JP6502023B2 - X-ray computed tomography apparatus and scan plan setting support apparatus - Google Patents

Description

  Embodiments of the present invention relate to an X-ray computed tomography apparatus (X-ray CT) and a scan planning setting support apparatus.

  Recent advances in low-dose imaging techniques have led to reductions in the dose of this scan used for diagnosis. A two-dimensional positioning image (also called positioning image scanogram) is taken at the scan planning stage to set the scan position and range of the main scan, determination of the reconstruction position and range, and modulation of the tube current. . As shown in FIG. 9, for example, the X-ray tube is fixed at the position of 0 degree, that is, the position in the front direction with respect to the subject, and the positioning image moves continuously or intermittently while moving the top Photographed by repeating photographing intermittently in synchronization with plate movement. In addition to the front direction (0 °), positioning images may be collected from two directions in the side direction (90 °) and further from any direction, but since the display direction is fixed in the shooting direction, the display direction It can not be changed.

  Therefore, the modulation setting of the tube current is limited to the range that can be set on the positioning image in the maximum two directions as illustrated in FIG. 10 and FIG. 11, and X is determined according to the shape of the organ and its position, the arrangement relationship between organs, etc. It was not possible to finely set the high tube current section and the low tube current section along the rotational trajectory of the wire tube.

  In addition, the exposure dose required for imaging positioning images has not changed much from before even though the exposure dose for this scan has been decreasing in recent years. Furthermore, in the case of automatic exposure control (CT-AEC) used in CT scan, there is a problem that even if the same subject is calculated, the calculated mA changes even if the bed height changes. The positioning image is a projection image, and the setting accuracy of the scan range and the like in the scan plan and the convenience of the setting operation are not so preferable.

Japanese Patent Laid-Open No. 7-23946

  The purpose is to enable precise dose control for each organ with respect to setting of scan range etc. in scan planning.

It is to

An X-ray computed tomography apparatus according to the present embodiment includes an X-ray tube apparatus, a high voltage generation unit that generates a tube voltage to be applied to the X-ray tube apparatus, an X-ray detector, and an object. A bed device to be placed, a rotation mechanism rotatably supporting the X-ray tube device and the X-ray detector around the subject, and storing projection data generated from an output of the X-ray detector At least one of a storage unit, a reconstruction processing unit that reconstructs volume data based on the projection data, an extraction processing unit that extracts an organ area from the volume data, and the organ area extracted from the volume data a two-dimensional image including the part, in at least a portion images generating unit that generates a three-dimensional image including, the scan according to the user operation on the displayed the two-dimensional image of the extracted organ region And the correction unit for correcting the main scan condition for each angle or section of the X-ray tube device in a converter orbit, and a display unit for displaying the 3-dimensional images containing information about the modified the main scan conditions, the Prepare .

FIG. 1 is a view showing the arrangement of an X-ray computed tomography apparatus according to this embodiment. FIG. 2 is a flow chart showing the processing procedure of the entire CT examination according to the present embodiment. FIG. 3 is a view showing a projection image generated from helical scan data in step S13 of FIG. FIG. 4 is a view showing a projection image generated from non-helical scan data in step S13 of FIG. FIG. 5 is a scan plan setting screen configured by the scan expert system of FIG. 1 and is a view showing an example in which a tube current modulation setting auxiliary line is displayed together with an axial image. FIG. 6 is a view showing a display change in which a high mA section is added in the screen of FIG. FIG. 7 is a view showing a display change in which the high mA section is shortened in the screen of FIG. FIG. 8 is a view showing a three-dimensional image displayed on the scan plan setting screen of FIG. 5 in place of the axial image. FIG. 9 is a view showing a projection image (positioning image) in one direction obtained by the conventional photographing method. FIG. 10 is a view showing a tube current modulation setting method using a positioning image in the front direction (0 °) acquired by the conventional imaging method. FIG. 11 is a diagram showing a tube current modulation setting method using a positioning image in the side direction (90 °) acquired by the conventional imaging method.

