Radiographic method and apparatus

Claim 2

A radiographic method for irradiating an object (6) with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object based upon a beam transmitted through the object (6), characterized by comprising: a radiation shielding means arranging step for preparing radiation shielding means (10, 34, 36) switchable between first and second states when the object (6) is irradiated with the radiation beam (4), the radiation shielding means (10, 34, 36) passing to an image converter (14) both some of transmitted primary radiation beams transmitted by and not scattered by the object and some of scattered radiation beams (8) scattered by the object (6) in the first state, and the radiation shielding means (10, 34, 36) shielding the transmitted primary radiation beams and passing to the image converter (14) some of the scattered radiation beams (8) scattered by the object (6) in the second state; an image forming step for obtaining, in a form of electrical signals, a first radiation image of the . object (6) when the object (6) is irradiated with the radiation beam (4) while the radiation shielding means (10, 34, 36) is in the first state, and obtaining, in the form of electrical signals, a second radiation image when the object (6) is irradiated with the radiation beam (4) while the radiation shielding means (10, 34, 36) is in the second state; and a reproduction/processing step for reproducing and displaying the two-dimensional transmitted image of the object (6) by electrically processing the first and second radiation images obtained in the image forming step, the two-dimensional transmitted image being free from the influence of spatial modulation made by the radiation shielding means and free from the influence of the scattered radiation beams (8).

Claim 3

A method according to claim 1, characterized in that the image forming step includes: a screen reception step for receiving the transmitted primary radiation beams and the scattered radiation beams (8) by the image converter (14), a conversion step for converting the received image into a converted image, an imaging step for imaging the converted image, and an electrical conversion step for electrically converting the image into image data; and the reproduction/processing step includes: a processing step for storing the image data and processing the image data of the first and second radiation images into image data of the radiation images, and a displaying step for reproducing and displaying the image data of the radiation images.

Claim 4

A method according to claim 1, characterized in that the radiation shielding means arranging step comprises preparing the radiation shielding means comprising a first radiation shielding element (10) for passing some of the transmitted primary radiation beams and some of the scattered radiation beams (8), a second radiation shielding element (10) for shielding the transmitted primary radiation beams transmitted through the first radiation shielding element (10) and for passing some of the scattered radiation beams (8) transmitted through the first radiation shielding element (10), and a driver (22) for switching said first and second radiation shielding elements (10) in one of the first and second states.

Claim 5

A method according to claim 1, characterized in that the radiation sheilding means arranging step comprises preparing the radiation shielding means comprising a first radiation shielding element (34) for passing some of incident radiation beams, a second radiation shielding element (36) for shielding the transmitted primary radiation beams transmitted through the first radiation shielding element (34) and the object (6) and for passing some of the scattered radiation beams (8), and a driver for switching said first and second radiation shielding elements (34, 36) in one of the first and second states.

Claim 6

A method according to claim 1, characterized in that the radiation shielding means arranging step includes: a first switching step for arranging radiation shielding elements (10, 34, 36) in a passing region of the transmitted primary radiation beams by a driver (22, 46, 48) of the radiation shielding means before the radiation shielding means is switched in the second state, thereby switching the radiation shielding elements (10, 34, 36) in the second state, and a second switching step for removing the radiation shielding elements (10, 34, 36) from the passing region of the transmitted primary radiation beams by the driver (22, 46, 48) of the radiation shielding means before the radiation shielding means is switched in the first state, thereby switching the radiation shielding elements (10, 34, 36) in the first state.

Claim 7

A method according to claim 1, characterized in that the radiation shielding means arranging step includes a continuous movement step of shifting or vibrating a radiation shielding element (10, 34, 36) with a velocity-component perpendicular to a propagating direction of the transmitted primary radiation beams in at least one of the first and second states of the radiation shielding means.

Claim 10

A radiographic method for irradiating an object with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object (6) based upon a beam transmitted through the object, characterized by comprising: a radiation shielding means arranging step for arranging radiation shielding means (54, 56, 70, 72); a radiation irradiating step for irradiating radiation beams (4) from first and second positions (50, 52, 66, 68) of two different radiation sources; an image forming step for allowing the radiation shielding means (54, 56, 70, 72) to pass to an image converter (14) some of transmitted primary radiation beams not scattered by but transmitted through the object and some of scattered radiation beams (8) scattered by the object (6) so as to obtain, in a form of electrical signals, a first radiation image of the object when the radiation source irradiates from the first position (50, 68), and for allowing the radiation shielding means (54, 56, 70, 72) to shield the transmitted primary radiation beams and to pass to the image converter (14) some of the scattered radiation beams (8) so as to obtain, in the form of electrical signals, a second radiation image of the object when the radiation source irradiates from the second position (52, 66); and a reproduction/processing step for obtaining the two-dimensional transmitted image of the object (6) by electrically processing the first and second radiation images obtained in the image forming step, the two-dimensional transmitted image being free from the influence of spatial modulation made by the radiation shielding means (54, 56, 70, 72) and free from the influence of the scattered radiation beams (8).

