JP4782641B2 - Digital X-ray equipment - Google Patents

Description

  The present invention performs X-ray exposure toward a subject (patient), and uses a flat panel detector (FPD) made of a semiconductor element to convert a captured image of the subject (patient) as electronic image data. With regard to so-called digital X-ray imaging apparatus for recording, in particular, divisional imaging in the longitudinal direction required when imaging a wide range of parts (called long imaging) such as the entire spine and all lower limbs of a subject (patient). The present invention relates to a digital X-ray imaging apparatus capable of automatically moving a mask plate for cutting unnecessary X-ray exposure on a subject (patient).

  A conventional digital X-ray imaging apparatus is a mask plate having a slidable irradiation port attached to the front surface of a collimator for each of the longitudinal division imaging required for long imaging. The (lead plate) was slid manually to cut useless X-ray exposure on the subject (patient). (For example, see Patent Document 1)

JP 2002-537050 A

  As an X-ray imaging apparatus (so-called X-ray apparatus) used in the medical field, film imaging using a silver salt film has been widely used. However, while convenience such as the ability to process a photographed image is required, in recent years, a so-called digital X-ray photographing apparatus that can use an X-ray photographed image as electronic image data has been replaced.

  As a digital X-ray imaging apparatus, for example, as exposed to a subject (patient) from an X-ray tube as in the digital X-ray imaging apparatus disclosed in Patent Document 1, a captured image of the subject (patient) is used. Is recorded as electronic image data using a flat panel detector (FPD) made of a semiconductor element.

  By the way, in the case of performing long shooting, in film shooting, it was possible to perform shooting with one X-ray exposure by using a long film. However, in digital X-ray imaging (referred to as FPD imaging), the size of the FPD is limited (about 17 inches), and the FPD is very expensive. It is normal to divide and perform X-ray exposure twice or three times.

  Among the properties of such a digital X-ray imaging apparatus, for example, in the digital X-ray imaging apparatus disclosed in Patent Document 1, in order to cut useless X-ray exposure on a subject (patient), a mask is provided for each imaging. The plate (lead plate) was slid manually.

  Therefore, it takes time and effort to manually slide the mask plate for every photographing, which is inconvenient. Further, since it takes time to manually slide the mask plate for one long photographing, there is a problem that the time from the photographing start to the photographing completion becomes long. In addition, the subject (patient) is required to remain stationary during shooting in order to suppress image blurring and image composition (image stitching) misalignment. was there.

  The present invention has been made to solve the above-described problems, and includes a sensor that detects the presence or absence of X-ray exposure and a mechanism that automatically slides a mask plate based on an output from the sensor. Thus, it is possible to obtain a digital X-ray imaging apparatus capable of improving the convenience of the X-ray imaging operator, shortening the time required for long imaging, and further reducing the inconvenience of the subject (patient).

  A digital X-ray imaging apparatus according to the present invention includes an X-ray tube that irradiates X-rays and a collimator that narrows the irradiation range from the X-ray tube, and performs imaging of a wide range of a subject (long-length imaging). At this time, the portion is divided into a plurality of portions in the longitudinal direction, and each of the divided portions is photographed while masking so that X-rays are not exposed to portions other than the portion to be photographed. In a digital X-ray imaging apparatus that records as electronic image data using (FPD: Flat Panel Detector), a mask plate having an irradiation port provided in front of the collimator, and interposed between the collimator and the subject And an X-ray detection sensor for detecting the presence or absence of X-ray exposure, and a mask plate moving means for moving the mask plate according to the output of the X-ray detection sensor.

  In the digital X-ray imaging apparatus according to the present invention, an X-ray imaging operation is provided by including a sensor for detecting the presence or absence of X-ray exposure and a mechanism for automatically sliding the mask plate by the output from the sensor. Improvement of convenience for the user, shortening of time required for long photographing, and reduction of inconvenience of the subject (patient).

