JP2011015899A - Radiographic imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate alignment of a relative position to an X-ray vessel and to secure safety without impairing portability by providing an appropriate X-ray shielding part.SOLUTION: An electronic cassette 1 is constituted to be attachable to and detachable from the X-ray shielding part 18 and an annunciation unit 19. Thus, according to a moving image/still image condition or in carrying to a different system, the X-ray shielding part 18 is attached and detached for photographing or movement. The annunciation unit 19 can determine a three-dimensional position coordinate of the electronic cassette 1 by receiving radio wave transmitted from the inside of a photographing chamber. The annunciation unit 19 calculates an inclination and a value obtained by correcting the relative position to the electronic cassette 1 in addition of its own position coordinate, and transmits center position information for an imaging area of the electronic cassette 1 to a control unit 20. The control unit 20 performs position adjustment by calculating an appropriate position of the X-ray vessel 16 based on irradiation position information obtained by adding image receiving surface position information of the electronic cassette 1 transmitted from the annunciation unit 19 to an irradiation distance matched to a photographing condition.

Description

  The present invention relates to a radiographic imaging apparatus that acquires an X-ray image from transmitted X-rays of a subject.

  2. Description of the Related Art Conventionally, in the field of medical diagnosis, apparatuses that obtain radiation images by irradiating a subject with radiation and detecting the intensity distribution of the transmitted radiation have been used. As a general method for photographing, a film / screen method is known in which a photosensitive film and a rare earth phosphor having sensitivity to X-rays are combined for photographing.

  On the other hand, in recent years, a digital X-ray imaging apparatus using a detector using a large-area solid-state imaging device has been put into practical use, and an improvement in efficiency of diagnosis and imaging work is expected as compared with a conventional analog X-ray imaging apparatus. Therefore, it is widely used.

  Furthermore, while an inexpensive system is desired, a portable digital X-ray imaging apparatus called an electronic cassette that has been miniaturized to a size equivalent to a moving image still image combined type or an analog cassette has been put into practical use. Yes.

  In general, the electronic cassette can be used for portable imaging as a single unit, and can be used for various imaging applications by being detachably used in various imaging systems such as an imaging table and a round-trip car. In this way, by using the electronic cassette for both portable shooting and general shooting on a shooting stand or the like, it is possible to cover most of the shooting that can be performed with one electronic cassette, and an expensive digital An X-ray imaging apparatus can be used effectively.

  Moreover, in Patent Document 1, in order to use the electronic cassette more efficiently, the relative position of the electronic cassette with respect to the imaging bed top plate is detected and automatically aligned to improve work efficiency. An image capturing device is disclosed.

  Conventionally, when an electronic cassette is mounted on a photographing stand and used, the mounting position of the electronic cassette can be uniquely specified in both portable photographing and general photographing. Then, the center of the imaging unit and the X-ray tube can be automatically linked with each unique system information. Further, in the case of moving image shooting, since it is necessary to limit the X-ray transmittance different from that for still image shooting, an X-ray shielding portion is provided at the attachment position of the electronic cassette.

JP 2005-204857 A

  However, when the electronic cassette is used at an arbitrary position, it can be used in various imaging postures, but it is difficult to align the relative positions of the X-ray effective area and the X-ray irradiation area of the electronic cassette. There are many parts that depend on the experience and feeling of the operator.

  In addition, the X-ray shielding portion must be arranged in accordance with the position of the electronic cassette during moving image shooting. However, when the X-ray shielding unit is provided in the electronic cassette body, the weight of the electronic cassette increases, and the operability is extremely deteriorated when used only for still image shooting. When the X-ray shielding part is provided separately from the electronic cassette, it is necessary for the operator to check whether or not the electronic cassette type or imaging condition and the shielding part are an appropriate combination. In addition, there is an increased risk of photographing in a state where sufficient X-ray shielding is not achieved due to forgetting to install the X-ray shielding unit.

  Patent Document 1 relates to an imaging bed having a top board, and there are problems related to X-ray shielding in shooting at an arbitrary position such as use on a general-purpose imaging table, a state where a cassette is set up on a table top, and moving image shooting. Not considered.

  The object of the present invention is to ensure the safety by providing an appropriate X-ray shielding part that can easily align the relative position with the X-ray tube even when using an electronic cassette at an arbitrary position. An object of the present invention is to provide a radiographic imaging apparatus that does not impair portability.

