1 rotates the rotating frame 14 that supports the X-ray tube 11 and the X-ray detector 12 so as to face each other around the patient P. , 360 ° of the patient P is collected. Note that the CT image reconstruction method is not limited to the full scan reconstruction method using 360 ° detection data. For example, the X-ray CT apparatus 1 may adopt a half reconstruction method of reconstructing a CT image based on detection data for a half circumference (180 °) + a fan angle.

  The X-ray high-voltage device 15 has an electric circuit such as a transformer (transformer) and a rectifier. The X-ray high voltage device 15 includes a high voltage generator (not shown) having a function of generating a high voltage applied to the X-ray tube 11 under the control of a control device 16 described below, and a control by the control device 16 described below. Below, an X-ray control device (not shown) for controlling the output voltage according to the X-ray emitted by the X-ray tube 11 is provided. The high voltage generator may be of a transformer type or an inverter type.

  The control device 16 has a processor and a memory, and a drive mechanism such as a motor and an actuator. The configuration of the processing circuit and the memory is the same as that of the processing circuit 44 and the memory 41 of the console device 40 described later, and thus the description is omitted.

  The control device 16 has a function of receiving an input signal from the input interface 43 of the console device 40 or an operation panel (not shown) attached to the gantry device 10 and controlling the operation of the gantry device 10 and the bed device 30. Have. For example, the control device 16 performs control to rotate the rotating frame 14 in response to the input signal, control to tilt the gantry device 10, and control to operate the bed device 30 and the top board 33. In addition, the control for tilting the gantry device 10 is performed by the control device 16 using the tilt angle (tilt angle) information input from the operation panel attached to the gantry device 10 so that the control device 16 rotates the rotation frame 14 about an axis parallel to the X-axis direction. Is realized by rotating. The control device 16 may be provided on the gantry device 10 or on the console device 40.

  Further, the control device 16 controls the angle of the X-ray tube 11 and the operations of a wedge 17 and a collimator 18 described later, based on imaging conditions input from an operation panel attached to the console device 40 or the gantry device 10. .

  The wedge 17 is provided on the rotating frame 14 so as to be arranged on the X-ray emission side of the X-ray tube 11. The wedge 17 is a filter for adjusting the X-ray dose emitted from the X-ray tube 11 under the control of the control device 16. Specifically, the wedge 17 is a filter that transmits and attenuates the X-rays radiated from the X-ray tube 11 so that the X-rays radiated to the patient P from the X-ray tube 11 have a predetermined distribution. It is. For example, the wedge 17 (wedge filter, bow-tie filter) is a filter formed by processing aluminum so as to have a predetermined target angle and a predetermined thickness.

  The collimator 18 is also called a stop or a slit, and is provided on the rotating frame 14 so as to be arranged on the X-ray emission side of the X-ray tube 11. The collimator 18 is a lead plate or the like for narrowing the irradiation range of the X-ray transmitted through the wedge 17 under the control of the control device 16, and forms an X-ray irradiation opening by a combination of a plurality of lead plates and the like. It should be noted that a collimator (not shown) different from the collimator 18 may be provided before the wedge 17.

  The couch device 30 includes a base 31, a couch driving device 32, a top plate 33, and a support frame. The couch device 30 is a device that places a patient P to be scanned and moves the patient P under the control of the control device 16.

  The base 31 is a housing that supports the support frame 34 so as to be movable in a vertical direction (y-axis direction). The couch driving device 32 is a motor or an actuator that moves the table 33 on which the patient P is placed in the long axis direction (z-axis direction) of the table 33. The top plate 33 provided on the upper surface of the support frame 34 is a plate having a shape on which the patient P can be placed.

  Note that the bed driving device 32 may move the support frame 34 in the long axis direction (z-axis direction) of the top plate 33 in addition to the top plate 33. Further, the bed driving device 32 may be moved together with the base 31 of the bed device 30. When the present invention is applied to the standing CT, a method of moving a patient moving mechanism corresponding to the top plate 33 may be used. In addition, in the case of performing imaging with a relative change in the positional relationship between the imaging system of the gantry device 10 and the top plate 33, such as scout (scout) imaging for helical scan and positioning, etc. Such changes may be made by driving the top plate 33, by running the fixed portion of the gantry device 10, or by a combination thereof.