Hereinafter, an X-ray computed tomography apparatus and a scan plan setting support apparatus according to the present embodiment will be described with reference to the drawings.
An X-ray computed tomography apparatus according to the present embodiment includes an X-ray tube apparatus, a high voltage generation unit that generates a tube voltage to be applied to the X-ray tube apparatus, an X-ray detector, and an object. A bed device to be placed, a rotation mechanism rotatably supporting the X-ray tube device and the X-ray detector around the subject, and storing projection data generated from an output of the X-ray detector A storage unit, a reconstruction processing unit that reconstructs volume data based on the projection data, an extraction processing unit that extracts an organ area from the volume data, and a two-dimensional image generation that generates a two-dimensional image from the volume data Section, a display section for displaying the two-dimensional image together with the extracted organ area, and the angle or section of the X-ray tube apparatus on the rotational trajectory in the main scan according to the user operation on the two-dimensional image ; And a correction unit for correcting the main scan condition.

  In the present embodiment, by performing a scan plan using volume data obtained by performing a helical scan, a volume scan and the like before the main scan, dangerous organs are extracted before the main scan and dangerous at the main scan. It will be possible to control x-rays to reduce the dose distribution of organs.

Positioning scan At this time, volume data may be collected with a plurality of energies using dual energy or the like by kV switching.

  In addition to being able to accurately identify the range and position of the target organ etc. of the subject in the scan range, the target organ to be scanned can be accurately confirmed on the cross section (axial image). The modulation of the tube current (mA) can be set precisely and precisely on the rotating orbit, and it can be realized with high operability.

  FIG. 1 is a view showing the arrangement of an X-ray computed tomography apparatus according to this embodiment. The X-ray computed tomography apparatus includes a rotation / rotation (ROTATE / ROTATE) type in which an X-ray tube device 101 and an X-ray detector 103 are combined to rotate around a subject around a rotation axis, and a ring shape. There are various types such as a fixed / rotation (STATIONARY / ROTATE) type in which a large number of detection elements are arrayed and only the X-ray tube device 101 rotates around the subject, and any type can be applied. Here, the rotation / rotation type currently in the mainstream is described. Also, in order to reconstruct tomographic image data of one slice, projection data of about 360 ° around one circumference of the subject is required, and projection data of 180 ° + fan angle is also required in the half scan method. . The present invention is applicable to any reconstruction scheme. Further, the mechanism for converting incident X-rays into charge includes an indirect conversion type in which X-rays are converted into light by a phosphor such as a scintillator and then converted into charges by a photoelectric conversion element such as a photodiode and The generation of electron-hole pairs in semiconductors and their transfer to electrodes, that is, the direct conversion type utilizing the photoconductivity phenomenon, is the mainstream. Although any method of those may be employ | adopted as an X-ray detection element, it demonstrates as the former indirect conversion type here. Further, in recent years, so-called multi-tube type X-ray computed tomography apparatus in which a plurality of pairs of an X-ray tube and an X-ray detector are mounted on a rotating ring has been commercialized, and development of peripheral technologies is advanced. There is. The present invention is applicable to either a conventional single-tube type X-ray computed tomography apparatus or a multi-tube type X-ray computed tomography apparatus. Here, it demonstrates as a single-tube type | mold.

  The X-ray computed tomography apparatus of the present embodiment has a gantry 100. The gantry 100 has an annular rotating frame 102. The rotating frame 102 constitutes a rotating mechanism together with the gantry driving unit 107. The rotating frame 102 is driven by the gantry driving unit 107 and rotates around the rotation axis RA. The X-ray tube device 101 and the X-ray detector 103 are mounted on the rotating frame 102 so as to face each other. At the time of scanning, a subject placed on the top plate of the bed apparatus 111 is inserted between the X-ray tube apparatus 101 and the X-ray detector 103. The top board is moved back and forth along its longitudinal direction by a drive unit (not shown) provided in the bed apparatus 111.

  The X-ray tube apparatus 101 receives application of a tube voltage and supply of a filament current from the high voltage generator 109 via the slip ring 108 to generate X-rays. The X-ray detector 103 has a plurality of X-ray detection elements that detect X-rays transmitted through the subject and output electrical signals reflecting the dose of incident X-rays. The plurality of X-ray detection elements are arranged in a two-dimensional form of, for example, 320 columns × 912 channels.