Embodiment 1 FIG.
A feature of the digital X-ray imaging apparatus according to the present invention is that, when performing long imaging of a subject (patient), for example, the entire spine and all lower limbs, the imaging region is divided into a plurality of parts in the longitudinal direction, and imaging is performed multiple times. Automatically move the mask plate that cuts unnecessary X-ray exposure to areas other than the region to be imaged according to the output of the X-ray detection sensor that detects the presence or absence of X-ray exposure. It is in.

  Therefore, the digital X-ray imaging apparatus according to the present invention, such as the structure of the X-ray tube, the structure of the collimator, the structure of the FPD, and the movement mechanism of the FPD, uses a well-known technique. Alternatively, hereinafter, the digital X-ray imaging apparatus according to the first embodiment will be described.

  FIG. 1 is an overall schematic diagram showing an imaging state of a subject (patient) using the digital X-ray imaging apparatus according to Embodiment 1 for carrying out the present invention. As an example, the digital X-ray imaging apparatus according to the first embodiment has a specification in which long imaging is performed in three parts.

  In FIG. 1, reference numeral 1 denotes an X-ray tube that emits X-rays. A collimator 2 adjusts the X-ray irradiation range. The structure of the X-ray tube 1 and the structure of the collimator 2 are well-known techniques and will not be described.

  Reference numeral 3 denotes an automatic iris unit, which includes a mask plate having an irradiation port, a mask plate moving means for moving the mask plate, a power supply for supplying power to the mask plate moving means, and an X-ray detection sensor for detecting the presence or absence of X-ray exposure. Etc. The structure of the automatic diaphragm unit 3 will be described later in detail.

  Reference numeral 4 denotes a patient table, and a support column 4c on which an FPD frame 4b having three contacts (MC1, MC2, MC3 shown in FIG. 3 described later) that can be electrically connected to the FPD 4a is installed. Yes. The FPD gantry 4b is movable in the Y direction in the figure within the column 4c. Such a patient table 4 is a well-known technique and will not be described in detail.

  Reference numeral 5 denotes a subject (hereinafter referred to as a patient). For example, when X-ray imaging of the entire spine is necessary, the X-ray irradiation range is adjusted by the collimator 2 and the patient's X-rays can be exposed to a wide area.

  X in the figure is the central axis of the imaging range when the patient 5 is standing on the patient table 4. That is, the X-ray tube 1, the collimator 2, and the automatic aperture unit 3 are moved together in the Y direction in the drawing so that the center of the collimator 2 is substantially coincident with the axis X. Similarly, the FPD gantry 4b is also moved in the Y direction in the drawing so that the center of the FPD gantry 4b substantially coincides with the axis X. The center of the FPD gantry 4b means the center of the FPD 4a when the FPD 4a is positioned at the B position at three positions (A position, B position, and C position shown in FIG. 3 described later). Such an initial position setting method at the time of X-ray imaging is a known technique, and detailed description thereof is omitted.

  FIG. 2A is a perspective view of the patient table 4. FIG. 2B is a conceptual diagram showing a drive mechanism of the FPD 4 a as viewed from the back surface of the patient table 4.

  As shown in FIGS. 2A and 2B, the FPD 4a is slidably held with respect to the guide rail 6, and the screw 7 is rotated by the motor 8 installed on the upper portion of the column 4c. It can be moved in the direction. Such a moving mechanism is a well-known technique and will not be described in detail.

  FIG. 3 is a conceptual diagram showing a connection state between the FPD 4a and the FPD mount 4b.

  In FIG. 3, the FPD 4a can be moved in the Y direction in the drawing as described in FIGS. 2 (a) and 2 (b). In the first embodiment, the long shooting is divided into three as described above. Therefore, the FPD 4a is moved to each of the A position, the B position, and the C position, and X-ray imaging is performed. At this time, contacts MC1, MC2 and MC3 for stopping the driving of the FPD 4a are provided at the respective positions (A position, B position and C position). The A position, the B position, and the C position are designed so that the FPD 4a overlaps between the positions. Such a moving mechanism of the FPD 4a is a well-known technique and will not be described in detail.

  FIG. 4 is a perspective view of the collimator 2.

