JP2002360558A - X-ray ct system and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save an operator labor for inputting a scanning range, to improve patient throughput and to reduce exposure dosage by providing an X-ray CT system whose starting position and finishing position of precise scanning is automatically set on an operation console and providing its controlling method. SOLUTION: The starting position and finishing position of scanning are easily measured by using a positioning light and the values of them are automatically set as scanning conditions. The operator operates a moving button 42 or 43 so as to match a desired scanning starting position with a light projecting position to adjust the position of a top plate and presses a Start Loc. button 44 to set the position of the top plate at that time as the scanning starting position. Similarly, the position of the top plate is adjusted to set a reference position and to set the scanning finishing position with a Ref. Loc. button 45 and an End Loc. button 46. The respective pieces of set positional information are transferred to the operation console.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an X-ray CT system for obtaining an X-ray tomographic image of a subject by X-ray irradiation and a control method thereof.

[0002]

2. Description of the Related Art X-ray CT (Computerized Tomography)
The system is roughly divided into a device having a donut-shaped cavity (generally called a gantry device), various control signals to the gantry device, and a signal (data) obtained from the gantry device. An operation console for reconstructing and displaying an X-ray tomographic image based on the information, and a table device for fixing and supporting the subject in the cavity of the gantry device and for transporting the subject toward the cavity. Is done.

A gantry apparatus is a rotating unit having a built-in X-ray source (X-ray tube) provided with the above-mentioned cavity interposed therebetween and an X-ray detector for detecting X-rays emitted from the X-ray source. Is provided.

An X-ray CT system uses an X-ray that has passed through a subject.
The main purpose is to collect projection data obtained from a line and reconstruct an X-ray tomographic image from the projection data. Specifically, first, the subject is laid on the above-mentioned table device and transported to the gantry device. Then, while rotating the X-ray tube, the rotating part (X-ray tube and X-ray detector) of the gantry device is rotationally driven to irradiate the subject with X-rays from different angles, and the subject at each angle is irradiated. X-rays transmitted through are detected. Then, the detected data (projection data)
Is received by the operation console, and an X-ray tomographic image is reconstructed by an arithmetic operation. The above-described series of steps for detecting X-rays is generally called scanning.

[0005] By the way, some preparations are required for performing a scan. First, it is necessary to perform positioning (positioning) of the subject with respect to the gantry device. In general, the positioning of an object is performed by a projector that emits visible light (also called a positioning light).
This is performed using For example, the table on which the subject is placed is moved to a projecting position of a positioning light arranged inside the gantry device, and a laser beam is projected from the projector onto the subject. Then, when the table position and / or the subject position is adjusted so that the laser beam matches a reference point (generally, a clinical reference position) corresponding to the target part of the subject, a predetermined reference point setting button is pressed. Pressing completes the alignment.

Next, it is necessary to make a plan for the scan conditions such as which area of the subject is to be scanned at what slice thickness and the conditions of the image reconstruction processing according to the diagnostic site and the diagnostic purpose. Such a plan is called a scan plan. An X-ray CT system generally provides a graphical user interface environment for making a scan plan from a scan plan screen displayed on a monitor of an operation console.

Conventionally, there has been known a scan planning technique in which a fluoroscopic image of a subject is displayed on a monitor, and the process is performed with reference to the fluoroscopic image. In order to obtain a fluoroscopic image of the subject, a so-called scout scan is performed. The scout scan is to obtain one fluoroscopic image from projection data obtained by continuously irradiating an X-ray while gradually transporting a subject with an X-ray tube fixed at a fixed angle. When the scout scan is completed, this perspective image (called a scout image) is displayed in a predetermined area of the scan plan screen. The operator proceeds with the scan plan while viewing the scout image.

Hereinafter, in the present specification, a scan for obtaining a main target X-ray tomographic image is referred to as a “main scan” to distinguish it from a scout scan. Further, the term “scan” simply includes a main scan and a scout scan.

[0009]

In the above-described scout scan, it is necessary to first set the start position and the end position. That is, the operator inputs the start position and the end position on the scout scan planning screen on the operation console. There is a problem that such an input operation is troublesome while an improvement in patient throughput is required.

In some cases, the start position and the end position of the scan are automatically set with a little margin compared to the standard protocol based on the set reference position. Since there is a problem that the exposure dose increases by the amount, it is desirable from the viewpoint of the exposure dose that the actual measurement value is input as accurately as possible.