  The data acquisition circuit 104 acquires the signal output from the X-ray detector 103 and converts it into a digital signal (referred to as pure raw data). The data acquisition circuit 104 is connected to the preprocessing unit 106 via the noncontact data transmission unit 105. The preprocessing unit 106 performs processing such as sensitivity correction and logarithmic conversion on the pure raw data to generate projection data. The projection data is stored in the storage unit 112. The scan control unit 110 controls the operations of the gantry drive unit 107, the high voltage generator 109, and the bed apparatus 111 in order to execute a scan in accordance with scan plan information described later.

  The image reconstruction unit 117 is provided to reconstruct image data with relatively low noise based on projection data acquired by scanning with low-dose X-rays similar to the imaging of conventional two-dimensional positioning images. . As the reconstruction method by the image reconstruction unit 117, any method that is relatively applicable to noise reduction is used. For example, an image reconstruction method (a successive approximation applied image reconstruction method) to which the successive approximation method is applied is used. Here, although the image reconstruction unit 117 is described below as reconstructing volume data by the successive approximation method-based image reconstruction method, it is not limited to the successive approximation method-based image reconstruction method as described above. .

  The image reconstruction unit 117 reconstructs image data, here volume data, based on the projection data stored in the storage device 112 by an algorithm based on the successive approximation applied reconstruction method. Volume data is stored in the storage device 112. The successive approximation application reconstruction process is applied essentially to the reconstruction of the positioning image (cross-sectional image, projection image, volume data) used for the scan plan before the main scan, but based on the projection data collected by the main scan The reconstruction of image data (tomographic image data, volume data) is selectively applied to the other type of reconstruction processing provided by the reconstruction processing unit 118 described later.

  The successive approximation applied reconstruction method is an application of the successive approximation method. The successive approximation method is, as is well known, a method of comparing the difference between measured values and calculated values with respect to projection data, and reconstructing an image while repeating correction. The successive approximation application reconstruction method is a method in which a process of removing noise on projection data and a process of removing noise in image data are added in an image reconstruction cycle of the successive approximation method. The algorithm of the successive approximation applied reconstruction method uses a statistical noise model and a scanner model to reduce noise on the collected projection data. Furthermore, by using an anatomical model, it is possible to see which is noise and which is true projection data in the image reconstruction domain, extract only the noise component, and remove and reduce the noise with high accuracy by repeating this process. Do. The successive approximation application reconstruction method is a reconstruction method in which low dose imaging and low noise high image quality are compatible.

  The reconstruction processing unit 118 uses, for example, the Feldkamp method, which is different from the successive approximation applied image reconstruction method in the image reconstruction unit 117, on the basis of projection data in the range of 360 ° or 180 ° + fan angle. Volume data is reconstructed by cone beam reconstruction. The Feldkamp method is a reconstruction method when the projection ray intersects the reconstruction plane like a cone beam, and is treated as a fan projection beam in the case of convolution assuming that the cone angle is small. Back projection is an approximate image reconstruction method that processes along rays during scanning. The cone beam reconstruction method is a reconstruction method which corrects projection data according to the angle of the ray with respect to the reconstruction surface as a method in which the cone angle error is suppressed more than the Feldkamp method. Volume data is stored in the storage device 112.

  In order to reconstruct volume data from projection data collected by positioning scan, for example, successive approximation applied reconstruction method that is highly applicable to noise reduction is applied, volume data is obtained from projection data collected by one positioning scan and main scan. For reconstruction, the successive approximation application reconstruction method, the Feldkamp method, and the cone beam reconstruction method are arbitrarily selected.

  The display device 116 is mainly provided to display an image generated from volume data and to display a scan planning support screen constructed by the scan expert system 120. The input device 115 includes a keyboard, a mouse, and the like to input an instruction of the operator.

