JP4753742B2 - Radiation imaging equipment - Google Patents

Description

The present invention relates to a ray imaging apparatus release you capturing a radiation image of an object by using a grid for removing scattered component of the radiation.

  2. Description of the Related Art Conventionally, in a radiographic imaging apparatus, for example, an X-ray imaging apparatus used in the medical field, a grid is provided between a radiation source that emits radiation and a detector that receives the radiation, and X-rays generated in a subject or the like. Scatter components are removed. As such a grid, for example, a structure in which a plurality of lead plates are arranged in parallel at intervals is used.

  By the way, in general, the grid is formed by arranging lead plates in a grid pattern in one direction, and the radiation other than the scattering component is partially removed. Called image spots). Therefore, as a method for preventing such image spots, many approaches have been made to reduce image spots by moving the grid itself during X-ray irradiation (for example, reciprocating in parallel) to reduce the grid contrast. .

  However, even if the grid itself is moved as described above, for example, the moving speed is zero at the return position in the reciprocating motion, and in this case, the grid is stopped. For this reason, the grid stops at the same folding position for each round trip, resulting in image spots in the captured image.

  Therefore, Patent Document 1 describes that in a radiation imaging apparatus that performs grid movement control, the grid movement speed is controlled in accordance with radiation intensity fluctuations and irradiation time. However, the movement control of the grid has a problem that depends on the performance of an automatic exposure control (AEC) apparatus, and it is necessary to control the movement of the grid while detecting various kinds of information such as intensity fluctuations. Therefore, there is a problem that the system becomes complicated.

  Patent Document 2 describes a conventional technique for locally reducing the acceleration / deceleration time (stagnation time) at the turn-back position by locally increasing the moving speed in the vicinity of the turn-back position in the grid reciprocation. . However, also in this case, the grid stops at the same folding position for each round trip, and image spots occur. Furthermore, since the grid is folded back at a high speed, the burden on the drive unit becomes large.

JP-A-10-305030 JP 2000-116648 A

The present invention has been made in consideration of the conventional problems described above, with a simple configuration, and to provide the possibility and to that radiological image capturing apparatus to reduce the image spots by the grid.

The present invention is a radiographic image capturing apparatus that captures a radiographic image of a subject with radiation irradiated by the radiation irradiating apparatus, the radiographic image information acquiring unit acquiring radiographic image information of the subject, the radiation irradiating apparatus, A grid disposed between the radiation image information acquisition unit and removing a scattered component of radiation; a second direction opposite to the first direction and the first direction on the radiation image information acquisition unit; comprising a grid moving unit for reciprocating in a direction, and gradually moving means for moving to the first direction and the second of said grid the first direction that reciprocates in a direction, the grid moving unit, A corrugated guide portion reciprocating in the first direction and the second direction is formed on the surface, and the grid is moved along the guide portion by rotating around an axial direction. Characterized Rukoto to have a cylindrical member to the reciprocating.

According to radiological imaging apparatus of the present invention, when performing the radiation image capturing by moving the grid, the grid at the same position can be prevented from being stopped. For this reason, the image spot by a grid can be suppressed significantly.

Hereinafter, like the embodiment will engage Ru radiological imaging apparatus of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an overall configuration diagram of a radiographic image processing system 10 including a mammography apparatus 12 as a radiographic imaging apparatus according to the first embodiment of the present invention. The mammography apparatus 12 is an apparatus that captures and acquires radiation image information of a breast that is a subject. In the present embodiment, the present invention will be described by taking the mammography apparatus 12 as an example of a radiographic image capturing apparatus. However, the present invention is not limited to this.

  A radiographic image processing system 10 is a CAD (Computer) that is an image processing apparatus that includes the mammography apparatus 12 and an image processing unit that performs image processing such as automatic detection of a lesion site on the radiographic image information acquired by the mammography apparatus 12. Aided Diagnosis) device 14 and image display devices (viewers) 16 and 18 for displaying radiographic image information image-processed by CAD device 14 for diagnosis by a doctor, and image output for outputting radiographic image information to a film or the like A device (printer) 20 and a radiation image information storage device 22 that is a server for storing radiation image information to which a diagnosis result by a doctor is added are provided. These devices are connected to each other by a network 24.