  In order to achieve the above object, a radiographic imaging apparatus according to the present invention includes an X-ray tube that irradiates a subject with radiation, an X-ray imaging unit that captures radiation transmitted through the subject as a radiographic image, and the X-ray tube. A control unit for obtaining a captured image by controlling the sphere and the X-ray imaging unit, and a radiation shielding unit and a position notification unit for shielding transmission of radiation to the back side of the X-ray imaging unit, The notifying means transmits the relative position between the X-ray tube and the X-ray imaging unit to the control unit, and the control unit adjusts the position of the X-ray tube based on the information based on the obtained relative position. It is characterized by.

  According to the radiographic image capturing apparatus according to the present invention, the type and presence / absence of the X-ray shielding unit and the electronic cassette are detachably provided to a plurality of types of imaging units having different sizes, thereby determining the type and presence / absence thereof. Detection can be determined. Even when shooting at an arbitrary position as an electronic cassette, the X-ray shielding that matches the shooting conditions minimizes the increase in weight and limits the shooting by aligning and combining the relative positions of the X-ray tubes. By doing it automatically, the danger is low and the work becomes easy.

1 is a cross-sectional view of an electronic cassette of Example 1. FIG. It is explanatory drawing of the usage example of an electronic cassette. FIG. 6 is a configuration diagram of an X-ray detection unit according to a second embodiment. It is explanatory drawing of an image receiving center and alerting | reporting unit relative positional relationship. It is a block diagram of a X-ray shielding part. It is a flowchart figure of a control method.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a cross-sectional view of an electronic cassette capable of capturing a moving image as a radiographic image of radiation transmitted through a subject. The housing 2 of the electronic cassette 1 that is an X-ray imaging unit has a structure in which a housing lid 2b made of a material having a high X-ray transmittance is sealed in a housing body 2a. A base 4 is held in the housing main body 2 a via a fixing portion 3. On the base 4, the photoelectric conversion element 5 b is two-dimensionally formed on the substrate 5 a made of a glass plate in consideration of the influence of the chemical action with the semiconductor element, temperature resistance of the semiconductor process, dimensional stability, and the like. It is arranged. Further, an X-ray detection panel 5 in which a fluorescent plate 5c obtained by applying a phosphor of a metal compound to a resin plate is integrated by adhesion is laminated on the photoelectric conversion element 5b.

  The photoelectric conversion element 5b is connected to a circuit board 7 for processing an electric signal converted by the photoelectric conversion element 5b via a flexible circuit board 6. A relay control unit 8 is connected to the circuit board 7, and the relay control unit 8 is connected to a control unit (not shown) outside the housing 2 through an external connection cable 9 for power supply and signal transfer. Has been.

  FIG. 2 shows a configuration diagram of a state in which the electronic cassette 1 shown in FIG. 1 is used in combination with the imaging table 11 as an example of using the electronic cassette 1 at an arbitrary position. The imaging table 11 includes an imaging table main body 12 and a top plate 13 that causes the subject to lie down.

  An X-ray generator 14 is attached to a ceiling (not shown) above the top plate 13, and the X-ray generator 14 supports an X-ray tube 16 via a tube holder 15. The tube holding portion 15 is a position where the irradiation direction of the X-ray tube 16 can be rotated (x, z axis), the height can be moved up and down (z direction), and moved in the plane direction (x, y direction) with respect to the floor surface. An adjustment mechanism is provided.

  An X-ray detector 17 that detects X-rays is placed on the top plate 13. The X-ray detection unit 17 has a state detection function for detecting the inclination relative to the floor and the three-dimensional position coordinates on the X-ray shielding unit 18 which is a radiation shielding unit for shielding radiation. A notification unit 19 having position notification means is stacked. Since the X-ray detection unit 17 has a structure in which the image receiving plane can be installed in the parallel direction and the vertical direction with respect to the top plate 13, it can also cope with horizontal X-ray irradiation imaging. The X-ray shielding unit 18 has a function of shielding X-rays toward the back side of the electronic cassette 1 in the plane range including the peripheral edge 30 mm with respect to the image receiving plane of the electronic cassette 1. Can be held and fixed at a predetermined position.

  The X-ray generator 14 and the X-ray detector 17 are respectively connected to the controller 20, and the controller 20 has a function of controlling the position adjustment mechanism of the tube holder 15, the X-ray tube 16 and the electronic cassette 1. For example, a function for controlling photographing, a function for performing image processing, and the like. The relative position between the X-ray tube 16 and the X-ray detection unit 17 can be adjusted by moving and rotating the tube holding unit 15.