  In the embodiment, the longitudinal direction of the rotation axis of the rotating frame 14 or the top plate 33 of the bed device 30 in the non-tilt state is perpendicular to the z-axis direction and the z-axis direction, and the axial direction that is horizontal to the floor surface is An axial direction perpendicular to the x-axis direction and the z-axis direction and perpendicular to the floor surface is defined as a y-axis direction.

  The console device 40 includes a memory 41, a display 42, an input interface 43, and a processing circuit 44. In the following description, the console device 40 executes all functions with a single console, but these functions may be executed by a plurality of consoles.

  The memory 41 is, for example, a semiconductor memory device such as a random access memory (RAM) or a flash memory, a hard disk, an optical disk, or the like, and has a configuration including a recording medium readable by a processor. The memory 41 stores a scan type table (shown in FIG. 7) indicating a plurality of scan types composed of a combination of the scan mode and the acquisition mode.

  The detection data generated by the X-ray CT apparatus 1 and the projection data and the reconstructed image data described later may be stored in the memory 41. Further, the detection data, projection data, and reconstructed image data generated by the X-ray CT apparatus 1 are transmitted to an external device such as an image server that can be connected to the X-ray CT apparatus 1 via a network such as a LAN (Local Area Network). It may be stored in a storage device. Similarly, some or all of the programs and data in the recording medium of the memory 41 may be downloaded by communication via a network, or may be given to the memory 41 via a portable storage medium such as an optical disk. Good.

  The display 42 displays various information. For example, the display 42 outputs a medical image (CT image) generated by the processing circuit 44, a GUI (Graphical User Interface) for receiving various operations from the user, and the like. For example, the display 42 is a liquid crystal display, a CRT (Cathode Ray Tube) display, an OLED (Organic Light Emitting Diode) display, or the like.

  The input interface 43 includes a circuit that inputs a signal from an input device that can be operated by an operator, and an input device. The input device is a trackball, a switch, a mouse, a keyboard, a touchpad that performs an input operation by touching a scanning surface, a touch screen in which a display screen and a touchpad are integrated, a non-contact input circuit using an optical sensor, And an audio input circuit. When an input device is operated by the operator, the input interface 43 generates an input signal corresponding to the operation and outputs the input signal to the processing unit 21.

  The processing circuit 44 is a processor that controls the overall operation of the X-ray CT apparatus 1 by reading and executing a program stored in the memory 41. The processing circuit 44 performs pre-processing such as correction processing on the detection data output from the data collection circuit 14 to generate projection data. Further, the processing circuit 44 performs reconstruction processing of the projection data, and generates two-dimensional image data of the axial tomographic image and three-dimensional image data based on the volume data as CT image data. The volume data is a set of voxel data having distribution information of CT values in a three-dimensional space. The processing circuit 44 generates volume data based on the two-dimensional image data of a plurality of axial tomographic images, thereby converting the image data of an arbitrary tomographic image (MPR: Multi-Planar Reconstruction) or the projected image data viewed from an arbitrary direction into three. Generate as two-dimensional image data. The projection image data is obtained by subjecting volume data to volume rendering processing or surface rendering processing.

Subsequently, the function of the X-ray CT apparatus 1 will be specifically described.
FIG. 6 is a block diagram illustrating functions of the X-ray CT apparatus 1.

  When the processor of the processing circuit 44 executes the program, the X-ray CT apparatus 1 realizes a scan type setting function 61, a scan execution function 62, and an image generation function 63. The case where the functions 61 to 63 function as software will be described as an example. However, all or a part of the functions 61 to 63 are provided in the X-ray CT apparatus 1 as hardware such as an ASIC. You may. All or a part of the functions 61 to 63 may be included in the control device 16.

  The memory 41 previously stores (presets) a plurality of scan types (for example, a scan type table shown in FIG. 7) formed of a combination of a scan mode and an acquisition mode. The scan type setting function 61 includes a function of selecting and setting a plurality of predetermined scan types from a plurality of scan types stored in the memory 41 and configured by a combination of a scan mode and a collection mode. The scan mode is also called a protocol. For example, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. Set the scan type. The scan type setting function 61 is an example of a setting unit.