  FIG. 2 is a perspective explanatory view of the mammography apparatus 12. The mammography apparatus 12 includes a base 26 that is installed in an upright state, an arm member 30 that is fixed to a turning shaft 28 that is disposed at a substantially central portion of the base 26, and a mammo of a subject 32 that is a subject. A radiation source for irradiating radiation to the (breast) is housed, and radiation image information is obtained by detecting radiation that has passed through a mammo that is a subject, and a radiation source housing section 34 fixed to one end of the arm member 30. An imaging table 36 that houses the solid state detector to be fixed and fixed to the other end of the arm member 30, and a pressing plate 38 that presses and holds the mammo of the subject 32 against the imaging table 36.

  The arm member 30 to which the radiation source storage unit 34 and the imaging stand 36 are fixed is configured to be adjustable in the imaging direction with respect to the mammo of the subject 32 by rotating in the arrow A direction about the rotation axis 28. The pressing plate 38 is disposed between the radiation source storage unit 34 and the imaging table 36 in a state of being connected to the arm member 30 and is configured to be displaceable in the arrow B direction.

  On the other hand, the base 26 displays imaging information of the subject 32 detected by the mammography device 12, imaging information such as the imaging direction, ID information of the subject 32, and the like, if necessary. Is displayed.

  In addition, the base 26 is directed to detect a specific part having a specific positional relationship with respect to a mammo that is an imaging part of the subject 32 on left and right parts having a vertical line including the pivot axis 28 as an axis of symmetry. Subject detection sensors 42a and 42b (detection units) having high characteristics are disposed. As the subject detection sensors 42a and 42b, for example, an infrared sensor that detects infrared rays reflected by the specific portion or infrared rays from the outside, a CCD camera that acquires image information of the specific portion, and the like can be used.

  FIG. 3 is a perspective view showing an internal configuration of the imaging stand 36 in the mammography apparatus 12. 4 is a schematic explanatory diagram of the internal configuration of the imaging table 36 in a cross section taken along line IV-IV in FIG. 3, and a mammo 44 that is an imaging region of the subject 32 is interposed between the imaging table 36 and the pressing plate 38. Indicates the set state.

  A solid state detector 46 (radiation image information acquisition unit) that accumulates radiation image information based on the radiation X output from the radiation source built in the radiation source storage unit 34 and outputs it as an electrical signal inside the imaging table 36. In order to read out radiographic image information stored and recorded in the solid state detector 46, a reading light source 48 for irradiating the solid state detector 46 with reading light, and an unnecessary charge accumulated in the solid state detector 46 are removed. And an erasing light source 50 for irradiating the solid state detector 46 with erasing light. In addition, a grid 52 for removing a scattered component of the radiation X generated in the mammo 44 as a subject is provided on the upper portion of the solid detector 46 (between the radiation source storage unit 34 and the solid detector 46).

  The solid state detector 46 is a direct conversion type and light readout type radiation solid state detector that accumulates radiation image information including the radiation X transmitted through the mammo 44 as an electrostatic latent image and reads light from the reading light source 48. Scanning generates a current corresponding to the electrostatic latent image. The solid state detector 46 is configured to move to a part close to the mammo 44 when recording radiographic image information, and to move to a part close to the erasing light source 50 when erasing.

  More specifically, the solid state detector 46 is formed on a glass substrate, transmits a first conductive layer that transmits radiation X, a recording photoconductive layer that generates charges when irradiated with the radiation X, A charge transport layer acting as a substantially conductive material for a transport polarity charge opposite to the latent image polarity charge, while acting as a substantially insulator for the latent image polarity charge charged in one conductive layer; The photoconductive layer for reading which produces | generates an electric charge by being irradiated and exhibits electroconductivity, and the 2nd conductive layer which permeate | transmits the radiation X are laminated | stacked in order. A power storage unit is formed at the interface between the recording photoconductive layer and the charge transport layer.