  In FIG. 4, reference numeral 2 a denotes an X-ray irradiation port irradiated from the X-ray tube 1. Reference numeral 2b denotes a rail for engaging and holding the automatic diaphragm unit 3, and the automatic diaphragm unit 3 is slid from the upper part in the figure to be engaged and held.

  FIG. 5 is a perspective view of the automatic diaphragm unit 3.

  In FIG. 5, reference numeral 3a denotes a storage body having a power source (not shown) for supplying power to a mask plate moving means, which will be described later, and a control circuit (not shown) for controlling the mask plate moving means. is there. In the first embodiment, the power source for supplying power to the mask plate moving means is a dry battery. Reference numeral 3 b denotes a rail insertion portion that is engaged with the rail 2 b in the collimator 2.

  Reference numeral 3c denotes a mask plate holding rail for holding the mask plate 9 so as to be slidable in the direction of arrow Y in the figure. The mask plate 9 is a lead plate that blocks transmission of X-rays, but has an irradiation port 9a for transmitting X-rays at a predetermined position.

  FIG. 6 is a cross-sectional view of the automatic diaphragm unit 3.

  In FIG. 6, reference numeral 3d denotes a holding plate of the X-ray detection sensor 10 (details of which will be described later), which are fastened to the automatic iris unit 3 by screws (not shown) at a fixing portion 3e. In the first embodiment, the X-ray detection sensor 10 is bonded and fixed to the holding plate 3d. However, the present invention is not limited to this, and screw fixing, adhesive fixing, or the like may be used. Further, in the first embodiment, the holding plate 3d is screwed (not shown) to the automatic aperture unit 3; however, the present invention is not limited to this, and adhesive fixing, adhesive fixing, or separate body Instead, it may be configured integrally.

  FIG. 7 is a perspective view of the holding plate 3d.

  In FIG. 7, 11 is an optical sensor. As shown in FIG. 8 to be described later, the X-ray detection sensor 10 according to the first embodiment emits light when irradiated with X-rays, and the optical sensor 11 detects the light emission.

  FIG. 8 is a configuration diagram of the X-ray detection sensor 10 and the optical sensor 11.

  In FIG. 8, reference numeral 10 a denotes a base material. In the first embodiment, a light guide for ensuring X-ray transmission and guiding light emitted from the X-ray detection sensor 10 to the optical sensor 11. However, the present invention is not limited to this, and a glass material may be used.

  Reference numeral 10b denotes an X-ray phosphor attached to both surfaces of the base material 10a, and has a property of emitting light when irradiated with X-rays or visible light. In the first embodiment, the X-ray phosphor uses an X-ray intensifying screen. In the first embodiment, the X-ray phosphor 10b is attached to both surfaces. However, the X-ray phosphor 10b may be attached to only one surface. Since the X-ray phosphor (X-ray intensifying screen) having the property of emitting light when irradiated with such X-rays is a known technique, a detailed description of its components and the like is omitted.

  10c is an aluminum film, and is affixed so that the whole base material 10a with which X-ray fluorescent substance 10b was affixed may be covered. By covering the entire base material 10a with the aluminum film 10c, visible light is blocked, and the optical sensor 11 can react only to the light emitted by the X-ray detection sensor 10. Further, the light emitted from the X-ray detection sensor 10 can be prevented from escaping from the base material 10a to the external space. Accordingly, the material for covering the base material 10a is not limited to an aluminum material, and any material can be used as long as the material does not transmit visible light and does not absorb light emitted from the X-ray sensor 10. Absent. However, when productivity, cost, etc. are taken into account, an aluminum film can be said to be a good material.

  FIG. 9 is a schematic view showing the structure of the mask plate moving means.

  As shown in FIG. 9, notches 9 b, 9 c, 9 d are formed on the side surface of the mask plate 9. In FIG. 9, 12a is an engaging part which engages with the notches 9b and 9d, and is made of a magnetic material. The engaging portion 12a is pressed against the side surface of the mask plate 9 in a state where a biasing force is applied by a coil spring (not shown). 12b is an engaging part which engages with the notch part 9c, and is formed of a magnetic material. The engaging portion 12b is pressed against the side surface of the mask plate 9 in a state where a biasing force is applied by a coil spring (not shown).