FIG. 7 is a diagram illustrating an example of the scan type table.
As shown in FIG. 7, the scan type includes a combination of a scan mode and a collection mode. For each scan mode, three acquisition modes are supported: a high definition mode, a standard resolution mode, and a low noise mode.

  The scan mode includes a volume scan, a dynamic volume scan, a helical scan, and the like. The volume scan refers to a scan for one time phase that is performed without changing the positional relationship between the gantry device 10 and the top board 12 using the X-ray detector 12 having a plurality of detection element arrays. The dynamic volume scan refers to a scan of a plurality of time phases performed using the X-ray detector 12 having one or a plurality of detection element rows without changing the positional relationship between the gantry device 10 and the top board 12. The helical scan is a method in which the X-ray detector 12 having one or a plurality of detection element rows is used to move the top 12 to the gantry 10 or the gantry 10 to the top 12 in the z-axis direction. Refers to a scan performed while moving to

  The acquisition mode includes a high definition mode, a standard resolution mode, a low noise mode, and the like. The high-definition mode is a mode in which detection data of m × r detection elements constituting the X-ray detector 12 are not added and output from the addition unit A as detection data of m × r pixels (FIG. 3). (Illustrated in (A)). The standard resolution mode and the low noise mode are m × n / s, that is, (m / i) by adding detection data of m × n detection elements constituting the X-ray detector 12 by an addition number s. ) × (n / j) pixels are output from the adder A as detection data (illustrated in FIGS. 3B and 3C).

  By selecting a plurality of scan types from the scan type table shown in FIG. 7, a plurality of different scan types can be treated as one scan, and the scan parameters such as a scan area are set in the scan parameter setting of the one scan. Can be set at one time.

  Returning to the description of FIG. 6, the scan execution function 62 includes a function of setting scan parameters for a plurality of scan types set by the scan type setting function 61, respectively. For example, the scan execution function 62 sets scan parameters according to an instruction from the operator via the input interface 43. The scan parameters include a scan area, a focus size, a helical pitch (for helical scan), an X-ray output (tube voltage and tube current, etc.), a scan speed, a view rate, a beam width, and the like.

  In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image.

  The scan execution function 62 sets the scan parameters related to the plurality of scan types set by the scan type setting function 61, and then controls the X-ray tube 11 and the like via the control device 16 to perform the plurality of scans. Includes a function to execute a plurality of scans for each type. The scan execution function 62 is an example of an execution unit.

  The image generation function 63 performs tomographic image data of axial tomography or three-dimensional image data based on detection data generated according to a scan related to at least one of the plurality of scan types executed by the scan execution function 62. Etc. for reconstructing CT image data. The image generating function 63 can also display the CT image data on the display 42 as a CT image. Further, the image generation function 63 can cause the memory 41 to store the CT image data. The image generation function 63 is an example of a generation unit.

  Next, the operation of the X-ray CT apparatus 1 will be described with reference to the flowchart shown in FIG.

  FIG. 8 is a view showing the operation of the X-ray CT apparatus 1 as a flowchart. In FIG. 8, reference numerals with numbers attached to “ST” indicate respective steps in the flowchart.

  First, the scan type setting function 61 selects and sets a plurality of predetermined scan types from a plurality of scan types composed of a combination of a scan mode and a collection mode (step ST1). For example, in step ST1, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. 7) preset in the memory 41 via the input interface 43. To set each scan type. In the description of FIG. 8, a description will be given assuming that a first scan type and a second scan type are set as a plurality of scan types.

  The scan execution function 62 sets scan parameters relating to the first and second scan types set in step ST1 (step ST2). For example, in step ST2, the scan execution function 62 sets scan parameters according to an instruction from an operator via the input interface 43. In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image.

  Also, the scan execution function 62 controls the control device 16 to adjust the gantry device 10 to be set according to the scan parameters of the first scan type set in step ST2, and set in step ST1. The first scan corresponding to the first scan type is executed (step ST4). In step ST4, the scan execution function 62 executes the first scan while controlling the adder A (shown in FIG. 5) via the control device 16 according to the addition number s of the acquisition mode corresponding to the first scan type. I do.