  The first conductive layer and the second conductive layer each constitute an electrode. The electrode of the first conductive layer is a two-dimensional flat plate electrode, and the electrode of the second conductive layer is a plurality of lines having a predetermined pixel pitch for detecting recorded radiographic image information as an image signal. Configured as an electrode. The arrangement direction of the linear electrodes corresponds to the main scanning direction, and the extending direction of the linear electrodes corresponds to the sub-scanning direction (see, for example, JP-A-2004-154409).

  The reading light source 48 includes, for example, a line light source configured by arranging a plurality of LED chips in a line, and an optical system that linearly irradiates the reading light output from the line light source onto the solid detector 46. The entire surface of the solid state detector 46 is moved by moving a line light source in which LED chips are arranged in a direction orthogonal to the extending direction of the linear electrode as the second conductive layer of the detector 46 in the extending direction of the linear electrode. Is scanned by exposure.

  The erasing light source 50 is preferably a light source that emits and extinguishes light in a short time and has very little afterglow. For example, the erasing light source 50 extends in the arrangement direction of the LED chips constituting the reading light source 48, and the arrangement direction. A plurality of external electrode type rare gas fluorescent lamps arranged in a direction perpendicular to the direction can be used.

  The grid 52 is configured by arranging a plurality of plates 56 made of, for example, a lead plate in parallel with each other with a predetermined interval (for example, about 0.3 mm) inside a rectangular frame 54 (FIGS. 5 and 5). 6). Each plate 56 is arranged so as to be directed to the radiation source (focal point). For this reason, the gaps 57 between the plates 56 are also formed so as to be directed to the radiation source, so that the grid 52 passes the unscattered radiation X and absorbs (removes) the scattered radiation X by the plate 56. To do.

  In order to prevent the shadow of the plate 56 from appearing in the radiation image information acquired by the solid state detector 46 and becoming an image spot on the grid 52, the grid 52 is placed on the grid 56 during imaging (during irradiation of radiation X). A grid moving mechanism 58 that moves in parallel in the direction perpendicular to the longitudinal direction (the direction of arrow C in FIG. 5) is attached.

  The grid moving mechanism 58 is attached to a motor 60 and a rotating shaft 62 of the motor 60 and is driven to rotate, and a substantially cylindrical rotating drum 64 (cylindrical member) having a sinusoidal groove 66 (guide portion) formed on the surface thereof. ), A ball screw 68 (threaded portion) projecting on the axial side surface opposite to the rotation shaft 62 of the rotating drum 64, and a support member 70 into which the ball screw 68 is screwed. As the screw portion, the ball screw 68 may not be used, and a screw portion may be directly formed on the circumferential surface of the rotating drum 64 and the screw portion may be screwed to the support member 70. Further, the rotational speed transmitted from the rotary drum 64 to the ball screw 68 or the like may be adjusted by a gear set or the like.

  As shown in FIG. 7, the rotating shaft 62 of the motor 60 has a hexagonal cross section and is inserted into the hexagonal hole 64 a of the rotating drum 64. Therefore, the rotary drum 64 can be rotated by the rotational driving force from the rotary shaft 62, and is supported in a freely displaceable manner without being fixed in the axial direction (the direction of arrow C in FIG. 5). The rotating shaft 62 and the hole 64a are not limited to the hexagonal shape described above, and may be various connecting methods such as a method of providing a key and a key groove as long as the rotating force can be transmitted and not fixed in the axial direction. Is mentioned.

  FIG. 8 shows a developed state of the circumferential surface where the groove 66 of the rotating drum 64 is formed. As shown in FIG. 8, the groove 66 has a sinusoidal shape.

  As described above, in the grid moving mechanism 58, the motor 60 and the rotary drum 64 are connected, and the ball screw 68 functioning as a feed screw is attached to the side surface of the rotary drum 64 opposite to the motor 60. Therefore, the rotating drum 64 advances in the direction of arrow C1 in FIG.