  Reference numerals 13a and 13b denote conductive wires wound around the engaging portions 12a and 12b, respectively, by controlling a power source (not shown) provided in the storage portion 3a (see FIG. 5) of the automatic throttle unit 3. , Current is allowed to flow.

  The mask plate moving means includes notches 9b, 9c, 9d, engaging portions 12a, 12b, and conducting wires 13a, 13b. That is, by applying an electric current to the conducting wires 13a and 13b in a predetermined direction, the engaging portions 12a and 12b made of a magnetic material are attached to the side surface of the mask plate 9 using the force of Fleming's left-hand rule. The driving means of the engaging portions 12a and 12b is configured to move in the direction of releasing the engagement with the notches 9b, 9c, and 9d against the force, and when the engagement is released, the mask plate 9 By dropping its own weight, it can be moved from the position shown in FIG. 9A to the position shown in FIG. 9B and from the position shown in FIG. 9B to the position shown in FIG. 9C. In addition, since the force by the Fleming's left-hand rule disappears when the current flowing through the conducting wires 13a and 13b is set to zero (OFF), the engaging portions 12a and 12b are caused by the biasing force applied to the engaging portions 12a and 12b. It is brought into pressure contact with the side surface of the mask plate 9.

  FIG. 10 is a timing chart showing the X-ray exposure from the X-ray tube 1, the driving (up and down movement) of the FPD 4a, the output from the optical sensor 11, the current ON / OFF of the conducting wires 13a and 13b, and the position of the mask plate 9. FIG.

  Hereinafter, an outline of the operation of the digital X-ray imaging apparatus according to the first embodiment (from the start of imaging to the completion of imaging) will be briefly described.

  When the patient 5 is photographed long, first, as shown in FIG. 1, the patient 5 is placed on the patient table 4 and the posture is forced to stand still in an upright state. Then, as described above, the X-ray tube 1, the collimator 2, and the automatic iris unit 3 are integrated, and the FPC gantry 4b is moved in the Y direction shown in FIG. 1, so that the center of the imaging range (axis X shown in FIG. ). Then, the FPD 4a is sequentially moved to the A position, the B position, and the C position shown in FIG. 3 to complete the shooting while performing the divided shooting. Such an operation is a known technique and will not be described in detail.

  Next, a mechanism for automatically moving the FPD 4a will be described with reference to FIGS.

  As shown in FIG. 10, at the start of imaging, the FPD 4a is in the A position (see FIG. 3), the mask plate 9 is in the position shown in FIG. 9A, and the irradiation port 9a corresponds to the A position. At this time, as shown in FIG. 9A, the mask plate 9 is fixed in position without the engagement portion 12a being engaged with the notch portion 9b and falling down by its own weight.

  When the X-ray imaging is completed at the A position, the X-ray tube 1 is turned off. When the X-ray tube 1 is ON, that is, when X-rays are exposed, the X-ray detection sensor 10 emits light, so the light sensor 11 detects the light emission and the light sensor 11 outputs an ON signal. is doing.

  When the X-ray imaging is completed at the A position and the X-ray tube 1 is turned off, the FPD 4a is driven to move from the A position to the B position. Such synchronization between the ON / OFF of the X-ray tube 1 and the movement of the FPD 4a is a well-known technique and will not be described in detail.

  Similarly, when the X-ray tube 1 is turned off, the optical sensor 11 is also turned off. Therefore, a control circuit (not shown) provided in the storage portion 3a (see FIG. 5) of the automatic iris unit 3 is provided with the optical sensor. 11 is detected to be OFF, a power source (not shown) stored in the storage unit 3a is controlled, and a current is passed through the conductor 13a. In FIG. 10, S1 is shown as ON to let a current flow through the conducting wire 13a. Similarly, in FIG. 10, S2 is shown as ON when a current is passed through the conductive wire 13b.