  When the first scan corresponding to the first scan type ends, the scan execution function 62 switches the scan type from the first scan type to the second scan type (step ST6). When switching the scan type in step ST6, the scan execution function 62 controls the control device 16 to change the gantry device 10 adjusted so as to be set according to the scan parameters of the first scan type to the second scan type. Adjust according to the scan parameters. Specifically, the scan execution function 62 controls the control device 16 to move the top board 33 according to the start position of the second scan, change the rotation speed of the rotating frame 14, change the focal size, , Change slit settings, collect offsets, and change correction data such as calibration.

  The scan execution function 62 executes a second scan corresponding to the second scan type set in step ST1 (step ST7). In step ST7, the scan execution function 62 executes the second scan via the control device 16 while controlling the adder A according to the addition number s of the acquisition mode corresponding to the second scan type.

  The image generating function 63 reconstructs CT image data based on detection data generated according to at least one of the first scan executed in step ST4 and the second scan executed in step ST6. The CT image data is displayed on the display 42 as a CT image (step ST8).

  The image generation function 63 stores the CT image data generated in step ST8 in the memory 41 (step ST9).

  As described above, according to the X-ray CT apparatus 1, it is possible to reduce the burden on the patient P in the examination in which the first scan and the second scan are continuously performed. For example, as a comparative example, in an inspection in which two acquisition modes are combined with one scan mode to execute two scans, a scan mode, a first acquisition mode, and scan parameters (including scano imaging) Is set and the first scan is executed, and then the scan mode, the second acquisition mode, and scan parameters (including scano imaging) are set and the second scan may be executed. In this case, time is required for mode switching, so that the throughput of the entire examination is poor, and the burden on the patient P increases.

  In order to solve such a problem, the X-ray CT apparatus 1 sets in advance a plurality of scan types (for example, a scan type table shown in FIG. 7) composed of a combination of a scan mode and an acquisition mode. In the examination in which the first scan and the second scan are performed successively, the throughput of the entire examination can be improved, and the burden on the patient P can be reduced.

  Next, a specific example of FIG. 8 will be described with reference to FIGS.

(First specific example)
FIG. 9 is a flowchart showing the operation in the first example of the plurality of scan types. In FIG. 9, reference numerals with numbers attached to “ST” indicate respective steps in the flowchart.

  The flowchart shown in FIG. 9 relates to a contrast examination of a chest or the like employing Real Prep. Here, the first scan is a temporary scan for real prep, and the second scan is a main scan for generating a diagnostic image. In that case, the X-ray CT apparatus 1 generates a non-contrast image (for example, a scano image) of the patient P in a non-contrast state, sets an ROI (Region Of Interest) and a threshold based on the non-contrast image, and sets a contrast agent. Start infusion of. Then, after starting the injection of the contrast agent, the X-ray CT apparatus 1 starts a temporary scan for real prep. The real prep detects the start timing (trigger) of the main scan before the main scan such as a dynamic scan, and starts the main scan when the CT value (or luminance value) in the ROI exceeds a threshold. is there.

  First, the scan type setting function 61 combines a dynamic volume scan “DV” as a scan mode with a standard resolution mode “NR” and a high-definition mode “HR” as an acquisition mode. A dynamic volume scan: NR-DV "and a second scan type" high definition dynamic volume scan: HR-DV "are selected and set (step ST21). For example, in step ST21, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. 7) preset in the memory 41 via the input interface 43. To set each scan type.

  The scan execution function 62 sets scan parameters relating to the first scan type “NR-DV” and the second scan type “HR-DV” set in step ST21 (step ST22). For example, in step ST22, the scan execution function 62 sets scan parameters according to an instruction from the operator via the input interface 43. In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image.

  The scan execution function 62 controls the control device 16 to adjust the gantry device 10 to be set in accordance with the scan parameters of the first scan type “NR-DV” set in step ST22, and start imaging. Then, real prep is started (step ST23). The scan execution function 62 controls the control device 16 to execute the first scan “NR-DV” corresponding to the first scan type “NR-DV” set in step ST21 (step ST24). In step ST24, the scan execution function 62, via the control device 16, according to the addition number s (for example, s = 4 shown in FIG. 3B) of the acquisition mode corresponding to the first scan type “NR-DV”. The first scan “NR-DV” is executed while controlling the adding unit A.