  The three-dimensional image processing unit 121 has a function of generating data of a three-dimensional image by volume rendering processing from volume data stored in the storage device 112, axial / sagittal / colonal or arbitrary from volume data by cross-section conversion processing (MPR processing) And the function of generating data of cross-sectional images related to the cross-sections of the oblique cross-sections. In the scan plan, axial images are generated. The projection image generation processing unit 122 generates projection image data as a positioning image from the projection data stored in the storage device 112. For example, when an arbitrary view angle is selectively designated from 0 °, 45 °, 90 ° on the scan planning support screen, when the X-ray tube device 101 is positioned at the view angle under the control of the scan expert system 120 The projection data collected in the image data is read out from the storage unit 112. The view angle is the angle on the rotational trajectory of the X-ray tube device 101 at the time of projection data collection. 0 ° represents that the X-ray tube device 101 is at the top of its rotational trajectory. The projection image generation processing unit 122 arranges the read projection data of the same view angle according to the respective top plate positions and combines them into one sheet, thereby generating a projection image, that is, data of an image for positioning equivalent to the conventional one. Do.

  The part extraction processing unit 123 extracts an organ area from the volume data stored in the storage device 112. Since volume data of CT values can be obtained, an organ area such as an examination object can be extracted by threshold processing, or the organ area can be identified by performing segmentation of the organ by matching processing with a standard anatomical model. For example, the part extraction processing unit 123 receives the examination target organ code included in the examination request information from the scan expert system 120, and extracts the organ area from the volume data according to the threshold value and the shape pattern applied to the examination target organ.

  Furthermore, the site extraction processing unit 123 performs threshold processing on the regions such as “testis”, “ovary”, “spinal cord”, “eyeball (lens)”, etc. that are highly X-ray sensitive and dangerous to X-ray irradiation. It extracts from volume data by the matching process with a typical anatomical model. The extracted organ area information is supplied to the scan expert system 120.

  By using volume data in the scan plan, it becomes possible to extract dangerous organs in three dimensions and control X-rays so as to suppress the dose distribution of dangerous organs in this scan. The scan expert system 120 automatically adjusts the scan conditions such as the tube current so that the radiation dose to the extracted dangerous organ does not exceed the specified value preset for each organ. The scan expert system 120 assists in manually correcting the scan conditions such as the tube current so that the radiation dose to the extracted dangerous organs does not exceed the specified value preset for each organ. It has a function. To that end, the scan expert system 120 constructs a screen that assists the user in setting up a scan plan. As illustrated in FIG. 5, the scan planning support screen includes a cross-sectional image and a positioning image. When the axial section line on the positioning image is moved by the operation of the input device 115 by the user, the three-dimensional image processing unit 121 switches the display to an axial image generated according to the position of the section line after movement. The scan expert system 120 superimposes the organ area extracted by the part extraction processing unit 123 on the cross-sectional image on the scan planning support screen, the projection image (positioning image), and the three-dimensional image in the allocated colors.

  In addition, areas such as “testis”, “ovary”, “spinal cord”, “eyeball (lens)” etc. are extracted from volume data by positioning scan as dangerous organs by X-ray irradiation with high X-ray sensitivity, and alerting color For example, in red, cross-sectional images, projected images (positioning images), and three-dimensional images are superimposed.

  The scan expert system 120 displays a message prompting the user to correct the scan conditions such as the tube current when the irradiation dose to the extracted dangerous organ exceeds the upper limit value preset for each organ Do.

  On the cross-sectional image on the scan planning support screen, an annular line representing the rotational trajectory of the X-ray tube device 101 and an auxiliary line representing the modulation section of the tube current are superimposed. The auxiliary lines consist of a pair of a start point auxiliary line representing the start point of the modulation section and an end point auxiliary line representing the end point of the modulation section. A section in which the reference tube current is a steady current and a section in which the reference tube current is modulated to a higher tube current and a section in which the reference tube current is modulated to a lower tube current are referred to as modulation sections. As the reference tube current, the tube current (mA) preset as a recommended value in the scan plan candidate, or the body thickness of the subject which can identify the preset recommended value from the volume data with high accuracy The value calculated according to the size of the organ is applied.