Claim 11

A radiographic method for irradiating an object with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object (6) based upon a beam transmitted through the object, characterized by comprising: a radiation shielding means arranging step for arranging radiation shielding means (54, 56, 70, 72); a radiation irradiating step for irradiating radiation beams (4) from first and second positions (50, 52, 66, 68) of two different radiation sources; an image forming step for allowing the radiation shielding means (54, 56, 70, 72) to pass to an image converter (14) some of transmitted primary radiation beams not scattered by but transmitted through the object and some of scattered radiation beams (8) scattered by the object (6) so as to obtain, in a form of electrical signals, a first radiation image of the object when the radiation source irradiates from the first position (50, 68), and for allowing the radiation shielding means (54, 56, 70, 72) to shield the transmitted primary radiation beams and to pass to the image converter (14) some of the scattered radiation beams (8) so as to obtain, in the form of electrical signals, a second radiation image of the object when the radiation source irradiates from the second position (52, 66); and a reproduction/processing step for obtaining the two-dimensional transmitted image of the object (6) by electrically processing the first and second radiation images obtained in the image forming step, the two-dimensional transmitted image being free from the influence of spatial modulation made by the radiation shielding means (54, 56, 70, 72) and free from the influence of the scattered radiation beams (8).

Claim 12

A method according to claim 9, characterized in that the image forming step includes: a screen reception step for receiving the transmitted primary radiation beams and the scattered radiation beams (8) by the image converter (14), a conversion step for converting the received image into a converted image, an imaging step for imaging the converted image, and an electrical conversion step for electrically converting the image into image data; and the reproduction/processing step includes: a processing step for storing the image data and processing the image data of the first and second radiation images into image data of the radiation images, and a displaying step for reproducing and displaying the image data of the radiation images.

Claim 13

A method according to claim 9, characterized in that the radiation shielding means arranging step comprises preparing first and second radiation shielding elements (54, 56), the first radiation shielding element (54) passing some of the transmitted primary radiation beams and some of the scattered radiation beams (8) when the radiation beams (4) are irradiated from the first and second positions, the second radiation shielding element (56) passing some of the transmitted primary radiation beams and some of the scattered radiation beams (18) transmitted through the first radiation shielding element (54) when the radiation beams are irradiated from the first position, and the second radiation shielding element (56) shielding the transmitted primary radiation beams transmitted through the first radiation shielding element (54) and passing some of the scattered radiation beams (8) transmitted through the first radiation shielding element (54) when the radiation beams (4) are irradiated from the second position.

Claim 14

A method according to claim 9, characterized in that the radiation shielding means arranging step comprises preparing first and second radiation shielding elements (70, 72), the first radiation shielding element (70) passing some incident radiation beams when the radiation beams (4) are irradiated from the first and second positions, the second radiation shielding element (72) passing some of the transmitted primary radiation beams and some of the scattered radiation beams (8) transmitted through the first radiation shielding element (70) and the object (6) when the radiation beams are irradiated from the first position, and the second radiation shielding element (72) shielding the transmitted primary radiation beams transmitted through the first radiation shielding element (70) and the object (6) and passing some of the scattered radiation beams (8) transmitted through the first radiation shielding element (70) when the radiation beams (4) are irradiated from the second position.

Claim 15

A method according to claim 9, characterized in that the radiation shielding means arranging step includes a continuous movement step for shifting or vibrating a radiation shielding element (54 or 56, 70 or 72) with a velocity-component perpendicular to a propagating direction of the transmitted primary radiation beams during at least one of radiation beam irradiating steps for irradiating the radiation beams (4) from the first and second positions.

Claim 16

A radiographic apparatus for irradiating an object (6) with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object based upon a beam transmitted through the object, characterized by comprising: radiation irradiating means for irradiating the object (6) with primary radiation beams of conical shape from a radiation source at least twice while the object is at a position with respect to the radiation source; radiation shielding means (10, 34, 36) arranged in a primary radiation beam passing region and being operative in one of first and second states, the radiation shielding means (10, 34, 36) passing both some of transmitted primary radiation beams transmitted through the object (6) and some of scattered radiation beams (8) scattered by the object when the radiation source is in the first state, and the radiation shielding means (10, 34, 36) shielding the transmitted primary radiation beams and passing some of the scattered radiation beams (8) when the radiation source (4) is in the second state; an image converter (14) arranged behind said radiation shielding means as viewed from the radiation source and having a screen opposing the object (6), the image converter receiving a first radiation image on the screen and converting the first radiation image into a converted image when the radiation shielding means (10, 34, 36) is in the first state, and the image converter (14) receiving a second radiation image on the screen (12) and converting the second radiation image into a converted image when the radiation shielding means (10, 34, 36) is in the second state; an imaging device (16), arranged to oppose the converted images of the image converter (14), for converting the respective converted images of the first and second radiation images into electrical signals, thereby obtaining image data; and reproduction/display means (18, 20), electrically connected to the imaging device, for storing the image data of the first and second radiation images and electrically processing the image data of the first radiation image based on the image data of the second radiation image, thereby reproducing and displaying the two-dimensional transmitted image of the object (6) which is not influenced by the scattered radiation beams (8).

