JP2019034023A - Radiographic image capturing system and method of setting long radiographic image capturing range - Google Patents

Abstract

To reduce imaging region setting errors due to the thickness of a subject in a radiographic image capturing system.SOLUTION: In a radiographic image capturing system 100, when one end Pt of an imaging region is set, a rotating mechanism 15 rotates a radiation source 14 to place the radiation source in a first rotation state, and control means stores, as first position information, a position Dt2 of the radiation source adjusted by moving a first moving mechanism 13 when the first rotation state is assumed, and when the other end Pb of the imaging region is set, the rotating mechanism rotates the radiation source to place the radiation source in a second rotation state, and the control means stores, as second position information, a position Db2 of the radiation source adjusted by moving the first moving mechanism when the second rotation state is assumed. After setting the one and other ends of the imaging region, the control means determines the position of the radiation source for image capturing based on the first position information and the second position information.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a radiation image capturing system and a method for setting a radiation long image capturing range using this system.

Among radiographic image capturing methods, there is a method called long image capturing. This is an imaging method for obtaining a wide range of images such as the entire spine and the entire length of the lower limb, for example.
In order to perform this long photographing, it is necessary to set the photographing region (radiation irradiation range) in advance. This setting has conventionally been performed while moving the radiation source along the body axis of the subject. Specifically, the radiation source is moved to a position where one end of the imaging region can be irradiated and the position is stored, and then the radiation source is moved to a position where the other end of the imaging region can be irradiated and the position is stored. To do. And the position of the radiation source at the time of imaging | photography is determined based on two positions (refer patent document 1).

However, the X-ray apparatus described in Patent Document 1 is configured so that irradiation light emitted from a radiation source for positioning is emitted in a direction perpendicular to the body axis of the subject. In order to determine one end and the other end, it is necessary to move the radiation source by substantially the same distance from one end to the other end of the imaging region. That is, simply moving the radiation source along the body axis increases the amount of movement of the radiation source, making it difficult to set the imaging region.
In particular, when performing long shooting in a standing position using this apparatus, the shooting area is set to be long in the vertical direction. For this reason, if the technician's back is lower than the subject, the technician must make settings while looking up at the subject, making it difficult to accurately set the upper end of the imaging region.

  Therefore, in recent years, there is a radiation imaging system that sets an imaging region by combining an operation of moving the radiation source in a direction along the body axis of the subject and an operation of rotating the radiation source (changing the irradiation angle of radiation). It has been proposed (see Patent Document 2). In this way, the moving distance of the radiation source is not shortened, so that the imaging region setting operation can be performed relatively easily.

Japanese Patent No. 5314437 JP 2011-72704 A

  In the system described in Patent Document 2, the position of the radiation source when setting the imaging range is closer to the upper side of the imaging region (the head side of the subject) than during imaging, and the radiation source is used as the radiation source. Is rotated in one direction so as to descend from the top to the bottom. For this reason, the incident angle of the marker when setting the imaging region and the incident angle of the radiation when actually imaging are greatly different, and an error occurs in the region irradiated with the radiation corresponding to the body thickness of the subject. End up. As a result, there has been a problem that a part to be photographed is not photographed or a part that is not intended to be photographed is exposed.

  The present invention has been made in view of the above points, and an object of the present invention is to reduce an imaging region setting error caused by the body thickness of a subject in a radiographic imaging system.

In order to solve the above problems, the present invention provides:
A radiation source for irradiating a subject placed at a predetermined position with radiation, a first moving mechanism capable of moving the radiation source along the body axis of the subject, and the radiation source with the first A rotating mechanism capable of changing the irradiation direction of the radiation by rotating the moving mechanism about the direction in which the radiation source is moved and a straight line orthogonal to the irradiation direction of the radiation, and taking a radiation image transmitted through the subject A radiation detector, a second movement mechanism for moving the radiation detector substantially parallel to a direction in which the first movement mechanism moves the radiation source, and a region substantially the same as the radiation irradiation mounted on the radiation source. A light irradiating unit that irradiates light, and a control unit that controls at least the operation of the rotating mechanism and the second moving mechanism, so that the radiation is irradiated in the direction in which the radiation detector exists. Irradiation direction An imaging region set in advance the position control to the fine said radiation detector and a plurality of times shooting, the plurality of radiation image data can be obtained a radiation image capturing system for obtaining long images,
When setting one end of the shooting area,
The rotation mechanism rotates the radiation source so as to be in a first rotation state in which an optical axis of the irradiated radiation is inclined toward the one end side;
The control means stores, as first position information, the position of the radiation source adjusted by moving the first moving mechanism in the first rotation state;
When setting the other end of the shooting area,
The rotation mechanism rotates the radiation source so as to be in a second rotation state in which the optical axis of the irradiated radiation is inclined to the other end side;
The control means stores, as second position information, the position of the radiation source adjusted by moving the first movement mechanism in the second rotation state;
After setting one end and the other end of the imaging region, the control means determines the position of the radiation source when performing imaging based on the first position information and the second position information. To do.