  A protrusion 72 is provided on the frame body 54 of the grid 52 so as to be directed toward the rotary drum 64, and the protrusion 72 is engaged with the groove 66 of the rotary drum 64. Further, guide members 74 that support the grid 52 so as to be able to move in parallel in the direction of arrow C in FIG. As a result, when the rotary drum 64 is driven to rotate by the motor 60, the grid 52 is synchronized with the amplitude of the groove 66 in the direction of arrow C due to the engagement between the groove 66 and the protrusion 72 and the guide action of the guide member 74. And move in the direction of arrow C1 while reciprocating in parallel. That is, the groove 66 or the like functions as a grid moving unit that reciprocates the grid 52 in the directions of the arrows C1 and C2, and a ball moving unit or the like that moves the groove 66 itself that is the grid moving unit in the direction of the arrow C1. Function as.

  FIG. 9 is a block diagram of a control circuit constituting the mammography apparatus 12.

  The mammography apparatus 12 includes a solid-state detector 46, a high-voltage supply unit 76 that supplies a high voltage to the solid-state detector 46, and a radiographic image that reads radiographic image information as an electrical signal from the solid-state detector 46 supplied with the high voltage. An imaging region determination unit 80 (acquisition of imaging region information) that determines an imaging region of the subject 32 by the mammography device 12 based on signals from the information reading unit 78, the subject detection sensors 42a and 42b, and the subject detection sensors 42a and 42b. Part), a turning position detection sensor 82 (imaging direction detection part) for detecting the turning position of the arm member 30 with respect to the base 26, and a position that is the imaging direction of the radiation image information based on a signal from the turning position detection sensor 82. The radiation image supplied from the position determination unit 84 (imaging direction information acquisition unit) and the radiation image information reading unit 78 Distribution and, and an information storage unit 86 for storing together with position information is shooting direction information supplied from the body part information and the position determination unit 84 is supplied from the display operation unit 40 or the imaging region determination unit 80. The radiation image information, imaging region information, and position information stored in the information storage unit 86 are transmitted to each device connected to the network 24 via an interface (I / F) 88.

  The radiation image processing system 10 of this embodiment is basically configured as described above, and the operation thereof will be described next.

  First, using a console, an ID card, etc. (not shown), ID information related to the subject 32, an imaging method, and the like are set. In this case, the ID information includes information such as the name, age, and sex of the examinee 32, and can be obtained from a host device connected to the network 24 or an ID card possessed by the examinee 32. Is possible. In addition, the imaging method includes information such as an imaging region and an imaging direction instructed by a doctor, and can be acquired from a higher-level device connected to the network 24 or input by a technician from a console. These pieces of information can be displayed and confirmed on the display operation unit 40 of the mammography apparatus 12.

  Next, the engineer sets the mammography apparatus 12 to a predetermined state according to the designated imaging method. For example, as a method of photographing the mammo 44, head-to-tail direction (CC) photographing (refer to FIG. 4) in which radiation X is irradiated from above, and side direction (ML) in which radiation X is irradiated from the side is photographed. There is imaging, inside / outside oblique (MLO) imaging in which radiation X is applied from an oblique direction, and the arm member 30 is pivoted about the pivot axis 28 in accordance with these imaging methods.

  In this case, the turning position detection sensor 82 detects the turning angle of the arm member 30 and supplies angle information to the position determination unit 84. The position determination unit 84 determines the position of the mammography apparatus 12 that is the photographing direction based on the supplied angle information.

  Next, the subject 32 is set to the designated imaging state with respect to the mammography apparatus 12. For example, when performing head-to-tail direction (CC) imaging of the left mammo 44 of the subject 32, as shown in FIG. 4, after the left mammo 44 is placed on the imaging table 36, the pressing plate 38 is depressed, A mammo 44 is held between the imaging stand 36 and the pressing plate 38.

  At this time, in a state where the left mammo 44 is held between the imaging stand 36 and the pressing plate 38, the subject 32 stands at a position on the right side with respect to the base 26. In this case, the right abdomen (specific part) of the subject 32 is disposed in front of the subject detection sensor 42b disposed on the base 26, and the subject 32 is not disposed in front of the subject detection sensor 42a. . Therefore, when the subject detection sensors 42 a and 42 b are composed of sensors that detect infrared rays reflected by the subject 32, only the subject detection sensor 42 b detects the subject 32. Therefore, the imaging region determination unit 80 determines that the imaging region of the subject 32 is the left mammo 44 based on the signals from the subject detection sensors 42a and 42b.