  When the CT value (or luminance value) in the ROI of the non-contrast image exceeds the threshold value, the scan execution function 62 ends the first scan “NR-DV” and sets the scan type to the first scan type “NR-DV”. “DV” is switched to the second scan type “HR-DV” (step ST26). In step ST26, the scan execution function 62 controls the control device 16 as in step ST6 (shown in FIG. 8).

  The scan execution function 62 executes the second scan “HR-DV” corresponding to the second scan type “HR-DV” set in step ST21 (step ST27). In step ST27, the scan execution function 62 via the control device 16 according to the addition number s (for example, s = 1 shown in FIG. 3A) of the acquisition mode corresponding to the second scan type “HR-DV”. The second scan “HR-DV” is executed while controlling the adding unit A (step ST27).

  The image generation function 63 reconstructs high-definition CT image data based on the detection data generated according to the second scan “HR-DV” executed in step ST27, and uses the CT image data as a CT image on the display 42. (Step ST28).

  The image generation function 63 stores the volume data obtained in step ST24 and the CT image data generated in step ST28 in the memory 41 (step ST29).

  As described above, according to the operation shown in FIG. 9 by the X-ray CT apparatus 1, the burden on the patient P can be reduced in a contrast examination of a chest or the like using real prep.

(Second specific example)
FIG. 10 is a flowchart showing the operation in the second example of the plurality of scan types. In FIG. 10, reference numerals in which “ST” is assigned a number indicate each step in the flowchart.

  First, the scan type setting function 61 performs a first scan type “standard resolution volume scan: NR-V” in which a volume scan “V” as a scan mode is combined with a standard resolution mode “NR” as an acquisition mode. The second scan type “high-definition helical scan: HR-H” in which the helical scan “H” as the mode is combined with the high-definition mode “HR” as the acquisition mode is selected and set (step ST41). For example, in step ST41, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. 7) preset in the memory 41 via the input interface 43. To set each scan type.

  The scan execution function 62 sets the scan parameters related to the first scan type “NR-V” and the second scan type “HR-H” set in step ST41 (step ST42). For example, in step ST42, the scan execution function 62 sets scan parameters according to an instruction from the operator via the input interface 43. In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image.

  Further, the scan execution function 62 controls the control device 16 to adjust the gantry device 10 to be set according to the scan parameters of the first scan type “NR-V” set in step ST42, The first scan “NR-V” corresponding to the first scan type “NR-V” set in ST41 is executed (step ST44). In step ST44, the scan execution function 62, via the control device 16, according to the addition number s (for example, s = 4 shown in FIG. 3B) of the acquisition mode corresponding to the first scan type “NR-V”. The first scan “NR-V” is executed while controlling the adding unit A.

  The image generation function 63 reconstructs CT image data based on the detection data generated according to the first scan “NR-V” executed in step ST44, and displays the CT image data on the display 42 as a CT image. (Step ST45). Here, the scan execution function 62 displays the scan area of the second scan type “HR-H” set in step ST42 on the displayed reconstructed image, so that the operator can input the scan area via the input interface. The scan area of the second scan “HR-H” may be finely corrected (reset).

  When the first scan “NR-V” corresponding to the first scan type “NR-V” ends, the scan execution function 62 changes the scan type from the first scan type “NR-V” to the second scan type “HR”. -H "(step ST46). In step ST46, the scan execution function 62 controls the control device 16 as in step ST6 (shown in FIG. 8).

  The scan execution function 62 executes the second scan “HR-H” corresponding to the second scan type “HR-H” set in step ST41 (step ST47). In step ST47, the scan execution function 62 via the control device 16 according to the addition number s of the acquisition mode corresponding to the second scan type “HR-H” (for example, s = 1 shown in FIG. 3A). The second scan “HR-H” is executed while controlling the adding unit A.

  The image generation function 63 reconstructs high-definition CT image data based on the detection data generated according to the second scan “HR-H” executed in step ST47, and uses the CT image data as a CT image on the display 42. (Step ST48). The image generating function 63 can also reconstruct the standard resolution CT image data based on the detection data generated according to the second scan “HR-H” executed in step ST47. As a method of adjusting the resolution, there is a method of digitally adding (digitally bundling) collected data in addition to a method using a reconstruction function and an image filter.

