Radiation imaging device and radiation imaging system

Abstract

A radiation image generating device (100) for sensing a radiation image, comprising: a radiation imaging panel (110) comprising a plurality of imaging substrates (112) and a scintillator (114) having a first surface (S1) and a second surface (S2) opposite to each other, wherein each imaging substrate (112) has a plurality of pixels each configured to detect light converted from radiation (160) by the scintillator (114), and a first number of image forming substrates (112) arranged in an array of the plurality of image forming substrates (112) in a first direction (y) is greater than a second number of image forming substrates (112) arranged in the array in a second direction (x) perpendicular to the first direction (y), characterized by a housing (150) configured to house the radiation imaging panel (110) and having a first plate-shaped portion (P1) and a second plate-shaped portion (P2); a first support member (120) located between the first surface (S1) of the scintillator (114) and the first plate-shaped portion (P1) of the housing (150) so as to support the scintillator (114) over the plurality of imaging substrates (112); and a second support member (140) located between the second surface (S2) of the scintillator (114) and the second plate-shaped portion (P2) of the housing (150) so as to support the scintillator (114), wherein the second support member (140) comprises a running portion extending in the first direction (y) so as to span the first number of image forming substrates (112) arranged in the first direction (y), and the second support member (140) is designed such that it supports, through the extending portion, an edge portion of the scintillator (114) extending in the first direction (y), and not a central portion of the scintillator (114) lying within the edge portion.

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The invention relates to a radiation imaging apparatus and a radiation imaging system. Description of the state of the art

[0002] In recent years, a radiation imaging device with a large area, for example, 40 cm x 40 cm, has been developed. To implement such a large-area radiation imaging device, in a radiation imaging device having a stacked structure of a sensor panel and a scintillator, the sensor panel is formed by a plurality of imaging substrates. For example, JP 2012-247401 A describes a radiation imaging device having a stacked structure of a sensor panel and a scintillator, in which the sensor panel is formed by arranging a plurality of image sensors. EP 0 943 831 A2 discloses a comparable radiation imaging device with a total of four image sensors, in which the sensor panel is supported on one side by support columns and on the other side by anchoring members, to the top and bottom of which an adhesive or a bonding agent is applied.Furthermore, from US 2014 / 0029721 A1 a radiation imaging device with the features of the preamble of claim 1 is known, in which twenty-four image sensors are arranged in twelve rows and two columns.

[0003] However, in the stacked structure of the scintillator and the sensor panel formed by arranging the plurality of image-forming substrates, deformation at a junction between the image-forming substrates may be greater than that in the image-forming substrate. Such deformation unevenness causes uneven warping of the scintillator, resulting in an artifact in an image sensed by the radiation imaging device. SUMMARY OF THE INVENTION

[0004] The invention provides a technique advantageous in reducing the warpage of a scintillator in an image forming apparatus having a stacked structure of the scintillator and a sensor panel formed by a plurality of image forming substrates.

[0005] A first embodiment of the invention provides a radiation image generating apparatus for sensing a radiation image, comprising the features of claim 1.

[0006] A second embodiment of the invention provides a radiation imaging system comprising the features of claim 14.

[0007] Further features of the invention will become apparent from the following description of exemplary embodiments (with reference to the accompanying drawings). BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view separately showing components of a radiation image forming apparatus according to a first embodiment of the invention; Fig. 2A and Fig. 2B are a sectional view and a plan view respectively showing the radiation image forming apparatus according to the first embodiment of the invention; Fig. 3A and Fig. 3B are a sectional view and a plan view, respectively, showing a radiation image forming apparatus according to a second embodiment of the invention; Fig. 4A and Fig. 4B are sectional views taken along two directions showing a radiation image forming apparatus according to a third embodiment of the invention; Fig. 5 is a plan view showing the radiation image forming apparatus according to the third embodiment of the invention; Fig. 6A and Fig. 6B are views each schematically showing the relationship between a wearing mode and the bending (warping) of a scintillator (or radiation imaging panel); and Fig. 7 is a view showing the configuration of a radiation imaging system according to an embodiment of the invention. DESCRIPTION OF THE EMBODIMENTS

[0008] The invention will now be described by means of exemplary embodiments with reference to the accompanying drawings.