  On the other hand, when the right mammo 44 is held between the imaging table 36 and the pressing plate 38, only the subject detection sensor 42 a detects the subject 32, so the imaging region of the subject 32 is the right mammo 44. It can be determined that

  If the subject detection sensors 42a and 42b are arranged in a region where they are not interfered with by the arm member 30, the test is performed in the same manner even when the imaging method is the lateral (ML) imaging and the inside / outside oblique (MLO) imaging. The imaging region of the person 32 can be determined. Note that only one of the subject detection sensors 42a and 42b can be provided on the arm member 30, and the imaging region of the subject 32 can be determined based on whether or not the subject 32 is detected. Further, the subject detection sensors 42a and 42b may be CCD cameras instead of infrared sensors, and an imaging region may be detected based on image information of the captured subject.

  The determination result of the imaging region by the imaging region determination unit 80 is displayed on the display operation unit 40. The engineer confirms the displayed determination result. If the determination result is inappropriate due to, for example, malfunction of the subject detection sensors 42a and 42b, the engineer operates the display operation unit 40 to shoot. It is possible to change the site.

  After the imaging region of the subject 32 is determined, the radiation source stored in the radiation source storage unit 34 is driven to capture radiographic image information.

  The radiation X transmitted through the mammo 44 held between the pressing plate 38 and the imaging table 36 is irradiated to the solid state detector 46 accommodated in the imaging table 36. The solid state detector 46 is disposed at a position indicated by a two-dot chain line in FIG. 4 after unnecessary light is removed by irradiating the entire surface with erasing light from the erasing light source 50 prior to photographing.

  During such imaging, for example, the shadow of the grid 52 appears in the radiation image for a predetermined time including the irradiation time of the radiation X (from a predetermined time before the start of the irradiation of the radiation X to a predetermined time after the end of the irradiation of the radiation X). In order to prevent this, the grid 52 is moved (displaced) by the grid moving mechanism 58.

  That is, first, the motor 60 is driven a predetermined time before the start of irradiation with the radiation X, and the rotary drum 64 is driven to rotate. Then, since the grid 52 is regulated by the guide member 74 so as to be displaceable only in the direction of arrow C in FIG. 5, the waveform of the groove 66 (by the rotation of the rotating drum 64 and the engagement of the protrusion 72 and the groove 66) ( It moves so as to reciprocate in the direction of arrow C according to the amplitude of FIG. That is, the grid 52 repeats the movement in the arrow C1 direction (first direction) and the movement in the arrow C2 direction (second direction).

  At this time, in this embodiment, since the ball screw 68 is attached to the side surface of the rotating drum 64 opposite to the rotating shaft 62, the ball screw 68 is screwed to the support member 70 in the direction of the arrow C1. Advance. For this reason, the rotating drum 64 itself moves in the direction of the arrow C1 by the advance of the ball screw 68. As a result, the engagement point between the protrusion 72 and the groove 66 has a locus as shown in FIG. I will draw.

  Accordingly, the grid 52 gradually moves in the C1 direction while reciprocating in the directions of the arrows C1 and C2. Thereby, the return position P1 (first return position) from the movement in the arrow C1 direction to the movement in the arrow C2 direction, and the return position P2 (second) from the movement in the arrow C2 direction to the movement in the arrow C1 direction. ) Is gradually displaced in the direction of the arrow C1.

  That is, when n is a natural number, the n-th turn-back position P1 and the (n + 1) -th turn-back position P1 at the turn-back position P1 that turns the grid 52 from the movement in the arrow C1 direction to the movement in the arrow C2 direction are the grid 52 ( The rotary drum 64) is displaced by the moving distance in the direction of the arrow C1. Similarly, at the turn-back position P2 where the grid 52 moves from the arrow C2 direction to the arrow C1 direction, the n-th turn position P2 and the (n + 1) -th turn position P2 of the grid 52 (the rotating drum 64). It is displaced by the moving distance in the direction of the arrow C1.

