JP4664551B2 - X-ray CT system, operation console, control method therefor, and phantom - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray CT system, an operation console, a control method therefor, and a phantom.
[0002]
[Prior art]
When a scan plan is input in the X-ray CT system, a slice thickness included in the scan plan is also input. Here, the scan plan refers to irradiating a predetermined part of the subject with X-rays, detecting X-rays transmitted through the predetermined part, and obtaining projection data of the predetermined part from the detected amount of X-rays ( Information such as the amount of X-rays and slice thickness for scanning. The X-ray CT system scans the subject with a slice thickness according to the input slice thickness. However, the input slice thickness may be slightly different from the slice thickness when actually scanning.
[0003]
Therefore, for example, for checking, a slice thickness at the time of actual scanning may be measured and compared with the input slice thickness. Conventionally, when this measurement is performed, a phantom having a wire in a predetermined posture at a predetermined position is used. FIG. 1 shows an X-ray CT system viewed from the side when measuring the slice thickness using this phantom.
[0004]
In the figure, reference numeral 100 denotes a table for laying a patient. A phantom 101 includes a wire 102 therein and is fixed to one end of the table 100. The wire 102 is provided at a predetermined position in the phantom 101 at a predetermined angle θ. Reference numeral 103 denotes a gantry that emits X-rays from 360 degrees around the wire 102 in the phantom 101 (360 degrees around the z axis in the figure) and outputs projection data of the wire 102. This projection data is transmitted to an operation console (not shown), and measurement processing described later is performed.
[0005]
FIG. 2 shows a slice thickness measurement method using this phantom. In FIG. 2A, reference numeral 102 denotes a wire, which is fixed at a predetermined position in the phantom housing at an angle θ. This wire 102 is irradiated with X-rays with x slice thicknesses (X-ray beams at both ends are 201 and 202, respectively) to obtain projection data, and this projection data is used to reconstruct an image on an operation console, for example. When the processing is performed, a captured image 203 of the wire 102 having a length y is obtained as shown in FIG. This is because the length between the upper end point and the lower end point intersecting the wire 102 is y when the X-ray beams 201 and 202 pass through the wire 102. Then, using the length y on the image shown in FIG. 5B and the inclination θ of the wire 102, the slice thickness x was obtained according to the following equation.
[0006]
x = y / tan θ (1)
[Problems to be solved by the invention]
However, the conventional slice thickness measurement method ignores the wire diameter of the wire 102. FIG. 3 shows the principle. In the figure, reference numeral 300 denotes a wire, and the above-mentioned upper end point and lower end point are indicated by A and B, respectively. In this case, the actual slice thickness x is expressed by the following equation.
[0007]
x = y / tan θ ′ (2)
Therefore, when the wire diameter is taken into consideration, the result (slice thickness) different from the equation (1) is obtained due to the difference between θ and θ ′, and the obtained slice thickness includes an error. turn into. In addition, this tendency becomes more conspicuous as the slice thickness to be obtained is thinner (in the case of Thin Slice having a slice thickness of 1 mm or less, for example, 0.5 mm or 0.625 mm). In addition, as shown in FIG. 3, when the wire diameter approaches 0 as much as possible, the difference between θ and θ ′ decreases, so it is ideal to measure the slice thickness using a wire whose wire diameter is as close to 0 as possible. .
[0008]
In order to cope with this, the slice thickness is measured using a wire having a wire diameter of 50 μm in part, but the strength of this wire is very small and is not generally distributed.
[0009]
This invention is made | formed in view of this problem, and it aims at calculating | requiring the slice thickness in case a wire diameter is infinitely close to zero.
[0010]
[Means for Solving the Problems]
In order to achieve the object of the present invention, for example, an X-ray CT system of the present invention comprises the following arrangement.
[0011]
That is, an X-ray tube that irradiates X-rays, a phantom that includes a slice thickness measurement wire so as to form a predetermined angle with the X-rays that the X-ray tube irradiates, and a detector that detects X-rays. A gantry device that outputs projection data of the wire by performing a scan in which the detector detects X-rays irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire An X-ray CT system comprising an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The operation console is
For each of the plurality of slice measurement wires that are parallel to each other and have different diameters, the gantry apparatus is used for scanning using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom. First calculating means for determining an estimated slice thickness;
Second calculation means for creating relationship information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is substantially 0 using the relationship information With.