[0009] Fig. 1 shows separately components of a radiation image forming apparatus 100 according to the first embodiment of the invention. Fig. 2A is a sectional view along the Fig. 1, showing the radiation image forming apparatus 100, and Fig. Figure 2B is a plan view showing the radiation imaging device 100. Note that Fig. 1 shows only a part of a housing 150 and that Fig. 2B shows the housing 150 after removal of its upper portion.

[0010] The radiation imaging device 100 is configured to sense an image (radiation image) formed by radiation emitted from a radiation source such as X-rays and passed through an object. The radiation imaging device 100 includes, for example, a radiation imaging panel 110, a first support member 120, a second support member 140, a circuit substrate 130, and the casing (outer member) 150. The radiation imaging panel 110 includes a plurality of imaging substrates 112 and a scintillator 114 having a first surface S1 and a second surface S2 opposite to each other. The radiation imaging device 100 or the radiation imaging panel 110 may further include a base 111 for supporting the plurality of imaging substrates 112.

[0011] The scintillator 114 may be arranged such that the plurality of imaging substrates 112 are clamped or arranged between the scintillator 114 and the submount 111, or such that the scintillator 114 is clamped or arranged between the plurality of imaging substrates 112 and the submount 111. The scintillator 114 may be a collection of row-shaped structures made of Ti-doped CsI. The scintillator 114 converts radiation 160 into light. The plurality of imaging substrates 112 are arranged one- or two-dimensionally to form an imaging plane or region. Each imaging substrate 112 may have a rectangular shape with short sides and long sides. A flexible circuit substrate 113 is connected to each imaging substrate 112. Each imaging substrate 112 may be, for example, a crystalline silicon CMOS sensor or an amorphous silicon PIN sensor or MIS sensor.Each imaging substrate 112 includes a plurality of pixels for detecting light converted from radiation by the scintillator 114. Each pixel includes a photoelectric converter.

[0012] The housing 150 is configured to house the radiation imaging panel 110 and includes a first plate-shaped portion P1, a second plate-shaped portion P2, and a side wall SW. The side of the second plate-shaped portion P2 is the radiation incident side 160. The first plate-shaped portion P1 and the second plate-shaped portion P2 are arranged to face each other, and the side wall SW connects the first plate-shaped portion P1 and the second plate-shaped portion P2. The first support member 120 is located between the first surface S1 of the scintillator 114 and the first plate-shaped portion P1 of the housing 150, so as to support the scintillator 114 or the radiation imaging panel 110.A part of the first support member 120 may be directly or indirectly connected to the radiation imaging panel 110, and another part of the first support member 120 may be directly or indirectly connected to the first plate-shaped portion P1 of the housing 150. The second support member 140 is located between the second surface S2 of the scintillator 114 and the second plate-shaped portion P2 of the housing 150, so as to support the scintillator 114 or the radiation imaging panel 110. A part of the second support member 140 may be directly or indirectly connected to the radiation imaging panel 110, and another part of the second support member 140 may be directly or indirectly connected to the second plate-shaped portion P2 of the housing 150.

[0013] The circuit substrate 130 may be located between the first support member 120 and the first plate-shaped portion P1 of the housing 150, and the circuit substrate 130 may be supported by the first support member 120. The circuit substrate 130 is connected to the plurality of image forming substrates 112 through the flexible circuit substrates 113. The circuit substrate 130 drives the plurality of image forming substrates 120 and processes signals output from the plurality of image forming substrates 112.