  According to the present invention, it is possible to reduce the setting error of the imaging region due to the body thickness of the subject.

It is a side view of the radiographic imaging system concerning this embodiment. It is a block diagram showing the one part electric structure in the radiographic imaging system of FIG. It is a flowchart showing the setting operation | work of the imaging area | region using the radiographic imaging system of FIG. It is a side view of the radiographic imaging system 100 of FIG. 1 in the middle of the setting of one end of the imaging region. It is a side view of the radiographic imaging system 100 of FIG. 1 in the middle of the setting of one end of the imaging region. It is a side view of the radiographic imaging system 100 of FIG. 1 in the middle of setting of an imaging area other end. It is a side view of the radiographic imaging system 100 of FIG. 1 in the middle of setting of an imaging area other end. It is a side view showing imaging operation | movement of the radiographic imaging system 100 of FIG. 1 after imaging region setting. It is a side view showing the positional relationship between the direction of the radiation source and the irradiation field light L and the radiation X at the time of setting the imaging region and at the time of imaging in the conventional radiographic imaging system. FIG. 2 is a side view showing a radiation source direction and a positional relationship between irradiation field light L and radiation X at the time of setting an imaging region and at the time of imaging in the radiographic imaging system of FIG.

  Hereinafter, embodiments of a radiographic imaging system according to the present invention will be described with reference to the drawings.

(Outline of radiation imaging system)
First, the configuration of the radiographic image capturing system 100 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a side view of the radiographic image capturing system 100, and FIG. 2 is a block diagram showing a partial electrical configuration of the system 100.
1 and the like will be described by taking as an example the case of performing standing imaging (imaging performed in a state where the subject S stands (the body axis of the subject S extends vertically)). It can also be applied to a system used for supine position imaging (imaging performed in a state where the subject S is lying down (the body axis of the subject S extends horizontally)).

The radiographic image capturing system 100 according to the present embodiment is configured to perform so-called long image capturing. As illustrated in FIG. 1, the radiation irradiation device 1, the long image standing image capturing table 2, and the like. The input / output terminal 3 is provided.
The radiographic imaging system 100 is connected to a console (not shown), a radiology information system (RIS), a picture archiving and communication system (PACS), or the like by wire or wirelessly. Is possible.

The radiation irradiation apparatus 1 includes a rail 11, a wagon 12, a support column 13, a radiation source 14, a rotating mechanism 15, a collimator 16, a generator (not shown), an exposure switch, and the like.
The rail 11 is provided on the ceiling surface C of the photographing room so as to extend in the X direction (horizontal direction: left and right direction in FIG. 1).
The wagon 12 engages with the rail 11 and can move in the X direction along the rail 11.
Further, the wagon 12 can also move in a Y direction (horizontal direction: a direction orthogonal to the paper surface of FIG. 1) orthogonal to the extending direction of the rail 11.
The wagon 12 may be provided with an actuator that operates in accordance with control from the outside (console or input / output terminal 3 to be described later) so that the wagon 12 can be automatically moved in the X direction and the Y direction.

The support column 13 is attached to the wagon 12 and can be moved in the vertical direction by extending and contracting.
Although the expansion / contraction mechanism of the support | pillar 13 is not specifically limited, As shown, for example in FIG. 1, the cylindrical members 13a-13c from which each differs in size are nested, and the outer cylindrical member 13a , 13b, the inner cylindrical members 13b, 13c can be extended and retracted to extend and retract, and the innermost cylindrical member 13c (lower end) can be moved.
Moreover, the support | pillar 13 is provided with the brake 13d which can regulate expansion-contraction according to control from the outside, as shown in FIG.
In addition, the support | pillar 13 is equipped with the actuator which operate | moves according to control from the outside, and it may be made to adjust automatically the extent (extension of a lower end part) of the support | pillar 13.

The radiation source 14 includes a rotating anode (not shown) that can generate the radiation X, a filament (not shown) that irradiates the rotating anode with an electron beam for generating radiation.
When a voltage corresponding to a preset tube voltage, tube current, irradiation time (mAs value), etc. is applied from the generator, an electron beam corresponding to the voltage to which the filament is applied is irradiated toward the rotating anode. The rotating anode generates a dose of radiation X corresponding to the intensity of the electron beam.