There is also a demand that the range of the main scan (the start position and the end position of the main scan) should not be set based on the scout image, but should be visually determined in front of the actual subject. If the scan range can be set without performing the scout scan, the amount of exposure can be reduced accordingly. Also, in this case, the same input operation as described above is required, and there is a problem that such input operation is troublesome while improvement in patient throughput is required.

The present invention has been made in view of these problems, and provides an X-ray CT system in which an accurate scan start position and an accurate scan end position are automatically set on an operation console, and a control method thereof. It is therefore an object of the present invention to save the trouble of inputting the scan range, and to improve the patient throughput and reduce the exposure dose.

[0013]

To achieve the above object, for example, an X-ray CT system according to the present invention has the following arrangement. That is, a gantry device for performing a scan for collecting projection data by irradiating the subject with X-rays, and outputting information related to the scan to the gantry device and receiving the projection data from the gantry device. An X-ray CT system comprising: an operation console for reconstructing a fluoroscopic image and / or an X-ray tomographic image of the subject; and a table device having a top for mounting the subject,
A light projecting unit that emits visible light for setting a scan range; an adjusting unit that adjusts a relative position of the top plate with respect to the gantry device; and an adjusting unit that adjusts the relative position to adjust the relative position. First input means for inputting position information of one end of the scan range with the light projection position of the light means;
By adjusting the relative position with the adjusting means, the second input means for inputting position information of the other end of the scan range with the light emitting position of the light emitting means, and the first and second input means. Output means for outputting the input position information to the operation console.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(System Configuration) FIG. 1 is an external perspective view showing an X-ray CT system according to the embodiment. Reference numeral 100 denotes a gantry device for performing scanning, and 200 denotes a table device. Reference numeral 300 denotes an operation console. The operation console 300 is usually installed in a separate room from the gantry device 100 and the table device 200.

The gantry apparatus 100 is provided with an X-ray tube and an X-ray detector (not shown) at opposite positions across the cavity (opening) 101. While maintaining the positional relationship, the cavity 1
It is structured to rotate around 01. Therefore,
By driving the X-ray tube and performing the detection operation of the X-ray detector while performing the rotation while the subject is positioned in the cavity 101, X-ray irradiation from different directions (projection angles) can be performed. This makes it possible to detect (scan) transmitted X-rays.

A positioning light 102 for projecting a laser beam in a vertical direction for setting a reference position and a scan range is provided above the gantry apparatus 100.

Reference numeral 103 denotes an operation panel from which a slide operation of the table device 200 and setting of a scan range, which will be described later, can be performed.

The table device 200 has a structure in which a subject is placed on a top plate (also called a cradle) 201 and then the top plate 201 is transferred into the hollow portion 101 of the gantry device 100. The top plate 201 on which the subject is placed is made of a material having a high X-ray transmittance (for example, a material in which a foam material such as acrylic is wrapped with CFRP (Carbon Fiber Reinforced Plastics) or the like and reinforced).

The operation console 300 is a gantry device 1
00 and a function of receiving projection data transferred from the gantry apparatus 100 and reconstructing an X-ray tomographic image.

FIG. 2 is a side view of the gantry device 100, which is shown in cross section for easy understanding of the structure. In the figure, reference numeral 105 denotes an X-ray tube that is a source of X-rays, and reference numeral 108 denotes an X-ray detection unit that detects X-rays generated from the X-ray tube 105.
And a structure that rotates around the hollow portion 101 while maintaining a state of facing each other. The straight line connecting the X-ray tube 105 and the X-ray detection unit 108 (the one-dot chain line arrow A in the figure) is the scan position. Of course, it also has other components to function as a gantry device,
The description of them will be described later. As shown, the positioning light 102 is provided above the entrance of the cavity 101, and can emit laser light in the vertical direction indicated by the dashed arrow P. Here, it is assumed that the distance L between the projection position of the positioning light 102 and the scan position is known.

The position of the positioning light is not limited to this. For example, it may be provided inside the gantry device so that the light projection position matches the actual scan position. Further, instead of vertically projecting light from the upper portion of the cavity, the light may be horizontally projected by being provided on the side of the cavity.