  When a current flows through the conducting wire 13a, as described above, the engaging portion 12a moves in the direction of the arrow L in FIG. 9A according to Fleming's left-hand rule, and the engagement with the notch portion 9b is released. Then, the mask plate 9 falls by its own weight and stops at the position shown in FIG. That is, as described above, since the engaging portions 12a and 12b are pressed against the side surface of the mask plate 9 with a biasing force applied by a coil spring (not shown), when the mask plate 9 falls by its own weight. The engaging portion 12b slides on the side surface of the mask plate 9 and is engaged with the notch portion 9c, so that the falling of the weight of the mask plate 9 stops.

  When the FPD 4a is moved to the B position and the mask plate 9 is moved to the position shown in FIG. 9B, the X-ray tube 1 is turned on again, and the second X-ray imaging is performed. When the second X-ray imaging is completed, the FPD 4a is moved from the B position to the C position by the same mechanism as that after the first imaging is completed, and the mask plate 9 is moved from the position shown in FIG. It moves to the position shown in c) by its own weight drop. Then, the third X-ray imaging is performed, and all X-ray imaging is completed.

  As described above, the digital X-ray imaging apparatus according to the first embodiment can automatically move the mask plate 4a according to the output of the optical sensor 11 for each imaging in the divided imaging at the long imaging. it can. Therefore, it is not necessary to manually slide the mask plate 9 for every imaging, and the convenience of the X-ray imaging operator is improved. In addition, since the time for manually sliding the mask plate 9 is not required for each divided photographing, the time required for the long photographing can be shortened. In addition, the patient 5 is forced to stand still during photographing, but the inconvenience of the patient 5 is reduced by shortening the time required for long photographing, and image blurring and image composition (image composing) ) Can also be reduced.

  Further, the digital X-ray imaging apparatus according to the first embodiment supplies power for flowing current to the conducting wires 13a and 13b from a power source (battery) provided in the storage unit 3a, and X-rays Since the presence or absence of exposure (X-ray exposure signal) is detected by the optical sensor 11 via the X-ray detection sensor 10, no wiring is required, and the degree of freedom of installation of the digital X-ray imaging apparatus is increased. .

Embodiment 2. FIG.
In the first embodiment described above, the movement direction of the mask plate 9 is the gravity direction, and the movement of the mask plate 9 is caused to fall by its own weight. However, the present invention is not limited to this. For example, the structure shown in FIG.

  FIG. 11 is a schematic diagram showing the structure of the mask plate moving means in the second embodiment, which is a modification of the mask plate moving means in the first embodiment.

  As shown in FIG. 11, the difference from the first embodiment is the moving direction of the mask plate 9. That is, in the first embodiment, the mask plate 9 has a structure in which the weight of the mask plate 9 falls in the vertical direction (gravity direction), but in the second embodiment, the mask plate 9 moves (slides) in the horizontal direction. The necessary driving force is realized by the coil spring 14.

Embodiment 3 FIG.
In the first embodiment and the second embodiment described above, the driving force for moving the mask plate 9 is realized by its own weight or spring force. This is an effective mechanism for power generation. However, it is needless to say that the configuration shown in FIG.

  FIG. 12 is a schematic diagram showing the structure of the mask plate moving means in the third embodiment, and is a modification of the mask plate moving means in the second embodiment.

  As shown in FIG. 12, the difference from the second embodiment is the moving mechanism of the mask plate 9. That is, in the second embodiment, the movement of the mask plate 9 is realized by the coil spring 14, but in the third embodiment, it is realized by the engagement of the gear and the motor drive.

  In this case, the effect of power saving is less than that of the first and second embodiments, but the same effects as those of the first and second embodiments can be obtained in other respects. .

  In the third embodiment, the moving direction of the mask plate 9 is the horizontal direction. However, as in the first embodiment, the movement of the mask plate can also be realized by the engagement of the gears and the motor drive in the vertical direction. Needless to say.

Embodiment 4 FIG.
In the third embodiment described above, the movement of the mask plate 9 is realized by the engagement of the gear and the motor drive. However, the present invention is not limited to this. For example, the configuration shown in FIG.