  The image generation function 63 stores the CT image data generated in steps ST45 and ST48 in the memory 41 (step ST49).

  As described above, according to the operation shown in FIG. 10 by the X-ray CT apparatus 1, the burden on the patient P is reduced in the examination in which the first scan “NR-V” and the second scan “HR-H” are continuously performed. Can be done.

(Third specific example)
FIG. 11 is a flowchart showing the operation in the third example of a plurality of scan types. In FIG. 11, reference numerals with numbers attached to “ST” indicate respective steps in the flowchart. In FIG. 11, a case will be described in which the whole is divided into three parts, a standard resolution helical scan, a high definition helical scan, and a standard resolution helical scan, and the mode switching is performed twice. However, the number of divisions and the number of switching are not limited to these.

  First, the scan type setting function 61 is a first scan type “standard resolution helical” that combines a helical scan “H” as a scan mode with a standard resolution mode “NR” and a high definition mode “HR” as an acquisition mode. Scan: NR-H ", the second scan type" high-definition helical scan: HR-H ", and the third scan type" standard-resolution helical scan: NR-H '"are set (step ST61). ). For example, in step ST61, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. 7) preset in the memory 41 via the input interface 43. To set each scan type.

  The scan execution function 62 sets scan parameters for the first scan type “NR-H”, the second scan type “HR-H”, and the third scan type “NR-H ′” set in step ST61, respectively. (Step ST62). For example, in step ST62, the scan execution function 62 sets scan parameters according to an instruction from the operator via the input interface 43. In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image. The scan execution function 62 may set scan areas individually for the three scan types, or may set the entire scan area (the total range of the three scan areas) and the second scan type “HR-H”. May be set.

  Further, the scan execution function 62 controls the control device 16 to adjust the gantry device 10 to be set according to the scan parameters of the first scan type “NR-H” set in step ST62, The first scan “NR-H” corresponding to the first scan type “NR-H” set in ST61 is executed (step ST64). In step ST64, the scan execution function 62, via the control device 16, according to the addition number s (for example, s = 4 shown in FIG. 3B) of the acquisition mode corresponding to the first scan type “NR-H”. The first scan “NR-H” is executed while controlling the addition unit A.

  The scan execution function 62 is provided at the end of the first scan “NR-H”, and at the joint between the scan area of the first scan “NR-H” and the scan area of the second scan “HR-H”, the tracking collimator. Is operated, the helical pitch is gradually reduced, the X-ray irradiation is stopped after the top 33 stops, and the data collection is stopped. When the first scan “NR-H” corresponding to the first scan type “NR-H” ends, the scan execution function 62 changes the scan type from the first scan type “NR-H” to the second scan type “HR-H”. -H "(step ST66). In step ST66, the scan execution function 62 controls the control device 16 similarly to step ST6 (shown in FIG. 8).

  The scan execution function 62 executes the second scan “HR-H” corresponding to the second scan type “HR-H” set in step ST61 (step ST67). In step ST67, the scan execution function 62 via the control device 16 according to the addition number s (for example, s = 1 shown in FIG. 3A) of the acquisition mode corresponding to the second scan type “HR-H”. The second scan “HR-H” is executed while controlling the adding unit A.

  The scan execution function 62 is provided at the end of the second scan “HR-H”, and at the joint between the scan area of the second scan “HR-H” and the scan area of the third scan “NR-H”, the tracking collimator. Is operated, the helical pitch is gradually reduced, the X-ray irradiation is stopped after the top 33 stops, and the data collection is stopped. When the second scan “HR-H” corresponding to the second scan type “HR-H” ends, the scan execution function 62 changes the scan type from the second scan type “HR-H” to the third scan type. Switch to "NR-H '" (step ST76). In step ST76, the scan execution function 62 controls the control device 16 as in step ST6 (shown in FIG. 8).

  The scan execution function 62 executes the third scan “NR-H ′” corresponding to the third scan type “NR-H ′” set in step ST61 (step ST77). In step ST77, the scan execution function 62 adds the acquisition number s (for example, s = 4 shown in FIG. 3B) of the acquisition mode corresponding to the third scan type “NR-H ′” via the control device 16. ), The third scan “NR-H ′” is executed while controlling the addition unit A.