FIG. 3 is a side perspective view of the table device 200. As shown in the drawing, a belt fixing portion 203 to which a belt 202 is fixed is provided near the rear end (far end when viewed from the gantry device) of the top plate 201.
The pulleys 204 and 205 are tightly attached. The rotating shafts of the pulleys 204 and 205 are configured to rotate by driving a table motor (not shown). Therefore, by rotating each motor, the top plate 201 can be slid toward the gantry device 110 or in the opposite direction.

FIG. 4 is a diagram showing an example of the operation panel 103 of FIG. In the figure, 41 is the positioning light 10
2 is a switch for switching ON / OFF. Reference numeral 42 denotes the top plate 201 on the gantry apparatus 100 side (hereinafter, “IN side”).
Button to instruct the user to slide
On the other hand, reference numeral 43 denotes a button for instructing the top plate 201 to move to a side away from the gantry device 100 (hereinafter, referred to as “OUT side”). This move button 42 or 43
While pressing, the top 201 moves in the designated direction, and stops moving when the button is released.

Reference numerals 44, 45, and 46 denote a scan start position (Start Loc.), A scan reference position (Ref. Loc.), And a scan end position (End Lo.
This is a button for setting c.).

Reference numeral 47 denotes an OK button for confirming the settings made by the setting buttons 44 to 46. 48
Is a cancel button for canceling the setting by the setting buttons 44 to 46.

Of course, it is possible to provide buttons for other purposes, but they are omitted here for the sake of simplicity.

Since the operation panel 103 includes the button for instructing the slide of the top plate 201, it may be provided on the table device 200.

FIG. 5 shows X in the embodiment shown in FIG.
It is a block configuration diagram of a line CT system.

The table device 200 moves the top plate 201 into the cavity 101 of the gantry device 100 by driving a table motor 206 as a motor for rotating the rotating shafts of the pulleys 204 and 205 shown in FIG. Transport. The driving of the table motor 206 is controlled by the table motor controller 207. Reference numeral 208 denotes a rotary encoder for detecting a rotation amount of the table motor 206. Using this encoder output, the top plate 201
Is measured. Reference numeral 209 denotes an interface for communicating with the gantry device 100.

The gantry device 100 has the following configuration, including a main controller 104 that controls the entire system.

Reference numeral 105a denotes an interface for performing communication with the operation console 300, and reference numeral 105b denotes an interface for performing communication with the table device 200. 1
Is a gantry having a cavity 101 for positioning a subject lying on a top plate 201 of a table device 200, and has therein an X-ray tube 105 (driven by an X-ray tube controller 106) which is an X-ray source. Controlled) collimator 1 having a slit for defining an X-ray irradiation range
07 is provided.

The gantry 1 has an X-ray detector 108 for detecting X-rays transmitted through the subject, and an X-ray detector 1
Also provided is a data collection unit 109 for collecting projection data obtained from the transmitted X-rays obtained in step 08. The X-ray tube 105 and the collimator 107 and the X-ray detection unit 108 are
1, that is, at positions opposing each other across the subject, and rotate around the cavity 101 in a state where the relationship is maintained. This rotation is performed by a rotation motor 111 driven by a drive signal from a motor controller 110.

A ROM 112 stores a program according to the flowcharts of FIGS. 6 and 7 described later. Reference numeral 113 denotes an RA which is used as a work area and secures an area for holding position information of the top plate 201 sent from a table device 200 described later.
M.

The main controller 104 analyzes various commands received via the interface 105a, and based on the analysis, executes the X-ray tube controller 106,
Various control signals are output to the motor controller 110, the data collection unit 109, and the table motor controller 207 of the table device 200. Further, after turning on the power, the main controller 104
The program according to the flowcharts of FIGS. 6 and 7 described below stored in M112 is loaded into the RAM 113,
Execute the program. Main controller 104
Further, it also performs a process of transmitting the projection data collected by the data collection unit 109 and the data stored in the RAM 113 to the operation console 300 via the interface 105a.

The operation console 300 is a so-called workstation, and as shown, a CPU 51 for controlling the entire apparatus, a ROM 52 for storing a boot program and the like, and a RAM 5 for functioning as a main storage.
3 and the following configuration.

The HDD 54 is a hard disk drive, and in addition to the OS, a program for planning a scan, various instructions to the gantry device 100,
A diagnostic program for reconstructing an X-ray tomographic image based on data received from the gantry device 100 is stored. The VRAM 55 is a memory for expanding the image data to be displayed. The image data and the like can be displayed on the CRT 56 by expanding the image data and the like. 57 and 58 are a keyboard and a mouse for performing various settings. 59 is a gantry device 1
This is an interface for communicating with 00.