  The positions of the start and end auxiliary lines of the modulation section are arbitrarily changed in accordance with the user's operation such as dragging of the input device 115. Thereby, the position and length of the modulation section can be modulated. Furthermore, two types of modulation area addition buttons are provided: low tube current area addition and high tube current area addition. A modulation interval can be arbitrarily added by clicking on the modulation interval addition button.

  When the “3D button” on the scan planning support screen is clicked, the scan expert system 120 displays a three-dimensional image generated by volume rendering processing from volume data at the three-dimensional image processing unit 121 instead of the axial image. Be done. As exemplified in FIG. 8, on the three-dimensional image, a mark of a mode in which the modulation section with respect to the reference section set on the axial image can distinguish them is superimposed, and the modulation section can be confirmed on the three-dimensional image. .

  In addition, a scan position, a scan range, a reconstruction position, a reconstruction range, a tube voltage, a slice thickness, a reconstruction function, and the like are specified on the scan planning support screen. The scan expert system 120 generates scan plan information according to the determined scan plan. The scan plan information is sent to the scan control unit 110, and the main scan is executed according to the scan plan information under the control of the scan control unit 110.

  In the scan expert system 120, when there are dangerous organs present in the X-ray irradiation range, the dose distribution of each dangerous organ under the scan conditions of the main scan specified on the scan planning support screen, such as CTDI and SSDE The exposure dose is calculated, and when the exposure dose exceeds the prescribed value set in advance for each dangerous organ, a message prompting manual correction of scan conditions such as tube current is displayed. The user corrects the scan conditions so that this message is hidden.

  While confirming the position of organs etc. on the axial image or 3D image on the scan planning support screen, it becomes possible to set the fine tube current mA so as not to apply the dose to the sensitive organ, and the axial image or 3D image The tube current modulation can be set precisely and precisely on the rotational trajectory of the above, and furthermore, it can be realized with high operability. In addition, indicators of exposure such as CTDI and SSDE for each organ can also be confirmed before scanning.

  As described above, in the present embodiment, volume data can be collected by a positioning scan before the main scan, and the locations of organs can be grasped three-dimensionally. Thus, for example, when it is desired to apply a dose to the liver but not to other organs, control can be performed such that a large amount of dose from a projection angle close to the liver is given and no dose is given to other sites. In addition, it is possible to calculate the exposure dose for each organ because the position of the organ can be grasped.

  FIG. 2 shows the processing procedure of the entire CT examination from the low dose positioning scan at the scan planning stage according to the present embodiment through the main scan to the final image display. In the scan planning stage, first, positioning scan by a helical scan method or non-helical scan method with a lower dose than the main scan for a relatively wide range such as the entire chest, entire abdomen, and entire upper body of the subject under control of the scan control unit 110 Is executed. In the case of the helical scan method, while the X-ray tube device 101 and the X-ray detector 103 rotate continuously around the subject, the X-ray detector 103 repeatedly detects the transmitted X-rays of the subject, The top on which the subject is placed is continuously moved. In the case of the non-helical scan method, projection data for one rotation is collected with the top plate stopped, and then the top plate is moved by a predetermined distance according to the cone spread angle, and projection data for one rotation at that position Are collected and such operations are repeated. The positioning scan collects 360 ° of projection data over a wide range along the body axis of the subject (S11). Based on the projection data collected by this positioning scan, volume data is reconstructed by the image reconstruction unit 117 (S12). Volume data is stored in the storage device 112.

  Among the projection data of the entire circumference collected by the positioning scan, projection data collected at an arbitrarily selected angle from the X-ray tube device 101 via the input device 115 from 0 °, 45 °, 90 °, for example The projection image generation processing unit 122 is read from the storage unit 112. The read projection data is arranged in accordance with the top position (the position in the body axis direction), and is combined into one sheet. Thereby, data of the positioning image (projected image) viewed from one direction is generated (S13). Initially, a positioning image of 0 ° is generated and displayed on the scan planning support screen as illustrated in FIG. 5 (S14). When another 45 ° or 90 ° projection direction is selected via the input device 115 (S15), the process returns to step S13 to generate the other selected 45 ° or 90 ° positioning image, It is switched to that display.

