JP4489228B2 - X-ray CT system, control method therefor, and storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray CT (computerized tomograpy) system that obtains a tomographic image of a patient by X-ray irradiation, a control method thereof, and a storage medium.
[0002]
[Prior art]
In an X-ray CT apparatus and system, a one-dimensional array comprising a plurality of detection elements arranged to irradiate a subject with a fan-shaped X-ray beam from an X-ray tube and arrange the transmitted X-rays in accordance with the spread of the fan-shaped beam The X-ray detection unit of Then, the measurement of the transmitted X-ray is performed in a plurality of view directions while rotating the X-ray tube and the X-ray detector around the subject. Such transmission X-ray measurement is called scanning. Then, an X-ray tomographic image is reconstructed based on the measurement data of a plurality of views obtained by scanning, and displayed on a monitor such as a CRT.
[0003]
Prior to such a scan, the operator needs to perform a scan planning process.
[0004]
The operator first performs imaging called scout scanning as the first phase of the scan planning process. This is because the X-ray tube is directly above the subject and the X-ray detector is directly below the subject, and the subject is gradually transported while the X-ray tube and the X-ray detector are fixed without rotating. While X-rays are continuously irradiated, each measurement data is arranged in the irradiation order to obtain one X-ray two-dimensional image.
[0005]
Subsequently, scan conditions are set as the second phase of the scan planning process. In general, an X-ray two-dimensional image (hereinafter referred to as a “scout image”) obtained by a scout scan is displayed on a monitor, and while viewing the scout image, which range of tomograms is measured at what millimeter intervals, what The scanning conditions are set by inputting parameters such as whether to obtain an image having a millimeter thickness.
[0006]
By the way, especially when measuring the torso, in order to prevent image quality deterioration due to breathing movement, the subject is asked to keep breathing stopped during the scanning process, but naturally the breathing is stopped. There is a limit to the time that can be taken, and the limit varies depending on the subject. For example, when a single-slice X-ray CT system that takes 1 second per scan is used to capture a CT image of a lung having a length of 30 cm, it is assumed that 60 scans are performed with a slice thickness of 5 mm. The scanning process takes at least 60 seconds, but if it is difficult to keep the subject breathing (breath holding) during that time, the scanning is interrupted halfway and a breathing time is given. Therefore, it is also necessary to make settings related to the scan execution timing in consideration of the subject's breath holding time (period), breathing time (period), and the like. The setting of scanning conditions including such a breath holding and breathing plan is called “grouping”.
[0007]
When these various parameters are input, each parameter is automatically adjusted from the viewpoint of diagnostic efficiency (patient throughput).
[0008]
FIG. 2 is a diagram illustrating an example of a scan condition setting screen that displays a scout image and sets each parameter of the scan condition. In FIG. 2, in the image area 401, a scout image is displayed on a z-x coordinate plane composed of a z-axis indicating the body axis direction and an x-axis orthogonal to the z-axis, and a line indicating the slice position is displayed thereon. Indicated. A line indicating the slice position is indicated by a broken line, but a line 402 indicating the scan start position and a line 403 indicating the scan end position are indicated by solid lines. The positions of these lines can be adjusted using a pointing device such as a mouse, and the operator can set the scan start position, scan end position, and slice thickness while viewing the scout image.
[0009]
Reference numeral 404 denotes an area for inputting or displaying various parameters of the scan condition. Numeric values can be entered in the boxes in each column. In FIG. 2, the boxes in each column are arranged in two rows. For example, when there are a plurality of parts to be measured, the scan condition can be set for each part. The number of columns can be arbitrarily changed by the operator.
[0010]
The [Scan Type] column 405 is a column for selecting a helical scan or an axial scan.
[0011]
The [StartLoc] column 406 is a column for inputting a scan start position, and inputs a predetermined reference position, for example, a position from the top of the subject. When a numerical value is entered in this field, a line 402 indicating the scan start position is interlocked and displayed at a position corresponding to the input value. If the line 402 indicating the scan start position is moved while being clicked with the mouse, a corresponding numerical value is displayed in this column in conjunction with the movement. The operator may set this parameter in either form.