Hereinafter, the gantry device 10 according to the embodiment will be described.
The setting process of the scan range and the reference position by the main controller 104 of 0 will be described with reference to the flowcharts of FIGS. As described above, the program according to the flowcharts of FIGS.
2 is stored in the RAM 1 after the power is turned on.
13 is executed by the main controller 104. Also, as described above, R
The AM 113 has an area for holding the position information of the top plate 201, and the data in this area is initialized after the power is turned on.

If only a scan range is to be set purely, only the start and end positions of the scan need to be set, and it can be said that the setting of the reference position is not always necessary. However, in a scan plan performed on the operation console, it is common to specify the scan start position and the end position with the reference position as the origin, and therefore, in the present embodiment, the reference position setting processing is also included.

First, after the power is turned on, the operator lays the subject on the top board 201 at a predetermined home position (for example, a limit position on the OUT side). Thereafter, the main controller 104 carries the top plate 201 into the hollow portion 101 of the gantry device 100 in response to the operator pressing the IN-side movement button 42 of the operation panel 103 (Step S1).

Next, in step S2, the operation panel 103
Positioning light ON by the changeover switch 41
Is turned on, the positioning light 102 is turned on.

The operator operates the move button 42 or 43 so that one end (eg, start position) of the desired scan range matches the light projection position. In step S3, the position of the top board 201 is adjusted according to this operation. Less than,
The position of the top plate 201 (for example, the amount of movement from the home position) is z1. The position z1 is specified from the output of the encoder 208.

After that, the operator presses the Start Loc. Button 44 when the operator adjusts the position to a desired position. In step S4, in response to the pressing of the Start Loc. Button 44, the top plate 201 at that time is pressed. Position z1
Is stored in the RAM 113 as scan start position information S.

Subsequently, the operator presses the move button 4 so that the reference position of the desired scan range matches the light projection position.
Operate 2 or 43. In step S5, the position of the top plate 201 is adjusted according to this operation.

After that, the operator presses the Ref. Loc. Button 45 when the operator has adjusted the position to the desired position. In step S6, in response to the pressing of the Ref. Loc. The position z2 of the plate 201 is stored in the RAM 113 as reference position information R.

Further, the operator operates the move button 42 or 43 so that the other end (for example, the end position) of the desired scan range matches the light projection position. Step S7
Then, the position of the top plate 201 is adjusted according to this operation.

After that, the operator presses the End Loc. Button 46 after adjusting the position to the desired position. In step S8, in response to the pressing of the End Loc. 201 position z3
Is stored in the RAM 113 as the reference position information E.

When the OK button 47 is pressed, the scan start position S and end position E stored in the RAM 113 are converted into relative positions (displacement amounts) with respect to the reference position R in step S9 shown in FIG. . For example, S is S
-R is updated and E is updated by ER. Then, the position data S, E, and R are transferred to the operation console 300 (Step S10).

Although not shown, if the cancel button 48 is pressed before the OK button 47 is pressed,
The contents of the position data stored in the RAM 113 are cleared, and the process returns to step S3.

In step S10, prior to the transfer to the operation console 300, it is evaluated whether or not the position data S, E, and R are each data having a value within an appropriate range. May be transferred to the operation console 300 only when is within the appropriate range. If any of the data is not within the proper range, it is preferable that the transfer is not performed and a warning is issued to the operator. For example, by evaluating whether or not the position data S, E, and R remain at the initial values, if there is data having the initial values, the reference position, the scan start position, and the end position are changed. It is determined that all the transfer has not been performed, and the transfer is not performed. As a means for issuing a warning, for example, generation of a warning sound, display by an LED (not shown) provided on the operation panel, or the like can be considered.

Note that the processes in steps S3 to S8 are based on the premise that the operator performs a setting operation in the order of the scan start position, the reference position, and the scan end position. The setting operation is not limited to this, and the operator can perform the setting operation in an arbitrary order.

Next, the operator operates the operation console 300 provided in another room. The processing procedure in the operation console 300 is substantially as shown in the flowchart of FIG.

First, in step S21, the above step S
10, position data S from the gantry device 100,
E and R are received. These position data are used as initial values of scan positions in a scout scan plan as described later.