[0012]
In order to achieve the object of the present invention, for example, a phantom of the present invention comprises the following arrangement.
[0013]
That is, a phantom including a slice thickness measuring wire so as to form a predetermined angle with the X-ray,
A plurality of slice thickness measuring wires that are parallel to each other and have different diameters are provided so as to form a predetermined angle with the X-ray.
[0014]
In order to achieve the object of the present invention, for example, an operation console of the present invention comprises the following arrangement.
[0015]
That is, from the projection data of the wire in the phantom that is provided with the wire for slice thickness measurement so as to form a predetermined angle with the X-ray obtained from the gantry device based on the instruction to scan the gantry device An operation console that generates a captured image of the wire and measures a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The operation console is
Used when the gantry apparatus performs a scan using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom for each of the plurality of parallel measurement wires having different diameters. First calculating means for determining an estimated slice thickness estimated to have been
Second calculation means for creating relationship information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is substantially 0 using the relationship information With.
[0016]
In order to achieve the object of the present invention, for example, an X-ray CT system of the present invention comprises the following arrangement.
[0017]
That is, an X-ray tube that irradiates X-rays, a phantom that includes a slice thickness measurement wire so as to form a predetermined angle with the X-rays that the X-ray tube irradiates, and a detector that detects X-rays. A gantry device that outputs projection data of the wire by performing a scan in which the detector detects X-rays irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire An X-ray CT system comprising an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to
The operation console is
Storage means for storing relationship information between an estimated slice thickness estimated for each wire for slice measurement parallel and different in diameter, and the wire diameter of the wire,
First calculation means for obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan, using a captured image of the wire included in the phantom and an angle of the wire with respect to the phantom;
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. Second calculating means for obtaining a slice thickness in the case of zero.
[0018]
In order to achieve the object of the present invention, for example, an operation console of the present invention comprises the following arrangement.
[0019]
That is, from the projection data of the wire provided in the phantom provided with the wire for slice thickness measurement so as to form a predetermined angle with the X-ray obtained from the gantry device based on the instruction to scan. An operation console for generating a captured image of the wire and measuring a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
Storage means for storing relationship information between an estimated slice thickness estimated for each wire for slice measurement parallel and different in diameter, and the wire diameter of the wire,
First calculation means for obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan using a captured image of the wire included in the phantom and an angle of the wire with respect to a predetermined direction of the phantom When,
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. Second calculating means for obtaining a slice thickness in the case of zero.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail according to preferred embodiments with reference to the accompanying drawings.
[0021]
[First Embodiment]
FIG. 4 is a block diagram of the X-ray CT system of this embodiment. As shown in the figure, the present system includes a gantry apparatus 100 that integrally attaches an X-ray irradiation to a subject and an X-ray detection mechanism for detecting X-rays transmitted through the subject, and various operations on the gantry apparatus 100. The operation console 200 is configured to perform setting and reconstruct and display an X-ray tomogram based on data output from the gantry apparatus 100.
[0022]
The gantry apparatus 100 has the following configuration including the main controller 1 that controls the entire system.
[0023]
2 is an interface for communicating with the operation console 200, and 3 has a cavity for transporting a subject (patient) lying on the table 12 (hereinafter also referred to as z-axis in a direction perpendicular to the drawing). The gantry includes an X-ray tube 4 that is an X-ray generation source (driven and controlled by the X-ray tube controller 5), a collimator 6 having a slit for defining an X-ray irradiation range, and a collimator 6 A motor 7a that is a motor for adjusting the slit width that defines the X-ray irradiation range is provided. The driving of the motor 7a is controlled by the collimator controller 7.
[0024]
The gantry 3 also includes an X-ray detection unit 8 that detects X-rays transmitted through the subject, and a data collection unit 9 that collects projection data obtained from the transmitted X-rays obtained by the X-ray detection unit 8. The X-ray tube 4 and the collimator 6 and the X-ray detection unit 8 are provided at positions facing each other with the cavity portion sandwiched therebetween, that is, with the subject sandwiched therebetween, and rotate around the gantry 3 while maintaining the relationship therebetween. It comes to move. This rotation is performed by the rotary motor 10 driven by a drive signal from the motor controller 11. The table 12 on which the subject is placed is transported in the z-axis direction, and is driven by the table motor 13. Moreover, the phantom 20 in this embodiment is attached to the table 12 as shown in FIG. The phantom 20 will be described later.