[0014] A gap is provided between the second plate-shaped portion P2 of the casing 150 and the radiation imaging panel 110 or the scintillator 114. This gap can prevent the casing 150 and the radiation imaging panel 110 from contacting each other even when external pressure is applied to the radiation imaging device 100, deforming the casing 150, thereby preventing damage to the radiation imaging panel 110 or the scintillator 114.

[0015] On the other hand, if vibration is applied to the radiation imaging device 100 or the radiation imaging device 100 is used with a horizontal or inclined imaging plane established, the radiation imaging panel 110 may be deformed. Typically, a deformation of the radiation imaging panel 110 at a joint between the imaging substrates 112 may be greater than a deformation of the radiation imaging panel 110 in the individual imaging substrates 112. Such uneven deformation causes uneven warping of the scintillator 114, resulting in an artifact in an image sensed by the radiation imaging device 110. As the number of imaging substrates 112 increases, the warping of the radiation imaging panel 110 becomes greater.

[0016] To reduce the warpage of the radiation imaging panel 110, there is a method of increasing the thickness of the base 111. However, this method also increases the thickness and weight of the radiation imaging apparatus 100. Furthermore, if only the thickness of the base 111 is increased, there is a limit to reducing artifacts. To solve this problem, in the first embodiment, the second support member 140 is located between the second surface S2 of the scintillator 114 and the second plate-shaped portion P2 of the case 150 to support the radiation imaging panel 110. The second support member 140 is configured to support the peripheral portion of the scintillator 114, not the central portion within the peripheral portion.Viewed from another perspective, the second support member 140 may be configured to support the scintillator 114 at a portion or area outside an image forming area formed by the plurality of image forming substrates 112.

[0017] Each image forming substrate 112 has a rectangular shape with short sides and long sides. When the plurality of image forming substrates 112 are arranged in the x- and y-directions, the number (4 in the figure shown in the Fig. 1, Fig. 2A and Fig. 2B) of the image forming substrates 112 arranged in the y-direction (first direction) is greater than the number (2 in the example shown in the Fig. 1, Fig. 2A and Fig. 2B) of the image forming substrates 112 arranged in the x-direction (second direction) perpendicular to the y-direction. The second support member 140 is designed to support the edge portion of the scintillator 114 at least at portions extending in the y-direction (first direction). The reason for this will be explained with reference to Fig. 6A and Fig. 6B explains. Fig. 6A schematically shows a case where the second support member 140 supports the edge portion of the scintillator 114 at portions extending in the y-direction (first direction). Fig. Fig. 6B schematically shows a case in which a second support member 140' extending in the x-direction (second direction) supports the edge portion of the scintillator 114. The amount of warpage (bending) of the scintillator 114 (or the radiation image forming panel) is in the Fig. 6A is smaller than in the carrying mode shown in Fig. 6B. That is, the carrying mode shown in Fig. 6A is the same as in Fig. 6B. This is because the mechanical strength at the connection between the image formation substrates 112 (the mechanical strength between the image formation substrates 112) is low, and the scintillator 114 (or the radiation image formation panel) bends easily at this portion.

[0018] In the Fig. 1, Fig. 2A and Fig. 2B, the plurality of image forming substrates 112 are arranged to form first and second rows, each extending along the y-direction (first direction). The second support member 140 has a first portion that supports, via the scintillator 114, the image forming substrates 112 forming the first row among the plurality of image forming substrates 112, and a second portion that supports, via the scintillator 114, the image forming substrates 112 forming the second row among the plurality of image forming substrates 112. Note that the first portion corresponds to the second support member 140 on the left side in the Fig. 1, Fig. 2A and Fig. 2B and that the second section corresponds to the second support member 140 on the right side in the Fig. 1, Fig. 2A and Fig. 2B corresponds.