Next, a scout scan is planned (step S22). The scout scan condition setting and execution command are performed via a setting screen 90 (displayed on the CRT 56 of the operation console 400) as shown in FIG. 9, for example. Here, in the “start position” and the “end position” of the scout scan setting column 91, the start position S and the end position E of the scout scan with respect to the received reference position data R are displayed as initial values (default values).
In the illustrated example, “R−20” and “R + 30” are displayed, respectively. Since these values are based on the values actually measured by the processes of FIGS. 6 and 7, the cases that need to be changed will be considerably reduced. In addition, a tube voltage and a tube current applied to the X-ray tube 105 and a projection angle can be set.

Upon completion of the scout scan plan, FIG.
After the start button 92 is clicked,
The gantry device 100 is instructed to execute the scout scan under the set conditions (step S23). Thereafter, projection data as a result of the scout scan transferred from the gantry device 100 is received (step S24).

Next, in step S25, a plan for the main scan is made. Although not shown, the main scan is also planned via a known setting screen. A scout image based on the projection data received in step S24 is also displayed on the setting screen, and various parameters are set based on the scout image. The setting items include, for example, a slice thickness, a current value given to the X-ray tube 105, and step S2 described later.
And the like for the image reconstruction performed in step S8.

When the main scan plan is completed, a predetermined operation of an operator's mouse, keyboard and the like is used as a trigger.
A main scan instruction is issued (step S26). Thereafter, a scan performed according to a known procedure is performed in the gantry device 100, and the projection data transferred from the gantry device 100 is received (step S27).
An X-ray tomographic image reconstruction process is performed based on the projection data (step S28), and output (display or print) is performed (step S29).

As described above, according to the embodiment of the present invention, it is possible to easily measure the scan start position and the scan end position by using the positioning light which has conventionally been used only for setting the reference position. Became. That is, the operator can set the scan start position and the end position in the positioning process of the reference position of the subject. This saves the operator the trouble of actually measuring the desired scan start position and end position with a measure or the like, and then inputting those numerical values on the operation console.

In some models, the scan start position and the scan end position are automatically set with some margin compared to the standard protocol based on the set reference position. However, there has been a problem that the exposure dose increases by a margin. However, according to the embodiment of the present invention, since the start position and the end position of the scan can be easily measured using the positioning light, it is not necessary to rely on such automatic setting, and the exposure dose can be reduced. It can be minimized.

By the way, in the series of processes shown in FIG. 7, the operation console 300 converts the position data (R, S, E) received from the gantry apparatus 100 on the assumption that a scout scan is performed prior to the main scan. ,
The scan reference position, the start position, and the end position in the scout scan are set as default values. However, in some cases, for example, in a mass screening, the main scan is directly performed or the main scan is executed without performing the scout scan. In such a case (that is, when the planning and execution of the scout scan have not been performed), the operation console 300 receives the position data (R, S,
E) is a scan reference position in the main scan,
It may be set as default values of the start position and the end position.

The process of converting the scan start position and the end position into relative values in step S9 in FIG. 6 may not be performed here, but may be performed on the operation console 300 after being transferred to the operation console 300.

Further, in the above-described embodiment, the top plate of the table device is slid to adjust the positional relationship between the gantry device and the top plate with respect to the gantry device having the fixed installation position. The description has been given on the premise of an X-ray CT system of a type in which setting and scanning are performed. However, the present invention provides an X-ray CT of this type.
Not limited to the system, on the other hand, by moving the gantry device with respect to the table device having the fixed top position and adjusting the positional relationship between the two, the scan range is set and the scan is performed. It is also applicable to a line CT system. That is, it can be said that the present invention can be applied to an X-ray CT system having means for adjusting the relative position of the tabletop with respect to the gantry device.

[0063]

As described above, according to the present invention,
Provided is an X-ray CT system in which an accurate scan start position and an accurate scan end position are automatically set on an operation console, and a control method therefor. Therefore, it is possible to save the trouble of inputting a scan range, and reduce the patient throughput. It is possible to improve and reduce the exposure dose.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an X-ray CT system according to an embodiment.

FIG. 2 is a side view of the gantry device according to the embodiment.

FIG. 3 is a side view of the table device according to the embodiment.

FIG. 4 is a diagram illustrating an example of an operation panel according to the embodiment.