[0025]
The main controller 1 analyzes various commands received via the interface 2, and based on the analysis, the X-ray tube controller 5, collimator controller 7, motor controller 11, table motor controller 14, and data collection unit 9 On the other hand, various control signals are output. The main controller 1 also performs a process of sending the projection data collected by the data collection unit 9 to the operation console 200 via the interface 2.
[0026]
The operation console 200 is a so-called workstation, and includes the following configuration including a CPU 51 that controls the entire apparatus, a ROM 52 that stores a boot program, and a RAM 53 that functions as a main storage device, as shown in the figure.
[0027]
The HDD 54 is a hard disk device. In addition to the OS and a slice thickness measurement program described later, the HDD 54 gives various instructions to the gantry device 100 and reconstructs an X-ray tomogram based on data received from the gantry device 100. A program is stored for this purpose. The VRAM 55 is a memory for developing image data to be displayed, and can be displayed on the CRT 56 by developing the image data or the like here. Reference numerals 57 and 58 denote a keyboard and a mouse for performing various settings. Reference numeral 59 denotes an interface for communicating with the gantry apparatus 100.
[0028]
FIG. 5 shows a basic configuration of the phantom 20 in the present embodiment. In the figure, reference numeral 500 denotes a phantom casing. In the casing 500, three wires 501, 502, and 503 having different wire diameters are parallel to different positions (in a predetermined direction, for example, in the z-axis direction in the figure). It is provided at an angle θ). These wires are irradiated with X-rays from the X-ray tube 4 with the same slice thickness, and the slice thickness is obtained in accordance with the equation (1) as described above (because this slice thickness is not a true value, hereinafter referred to as an estimated slice thickness). ) Find x. Assume that the estimated slice thicknesses obtained using the wires 501, 502, and 503 are x1, x2, and x3, respectively. As described above, the estimated slice thicknesses x1, x2, and x3 are obtained by ignoring the wire diameters of the wires 501, 502, and 503, and therefore include errors and are not true values.
[0029]
Therefore, as shown in FIG. 6, the horizontal axis represents the wire diameter, the vertical axis represents the estimated slice thickness, and the estimated slice thickness obtained from each wire 501, 502, 503 in this coordinate system (in the figure, 601, 602). 603) is plotted. Then, a straight line to be interpolated using these points 601, 602, 603 is obtained. This straight line is a relational expression between the wire diameter and the estimated slice thickness, and is assumed to be a straight line here. The method for obtaining this straight line is not particularly limited. For example, the straight line may be obtained using the least square method using the coordinate values of the points 601, 602, and 603.
[0030]
Moreover, as long as four or more points are plotted, the line is not limited to a straight line. That is, if four or more points are used, curve interpolation such as spline interpolation may be used.
[0031]
After obtaining a straight line to be interpolated using these three points 601, 602 and 603, a y-intercept, that is, a y-coordinate value at the point 604 is obtained. That is, since the y coordinate value is a slice thickness when the wire diameter is 0, the slice thickness is an ideal true value.
[0032]
As described above, an ideal slice thickness (a slice thickness obtained using a wire having a wire diameter of 0) can be obtained. In this embodiment, three wires are provided in the phantom, but the number is not limited to this. That is, by providing more wires, it takes more time to obtain the estimated slice thickness for all wires, but the data for obtaining the straight line shown in FIG. 6 increases, so the straight line can be obtained more accurately. .
[0033]
FIG. 7 shows a flowchart of processing when the above-described slice thickness is measured using the X-ray CT system in the present embodiment. A phantom is attached to one end of the table of the gantry apparatus 100 before the processing according to this flowchart is executed. Further, it is assumed that the angle θ of each wire in the phantom 20 is known.
[0034]
First, on the operation console 200, a scan plan including a slice thickness is input using the keyboard 57 and the mouse 58 (step S701), and the input scan plan is transmitted to the gantry apparatus 100 (step S702). The gantry apparatus 100 receives the scan plan (step S751), and performs a scan based on the received scan plan (step S752). This scan is performed on the wire provided in the phantom 20. Then, the projection data of each wire obtained as a result of the scan is transmitted to the operation console 200 (step S753).