[0012]
The [EndLoc] column 407 is a column for inputting a scan end position. Like the [StartLoc] column 406, a position from a predetermined reference position can be input, and a line 403 indicating the scan end position is clicked with the mouse. If the user moves in this manner, the corresponding numerical value is displayed in this column in conjunction with the movement. The operator may set this parameter in either form.
[0013]
[Thick] column 408 is a column for inputting a slice thickness. When a numerical value is entered in this field, the slice position lines (except for 402 and 403) are linked and displayed at a thickness interval corresponding to the input value.
[0014]
The [GantryTilt] column 409 is a column for inputting a tilt angle of a gantry having a cavity for transporting a subject lying on a table.
[0015]
[kV] column 410 is a column for inputting X-ray tube voltage, and [mA] column 411 is a column for inputting X-ray tube current.
[0016]
The [PrepDelay] column 412 is a column for inputting an extension (delay) time from when the operator gives an instruction to start the scanning process to when the X-ray irradiation is actually started.
[0017]
[ISD] column 413 is a column for inputting an interval time between scans when an axial scan is selected in [Scan Type] column 405.
[0018]
The [BreathHold] column 414 is a column for inputting the subject's breath holding time, and the [BreatheTime] column 415 is a column for inputting the breathing time of the subject.
[0019]
When the [Preview] button 416 is clicked after inputting the various parameters described above, the parameters are automatically adjusted so as to optimize the patient throughput, and the grouping result as shown in FIG. 3 instead of FIG. 2 is displayed on the monitor. A preview screen for is displayed. In the example of FIG. 3, bar graphs 503 and 504 indicating breath holding and breathing are displayed along the time axes 501 and 502 indicating the elapsed time of the scan execution, and the breathing time (BreatheTime) ), The time zone where the height of the bar is high represents the breath holding time (BreatheHold). Here, Prep Delay is shown in the time zone from 0 seconds to 30 seconds. Further, at the place of the breath holding start time and the breath holding release time, the scan start position and the scan end position of the subject with an initial “p” are displayed. Thus, according to the preview screen, it is possible to visually confirm how the combination of the breath holding time and the breathing time is related to the scan position.
[0020]
[Problems to be solved by the invention]
In order to display the scan condition setting screen for displaying the scout image in an easy-to-read manner, a considerable area is required. With a general monitor screen area, it is practical to display the scan condition setting screen and the preview screen at the same time. Have difficulty. Therefore, as described above, the scan condition setting screen of FIG. 2 and the preview screen of FIG. 3 must be switched and displayed.
[0021]
Therefore, the operator inputs parameters on the scan condition setting screen of FIG. 2, clicks the [Preview] button 416, switches to the preview screen of FIG. 3, confirms the grouping result, and when this grouping result is not appropriate. Click the [Prior] button 505 in FIG. 3 to display the scan condition setting screen in FIG. 2 again, re-enter each parameter, and click the [Preview] button 416 again to switch to the preview screen in FIG. The process of reconfirming the grouping result is repeated. Such an operation is very complicated, and there is a problem that the burden on the operator is large.
[0022]
The present invention has been made in view of the above-described problems, and provides an X-ray CT system, a control method therefor, and a storage medium that can perform scan planning more easily and reduce the burden on the operator. The purpose is to do.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, the X-ray CT system of the present invention detects X-rays transmitted through the subject from multiple directions by irradiating the subject with X-rays from the X-ray tube in accordance with predetermined conditions. An X-ray CT system for performing a scanning process to reconstruct an X-ray tomographic image of the subject, and transporting the subject while the X-ray tube is fixed at a predetermined position to thereby obtain a two-dimensional view of the subject Means for acquiring an image, and scanning condition setting means for setting at least information relating to timing of breath holding and breathing of the subject, wherein the scanning condition setting means includes a two-dimensional image of the subject, a slice position And display means for displaying on the same screen of the monitor the information indicating the timing of breath holding and breathing timing of the subject.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the first embodiment will be described in detail with reference to the drawings.
[0025]
FIG. 1 is a diagram showing a system configuration of the X-ray CT system of the present embodiment.