As shown in FIG. 1, the radiation source 14 is attached to the lower end of the support column 13 so that the irradiation port of the radiation X faces the long imaging stand 2. X can be irradiated.
As described above, the support column 13 can be expanded and contracted to move the lower end portion (tubular member 13 c) in the vertical direction. Therefore, the radiation source 14 attached to the lower end portion of the support column 13 can be expanded and contracted. In addition, it is possible to move in the vertical direction (the direction along the body axis of the subject S standing at a predetermined position). That is, the support | pillar 13 makes | forms the 1st moving mechanism in this invention.
Note that when the present invention is used for the supine imaging, the wagon 12 that can move in the horizontal direction (the direction along the body axis of the subject S lying at a predetermined position) is the first moving mechanism.

The rotation mechanism 15 is provided between the radiation source 14 and the lower end portion of the column 13.
Then, the rotation mechanism 15 includes a radiation source 14 that includes the extending and contracting direction of the support column 13 (moving direction by the first moving mechanism) and the irradiation direction of the radiation X (the radiation irradiation device 1 and the standing photographing stand 2 for long photographing). It is possible to change the direction of the radiation irradiation port (radiation direction of radiation) by rotating it with a rotation shaft extending so as to be orthogonal to each other (in the Y direction).
Further, as shown in FIG. 2, the rotation mechanism 15 of the present embodiment includes an actuator 15 a that operates in accordance with external control, and can rotate automatically.
The rotation mechanism 15 of the present embodiment includes a clutch that disconnects the connection with the actuator 15a according to control from the outside, and a brake that controls rotation, and is manually operated by controlling the clutch and the brake. It is good also as a structure which can be rotated.

The collimator 16 is for adjusting the irradiation range (irradiation field) of the radiation generated by the radiation source 14, and includes a plurality of shielding wings, a range adjusting mechanism, etc. (not shown).
Each shielding wing is overlapped so as to form a rectangular opening, and at least a part of the radiation X emitted from the radiation source 14 is arranged to pass through the opening.
The range adjusting mechanism includes an actuator that operates according to control from the outside (console or the like), and can move each shielding blade so that the height and width of the opening change.
The collimator 16 configured in this way can irradiate the radiation X in a rectangular shape to a range desired by the photographer U.

Moreover, the collimator 16 of this embodiment is provided with the light irradiation part 16a, and can selectively irradiate either a laser beam or the irradiation field light L according to control from the outside. Yes.
The laser light is visible light for clearly indicating the directions of the radiation source 14 and the collimator 16, and is irradiated so as to coincide with the radiation irradiation axis Xa of the radiation X as shown in FIG.
The irradiation field light L is visible light, and is applied to the same region as the region (irradiation field) irradiated with the radiation X. That is, the irradiation range of the irradiation field light L can be controlled by the collimator 16 at one end (upper end) Lt and the other end (lower end) Lb, similarly to the radiation X.
Hereinafter, a straight line passing through the focal point of the radiation X and the center of the rectangular irradiation field is referred to as a radiation irradiation axis Xa. The angle formed by the radiation irradiation axis Xa and one end Xt of the irradiation field is represented as St, and the angle formed by the radiation irradiation axis Xa and the other end Xb of the irradiation field is represented by Sb.

The long imaging stand 2 is composed of a rail 21, a detector holder 22, a radiation detector 23, and the like.
The rail 21 is attached to the reference portion W so as to extend vertically.
The reference portion W is a reference for the installation position of the long-standing photographing stand 2 in the photographing room, and uses a column or a base fixed at a predetermined position in the photographing room, a wall or a floor of the photographing room, and the like. be able to.
In the case where the present invention is used for the upside-down photographing, the rail 21 is attached so as to extend horizontally on the floor of the photographing room or in the photographing stand.

The detector holder 22 is formed in a box shape having an opening on the side surface, and the radiation detector 23 can be accommodated by inserting the radiation detector 23 through the opening.
The detector holder 22 engages with the rail 21 and can move in the Z direction (vertical direction: up and down direction in FIG. 1) along the rail 21 (stretching direction of the support column 13). .
Further, as shown in FIG. 2, the detector holder 22 includes an actuator 22 a that operates according to control from the outside, and can automatically move in accordance with the operation of the rotation mechanism 15 of the radiation irradiation apparatus 1. It is possible.