[0035]
The operation console 200 receives the projection data of each wire transmitted from the gantry apparatus 100 (step S703), performs image reconstruction processing on the received projection data (step S704), and captures the captured image of each wire. obtain. Next, the length of each wire (for example, the length y of the wire image in FIG. 2) is measured from the obtained captured image of each wire (step S705). Although this measurement method is not particularly limited, for example, it may be calculated by the operation console 200 based on the number of pixels constituting the wire image, the photographing magnification, and the like.
[0036]
And as above-mentioned, the estimated slice thickness with respect to each wire is calculated | required using Formula (1) (step S706), the straight line illustrated in FIG. 6 is calculated | required by making (wire diameter, estimated slice thickness) into coordinate information, and this straight line Y slice, that is, the slice thickness when the wire diameter is 0 is obtained (step S707).
[0037]
[Second Embodiment]
In the first embodiment, the slice thickness is measured using a plurality of (different diameters) wires. However, in this embodiment, a plurality of relational expressions between the wire diameter and the estimated slice thickness obtained by the slice thickness measurement method shown in the first embodiment are obtained by measuring a plurality of different slice thicknesses. Is stored in the HDD 54 of the operation console 200.
[0038]
FIG. 8 shows an example of this table. This table describes the slope of a straight line with respect to each slice thickness when the relational expression is a straight line. The table will be described taking the straight line shown in FIG. 6 as an example. The slope of the straight line passing through the points 601, 602, 603, and 604 with respect to the y-intercept (slice thickness) of the point 604 is described. When the relational expression is a curve, for example, a point on the curve may be sampled, and data of the sampled point may be described in this table.
[0039]
Therefore, when the estimated slice thickness is obtained using a single wire, the straight line closest to the point where the coordinates are expressed as (wire diameter of this wire, obtained estimated slice thickness) is shown in FIG. Selection is made from a plurality of straight lines specified by the slice thickness and inclination data.
[0040]
FIG. 9 shows the straight line closest to the point where the coordinates are represented as (wire diameter of this wire, calculated estimated slice thickness) when the estimated slice thickness is measured using one wire. A method for selecting from a plurality of straight lines specified by the data shown in FIG.
[0041]
In the figure, straight lines 901, 902, and 903 corresponding to different slice thicknesses (a plurality of straight lines specified by slice thicknesses and inclinations described in the table shown in FIG. 8) are used. Here, when the estimated slice thickness is obtained using a single wire, a point having the coordinates of (the wire diameter of the wire and the obtained estimated slice thickness) is defined as 904. In this case, since the closest straight line is 902, the y-intercept of the straight line 902 is an ideal slice thickness in this case.
[0042]
In the X-ray CT system in the present embodiment, a flowchart of processing when measuring the slice thickness using one wire is shown in FIG. Note that the flowchart shown in FIG. 10 is different from that shown in FIG. 7. In the flowchart shown in FIG. 10, the slice thickness is measured using one wire, and the processing in step S1007 is new. It is a point added to. In step S1007, using the estimated slice thickness obtained in step S1006, the straight line closest to the point whose coordinates are represented by (the wire diameter of this wire, the obtained estimated slice thickness) is selected from the table illustrated in FIG. . In step S1008, the y-intercept of the selected straight line is obtained.
[0043]
Therefore, when the table shown in FIG. 8 is used, an ideal slice thickness can be obtained using one wire.
[0044]
[Other Embodiments]
Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and to perform a computer (or CPU or CPU) of the system or apparatus. (MPU) can also be realized by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read out by the computer (operation console), not only the functions of the above-described embodiments are realized, but also an operating system running on the computer based on the instruction of the program code ( OS) etc. perform part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0045]
When the present invention is applied to the above-mentioned storage medium, the storage medium stores program codes corresponding to the above-described (a part or all of the flowcharts shown in FIGS. 7 and 10).
[0046]
As a storage medium for storing such a program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Furthermore, it may be downloaded via a medium called a network (for example, the Internet).
[0047]
【The invention's effect】
As described above, according to the present invention, the slice thickness when the wire diameter is as close to 0 as possible can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an X-ray CT system viewed from the side when measuring a slice thickness using a phantom.
FIG. 2 is a diagram showing a conventional slice thickness measurement method using a phantom.
FIG. 3 is a diagram for explaining that a conventional slice thickness measurement method ignores the wire diameter.
FIG. 4 is a block configuration diagram of the X-ray CT system in the first embodiment of the present invention.
FIG. 5 is a diagram showing a basic configuration of a phantom 20 in the first embodiment of the present invention.