  At the turn-back positions P1 and P2 as described above, the moving speed of the grid 52 becomes zero. Therefore, in consideration of a very short time, the grid 52 stops and an inconvenience that an image spot due to the grid 52 appears on the radiographic image occurs. End up. However, in the present embodiment, as described above, the folding positions P1 and P2 are gradually displaced in the direction of the arrow C1, so that it is avoided that the grid 52 always stops at the same position, and the image spots due to the grid 52 appear on the radiographic image. Can be greatly suppressed.

  The traveling distance of the grid 52 (rotating drum 64) in the direction of the arrow C1 is, for example, when the distance between the plates 56 of the grid 52 is dg and the total number of turns is p (≧ 2). While the grid 52 performs one-way reciprocation in the reciprocation in the direction of arrow C (for example, movement from the turn-back position P1 to the turn-back position P2), it is preferable to advance a distance of m · dg / (p + 1). . However, in this case, m is an integer equal to or greater than 1, and m / (p + 1) is not an integer.

  Then, a high voltage is applied from the high voltage supply unit 76 between the first conductive layer and the second conductive layer, and further, the radiation X carrying the radiation image information is applied to the solid state detector 46 while the grid 52 is moving. Then, positive and negative charge pairs are generated in the recording photoconductive layer of the solid state detector 46, and the negative charges are accumulated in the power storage unit formed at the interface between the recording photoconductive layer and the charge transport layer. . The amount of the accumulated negative charge, that is, the latent image polar charge, is approximately proportional to the dose of the radiation X transmitted through the mammo 44. The positive charge generated in the recording photoconductive layer is attracted to the first conductive layer, and disappears in combination with the negative charge supplied from the high voltage supply unit 76.

  At this time, as described above, since the grid 52 is translated (reciprocating in the directions of arrows C1 and C2) and translated (moving in the direction of arrow C1), the grid 52 removes the scattered component of the radiation X. However, it is possible to prevent the shadow of the grid 52 from being recorded in the radiographic image information and causing image spots on the radiographic image. In addition, it is good to retreat the grid 52 (rotary drum 64) to the arrow C2 direction (origin position) by reversely rotating the motor 60 after such radiation irradiation.

  After the radiographic image information is captured, the solid state detector 46 moves to the reading position indicated by the solid line in FIG. Next, when the reading light source 48 moves in the direction of the arrow along the solid state detector 46 and is irradiated with reading light, positive and negative charge pairs are generated in the reading photoconductive layer, and the positive charges are accumulated in the power storage unit. It moves in the charge transport layer so as to be attracted to the negative charge (latent image polar charge), and disappears in combination with the negative charge of the power storage unit. On the other hand, the negative charge generated in the reading photoconductive layer is combined with the positive charge supplied from the high voltage supply unit 76 to the second conductive layer and disappears. In this way, the negative charges accumulated in the solid state detector 46 are extinguished by charge coupling, and a current is generated in the solid state detector 46 due to the movement of the charge during the charge coupling.

  The radiation image information reading unit 78 reads the current generated in the plurality of linear electrodes constituting the second conductive layer as radiation image information and stores it in the information storage unit 86. In this case, the information storage unit 86 is supplied with the imaging region information of the subject 32 determined by the imaging region determination unit 80 via the display operation unit 40, and the position determined by the position determination unit 84. Information is supplied. Therefore, the radiation image information is stored in the information storage unit 86 in a state associated with the imaging region information and the position information of the subject 32. Therefore, an engineer who performs imaging can perform imaging without being aware of the imaging order with respect to the imaging region and the imaging method, for example.

  The solid state detector 46 from which the radiation image information has been read is irradiated with erasing light emitted from an erasing light source 50 to remove the accumulated unnecessary charges in order to perform the next imaging.

  On the other hand, each apparatus connected to the network 24 acquires radiation image information, its imaging region information, and position information from the mammography apparatus 12 via the network 24 and performs predetermined processing.