Although not shown, the radiation detector 23 includes a housing, a substrate, a readout circuit, a control unit, a communication unit, a battery, and the like.
The housing is formed in a thin rectangular parallelepiped shape (panel shape).
The substrate has a plurality of radiation detection elements that generate radiation according to the dose by receiving radiation X, and a plurality of pixels that have switch elements that control charge accumulation and emission, arranged in a two-dimensional form (matrix). It is stored in the housing so as to be parallel to the radiation receiving surface of the housing.
The readout circuit reads out a signal value corresponding to the amount of charge accumulated in each radiation detection element.

The control unit generates image data based on each signal value read by the reading circuit.
The communication unit is configured to be able to receive a control signal from an external device such as a console or RIS, or to transmit image data to an external device.
Note that the control unit may have a function of generating a long image of a subject from a plurality of radiographic images obtained by performing long imaging (details will be described later). In that case, the radiation detector 23 of the present embodiment constitutes an image processing means in the present invention.

As shown in FIG. 1, the radiation detector 23 configured in this way is arranged such that the radiation receiving surface (or the substrate inside) of the housing faces the radiation irradiation apparatus 1 on the detector holder 22. Loaded.
As described above, since the detector holder 22 can move in the vertical direction, the radiation detector 23 loaded in the detector holder 22 also moves in the vertical direction in accordance with the movement of the detector holder 22. Is possible. That is, the detector holder 22 forms a second moving mechanism in the present invention.
Further, when the radiation source 14 emits the radiation X so that the radiation irradiation axis Xa is horizontal, the radiation irradiation axis Xa is orthogonal to the surface (or substrate) receiving the radiation of the radiation detector 23.

Further, the standing photographing stand 2 for long photographing according to the present embodiment includes a partition 24. The partition 24 is for separating the subject S from the moving detector holder 22 and is formed in a plate shape with a material that transmits radiation. Between the radiation irradiation apparatus 1 and the radiation detector 23, radiation detection is performed. It arrange | positions so that it may become parallel to the surface which receives the radiation of the container 23. FIG.
1 illustrates the partition 24 separated from the reference part W or the long-standing standing stand 2 but the reference part W or the long-standing stand 2 is not moved. It may be united.
In addition, when the present invention is used for the vertical photographing, the long photographing photographing position provided with a top plate for the subject to lie above the horizontally extending rail 21 and detector holder 22 instead of the partition 24. A photographing stand will be used.

The input / output terminal 3 is provided in the vicinity of the radiation source 14 in this embodiment.
In FIG. 1 and the like, the input / output terminal 3 attached to the radiation irradiation apparatus 1 is illustrated, but the input / output terminal 3 may be portable and independent from the radiation irradiation apparatus 1.
In addition, FIG. 1 and the like illustrate an example in which the input / output terminal 3 is fixed to the column 13 and the angle of the input / output terminal 3 does not change even when the radiation source 14 or the collimator 16 moves. The input terminal 3 may be disposed in the vicinity of the radiation source 14 and the collimator 16 so that the angle of the input terminal 3 changes in conjunction with the angles of the radiation source 14 and the collimator 16.

As shown in FIG. 2, the input / output terminal 3 includes a control unit 31, a storage unit 32, a display unit 33, an operation unit 34, and the like.
The storage unit 32 stores a program (including images and character data to be displayed on the display unit 33, a rotation angle of the radiation source 14, etc.) for executing various processes such as setting of an imaging region.
The storage unit 32 can store information on the state of the radiation source 14 such as the position and angle of the radiation source 14.
As the operation unit 34, for example, a touch panel provided integrally with the display unit 33 can be used.
The input / output terminal 3 may be provided with a communication unit that can acquire information such as a photographing order from an external device such as a console or RIS.

The input / output terminal 3 then displays an instruction to the photographer U, an advance notice of the operation of the radiation irradiation apparatus 1 to be performed on the display unit 33, and receives an instruction from the photographer U by the operation unit 34. It is possible.
The input / output terminal 3 controls the operation and release of the brake 13d of the support column 13.
The input / output terminal 3 controls the turning on and off of the laser light or the irradiation field light by the light irradiation unit 16 a of the collimator 16.
The input / output terminal 3 controls at least the operations of the rotation mechanism 15 and the actuators 15a and 22a of the detector holder described later. As described above, when the support 13 is provided with an actuator for automatically expanding and contracting, the operation of this actuator is also controlled.
In addition, you may make it give each function mentioned here to apparatuses other than the input / output terminal 3, such as a console.