FIG. 6 is a graph showing a relationship between a wire diameter and an estimated slice thickness.
FIG. 7 is a flowchart of processing when slice thickness is measured using the X-ray CT system according to the first embodiment of the present invention.
FIG. 8 is a diagram illustrating an example of a table in which a relational expression between a wire diameter and an estimated slice thickness is described for each of a plurality of different slice thicknesses.
FIG. 8 shows a straight line closest to a point where coordinates are expressed as (wire diameter of this wire, calculated estimated slice thickness) when the estimated slice thickness is obtained using one wire. It is a figure explaining the method to select from a plurality of straight lines specified by performed data.
FIG. 10 is a flowchart of processing when measuring a slice thickness using the X-ray CT system according to the second embodiment of the present invention.

Claims (28)

An X-ray tube for irradiating X-rays, a phantom including a wire for slice thickness measurement so as to form a predetermined angle with the X-rays irradiated by the X-ray tube, and a detector for detecting X-rays, A gantry device that outputs projection data of the wire by performing scanning in which the detector detects X-rays that are irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire An X-ray CT system comprising an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The operation console is
For each of the plurality of slice measurement wires that are parallel to each other and have different diameters, the gantry apparatus is used for scanning using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom. First calculating means for determining an estimated slice thickness;
Second calculation means for creating relationship information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is substantially 0 using the relationship information An X-ray CT system comprising: The first calculation means is used when the gantry apparatus performs scanning using the length of the photographed wire and the angle of the wire with respect to a predetermined direction of the phantom in the photographed image of the wire. The X-ray CT system according to claim 1, wherein an estimated slice thickness is obtained. It is a point having the coordinates of the wire diameter of the wire and the estimated slice thickness obtained by the first calculation means using the wire,
The second calculation means obtains, as the relation information, a straight line or a curve interpolated using the points corresponding to the slice measuring wires that are parallel to each other and have different diameters. The X-ray CT system according to claim 1, wherein the X-ray CT system is calculated as a slice thickness when the slice thickness is approximately zero. Furthermore, the operation console
Storage means for storing a plurality of the relationship information calculated by the second calculation means in association with a slice thickness when the wire diameter is substantially zero;
Corresponding relation information is selected from the storage means using the wire diameter of the attention wire and the estimated slice thickness obtained by the first calculation means using the attention wire, and further corresponds to the relation information. The X-ray CT system according to any one of claims 1 to 3, further comprising selection means for selecting a slice thickness from the storage means when the wire diameter is approximately zero. The storage means stores the slope of the straight line calculated by the second calculating means in association with the slice thickness when the wire diameter represented by the y-intercept of the straight line is approximately zero. The X-ray CT system according to claim 4. From the straight line group specified by the slope of the straight line stored by the storage means and the slice thickness when the wire diameter represented by the y-intercept of the straight line is approximately 0, the selection means is configured to obtain the wire diameter of the wire of interest. And the straight line closest to the point having the estimated slice thickness obtained by the first calculation means using the wire of interest as a coordinate is selected from the straight line group, and the y-intercept of the selected straight line is approximately the wire diameter. The X-ray CT system according to claim 4, wherein the X-ray CT system is obtained as a slice thickness when 0. A phantom including a slice thickness measuring wire so as to form a predetermined angle with an X-ray,
A phantom comprising a plurality of slice thickness measurement wires that are parallel to each other and have different diameters so as to form a predetermined angle with the X-ray. A scan is instructed to the gantry apparatus, and the wire is obtained from projection data of the wire in a phantom provided with a slice thickness measurement wire so as to form a predetermined angle with the X-ray obtained from the gantry apparatus based on the instruction. An operation console for measuring a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The operation console is
For each of the plurality of slice measurement wires that are parallel to each other and have different diameters, the gantry apparatus is used for scanning using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom. First calculating means for determining an estimated slice thickness;
Second calculation means for creating relationship information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is substantially 0 using the relationship information And an operation console. Storage means for storing a plurality of the relationship information calculated by the second calculation means in association with the slice thickness when the wire diameter is substantially zero;