  FIG. 3 shows the composition of the positioning image (projected image) when the positioning scan is performed by the helical scan, and FIG. 4 shows the composition of the positioning image when the positioning scan is performed by the non-helical scan ing. In the present embodiment, projection data for the entire circumference is collected by scanning, so that positioning images can be generated in an arbitrary direction, and the positioning images are fixed in the shooting direction at the time of shooting as in the prior art. The positioning image can be observed from the direction, and there is no restriction that the direction of the positioning image is not taken after photographing. Here, it is exemplified that the projection direction is selected from 0 °, 45 °, and 90 °, but this includes that an arbitrary angle can be set.

  An axial section line is superimposed on the positioning image on the scan planning support screen. The three-dimensional image processing unit 121 generates an axial image of an axial section indicated by an axial section line from the volume data by section conversion processing (MPR processing) (S16), and is displayed on the scan planning support screen (S17) . When the axial section line superimposed on the positioning image is moved back and forth along the body axis by the operation of the input device 115 by the user (S18), the axial section line after movement by the three-dimensional image processing unit 121 The display is switched to the generated axial image according to the position.

  FIG. 5 shows a scan planning support screen constructed by the scan expert system 120. The scan planning support screen numerically indicates the scan conditions in the scan plan. Scan start time, pause time, scan start position, scan end position, scan mode, number of scans, tube voltage (kV), tube current (mA), scan range (C-FOV), reconstruction range (D-FOV), Recommended values such as scan speed (total time), imaging slice thickness, movement range, movement amount after scan are individually represented by numerical values, and can be arbitrarily changed by the user. Further, a positioning image, in this example, a positioning image in the front direction (0 °) is displayed on the scan planning support screen. As described above, the axial section line is superimposed on the positioning image. An axial image of the cross section indicated by the axial cross section line is displayed together with the positioning image.

  The scan expert system 120 generates an annular line representing the rotational trajectory of the X-ray tube device 101 and an auxiliary line representing the modulation section of the tube current (S19), and is superimposed on the axial image (S20). As a modulation auxiliary line, a start point auxiliary line representing the start point of the modulation section and an end point auxiliary line representing the end point of the modulation section making a pair with it are generated. In this example, a high tube current (mA) section higher than the reference tube current of the reference section is added as the modulation section. The modulation section is initially set to a section facing the examination target organ extracted by the part extraction processing unit 123.

  As shown in FIG. 6, according to the user's operation such as dragging of the input device 115, the positions of the start and end auxiliary lines of the modulation section are arbitrarily changed. The user can arbitrarily change the position of the modulation section on the rotational trajectory and its section length while confirming the organ area in the axial image (S21). Furthermore, when one of the two types of modulation interval addition buttons of low tube current interval addition and high tube current interval addition is clicked, as shown in FIG. 7, the start point auxiliary line (2 ), End point auxiliary line (2) is added. The modulation section is deleted by bringing the start point auxiliary line and the end point auxiliary line closer to each other than a predetermined distance.

  By this operation, for example, when it is desired to apply a dose to the liver but not to other organs, it is possible to set a large dose from the projection angle close to the liver and not apply the dose to other parts. .

  By clicking the "3D" button on the scan planning support screen, as shown in FIG. 8, the axial image is switched to a three-dimensional image representing the extracted examination target organ region or highly sensitive organ region. A mark indicating a reference section and a mark indicating a modulation section are superimposed on the three-dimensional image. As a result, it is possible to adjust the modulation section for the examination target organ area and the highly sensitive organ area even on the three-dimensional image.

  The scan plan is determined by clicking on the "confirm" button in the scan plan support screen. As a result, the scan position, scan range, reconstruction position, reconstruction range and the like are determined (S22), and the modulation setting such as the presence or absence of modulation of the tube current and the modulation interval is determined (S23).

  When the scan plan is determined, scan plan information is generated according to the determined scan plan by the scan expert system 120, and the main scan is executed under the control of the scan control unit 110 according to the scan plan information (S24).

  Volume data is reconstructed by, for example, a cone beam reconstruction method based on projection data collected by the main scan, and a three-dimensional image is generated by the three-dimensional image processing unit 121 and displayed on the display device 116 (S25).