  Also, the initial position information in which the position information of the X-ray tube 16 at a certain arbitrary position is defined as the coordinate origin in the three-dimensional space of the imaging room in which the radiographic image capturing apparatus is installed is registered in the control unit 20. ing.

  The X-ray shielding part 18 on which the electronic cassette 1 is placed and the contact surface of the electronic cassette 1 are made of materials having different friction coefficients. For example, by making the friction coefficient smaller than that of the electronic cassette 1, the X-ray shielding part 18 slides on the top plate 13. It can be made easier. Since the electronic cassette 1 is detachable from the X-ray shielding unit 18 and the notification unit 19, X-rays may be used as necessary when taking the electronic cassette 1 in shooting conditions such as moving images / still images and transporting it to another system. The shield 18 can be attached and detached to perform shooting and movement.

  A receiving unit (not shown) provided in the notification unit 19 receives a radio signal transmitted from a transmitting unit (not shown) installed at three locations in the photographing room, thereby determining the three-dimensional position coordinates of the electronic cassette 1. be able to. Using this state detection function, the notification unit 19 calculates a value obtained by correcting the tilt and the relative position with respect to the electronic cassette 1 in addition to its own position coordinates, and sends the position information of the center of the imaging area of the electronic cassette 1 to the control unit 20. introduce.

  Then, the control unit 20 calculates an appropriate position of the X-ray tube 16 based on the imaging area information of the electronic cassette 1 transmitted from the notification unit 19 and the irradiation position information including the irradiation distance that matches the imaging conditions. Adjust the position. Further, the relative positions of the X-ray tube 16 and the electronic cassette 1 can be adjusted by automatically controlling and adjusting the position adjusting mechanism of the tube holding unit 15. Such a system configuration enables easy photographing by automatic alignment regardless of the photographing direction and the installation location.

  Further, in the case of supporting a plurality of types of electronic cassettes 1 having different sizes, one type can be used as long as the structure can be adapted to the maximum size electronic cassette 1 and the image receiving centers of the various types of electronic cassettes 1 can be held and fixed at the same position. X-ray shielding part 18 may be prepared.

  However, depending on the type of electronic cassette, the weight increases excessively and the operability deteriorates. Therefore, in the second embodiment, in consideration of these points, in addition to the first embodiment, a plurality of types of electronic cassettes having different sizes are supported.

  As shown in FIG. 3, the notification unit 25 is a detachable common unit for the electronic cassettes 21 and 22 having different sizes and the X-ray shielding units 23 and 24 adapted to the sizes of the electronic cassettes 21 and 22. Yes.

  The notification unit 25 has a function of detecting a combination of the electronic cassettes 21 and 22 and the X-ray shielding units 23 and 24. In addition, since the notification unit 25 is relatively expensive compared to the X-ray shielding units 23 and 24, the notification unit 25 is effective in terms of management and cost reduction by being a common unit.

  FIG. 4 is a plan view in which the electronic cassette 21 and the notification unit 25 are combined. The relative position between the image receiving surface center point A of the electronic cassette 21 and the position detection point B in the notification unit 25 is different for each type of electronic cassette. It is fixed in a predetermined positional relationship. That is, the value of the three-dimensional coordinate (x, y, z) of the image receiving surface center point B when the position detection point B is set to the three-dimensional coordinate origin (0, 0, 0) is recognized, and this value is used as correction data. Used.

  The electronic cassettes 21 and 22 and the X-ray shielding units 23 and 24 are each provided with an ID tag (not shown). The cassette type detection unit and the shielding unit type detection unit (not shown) in the notification unit 25 are used to identify the ID tag. Identify. Further, the identified ID tag is collated to determine whether or not the combination of both is appropriate.

  The correction data of the electronic cassette 21 is registered in the notification unit 25 or the control unit 20, and the correction data matched with the identified ID tag is selected by detecting various types of electronic cassettes. .

  Also, as shown in FIG. 5A, the X-ray shielding part 41 and the expansion X-ray shielding part 42 are assembled as shown in FIG. it can. In this way, by configuring the X-ray shielding part 41 to be compatible with a plurality of types of electronic cassettes, it is possible to minimize an increase in weight even when a plurality of types of electronic cassettes having different sizes are used. , Operability is improved.