[0026]
As shown in FIG. 1, the X-ray CT system of the present embodiment issues an X-ray CT main body 100 that irradiates X-rays to acquire detection data, and issues various control instruction commands to the X-ray CT main body 100. An operation console 101 that performs image reconstruction processing based on the data transferred from the X-ray CT main body 100 and displays it, and an external storage device 102 that mainly stores the transferred data in a predetermined storage medium, The image forming apparatus 103 includes a CT image forming apparatus 103 that forms a CT image on a film and outputs the image, and an image reconstruction calculating apparatus 104 for performing image reconstruction calculation at high speed.
[0027]
In the X-ray CT main body 100, reference numeral 105 denotes a main controller that controls the entire X-ray CT main body, and reference numeral 106 denotes an I / O controller that controls access to the operation console 101. Reference numeral 107 denotes a gantry having a cavity for transporting a subject (subject) lying on a table 108, and an X-ray tube 109 and a collimator 110 having a slit for defining an X-ray irradiation range inside. Is provided. The X-ray generation amount generated by the X-ray tube 109 is controlled by the X-ray controller 111, and the opening / closing control of the slit of the collimator 110 is performed by the collimator controller 112, and these X-ray controller 111 and collimator controller 112 are controlled by the main controller 105. Will follow the instructions.
[0028]
In addition, a detection unit 113 that detects X-rays transmitted through the subject and a data collection unit 114 that collects data obtained from the detection unit 113 are also provided. The data collection unit 114 also performs data collection processing based on a control command from the main controller 105. The collected data is sent to the operation console 101 via the main controller 105 and the I / O controller 106, and an X-ray tomographic image reconstruction process is performed in the image reconstruction calculation device 104 via this.
[0029]
Further, the X-ray tube 109, the collimator 110, and the detection unit 113 are provided at positions facing each other with the hollow portion interposed therebetween, and are rotated around the hollow portion while maintaining the relationship. This rotation is performed by the rotation motor 115, and the drive control is performed by the motor controller 116. The table 108 on which the subject is placed is configured to be movable in the body axis direction of the subject (the direction perpendicular to the drawing), and is driven by the table motor 118 under the control of the table motor controller 117. . The main controller 105 also outputs various control signals to the motor controller 116 and the table motor controller 117. As described above, the main controller 105 sends various control command signals to the X-ray controller 111, the collimator controller 112, the motor controller 116, and the table motor controller 117 in accordance with the instruction control signal (command) from the operation console 101. A process of taking the timing of the output and its command signal and transferring the information obtained by the data collection unit 114 to the operation console 101 is performed.
[0030]
Each device constituting the operation console 101 is connected by a bus.
[0031]
The CPU 119 is a microprocessor as a central processing unit, and controls the entire X-ray CT system.
[0032]
The RAM 120 is a readable / writable memory that stores a program as a main memory of the CPU 119 and includes a temporary storage area for various data used as a work data area when the CPU 119 executes control. The ROM 121 is a read-only memory that stores invariant instruction sequences such as data for the CPU 119 to perform various controls and a boot program.
[0033]
The hard disk 122 is a storage medium that stores various data or stores an operating system (OS), an X-ray CT system control program, a scan plan processing program, and the like that are downloaded to the RAM 120 and executed as shown in the figure. Are connected to the disk controller 123. The disk controller 123 controls access to the hard disk 122.
[0034]
A monitor 124 that displays various setting information and CT images is connected to a video controller 126 that controls access to the video RAM 125 via a video RAM 125 that stores data to be displayed.
[0035]
A keyboard 127 and a mouse 128 are also connected as input devices for inputting various data and commands.
[0036]
The I / O controller 129 controls access to the external storage device 102 and the CT image forming apparatus 103.
[0037]
Note that a general-purpose workstation can be used as the operation console 101. As a storage medium used for the external storage device 102, a hard disk, a floppy disk, a magnetic tape, an MO, an IC memory card, a DVD-RAM, and the like are conceivable.
[0038]
In the above configuration, when the power is turned on, the operating system and the X-ray CT system control program stored in the hard disk 122 are read into the RAM 120 by the initial program loading function, the operating system is started, and the X-ray CT system can be used. It becomes a state.
[0039]
In this state, when the operator gives an instruction to start the scan plan processing program, the scan plan processing program stored in the hard disk 122 is read into the RAM 120 and the program operation starts.
[0040]
As described above, in the scan planning process, a scout scan and a scan condition setting process are performed.