  The image generation function 63 reconstructs the standard resolution CT image data based on the detection data generated according to the first and third scans “NR-H, NR-H ′” executed in steps ST64 and ST77. Reconstructing high-definition CT image data based on the detection data generated according to the second scan “HR-H” performed in step ST67, and displaying the CT image data on the display 42 as a CT image (step ST78).

  Further, the image generation function 63 corresponds to the first and third scans “NR-H, NR-H ′” based on the detection data generated according to the second scan “HR-H” executed in step ST67. It is also possible to reconstruct the standard resolution CT image data having the same image resolution as the standard resolution CT image data. In that case, the image generation function 63 connects three standard resolution CT image data corresponding to three scan areas related to the first to third scans “NR-H, HR-H, NR-H ′”. In addition, standard resolution volume data representing the entire three scan areas is generated.

  The image generation function 63 stores the CT image data generated in step ST78 in the memory 41 (step ST79).

  As described above, according to the operation shown in FIG. 11 by the X-ray CT apparatus 1, in the examination in which the first to third scans “NR-H, HR-H, NR-H ′” are continuously performed, the patient P The burden can be reduced.

(Fourth specific example)
FIG. 12 is a flowchart showing an operation in the fourth example of a plurality of scan types. In FIG. 12, reference numerals with numbers attached to “ST” indicate respective steps in the flowchart. Note that FIG. 12 illustrates a case where “volume scan” is selected as the collection mode, but the present invention is not limited to this case. For example, in FIG. 12, “Dynamic Volume Scan” may be adopted as the collection mode instead of “Volume Scan”.

  First, the scan type setting function 61 is a first scan type “standard resolution volume scan” in which a volume scan “V” as a scan mode is combined with a standard resolution mode “NR” and a high definition mode “HR” as an acquisition mode. : NR-V "and the second scan type" high-definition volume scan: HR-V "are selected and set (step ST81). For example, in step ST81, the scan type setting function 61 allows the operator to select a predetermined scan type from a scan type table (shown in FIG. 7) preset in the memory 41 via the input interface 43. To set each scan type.

  The scan execution function 62 sets scan parameters relating to the first scan type “NR-V” and the second scan type “HR-V” set in step ST81 (step ST82). For example, in step ST82, the scan execution function 62 sets scan parameters according to an instruction from the operator via the input interface 43. In general, the scan execution function 62 executes 2D or 3D scano imaging to generate a scano image, and sets scan parameters such as a scan area for each scan type based on the scano image.

  Further, the scan execution function 62 controls the control device 16 to adjust the gantry device 10 to be set according to the scan parameter of the first scan type “NR-V” set in step ST82. The first scan “NR-V” corresponding to the scan type “NR-V” set in ST81 is executed (step ST84). In step ST84, the scan execution function 62, via the control device 16, according to the addition number s (for example, s = 4 shown in FIG. 3B) of the acquisition mode corresponding to the first scan type “NR-V”. The first scan “NR-V” is executed while controlling the adding unit A.

  The image generation function 63 reconstructs CT image data based on the detection data generated according to the first scan “NR-V” corresponding to the first scan type “NR-V” executed in step ST84, The CT image data is displayed on the display 42 as a CT image (step ST85). Here, the scan execution function 62 displays the scan area of the second scan type “HR-V” set in step ST82 on the displayed reconstructed image, so that the operator can input the scan area via the input interface. The scan area of the second scan “HR-V” may be finely corrected (reset).

  When the first scan “NR-V” corresponding to the first scan type “NR-V” ends, the scan execution function 62 changes the scan type from the first scan type “NR-V” to the second scan type “NR-V”. HR-V "(step ST86). In step ST86, the scan execution function 62 controls the control device 16 as in step ST6 (shown in FIG. 8).

  The scan execution function 62 executes the second scan “HR-V” corresponding to the second scan type “HR-V” set in step ST81 (step ST87). In step ST87, the scan execution function 62 via the control device 16 according to the addition number s of the acquisition mode corresponding to the second scan type “HR-V” (for example, s = 1 shown in FIG. 3A). The second scan “HR-V” is executed while controlling the addition unit A.

  The image generating function 63 reconstructs high-definition CT image data based on the detection data generated according to the second scan “HR-V” executed in step ST87, and uses the CT image data as a CT image on the display 42. (Step ST88). Further, the image generation function 63 can also reconstruct the standard resolution CT image data based on the detection data generated according to the second scan “HR-V” executed in step ST87.