Long imaging using the radiographic imaging system 100 of the present embodiment configured as described above is performed as follows.
First, an order for performing long imaging on the subject S is input from the imaging order system RIS or HIS. The inputted order information is displayed on the console or the input / output terminal 3.
Next, the photographer U performs an operation for instructing the radiographic image capturing system 100 to start long image capturing in accordance with the input order.

Next, the subject S is placed in front of the partition 24, and the imaging range is set. That is, one end and the other end of the range where radiation is irradiated are set. Details of the setting of the photographing range will be described later.
Next, the radiation source 14 is moved to the imaging position.
In addition, when the support | pillar 13 is equipped with an actuator, this operation | movement is performed automatically.

Next, the photographer U operates the exposure switch to start long shooting. Then, the radiation source 14 rotates to direct the irradiation port toward one end of the imaging region, and irradiates the radiation. Thereafter, the radiation source 14 is rotated so that the irradiation port faces the other end of the imaging region, and the radiation X is irradiated. At this time, the radiation detector 23 moves so as to be positioned in the radiation irradiation field when the radiation source 14 rotates.
Depending on the size (length) of the imaging area, the radiation opening of the radiation source 14 is directed toward the intermediate part of the imaging area, and the radiation detector 23 is moved to the intermediate part. There is.
That is, depending on the size (length) of the shooting area, it may be covered by two shots, or may be covered by two or more shots, for example, three shots. Whether to cover with these two images or to cover with two or more images is calculated automatically from the size (length) of the imaging region and the size (length) of the radiation detector 23. Is possible. It is also possible to manually set or manually correct the number of shots determined automatically.

The radiation X irradiated from the radiation source 14 partially passes through the subject S and is irradiated to the radiation detector 23.
The radiation detector 23 accumulates charges corresponding to the received radiation dose in each pixel, and generates a plurality of pieces of image data based on the charge amount of each pixel. Then, the obtained plurality of pieces of image data are transmitted to an external device such as a console.
An external device generates a long image from a plurality of pieces of image data.

(How to set the shooting area)
Next, details of setting of an imaging region using the radiographic imaging system 100 of the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the setting operation of the imaging region, FIGS. 4 to 7 are side views of the radiographic image capturing system 100 in the middle of setting, and FIG. 8 is a side view showing the imaging operation of the radiographic image capturing system 100 after setting. is there.

After performing an operation for instructing the start of long imaging according to an order input from RIS or the like, the photographer U firstly controls the patient to avoid unnecessary exposure, as shown in FIG. The collimator 16 is operated while irradiating the irradiation field light L to adjust the degree of opening of the shielding wings, so that the radiation field is the same as or slightly wider than the radiation detector 23 (step S1). .
Then, one end of the shooting area is set. First, the photographer U operates a shooting area setting start button of the input / output terminal 3 (step S2). Then, a rotation advance notice of the radiation source 14 (for example, “the radiation source is rotated to set the upper end position of the imaging region”) is displayed on the display unit 33 of the input / output terminal 3 (step S3). ). Then, the radiation source 14 and the collimator 16 are inclined such that the radiation irradiation axis Xa of the irradiated radiation is inclined toward one end (head) side of the subject S by a predetermined imaging region one end set angle At1 with respect to the horizontal plane. It rotates so that it may become a rotation state (refer step S4 and FIG. 4).

Note that step S3 may be performed after the photographer U operates the input / output terminal 3 (for example, pressing the “OK” button).
Further, the imaging region one end set angle At1 may be a numerical value input by the photographer, or preset values corresponding to the imaging region and the physique of the subject S are stored in advance, and the input imaging region and subject are input. It may be automatically set according to the physique of S.

  When the radiation source 14 and the collimator 16 have finished rotating, the display unit 33 of the input / output terminal 3 is instructed to adjust the position of the radiation source 14 (for example, “the radiation source so that the upper end of the irradiation field light coincides with the upper end of the imaging region). Is displayed "(step S5). Then, the brake 13d of the column 13 is released (step S6), and the column 13 can be expanded and contracted by manual operation or an electric operation linked to the button operation of the input / output terminal 3, that is, the positions of the radiation source 14 and the collimator 16 (Distance from the floor surface of the radiographing room to the focal point of the radiation X, and in the case of lying down photography, the distance from the reference such as the wall surface to the focal point) can be changed. At the same time as or before or after step S6, the irradiation field light L is emitted from the light irradiation unit 16a of the collimator 16 (step S7).