[0041]
First, the subject is laid on the table 108 and a scout scan is performed. As described above, the scout scan is fixed without rotating the X-ray tube 109 and the detection unit 113 in a state where the X-ray tube 109 is directly above the subject and the detection unit 113 is directly below the subject. The X-ray is continuously irradiated while gradually moving the table 108 on which the subject is placed, and one X-ray two-dimensional image is obtained by arranging each measurement data in the irradiation order.
[0042]
When the scout scan is finished, a scan condition setting screen as shown in FIG. At this time, a scout image is displayed in the image area 401, and a line indicating a slice position is displayed based on a scan start position, a scan end position, and a slice thickness according to predetermined default values. Hereinafter, this screen displayed in the image area 401 is referred to as a localization screen. Then, the operator inputs each parameter using the mouse 128 and the keyboard 127 by the method described above while looking at the localization screen.
[0043]
Examples of lines indicating slice positions displayed on the localization screen by setting the above scan conditions are shown in FIGS. FIG. 5 is an example when [GantryTilt] is set. In order to make the figure easier to see, the display of the scout image is omitted, and the case where the breathing time is provided is shown once. As shown in the figure, the color of the line indicating the slice position in the section from the scan start position to the position where the breath is taken (the first breath holding section) is displayed in red, and after the breath is finished, the scan is finished from the scan restart position. The color of the line indicating the slice position in the section up to the position (second breath-holding section) is displayed in blue.
[0044]
As described above, since the color of the line indicating the slice position is changed for each breath holding section, the preview is clicked to switch to the preview screen as shown in FIG. It is possible to proceed with the scan planning process without confirming the above.
[0045]
When the scan condition setting process described above is completed, the scan plan process ends, and the contents set here are recorded in the RAM 120. When the operator instructs the start of the scanning process, the X-ray CT system control program read into the RAM 120 starts the scanning process based on the scan condition setting contents recorded in the RAM 120. At this time, in the set breath holding section, the table 108 moves at a speed calculated from the set condition, and the table 108 stops within the breath connecting time (BreatheTime) at the position where the breath connecting is provided. .
[0046]
Further, as means for improving the visibility by dividing the line indicating the slice position for each breath-holding section, not only the above-described color but also various forms are conceivable. Furthermore, it can also be used combining each form.
[0047]
For example, in FIG. 6, the number of the breath holding section is assigned below the line indicating the slice position for each breath holding section. In the example of FIG. 6, the slice position in the breath holding section 1 is illustrated. The line is numbered 1, the line indicating the slice position in the breath holding section 2 is numbered 2, and the line indicating the slice position in the breath holding section 3 is numbered 3.
[0048]
FIG. 7 shows a triangular mark displayed at a position where a breathing time is provided. FIG. 8 shows the position where the breathing time is provided in a scale. The set breath holding time (BreathHold) is displayed in the area between the scales. FIG. 9 is displayed in the form of a band graph, and the breath holding time (BreathHold) set in the same manner as in FIG. 8 is displayed. In addition, the breathing time (BreatheTime) is displayed at the position where the breathing time is provided.
[0049]
Further, the various means for improving the visibility as described above are not limited to the application to those which are divided every breath holding time. For example, as shown in FIG. 10, it is also possible to display by color-coded for each part to be measured.
[0050]
In the above-described localization screen, when the slice thickness is thin, it is difficult to see a line indicating all slice positions.
[0051]
【The invention's effect】
As described above, according to the present invention, since the color of the line indicating the slice position changes and is displayed for each breath holding section, there is no need to check the grouping result by switching to the preview screen as in the past. Since it is possible to proceed with the scan planning process, it is possible to provide an X-ray CT system, a control method thereof, and a storage medium that can perform the scan planning process more easily and reduce the burden on the operator. it can.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration of an X-ray CT system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a scan condition setting screen.
FIG. 3 is a diagram illustrating an example of a preview screen related to a grouping result.
FIG. 4 is a diagram illustrating an example of a line indicating a slice position displayed on a localization screen.
FIG. 5 is a diagram illustrating an example of a line indicating a slice position displayed on a localization screen when [GantryTilt] is set.