  That is, the CAD device 14 automatically detects a lesion site or the like with respect to the radiation image information in accordance with the acquired imaging site information and position information, and performs processing such as marking indicating the lesion site on the radiation image information. In this case, the radiographic image information is attached with the imaging site information and the position information, so that automatic detection processing of a lesion site or the like can be performed easily and with high accuracy. Furthermore, in this embodiment, the scattering component is removed by the grid 52, and image spots on the grid 52 are also suppressed, so that more accurate detection is possible.

  In addition, the image display devices 16 and 18 acquire the imaging region information and position information automatically acquired by the mammography device 12 and information such as the lesion site detected by the CAD device 14 via the network 24, and the information. Accordingly, a highly accurate diagnosis can be performed.

  Furthermore, imaging part information, position information, and radiation image information are transmitted to the image output device 20 and the radiation image information storage device 22 via the network 24 as necessary, and output to a film or the like using the image output device 20. At the same time, it can be stored in the radiation image information storage device 22.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 11 and 12, the same reference numerals as those shown in FIGS. 1 to 10 indicate the same or similar configurations, and therefore the same or similar functions and effects are obtained, and so on. And

  In the second embodiment, compared to the grid moving mechanism 58 shown in FIG. 5 and the like, a grid moving mechanism 92 having no ball screw 68 and support member 70 and having a rotating drum 90 instead of the rotating drum 64 is provided. The point to prepare is different.

  As shown in FIG. 11, a groove 94 is formed in the rotating drum 90 in the grid moving mechanism 92. FIG. 12 shows a developed state of the circumferential surface where the groove 94 of the rotating drum 90 is formed.

  As shown in FIG. 12, the groove 94 has substantially the same shape as the locus (see FIG. 10) of the engagement point between the groove 66 and the protrusion 72 in the first embodiment. Has more than the wavelength. For this reason, the grid moving mechanism 92 displaces the folding positions P1 and P2 without using the ball screw 68 or the like, and translates (reciprocates in the directions of arrows C1 and C2) and translates (arrow C1). Movement in the direction).

  That is, the groove part 94 which is a grid moving part in the present embodiment includes, for example, a first turning part 94a that turns back the movement of the n-th grid 52 in the arrow C1 direction at the first position, and the (n + 1) th grid 52. And a second folding part 94b that folds the movement in the arrow C1 direction at a second position different from the first position (moves in the arrow C1 direction).

  Therefore, in this embodiment, since components such as the ball screw 68 and the support member 70 can be reduced, the scattered components of the radiation X can be removed and the image spots caused by the grid 52 can be reduced while reducing the cost and further simplifying the system. It becomes possible to suppress.

  As shown in FIG. 11, a rotating shaft 69 projects from an axial side surface opposite to the rotating shaft 62 of the rotating drum 90, and the rotating shaft 69 is supported by a bearing (not shown) provided on the support member 71. When supported, the rotating drum 90 can be rotated more smoothly.

  In addition, the shape of the groove part 94 in this embodiment is not restricted to the shape as shown in FIG. 12, For example, even if it is a shape as shown in FIG. 13, the grid 52 is reciprocated, displacing the folding positions P1 and P2. It is possible.

  Next, a third embodiment of the present invention will be described with reference to FIGS.

  In the third embodiment, a substantially circular grid 96 is provided instead of the grid 52 in each of the above embodiments, and a grid moving mechanism 98 is provided instead of the grid moving mechanisms 58 and 92.

  As shown in FIGS. 14 and 15, the grid 96 has a substantially circular shape and plates 56 are arranged inside the frame body 100 in which the gear portion 99 is formed. Further, the frame body 100 abuts on the four guide members 102, and the grid 96 is rotatably supported by the guide members 102.

  The grid moving mechanism 98 includes a gear 104 that meshes with the gear portion 99 of the frame 100 and a motor 106 that rotationally drives the gear 104.

  As described above, in this embodiment, the grid 96 is rotated around the normal direction of the solid state detector 46 by the motor 106 at the time of photographing, thereby preventing the grid 96 from being stopped and causing image spots. Can be suppressed. Since the center point O of the grid 96 does not move, the plate 56 may be arranged avoiding the center point O.