Thereafter, the radiographer U observes the position of the irradiation field light L falling on the subject S so that the upper end Lt of the irradiation region of the irradiation field light L coincides with the upper end of the region to be imaged of the subject S. 14 and the position of the collimator 16 are adjusted (step S8, see FIG. 5). Note that the symbol Pt in FIG. 5 represents the height at which the upper end of the coincident irradiation field light L intersects the extended line of the surface of the radiation detector 23.
After the adjustment, when the photographer U presses the upper end setting completion button of the input / output terminal 3 (step S9), the brake 13d is actuated on the support column 13 to restrict the subsequent expansion and contraction (step S10), and the irradiation field light L is generated. The light is turned off (step S11). At this time, the position Dt2 (first position information) of the radiation source 14 at that time, the imaging region upper end setting angle At1 of the radiation source 14, the upper irradiation field angle St, the distance SID between the radiation source 14 and the surface of the radiation detector 23 (Source Image receptor Distance) is stored in the storage unit 32 of the input / output terminal 3, for example.

  Subsequently, the photographer U sets the lower end of the shooting area. After step S9, the rotation notice of the radiation source 14 (for example, “the radiation source is rotated to set the lower end position of the imaging region”) is displayed on the input / output terminal 3 (step S12). . Then, the radiation source 14 and the collimator 16 have the other end of the subject S (existence of the head) by a predetermined imaging region lower end setting angle Ab1 from a state where the radiation irradiation axis Xa of the irradiated radiation is located on the horizontal plane. It rotates so that it may be in the 2nd rotation state inclined to the side opposite to the side to perform (refer step S13, FIG. 6).

Note that step S13 may be performed after the photographer U operates the input / output terminal 3 (for example, pressing the “OK” button).
Further, the imaging region lower end setting angle Ab1 may be a numerical value input by the photographer, or preset values corresponding to the imaging region and the physique of the subject S are stored in advance, and the input imaging region or object is detected. It may be automatically set according to the physique of the specimen S.

  When the radiation source 14 and the collimator 16 have finished rotating, the display unit 33 of the input / output terminal 3 is instructed to adjust the position of the radiation source 14 (for example, “the radiation source so that the lower end of the irradiation field light coincides with the lower end of the imaging region). "Please move" "is displayed (step S14). Then, the brake 13d of the support column 13 is released (step S15), and the positions of the radiation source 14 and the collimator 16 can be changed by manual operation or button operation of the input / output terminal 3. At the same time as or before or after step S15, the irradiation field light L is emitted from the light irradiation unit 16a of the collimator 16 (step S16).

Thereafter, the radiographer U observes the position of the irradiation field light L falling on the subject S, so that the lower end Lb of the irradiation region of the irradiation field light L coincides with the lower end of the region to be imaged of the subject S. 14 and the position of the collimator 16 are adjusted (see step S17, FIG. 7). In addition, the code | symbol Pb in FIG. 7 represents the height where the lower end of the irradiation field light L after a match | intersection crosses the extended line of the surface of the radiation detector 23. FIG.
After the adjustment, when the photographer U presses the lower end setting completion button of the input / output terminal 3 (step S18), the brake 13d is actuated on the support column 13 and the subsequent expansion / contraction is restricted (step S19), and the irradiation field light L is generated. The light is turned off (step S20). At this time, the position Db2 (second position information) of the radiation source 14 at that time, the imaging region lower end setting angle Ab1 of the radiation source 14, the lower irradiation field angle Sb, and the surfaces of the radiation source 14 and the radiation detector 23 The distance SID is stored in the storage unit 32 of the input / output terminal 3, for example.

Thereafter, when the photographer U presses the shooting area setting end button of the input / output terminal 3 (step S21), the input / output terminal 3 (calculation means) takes a long image according to the following expressions (1) and (2). The upper end Pt and the lower end Pb are calculated (step S22).
Pt = Dt2 + SID × {tan (At1 + St)} (1)
Pb = Db2-SID × {tan (Ab1 + Sb)} (2)

Thereafter, the input / output terminal 3 calculates Dc that is the center of the imaging region in the direction along the body axis of the subject S by the following equation (3) (step S23).
Dc = (Pt + Pb) / 2 (3)
Then, the radiation source 14 and the collimator 16 are moved to the position Dc (step S24). Up to this point is the setting of the shooting area.
Thereafter, when the photographer U operates the exposure switch, as shown in FIG. 8, long imaging is performed by irradiating the radiation X while rotating the radiation source 14 and the collimator 16 at the height Dc. Done.
Here, the radiation source 14 and the collimator 16 for rotating the radiation source 14 and the collimator 16 at the height Dc to irradiate the radiation X to the heights of Pt and Pb on the surface of the radiation detector 23. The upper rotation angle At2 and the lower rotation angle Ab2 are values calculated by the following equations (4) and (5).
At2 = tan ⁻¹ {(Pt−Dc) / SID} −St ·· (4)
Ab2 = tan ⁻¹ {(Dc−Pb) / SID} −Sb (5)

(effect)
Next, the effects of the present invention will be described with reference to FIGS. 9 and 10 are side views showing the orientation of the radiation source and the positional relationship between the irradiation field light L and the radiation X at the time of setting the imaging region and at the time of imaging, FIG. 9 is a conventional one, and FIG. 10 is the present invention. The thing concerning is shown.