[0019] With reference to the Fig. 3A and Fig. 3B, the arrangement of a radiation imaging apparatus 100 according to the second embodiment of the invention is described. Note that the details not mentioned in the second embodiment may be the same as those in the first embodiment. Fig. 3A and Fig. 3B correspond to the Fig. 2A and Fig. 2B. The radiation imaging apparatus 100 according to the second embodiment includes a support plate 115 between a second surface S2 of a scintillator 114 and a second support member 140, so as to support the scintillator 114 (or a radiation imaging panel 110). One surface of the support plate 115 is directly or indirectly connected to the scintillator 114 (or radiation imaging panel 110), and the other surface of the support plate 115 is directly or indirectly connected to the second support member 140. The support plate 115 may have a portion that supports the entire second surface S2 of the scintillator 114. The support plate 115 may be arranged such that a plurality of imaging substrates 112 and the scintillator 114 are clamped or arranged between a substructure 111 and the support plate 115. The support plate 115 must be a single component and have a thickness that allows radiation to pass through.The support plate 115 can be made of, for example, amorphous carbon, carbon fiber reinforced plastic, aluminum or titanium.

[0020] The radiation imaging apparatus 100 according to the second embodiment may further include, at a region outside a region where the plurality of image forming substrates 112 and the scintillator 114 are arranged, a connecting member 116 for connecting the base 111 and the support plate 115. The connecting member 116 may be made of, for example, a resin such as silicone resin, acrylic resin, epoxy resin, or polyurethane resin. The connecting member 116 may, for example, be arranged to partially or entirely surround the plurality of image forming substrates 112 and the scintillator 114. The plurality of image forming substrates 112 may be supported by the second support member 140 via the connecting member 160 and the support plate 115. The second support member 140 may be configured to support the support plate 115 in a region outside a region in which the scintillator 114 is located.This structure is advantageous in that it expands the effective pixel area.

[0021] With reference to the Fig. 4A, Fig. 4B and Fig. 5, the configuration of a radiation imaging apparatus 100 according to the third embodiment will be described. Note that details not mentioned in the third embodiment may be the same as those in the first or second embodiment. Fig. 4A corresponds to Fig. 2A, and Fig. 5 corresponds to Fig. 2B. Fig. 4B is a sectional view taken along a direction perpendicular to that shown in Fig. 4A. In the third embodiment, a second support member 140 is configured to support the four sides of a scintillator 114. That is, in the third embodiment, the second support member 140 supports the edge portion of the scintillator 114 at a portion extending in the first direction (y-direction) and a portion extending in the second direction (x-direction).

[0022] With reference to Fig.7, a radiation imaging system 200 according to an embodiment of the invention will now be described. The radiation imaging system 200 includes a radiation source 204 for emitting radiation such as X-rays, the above-described radiation imaging device 100 for receiving the radiation emitted from the radiation source 204 through an object, and a control unit 201. In this embodiment, the radiation imaging system 200 is configured as a C-arm fluoroscopy diagnostic device. That is, the radiation source 204 and the radiation imaging device 100 are mounted on a rotatable C-arm 203 so that they face each other. It is possible to change the radiation direction toward the object by rotating the C-arm 203 without changing the posture of the object. This allows 3D radiation imaging (three-dimensional radiation imaging).Each radiation image sensed by the radiation imaging device 100 is provided to the control unit 201 and processed by the control unit 201. A resulting 3D image may be output to a display unit 202.