  Note that the grid 96 in the present embodiment is not limited to the shape shown in FIG. 14, and for example, as shown in FIG. 16, the plates 56 may be arranged in a mesh shape. Also in this case, it is preferable that the plate 56 is not disposed at the center point O of the grid 96.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

  For example, the groove portions 66 and 94 in each of the above embodiments may be formed in a protrusion shape, and a groove-shaped recess portion may be provided at the tip portion of the protrusion 72.

  Further, instead of the solid state detector 46, when irradiated with radiation, a part of the radiation energy is accumulated, and then excited light emission corresponding to the accumulated energy is performed by irradiating excitation light such as laser light or visible light. Alternatively, a stimulable phosphor sheet having a stimulable phosphor layer or a cassette containing an X-ray film may be used.

1 is an overall configuration diagram of a radiation image processing system according to a first embodiment of the present invention. It is a perspective explanatory view of the mammography device of the embodiment. It is a perspective view which shows the internal structure of the imaging stand in the said mammography apparatus. FIG. 2 is a schematic explanatory diagram of an internal configuration of a photographing stand in the mammography apparatus. It is a top view of the imaging stand in the said mammography apparatus. FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. 3. It is an expansion perspective view which shows the connection structure of the motor and rotary drum of the grid moving mechanism in the said mammography apparatus. It is explanatory drawing which shows the state which expand | deployed the surface of the circumferential direction in which the groove part of the said rotating drum is formed. It is a block diagram of the control circuit which comprises the said mammography apparatus. It is explanatory drawing which shows the locus | trajectory of the engagement point of the protrusion of a grid and the said groove part in the said mammography apparatus. It is a top view of the imaging stand in the 2nd Embodiment of this invention. It is explanatory drawing which shows the state which expand | deployed the surface of the circumferential direction in which the groove part of the rotating drum in the said embodiment is formed. It is explanatory drawing which shows the state which expand | deployed the surface of the circumferential direction in which the groove part of the rotating drum in the modification of the said embodiment is formed. It is a top view of the imaging stand in the 3rd Embodiment of this invention. 2 is a schematic explanatory diagram of an internal configuration of the photographing stand. FIG. It is a top view of the imaging stand in the modification of the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Radiation image processing system 12 ... Mammography apparatus 14 ... CAD apparatus 16, 18 ... Image display apparatus 20 ... Image output apparatus 22 ... Radiation image information storage apparatus 24 ... Network 26 ... Base 32 ... Subject 34 ... Radiation source storage Unit 36 ... photographing base 40 ... display operation unit 42a, 42b ... subject detection sensor 44 ... mammo 46 ... solid state detector 52, 96 ... grid 54, 100 ... frame 56 ... plate 58, 92, 98 ... grid moving mechanism 60, DESCRIPTION OF SYMBOLS 106 ... Motor 62, 69 ... Rotary shaft 64, 90 ... Rotary drum 66, 94 ... Groove 68 ... Ball screw 70, 71 ... Support member 72 ... Protrusion 74, 102 ... Guide member 104 ... Gear

Claims (3)

A radiographic image capturing device that captures a radiographic image of a subject by radiation irradiated by the radiation irradiating device,
A radiation image information acquisition unit for acquiring radiation image information of the subject;
A grid disposed between the radiation irradiating device and the radiation image information acquisition unit to remove a scattered component of radiation;
A grid moving unit for reciprocating in a second direction opposite the first direction and the first direction the grid on the radiographic image information acquisition unit,
Moving means for gradually moving the grid that reciprocates in the first direction and the second direction in the first direction ;
Equipped with a,
The grid moving part is formed with a corrugated guide part that reciprocates in the first direction and the second direction on the surface, and rotates around the axial direction to move the grid along the guide part. radiographic imaging apparatus according to claim Rukoto to have a cylindrical member to the reciprocating. The radiographic imaging apparatus according to claim 1,
The radiographic imaging apparatus according to claim 1, wherein the moving unit includes a grid moving unit moving unit that gradually moves the columnar member in the first direction along an axial direction. The radiographic imaging apparatus according to claim 1,
The radiographic apparatus according to claim 1, wherein the moving unit includes the guide unit in which a folding position between the first direction and the second direction in the waveform is displaced.

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