  As shown in FIG. 9, the setting of the imaging region of the subject S according to the prior art is performed in such a state that the radiation source 14A is positioned closer to one end of the imaging region and the radiation source 14A is moved from one end side to the other end side. However, the actual irradiation with the radiation X is performed with the radiation source 14A positioned below the setting time. For this reason, the photographer U sets the irradiation region, and sets the region irradiated with the radiation X from the position where the irradiation field light L irradiated from the collimator 16 hits the subject S. Since the irradiation field light L is visible light, the photographer U can know only the surface layer of the subject close to the radiation source 14 about the region where the irradiation field light L is hitting the subject S. Then, the area indicated by the symbol A in FIG. 9 (hereinafter referred to as error area A) is an area through which the radiation X is transmitted and exposed in actual imaging, although the radiation X is not transmitted at the time of setting the irradiation area. End up.

On the other hand, the area indicated by the symbol B in FIG. 9 (hereinafter referred to as error area B) is an area where the radiation X is transmitted when the irradiation area is set, but the radiation X cannot pass through in actual imaging. This is an area that is not photographed.
As described above, according to the conventional method for setting an imaging region, the irradiation angle with respect to the horizontal plane differs greatly between the irradiation field light L and the radiation X between the setting of the imaging region and the actual imaging, and the region that is not desired to be exposed is exposed to radiation. There are problems such as exposure by X and the area to be photographed not photographed.

  On the other hand, in the long imaging region setting according to the technique of the present invention, as shown in FIG. 10, the positions of the radiation source 14 and the collimator 16 are substantially the same when the imaging region is set and during actual imaging. Therefore, the irradiation field light L and the radiation X have substantially the same irradiation angle with respect to the horizontal plane. For this reason, the setting error of the imaging region due to the body thickness of the subject S can be reduced, that is, the size of the error region A and the error region B can be reduced, and the region that is not desired to be exposed is exposed by radiation. It is possible to minimize the problem that the area to be photographed is not photographed.

In order to reduce an error in setting the irradiation area by the irradiation field light L and imaging by the radiation X, the irradiation area setting by the irradiation field light L is considered in consideration of the effect of the angle difference between the irradiation area setting and the imaging. Sometimes, the irradiation region can be set in a wider range than the surface of the radiation source side of the subject S with respect to the irradiation region, but experience is necessary to make such a setting in consideration of the angular difference. When setting, it is necessary to consider the body thickness of the subject S, the position of the body thickness where the region to be photographed is, and the like, and the work becomes complicated.
However, according to the present invention, the angle difference between the setting of the irradiation area and the time of photographing is greatly reduced as compared with the conventional case, so that it is not necessary to set the irradiation area while making such a complicated examination.

Further, when setting the upper end (lower end) of the irradiation area, the photographer U performs the setting while looking at the irradiation direction of the irradiation field light L, so the setting is often made while looking at the upper side (lower side).
However, when the input terminal 3 is arranged in the vicinity of the collimator 14 and the angle of the input terminal 3 changes in conjunction with the angle of the collimator 14 as described above, the upper end (lower end) is set. In this case, since the display unit 33 of the input terminal 3 faces upward (downward), the photographer U can easily see the display unit 33.

DESCRIPTION OF SYMBOLS 100 Radiation imaging system 1 Radiation irradiation apparatus 11 Rail 12 Wagon (1st moving mechanism in the case of moving a radiation source horizontally)
13 Support (first moving mechanism for moving the radiation source vertically)
13a-13c Cylindrical member 14 Radiation source 14A Conventional radiation source 15 Rotating mechanism 15a Actuator 16 Collimator 16a Light irradiation unit 2 Standing photographing stand for long photographing 21 Rail 22 Detector holder (second moving mechanism)
22a Actuator 23 Radiation detector 24 Screen 3 Input / output terminal 31 Control unit (control means)
32 Storage section 33 Display section 34 Operation section A, B Error area Ab1 Imaging area lower end setting angle At1 Imaging area upper end setting angle C Ceiling surface Db2 (at the time of setting the other end of the imaging area) Radiation source position Dt2 (one end of imaging area) Radiation source position L (when setting) Irradiation field light Lb Lower end of irradiation field light Lt Upper end of irradiation field light Pb Other end (lower end) of imaging range
One end (upper end) of Pt shooting range
S Subject Sb, St Irradiation field angle SID Distance from radiation source to radiation detector U Photographer X Radiation Xa Radiation irradiation axis Xb The other end (lower end) of radiation
Xt One end (upper end) of radiation