  Conventionally, a positioning image for determining a scan range is taken by irradiating X-rays while keeping the X-ray tube fixed, usually in the 0 ° direction without rotating the X-ray tube and moving the bed in the Z direction. At the time of scan planning, a scan range or the like is merely set from the one-direction positioning image or at most two-direction positioning image. In this embodiment, projection data in the direction of 360 ° is collected while rotating the X-ray tube in the same manner as a normal scan, and a three-dimensional image is generated using the obtained projection data in the entire circumferential direction. The three-dimensional structure can be confirmed, a cross-sectional image can be generated at an arbitrary position or direction, the direction of the positioning image (projected image) can be freely changed, and volume data of CT values can be obtained. Etc. can be easily extracted by threshold processing etc., and the scan range can be automatically set initially, and the position of an organ etc. can be confirmed on an axial image or a three-dimensional image, and an organ with high sensitivity is obtained. It becomes possible to set fine mA not to apply the dose, and it is possible to set the tube current modulation precisely and precisely on the rotational orbit of axial image and 3D image, and also with high operability. Can be obtained represents. In addition, indicators of exposure such as CTDI and SSDE for each organ can also be confirmed before scanning.

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

  DESCRIPTION OF SYMBOLS 100 ... Gantry, 101 ... X-ray tube, 102 ... Rotation frame, 103 ... X-ray detector, 104 ... Data acquisition circuit, 105 ... Noncontact data transmission apparatus, 106 ... Pre-processing apparatus, 107 ... Mounting drive part, 108 ... Slip ring 109 High voltage generator 110 Host controller 112 Storage device 115 Input device 116 Display device 120 Scan expert system 121 Three-dimensional image processor 122 Projection image generation processing Part, 123 ... part extraction processing part.

Claims (7)

An X-ray tube device,
A high voltage generating unit for generating a tube voltage to be applied to the X-ray tube apparatus;
X-ray detector,
A bed apparatus on which the subject is placed;
A rotation mechanism rotatably supporting the X-ray tube apparatus and the X-ray detector around the subject;
A storage unit for storing projection data generated from the output of the X-ray detector;
A reconstruction processing unit that reconstructs volume data based on the projection data;
An extraction processing unit that extracts an organ area from the volume data;
An image generation unit configured to generate a two-dimensional image including at least a part of the extracted organ area and a three-dimensional image including at least a part of the extracted organ area from the volume data;
A correction unit that corrects a main scan condition for each angle or section of the X-ray tube device on a rotational trajectory in a main scan according to a user operation on the displayed two-dimensional image;
A display unit for displaying the three-dimensional image including information on the corrected main scan condition;
An X-ray computed tomography apparatus comprising:   The X-ray computed tomography apparatus according to claim 1, wherein the two-dimensional image is an axial image.   The X-ray computer according to claim 1 or 2, further comprising an exposure dose calculation unit that calculates an exposure dose for each of the extracted organ areas based on the information related to the corrected main scan condition. Tomography device.   The X-ray computed tomography apparatus according to claim 3, wherein a message prompting correction of the main scan condition is displayed when the radiation dose calculated for each of the extracted organ regions exceeds a predetermined upper limit value. .   The display unit sets the tube current different from the figure showing the reference section which is the section set to the reference tube current and corresponds to the main scan condition corrected by the correction unit. The X-ray computed tomography apparatus according to any one of claims 1 to 4, wherein a graphic representing a modulation section which is a section to be displayed is added to the two-dimensional image and displayed. The X-ray computed tomography apparatus according to claim 5 , wherein the display unit adds a graphic indicating the reference section and a graphic indicating the modulation section to the three-dimensional image for display. A storage unit that stores volume data related to the subject;
From the volume data, an image generating unit that generates a two-dimensional image including at least part of the extracted issued organ region, and a 3-dimensional image including at least part of the extracted organ region,
A correction unit that corrects the main scan condition for each angle or section of the X- ray tube apparatus on the rotation trajectory in the main scan according to the user operation on the displayed two-dimensional image, and information on the corrected main scan condition A display unit for displaying the three-dimensional image including
A scan plan setting support device characterized by comprising.