Corresponding relation information is selected from the storage means using the wire diameter of the attention wire and the estimated slice thickness obtained by the first calculation means using the attention wire, and further corresponds to the relation information. The operation console according to claim 8, further comprising selection means for selecting a slice thickness from the storage means when the wire diameter is approximately zero. The storage means stores the slope of the straight line calculated by the second calculating means in association with the slice thickness when the wire diameter represented by the y-intercept of the straight line is substantially zero. The operation console according to claim 9. From the straight line group specified by the slope of the straight line stored by the storage means and the slice thickness when the wire diameter represented by the y-intercept of the straight line is approximately 0, the selection means is configured to obtain the wire diameter of the wire of interest And the straight line closest to the point having the estimated slice thickness obtained by the first calculation means using the wire of interest as a coordinate is selected from the straight line group, and the y-intercept of the selected straight line is approximately the wire diameter. The operation console according to claim 9 or 10, wherein the operation console is obtained as a slice thickness in the case of zero. An X-ray tube for irradiating X-rays, a phantom including a wire for slice thickness measurement so as to form a predetermined angle with the X-rays irradiated by the X-ray tube, and a detector for detecting X-rays, A gantry device that outputs projection data of the wire by performing scanning in which the detector detects X-rays that are irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire An X-ray CT system comprising an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to
The operation console is
Storage means for storing relationship information between an estimated slice thickness estimated for each wire for slice measurement parallel and different in diameter, and the wire diameter of the wire,
First calculation means for obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan using a captured image of the wire included in the phantom and an angle of the wire with respect to a predetermined direction of the phantom When,
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. An X-ray CT system comprising: second calculation means for obtaining a slice thickness in the case of zero. A scan is instructed to the gantry apparatus, and the wire is obtained from the projection data of the wire provided in the phantom provided with the wire for slice thickness measurement so as to form a predetermined angle with the X-ray obtained from the gantry apparatus based on the instruction. An operation console for measuring a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
Storage means for storing relationship information between an estimated slice thickness estimated for each wire for slice measurement parallel and different in diameter, and the wire diameter of the wire,
First calculation means for obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan using a captured image of the wire included in the phantom and an angle of the wire with respect to a predetermined direction of the phantom When,
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. An operation console comprising: second calculation means for obtaining a slice thickness in the case of 0. An X-ray tube for irradiating X-rays, a phantom including a wire for slice thickness measurement so as to form a predetermined angle with the X-rays irradiated by the X-ray tube, and a detector for detecting X-rays, A gantry device that outputs projection data of the wire by performing scanning in which the detector detects X-rays that are irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire And an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to the X-ray CT system,
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The control method of the operation console is as follows:
For each of the plurality of slice measurement wires that are parallel to each other and have different diameters, the gantry apparatus is used for scanning using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom. A first calculation step for determining an estimated slice thickness;
A second calculation step of creating relation information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is approximately 0 using the relation information An X-ray CT system control method comprising: In the first calculation step, in the captured image of the wire, the length of the captured wire and the angle of the wire with respect to a predetermined direction of the phantom are used when the gantry apparatus performs a scan. The method for controlling an X-ray CT system according to claim 14, wherein an estimated slice thickness is obtained. It is a point that coordinates the wire diameter of the wire and the estimated slice thickness obtained in the first calculation step using the wire,
In the second calculation step, a straight line or a curve interpolated using the points corresponding to the slice measuring wires that are parallel to each other and have different diameters is obtained as the relation information, and the y-intercept is calculated based on the wire diameter. 16. The method of controlling an X-ray CT system according to claim 14 or 15, wherein the slice thickness is obtained when the slice thickness is substantially zero. Furthermore, the control method of the operation console includes:
A plurality of the relationship information calculated in the second calculation step is stored in the storage means in association with the slice thickness when the wire diameter is approximately 0,
Corresponding relationship information is selected from the storage means using the wire diameter of the wire of interest and the estimated slice thickness obtained in the first calculation step using the wire of interest, and further corresponds to the relationship information The method for controlling an X-ray CT system according to any one of claims 14 to 16, further comprising a selection step of selecting a slice thickness when the wire diameter is substantially zero from the storage means. From the straight line group specified by the slope of the straight line stored by the storage means and the slice thickness when the wire diameter represented by the y-intercept of the straight line is substantially 0, in the selection step, the wire diameter of the wire of interest And the straight line closest to the point having the estimated slice thickness obtained in the first calculation step as a coordinate using the wire of interest is selected from the straight line group, and the y-intercept of the selected straight line is approximately the wire diameter. 18. The method of controlling an X-ray CT system according to claim 17, wherein the slice thickness is obtained as 0 when it is zero. A scan is instructed to the gantry apparatus, and the wire is obtained from projection data of the wire in a phantom provided with a slice thickness measurement wire so as to form a predetermined angle with the X-ray obtained from the gantry apparatus based on the instruction. A method for controlling an operation console for measuring a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