FIG. 5 is a block diagram of an X-ray CT system according to the embodiment.

FIG. 6 is a flowchart illustrating a procedure for setting a scan range and a reference position according to the embodiment.

FIG. 7 is a flowchart illustrating a procedure for setting a scan range and a reference position according to the embodiment.

FIG. 8 is a flowchart illustrating a processing procedure in the operation console according to the embodiment.

FIG. 9 is a diagram illustrating an example of a scout scan setting screen according to the embodiment.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Katsumi Atsu 4-7, Asahigaoka, Hino-shi, Tokyo 127 GE Yokogawa Medical System Co., Ltd. F-term (reference) 4C093 AA22 CA18 CA34 EA17 EC46

Claims (9)

[Claims] 1. A gantry apparatus for performing a scan for collecting projection data by irradiating a subject with X-rays, outputting information about the scan to the gantry apparatus, and outputting the projection data from the gantry apparatus. An X-ray CT system including an operation console configured to receive the X-ray image and reconstructs a fluoroscopic image and / or an X-ray tomographic image of the subject, and a table device having a top plate on which the subject is mounted. Light emitting means for emitting visible light for setting; adjusting means for adjusting a relative position of the top plate with respect to the gantry device; and adjusting the relative position with the adjusting means, whereby the light emitting means A first input unit for inputting position information of one end of the scan range with the light projecting position; and adjusting the relative position by the adjusting unit, the light projecting position of the light projecting unit is also adjusted. Second input means for inputting the position information of the other end of the scan range, and output means for outputting the respective position information input by the first and second input means to the operation console. An X-ray CT system characterized by the above-mentioned. 2. The apparatus according to claim 1, further comprising: third input means for inputting scan reference position information based on a light projecting position of the light projecting means by adjusting the relative position by the adjusting means. The X-ray CT system according to claim 1, wherein the scan reference position information input by a third input unit is output to the operation console. 3. The output means converts each position information input by the first and second input means into relative position information with respect to the scan reference position input by the third input means. The X-ray CT system according to claim 2, wherein the X-ray CT system outputs the data. 4. The output means includes a determination means for determining whether or not each of the position information to be output is within a predetermined appropriate range. 4. The X-ray CT system according to claim 1, wherein when it is determined that the position information is not within the predetermined appropriate range, the output of the position information to the operation console is stopped. 5. 5. The X-ray CT system according to claim 4, further comprising a notifying unit for notifying that the output has been stopped. 6. The operation console includes a scan condition setting unit for setting a scan start position and a scan end position, and initial values of the scan start position and the scan end position are set to respective position information from the output unit. The X-ray CT system according to any one of claims 1 to 5, wherein the X-ray CT system is set on the basis of: 7. A gantry device for performing a scan for collecting projection data by irradiating a subject with X-rays, outputting information about the scan to the gantry device, and outputting the projection data from the gantry device. An operation console for receiving an X-ray tomographic image and reconstructing an X-ray tomographic image, a table device having a table for mounting a subject, a light projecting unit for projecting visible light for setting a scan range, An adjusting means for adjusting a relative position of the plate with respect to the gantry device, wherein the adjusting means adjusts the relative position so that the light emitting position of the light emitting means is adjusted. A first input step of inputting position information of one end of a scan range, and adjusting the relative position by the adjustment unit, so that the scan range is determined by the light projection position of the light projection unit A second input step of inputting the position information of the other end; and an output step of outputting the respective position information input in the first and second input steps to the operation console. An X-ray CT system control method. 8. A gantry device for performing a scan for collecting projection data by irradiating an object with X-rays, outputting information about the scan to the gantry device, and outputting the projection data from the gantry device. An operation console for receiving an X-ray tomographic image and reconstructing an X-ray tomographic image, a table device having a table for mounting a subject, a light projecting unit for projecting visible light for setting a scan range, An adjusting means for adjusting a relative position of the plate with respect to the gantry device, a program for controlling an X-ray CT system, wherein the adjusting means adjusts the relative position, whereby a light emitting position of the light emitting means is adjusted. And a program code of a first input step of inputting position information of one end of the scan range with the adjusting means, and adjusting the relative position by the adjusting means. A program code of a second input step of inputting position information of the other end of the scan range with the light position, and an output step of outputting the respective position information input in the first and second input steps to the operation console A program characterized by having a program code of 9. A storage medium storing the program according to claim 8.