  The image generation function 63 stores the CT image data generated in steps ST85 and ST88 in the memory 41 (step ST89).

  As described above, according to the operation shown in FIG. 12 by the X-ray CT apparatus 1, the burden on the patient P is reduced in the examination in which the first scan “NR-V” and the second scan “HR-V” are continuously performed. Can be done.

  In the above embodiment, the term “processor” refers to, for example, a dedicated or general-purpose CPU (Central Processing Unit) and a GPU (Graphics Processing Unit), as well as an application-specific integrated circuit (ASIC) and It means a circuit such as a programmable logic device. The programmable logic device includes, for example, a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA). The processor realizes various functions by reading and executing the program stored in the storage medium.

  Further, in the above embodiment, an example in which a single processor of the processing circuit realizes each function has been described. However, a processing circuit is configured by combining a plurality of independent processors, and each processor realizes each function. Is also good. In the case where a plurality of processors are provided, the storage medium for storing the program may be provided separately for each processor, or one storage medium may collectively store programs corresponding to the functions of all processors. Is also good.

  The scan type setting function 61 is an example of a setting unit. The scan execution function 62 is an example of an execution unit. The image generation function 63 is an example of a generation unit.

  According to at least one embodiment described above, it is possible to reduce the burden on the subject in an examination that executes a plurality of scans according to a plurality of scan types.

  While some embodiments of the invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 10 Mounting apparatus 11 X-ray tube 12 X-ray detector 13 DAS
16 control device 41 memory 44 processing circuit 61 scan type setting function 62 scan execution function 63 image generation function A adder

Claims (10)

An X-ray generation unit that generates X-rays for irradiating the subject;
An X-ray detection unit including a plurality of detection elements for detecting the X-rays, a detection element row including a plurality of detection elements arranged in a channel direction, and a plurality of detection element rows in the row direction.
A setting unit configured to select and set two or more scan types from a plurality of scan types stored in the storage unit and configured by a combination of the scan mode and the collection mode;
After setting the scan parameters for the two or more scan types, respectively, the X-ray generation unit and the X-ray detection unit are controlled to execute two or more scans for the two or more scan types, respectively. An execution unit,
X-ray CT apparatus having: Classifying the plurality of detection element rows into a first detection element row group and a second detection element row group;
In the case of the first acquisition mode, a plurality of detection data output from a plurality of detection elements included in the first detection element row group and the second detection element row group are added,
In the case of the second acquisition mode, a plurality of detection data output from a plurality of detection elements included in the first detection element row are not added,
Further comprising an adder,
The X-ray CT apparatus according to claim 1. The addition unit includes a plurality of detection elements included in the first detection element row group and the second detection element row group and corresponding to a plurality of pieces of detection data to be added, adjacent to each other in the channel direction and the column direction. A plurality of detection elements,
The X-ray CT apparatus according to claim 2. The adding unit is configured to output a plurality of detection elements output from a plurality of detection elements included in the first detection element row group and the second detection element row group by an addition number of the detection data according to the first acquisition mode. Add the detection data of
The X-ray CT apparatus according to claim 2. A generating unit configured to reconstruct CT image data based on detection data generated according to at least one of the two or more scans according to the two or more scan types;
The X-ray CT apparatus according to claim 1. The execution unit sets two or more scan areas related to the two or more scan types as scan parameters related to the two or more scan types.
The X-ray CT apparatus according to claim 5. The execution unit, during the execution of the two or more scans, based on CT image data based on the immediately preceding scan, resets the scan area for a subsequent scan,
The X-ray CT apparatus according to claim 6. The generating unit reconstructs two or more CT image data having the same image resolution based on the detection data generated according to the two or more scans,
The X-ray CT apparatus according to claim 6. The generation unit generates volume data representing the entirety of the two or more scan areas by joining the two or more CT image data having the same image resolution.
An X-ray CT apparatus according to claim 8. The storage unit further stores a scan type table indicating the plurality of scan types,
The setting unit selects and sets the two or more scan types from the scan type table stored in the storage unit.
The X-ray CT apparatus according to claim 1.

Images