Claims (7)

A radiation source for irradiating a subject placed at a predetermined position with radiation, a first moving mechanism capable of moving the radiation source along the body axis of the subject, and the radiation source with the first A rotating mechanism capable of changing the irradiation direction of the radiation by rotating the moving mechanism about the direction in which the radiation source is moved and a straight line orthogonal to the irradiation direction of the radiation, and taking a radiation image transmitted through the subject A radiation detector, a second movement mechanism for moving the radiation detector substantially parallel to a direction in which the first movement mechanism moves the radiation source, and a region substantially the same as the radiation irradiation mounted on the radiation source. A light irradiating unit that irradiates light, and a control unit that controls at least the operation of the rotating mechanism and the second moving mechanism, so that the radiation is irradiated in the direction in which the radiation detector exists. Irradiation direction An imaging region set in advance the position control to the fine said radiation detector and a plurality of times shooting, the plurality of radiation image data can be obtained a radiation image capturing system for obtaining long images,
When setting one end of the shooting area,
The rotation mechanism rotates the radiation source so as to be in a first rotation state in which an optical axis of the irradiated radiation is inclined toward the one end side;
The control means stores, as first position information, the position of the radiation source adjusted by moving the first moving mechanism in the first rotation state;
When setting the other end of the shooting area,
The rotation mechanism rotates the radiation source so as to be in a second rotation state in which the optical axis of the irradiated radiation is inclined to the other end side;
The control means stores, as second position information, the position of the radiation source adjusted by moving the first movement mechanism in the second rotation state;
After setting one end and the other end of the imaging region, the control means determines the position of the radiation source when performing imaging based on the first position information and the second position information. Radiation imaging system.   The control means moves the rotation mechanism so that the radiation source rotates at a predetermined rotation angle when the radiation source is set to the first rotation state or the second rotation state. The radiographic imaging system according to claim 1.   The radiographic image capturing system according to claim 2, wherein the control unit determines the rotation angle based on input information related to the subject. The control means is configured to control the operation of the first moving means,
The radiographic image according to claim 1, wherein the first moving mechanism moves the radiation source horizontally or vertically when the rotating unit sets one end or the other end of the imaging region. Shooting system.   The control means moves the first movement mechanism so that the radiation source moves by a predetermined movement distance when the radiation source is set to the first rotation state or the second rotation state. The radiographic imaging system according to claim 4.   The radiographic image capturing system according to claim 5, wherein the control unit determines the moving distance based on input information related to the subject. A radiation source for irradiating a subject with radiation; a first movement mechanism capable of moving the radiation source horizontally or vertically; and a movement direction of the first movement mechanism and a radiation irradiation direction of the radiation source. A rotation mechanism capable of rotating an orthogonal straight line as an axis to change the radiation irradiation direction, a radiation detector that captures a radiation image transmitted through the subject, and the radiation detector as the first movement mechanism A second moving mechanism for moving the radiation source substantially in parallel with the moving direction of the radiation source, a light irradiation unit for irradiating light to the same region as the radiation irradiation mounted on the radiation source, at least the rotating mechanism and the first 2 and a control means for controlling the operation of the moving mechanism, and is preset by controlling the radiation direction and the position of the radiation detector so that the radiation is emitted in the direction in which the radiation detector exists. The imaging region multiple times photographing using radiation imaging system capable of obtaining a plurality of radiation image data to obtain a long image, in the setting method of radiographic long image capturing range,
When setting one end of the shooting area,
The radiation source is rotated so that the optical axis of the irradiated radiation is in a first rotation state in which the optical axis is inclined toward the one end side,
The position of the radiation source is adjusted by moving the first movement mechanism in the first rotation state, and the position of the radiation source after adjustment is set as first position information,
When setting the other end of the shooting area,
The radiation source is rotated so that the optical axis of the irradiated radiation is in a second rotation state in which the optical axis of the radiation is inclined toward the other end side,
The position of the radiation source is adjusted by moving the first movement mechanism in the second rotation state, and the position of the radiation source after the adjustment is used as second position information,
Thereafter, the position of the radiation source at the time of performing imaging is calculated based on the first position information and the second position information.

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