  FIG. 13 is a schematic diagram showing the structure of the mask plate moving means in the fourth embodiment, which is a modification of the mask plate moving means in the third embodiment.

  As shown in FIG. 13, the difference from the third embodiment is a moving mechanism of the mask plate 9. That is, in the third embodiment, the movement of the mask plate 9 is realized by gear engagement and motor drive, but in the fourth embodiment, the movement is realized by a belt, a pulley, and a motor.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole schematic diagram which shows the imaging | photography state of the to-be-photographed object (patient) using the digital X-ray imaging apparatus in Embodiment 1 for implementing this invention. (A) is a perspective view of the patient table 4. (B) is a conceptual diagram showing a drive mechanism of the FPD 4 a as viewed from the back surface of the patient table 4. It is a conceptual diagram which shows the connection state of FPD4a and FPD mount frame 4b. 2 is a perspective view of a collimator 2. FIG. FIG. 3 is a perspective view of an automatic diaphragm unit 3. FIG. 3 is a cross-sectional view of the automatic aperture unit 3. It is a perspective view of 3d of holding plates. 2 is a configuration diagram of an X-ray detection sensor 10 and an optical sensor 11. FIG. It is the schematic which shows the structure of a mask board moving means. 4 is a timing chart showing the X-ray exposure from the X-ray tube 1, the driving (up and down movement) of the FPD 4a, the output from the optical sensor 11, the current ON / OFF of the conducting wires 13a and 13b, and the position of the mask plate 9. FIG. It is the schematic which shows the structure of the mask board moving means in this Embodiment 2. It is the schematic which shows the structure of the mask board moving means in this Embodiment 3. It is the schematic which shows the structure of the mask board moving means in this Embodiment 4.

Explanation of symbols

1 X-ray tube 2 Collimator 4a FPD
DESCRIPTION OF SYMBOLS 9 Mask board 9a Irradiation port 9b, 9c, 9d Notch 10 X-ray detection sensor 10a Base material 10b X-ray fluorescent substance 12a, 12b Engagement part

Claims (6)

When an X-ray tube that irradiates X-rays and a collimator that narrows the irradiation range from the X-ray tube,
The region is divided into a plurality of portions in the longitudinal direction, and each of the divided portions is imaged while masking so that X-rays are not exposed to portions other than the region to be imaged, and the captured image is obtained by a flat detector (FPD). : Flat Panel Detector), in digital X-ray imaging equipment that records as electronic image data,
A mask plate having an irradiation port provided in front of the collimator;
An X-ray detection sensor that is interposed between the collimator and the subject and detects the presence or absence of X-ray exposure, and a mask plate moving means for moving the mask plate according to the output of the X-ray detection sensor A digital X-ray imaging apparatus characterized by comprising. The X-ray detection sensor is based on a transparent resin plate or glass plate that transmits X-rays, and an X-ray phosphor that emits light when X-rays are exposed to one or both sides of the substrate is attached. 2. The digital X-ray imaging apparatus according to claim 1, wherein the entire base material to which the X-ray phosphor is attached is covered with a light shielding material that shields visible light. The mask plate includes a plurality of notches at predetermined positions on both side surfaces, and
The mask plate moving means drives the engagement portion in an engagement portion that engages with the notch portion of the mask plate, a direction in which the engagement portion is engaged with the notch portion, and a direction in which the engagement is released. The digital X-ray imaging apparatus according to claim 1, further comprising a driving unit configured to drive the digital X-ray. 4. The digital X-ray imaging apparatus according to claim 3, wherein the mask plate moves by its own weight when the engagement with the mask plate sliding means is released. 4. The digital X-ray imaging apparatus according to claim 3, wherein the mask plate is moved by an elastic force applied to the mask plate when the engagement with the mask plate sliding means is released. The engaging part is made of a magnetic material,
6. The digital device according to claim 3, wherein the driving unit includes a conductive wire spirally wound around the engaging portion, and a power source that supplies a current to the conductive wire. 7. X-ray imaging device.

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