The phantom is
A plurality of wires for slice thickness measurement that are parallel to each other and have different diameters so as to form a predetermined angle with the X-rays irradiated by the X-ray tube,
The control method of the operation console is as follows:
For each of the plurality of slice measurement wires that are parallel to each other and have different diameters, the gantry apparatus is used for scanning using a captured image of the wire and an angle of the wire with respect to a predetermined direction of the phantom. A first calculation step for determining an estimated slice thickness;
A second calculation step of creating relation information between the estimated slice thickness obtained for each wire and the wire diameter of the wire, and obtaining the slice thickness when the wire diameter is approximately 0 using the relation information An operation console control method characterized by comprising: Furthermore, a plurality of the relationship information calculated in the second calculation step is stored in the storage means in association with the slice thickness when the wire diameter is approximately 0,
Corresponding relationship information is selected from the storage means using the wire diameter of the wire of interest and the estimated slice thickness obtained in the first calculation step using the wire of interest, and further corresponds to the relationship information The operation console control method according to claim 19, further comprising a selection step of selecting a slice thickness when the wire diameter is approximately zero from the storage unit. From the straight line group specified by the slope of the straight line stored by the storage means and the slice thickness when the wire diameter represented by the y-intercept of the straight line is substantially 0, in the selection step, the wire diameter of the wire of interest And the straight line closest to the point having the estimated slice thickness obtained in the first calculation step as a coordinate using the wire of interest is selected from the straight line group, and the y-intercept of the selected straight line is approximately the wire diameter. 21. The operation console control method according to claim 20, wherein the slice thickness is obtained as a slice thickness when 0. An X-ray tube for irradiating X-rays, a phantom including a wire for slice thickness measurement so as to form a predetermined angle with the X-rays irradiated by the X-ray tube, and a detector for detecting X-rays, A gantry device that outputs projection data of the wire by performing scanning in which the detector detects X-rays that are irradiated from the X-ray tube and transmitted through the wire included in the phantom;
The gantry apparatus is instructed to scan, and a captured image of the wire is generated from the projection data of the wire obtained from the gantry apparatus based on the instruction, and the captured image and a predetermined direction of the phantom of the wire And an operation console for measuring a slice thickness when the gantry apparatus performs the scan using an angle with respect to the X-ray CT system,
The control method of the operation console is as follows:
The relationship between the estimated slice thickness and the wire diameter of the wire estimated for each slice measurement wire parallel and different in diameter is stored in the storage means,
A first calculation step of obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan using a captured image of a wire included in the phantom and an angle of the wire with respect to a predetermined direction of the phantom When,
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. A control method for an X-ray CT system, comprising: a second calculation step of obtaining a slice thickness in the case of zero. A scan is instructed to the gantry apparatus, and the wire is obtained from the projection data of the wire provided in the phantom provided with the wire for slice thickness measurement so as to form a predetermined angle with the X-ray obtained from the gantry apparatus based on the instruction. A method for controlling an operation console for measuring a slice thickness when the gantry apparatus performs the scan using the captured image and an angle of the wire with respect to a predetermined direction of the phantom,
The relationship between the estimated slice thickness and the wire diameter of the wire estimated for each slice measurement wire parallel and different in diameter is stored in the storage means,
A first calculation step of obtaining an estimated slice thickness that is estimated to be used when the gantry apparatus performs a scan using a captured image of a wire included in the phantom and an angle of the wire with respect to a predetermined direction of the phantom When,
Using the estimated slice thickness and the wire diameter of the wire included in the phantom, the corresponding relation information is selected from the storage means, and further, the wire diameter is approximately from the storage means using the selected relation information. A control method for an operation console, comprising: a second calculation step of obtaining a slice thickness in the case of 0. The program which performs the control method of the X-ray CT system of any one of Claims 14 thru | or 18. The program which performs the control method of the operation console of any one of Claims 19 thru | or 21. The program which performs the control method of the X-ray CT system of Claim 22. The program which performs the control method of the operation console of Claim 23. A storage medium storing the program according to any one of claims 24 to 27 and readable by a computer.

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