  FIG. 6 is a work flowchart of the second embodiment. First, in step S1, it is determined whether or not the notification unit 25 and the electronic cassette are connected. If it is determined that the electronic cassette is not connected, the process proceeds to step S2, and it is recommended that automatic alignment photographing cannot be performed. If it is determined that the electronic cassette is connected, the process proceeds to step S3, the ID tag of the electronic cassette is detected, an appropriate correction value is selected from the identified ID tag in step S4, and the image is received in step S5. Obtain center correction data. In step S6, the image receiving center correction data and the inclination data detected from the inclination sensor of the notification unit are obtained. In step S7, the three-dimensional coordinate reception data detected from the three-dimensional position coordinate detection is obtained. In step S8, these data are added together to calculate cassette position data.

  Next, the process proceeds to step S9, where the presence / absence of the X-ray shielding unit 41 is detected, and if it is determined that the X-ray shielding unit 41 is not present, the process proceeds to step S10, the imaging mode is limited, and only still image shooting can be performed. Proceeding to S11, the photographing setting operation is permitted.

  If it is determined in step S9 that the X-ray shielding unit 41 is present, the process proceeds to step S12, the type of the X-ray shielding unit 41 is detected, collated with the type of electronic cassette detected in step S3, and an appropriate combination is obtained. to decide. If it is determined in step S12 that the combination is not appropriate, the process proceeds to step S13 to give a warning. In step S13, the frame rate can be limited or shooting can be prohibited.

  If it is determined in step S12 that the combination is appropriate, the process proceeds to shooting mode selection in step S14. If the shooting mode detects the selection of a still image in step S14, the process proceeds to step S15 and attention is recommended. If the selection of a moving image is detected, the process proceeds to step S11, and permission is given by setting the shooting conditions.

  In step S16, the X-ray detection unit is set. In step S17, the X-ray tube is manually moved to an approximate position, and imaging conditions are set using the operation panel. Subsequently, when an alignment operation is executed in step S18, in step S19, the control unit 20 reads tube position data, focal length data set in imaging conditions, and cassette position data information. In step S20, the amount of movement of the X-ray tube 16 is calculated from these data. Based on the amount of movement, the X-ray tube position adjusting mechanism in step S21 is controlled to automatically execute alignment. In step S22, photographing is performed after the alignment is completed.

  With such a system configuration, it is possible to perform imaging by automatic alignment with reduced setting errors for a plurality of types of electronic cassettes having different sizes, and it is possible to improve the efficiency of imaging.

1, 2, 22 Electronic cassette 11 Imaging table 14 X-ray generator 17 X-ray detection unit 18, 23, 24, 41, 43 X-ray shielding unit 19, 25 Notification unit 20 Control unit 42 X-ray shielding unit for expansion

Claims (7)

  An X-ray tube that irradiates a subject with radiation, an X-ray imaging unit that captures radiation transmitted through the subject as a radiation image, and a control for obtaining an image captured by controlling the X-ray tube and the X-ray imaging unit And a radiation shielding means and a position notification means for shielding transmission of radiation to the back side of the X-ray imaging section, and the position notification means is a relative position between the X-ray tube and the X-ray imaging section. Is transmitted to the control unit, and the control unit adjusts the position of the X-ray tube based on the obtained information based on the relative position.   The radiographic image capturing apparatus according to claim 1, wherein the position notification unit and the radiation shielding unit are configured to be detachable from the X-ray imaging unit.   The position notification means can be attached to and detached from a plurality of types of the X-ray imaging units or / and the radiation shielding units having different sizes, and the radiation shielding unit is an appropriate size for the plurality of types of X-ray imaging units having different sizes. The radiographic imaging apparatus according to claim 1, comprising:   The position notifying unit has a cassette type detecting unit for determining the type of the X-ray imaging unit, and enables holding and fixing at a predetermined relative position for each of a plurality of types of X-ray imaging units having different sizes. Determining the relative position of the X-ray imaging unit detected by the detecting means with respect to the center of the imaging region, and transmitting the determined relative position to the control unit in consideration of the determined information. The radiographic image capturing apparatus according to claim 2, wherein the radiographic image capturing apparatus is a radiographic image capturing apparatus.   The position notification means determines the type or / and presence / absence of the X-ray imaging unit and / or the radiation shielding unit, and warns when a combination of the X-ray imaging unit and the radiation shielding unit is not properly selected. The radiographic image capturing apparatus according to claim 2, further comprising a unit for performing the operation and / or a unit for limiting the frame rate or prohibiting the imaging.   The radiographic image capturing apparatus according to claim 1, wherein the radiation shielding unit holds the X-ray imaging unit in a parallel direction or a vertical direction with respect to a floor surface.   2. The radiographic image capturing apparatus according to claim 1, wherein a contact surface of the radiation shielding unit with the top plate is different from a friction coefficient on a back side of the X-ray imaging unit.

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