[0023] Although the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Claims

[1] A radiation image generating device (100) for sensing a radiation image, comprising: a radiation imaging panel (110) comprising a plurality of imaging substrates (112) and a scintillator (114) having a first surface (S1) and a second surface (S2) opposite to each other, wherein each imaging substrate (112) has a plurality of pixels each configured to detect light converted from radiation (160) by the scintillator (114), and a first number of image forming substrates (112) arranged in an array of the plurality of image forming substrates (112) in a first direction (y) is greater than a second number of image forming substrates (112) arranged in the array in a second direction (x) perpendicular to the first direction (y), characterized by a housing (150) configured to house the radiation imaging panel (110) and having a first plate-shaped portion (P1) and a second plate-shaped portion (P2); a first support member (120) located between the first surface (S1) of the scintillator (114) and the first plate-shaped portion (P1) of the housing (150) so as to support the scintillator (114) over the plurality of imaging substrates (112); and a second support member (140) located between the second surface (S2) of the scintillator (114) and the second plate-shaped portion (P2) of the housing (150) so as to support the scintillator (114), wherein the second support member (140) comprises a running portion extending in the first direction (y) so as to span the first number of image forming substrates (112) arranged in the first direction (y), and the second support member (140) is designed such that it supports, through the extending portion, an edge portion of the scintillator (114) extending in the first direction (y), and not a central portion of the scintillator (114) lying within the edge portion. [2] Device (100) according to claim 1, further comprising: a support plate (115) located between the second surface (S2) of the scintillator (114) and the second support member (140) so as to support the scintillator (114). [3] The device (100) of claim 2, wherein the support plate (115) has a portion that supports the entire second surface (S2) of the scintillator (114). [4] Device (100) according to claim 2 or 3, further comprising: a base (111) configured to support the plurality of image forming substrates (112), wherein the first support member (120) supports the scintillator (114) via the base (111) and the plurality of imaging substrates (112). [5] The apparatus (100) according to claim 4, wherein the support plate (115) is arranged such that the plurality of image forming substrates (112) and the scintillator (114) are clamped between the base (111) and the support plate (115). [6] Device (100) according to claim 5, further comprising: a connecting member (116) configured to connect the base (111) and the support plate (115) at a region outside a region in which the plurality of image forming substrates (112) and the scintillator (114) are arranged. [7] Device (100) according to one of claims 1 to 6, wherein each of the plurality of image forming substrates (112) has a rectangular shape with short sides and long sides and the edge portion of the scintillator (114) supported by the extending portion of the second supporting member (140) is a portion located outside an image forming area formed by the plurality of image forming substrates (112). [8] The apparatus (100) according to claim 7, wherein the plurality of image formation substrates (112) are arranged to form a first row and a second row each extending along the first direction (y), and the extending portion of the second support member (140) includes a first extending portion configured to support, via the scintillator (114), the first number of image formation substrates (112) constituting the first row among the plurality of image formation substrates (112), and a second extending portion configured to support, via the scintillator (114), the first number of image formation substrates (112) constituting the second row among the plurality of image formation substrates (112). [9] The device (100) of any one of claims 1 to 8, wherein the second support member (140) is configured to support four sides of the scintillator (114). [10] The apparatus (100) according to claim 1, wherein the extending portion of the second supporting member (140) comprises a first part connected directly or indirectly to the radiation imaging panel (110) and a second part connected directly or indirectly to the second plate-shaped portion (P2). [11] The apparatus (100) according to claim 8, wherein the first and second extending portions of the second supporting member (140) each comprise a first part directly or indirectly connected to the radiation imaging panel (110) and a second part directly or indirectly connected to the second plate-shaped portion (P2). [12] Device (100) according to claim 10 or 11, wherein the housing (150) has a side wall (SW) arranged parallel to the first direction (y) so as to connect the first plate-shaped portion (P1) and the second plate-shaped portion (P2), and the second support member (140) is not connected to the side wall (SW). [13] Device (100) according to claim 1, wherein each of the plurality of image forming substrates (112) has a rectangular shape with short sides and long sides, the housing (150) has a rectangular shape with short sides and long sides and the long sides of the housing (150) are parallel to the long sides of each of the plurality of imaging substrates (112). [14] Radiation imaging system (200) comprising: a radiation source (204); and a radiation imaging device (100) according to any one of claims 1 to 13, arranged to detect radiation emitted by the radiation source (204). [15] The system (200) of claim 14, wherein the radiation source (204) and the radiation imaging device (100) are arranged to face each other. [16] The system (200) of claim 15, wherein the radiation source (204) and the radiation imaging device (100) are mounted on a rotatable C-arm (203).

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