FIG. 6 is a diagram illustrating another example in which a line indicating a slice position is displayed on the localization screen while being divided for each breath holding section.
FIG. 7 is a diagram illustrating another example in which a line indicating a slice position is displayed on the localization screen while being divided for each breath holding section.
FIG. 8 is a diagram illustrating another example in which a line indicating a slice position is displayed on the localization screen while being divided for each breath holding section.
FIG. 9 is a diagram illustrating another example in which a line indicating a slice position is displayed on the localization screen while being divided for each breath holding section.
FIG. 10 is a diagram illustrating an example in which a line indicating a slice position is displayed in a color-coded manner for each region to be measured on a localization screen.

Claims (8)

In accordance with a predesignated condition, the subject is irradiated with X-rays from an X-ray tube and X-rays transmitted through the subject are detected from multiple directions, and an X-ray tomographic image of the subject is reproduced. An X-ray CT system comprising:
Means for acquiring a two-dimensional image of the subject by transporting the subject while the X-ray tube is fixed at a predetermined position;
Scan condition setting means for setting information on at least the conditions of the scan processing of the subject and the breath holding and breathing timing of the subject during the scanning processing ,
The scan condition setting means includes a two-dimensional image of the subject and a slice based on a scan start position, a scan end position, and a slice thickness set in the scan condition setting means superimposed on the two-dimensional image of the subject On the two-dimensional image in which the line indicating the position and the line indicating the slice position are superimposed, the position of the breath holding and breathing timing of the subject during the scanning process set by the scan condition setting unit is displayed. An X-ray CT system comprising display means for performing the above-described operation. 2. The X-ray according to claim 1, wherein the display unit displays the position of breath holding and breathing timing of the subject by changing a color of a line indicating a slice position for each breath holding section. CT system. The display means displays the position of breath holding and breathing timing of the subject by attaching a code for identifying the breath holding section to which the line indicating the slice position belongs in the vicinity of the line indicating each slice position. The X-ray CT system according to claim 1. 2. The X-ray CT system according to claim 1, wherein the display unit displays a position of timing of breath holding and breathing of the subject by attaching a predetermined mark to a position where the breathing is provided.  The X-ray CT system according to claim 1, wherein the display unit further displays a breath holding time in each breath holding section.  The X-ray CT system according to claim 1, wherein the display unit further displays a breathing time at a position where each breathing is provided. In accordance with a predesignated condition, the subject is irradiated with X-rays from an X-ray tube and X-rays transmitted through the subject are detected from multiple directions, and an X-ray tomographic image of the subject is reproduced. A method for controlling an X-ray CT system comprising:
Obtaining a two-dimensional image of the subject by transporting the subject while the X-ray tube is fixed at a predetermined position;
At least a scan condition setting step for setting information on the conditions of the scan processing of the subject and the breath holding timing of the subject during the scanning processing , and breath timing,
The scan condition setting step includes a two-dimensional image of the subject and a slice based on a scan start position, a scan end position, and a slice thickness set in the scan condition setting means superimposed on the two-dimensional image of the subject On the two-dimensional image in which the line indicating the position and the line indicating the slice position are superimposed, the position of the breath holding and breathing timing of the subject during the scanning process set by the scan condition setting unit is displayed. A control method for an X-ray CT system, comprising: a display step of: In accordance with a predesignated condition, the subject is irradiated with X-rays from an X-ray tube and X-rays transmitted through the subject are detected from multiple directions, and an X-ray tomographic image of the subject is reproduced. A storage medium storing a control program code for an X-ray CT system to be configured,
A program code for obtaining a two-dimensional image of the subject by conveying the subject while the X-ray tube is fixed at a predetermined position;
At least a program code of a scan condition setting step for setting information regarding the conditions of the scan processing of the subject and the breath holding and breathing timing of the subject during the scanning processing ,
The program code of the scan condition setting step includes a two-dimensional image of the subject and a scan start position, a scan end position, and a slice thickness set in the scan condition setting means superimposed on the two-dimensional image of the subject. On the two-dimensional image in which the line indicating the slice position and the line indicating the slice position are overlapped , the timing of breath holding and breathing timing of the subject during the scan processing set in the scan condition setting means A storage medium comprising a program code for a display process for displaying a position .

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