Claim 17

A radiographic apparatus for irradiating an object (6) with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object based upon a beam transmitted through the object, characterized by comprising: radiation irradiating means for irradiating the object (6) with primary radiation beams of conical shape from a radiation source at least twice while the object is at a position with respect to the radiation source; radiation shielding means (10, 34, 36) arranged in a primary radiation beam passing region and being operative in one of first and second states, the radiation shielding means (10, 34, 36) passing both some of transmitted primary radiation beams transmitted through the object (6) and some of scattered radiation beams (8) scattered by the object when the radiation source is in the first state, and the radiation shielding means (10, 34, 36) shielding the transmitted primary radiation beams and passing some of the scattered radiation beams (8) when the radiation source (4) is in the second state; an image converter (14) arranged behind said radiation shielding means as viewed from the radiation source and having a screen opposing the object (6), the image converter receiving a first radiation image on the screen and converting the first radiation image into a converted image when the radiation shielding means (10, 34, 36) is in the first state, and the image converter (14) receiving a second radiation image on the screen (12) and converting the second radiation image into a converted image when the radiation shielding means (10, 34, 36) is in the second state; an imaging device (16), arranged to oppose the converted images of the image converter (14), for converting the respective converted images of the first and second radiation images into electrical signals, thereby obtaining image data; and reproduction/display means (18, 20), electrically connected to the imaging device, for storing the image data of the first and second radiation images and electrically processing the image data of the first radiation image based on the image data of the second radiation image, thereby reproducing and displaying the two-dimensional transmitted image of the object (6) which is not influenced by the scattered radiation beams (8).

Claim 18

An apparatus according to claim 14, characterized in that the radiation shielding means is interposed between the object (6) and the screen (12) of the image converter (14); and the radiation shielding means (54, 56) includes a first radiation shielding element (10) for passing some of the transmitted-primary radiation beams and some of the scattered radiation beams (8), a second radiation shielding element (10) which is arranged at a predetermined distance from the first radiation shielding element (54) toward the screen (12) of the image converter (14) and which shields the transmitted primary radiation beams and passes some of the scattered radiation beams (8), and a driver for switching the first and second radiation shielding elements in one of the first and second states.

Claim 19

An apparatus according to claim 14, characterized in that the radiation shielding means includes: a first radiation shielding element (34) which is interposed between the radiation source and the object (6) and transmits some of the radiation beams from the radiation source; a second radiation shielding element (36) which is interposed between the object (6) and the screen (12), located at a predetermined distance from the first radiation shielding element (34), shields the transmitted primary radiation beams transmitted through the first radiation shielding element (34) and the object (6), and transmits some of the scattered radiation beams (8); and a driver (46, 48) for switching the first and second radiation shielding elements (34, 36) in one of the first and second states.

Claim 24

A radiographic apparatus for irradiating an object (6) with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object based upon a beam transmitted through the object (6), characterized by comprising: radiation irradiating means for irradiating the object (6) from first and second positions of two different radiation sources; radiation shielding means (54, 56, 70, 72), arranged in a primary radiation beam passing region, for passing both some of transmitted primary radiation beams and some of scattered radiation beams when the radiation source irradiates from the first position (50, 68) and for shielding the transmitted primary radiation beams transmitted through the object (6) and passing some of the scattered radiation beams (8) scattered by the object (6) when the radiation source irradiates from the second position (52, 66); an image converter (14) arranged behind the radiation shielding means (54, 56, 70, 72) as viewed from the radiation source and having a screen (12) opposing the object (6), the image converter (14) receiving a first radiation image on the screen (12) and converting the first radiation image into a converted image when the radiation shielding means (54, 56, 70, 72) is in the first state, and the image converter receiving a second radiation image on the screen (12) and converting the second radiation image into a converted image when the radiation shielding means (54, 56, 70, 72) is in the second state; an imaging device, arranged to oppose the converted images of the image converter (14), for converting the respective converted images of the first and second radiation images into electrical signals, thereby obtaining image data; and reproduction/display means, electrically connected to the imaging device, for storing the image data of the first and second radiation images and electrically processing the image data of the first radiation image based on the image data of the second radiation image, thereby reproducing and displaying a two-dimensional transmitted image of the object (6) which is free from the influence of the scattered radiation beams (8).

Claim 25

A radiographic apparatus for irradiating an object (6) with a conical radiation beam (4) and for obtaining a two-dimensional transmitted image of the object based upon a beam transmitted through the object (6), characterized by comprising: radiation irradiating means for irradiating the object (6) from first and second positions of two different radiation sources; radiation shielding means (54, 56, 70, 72), arranged in a primary radiation beam passing region, for passing both some of transmitted primary radiation beams and some of scattered radiation beams when the radiation source irradiates from the first position (50, 68) and for shielding the transmitted primary radiation beams transmitted through the object (6) and passing some of the scattered radiation beams (8) scattered by the object (6) when the radiation source irradiates from the second position (52, 66); an image converter (14) arranged behind the radiation shielding means (54, 56, 70, 72) as viewed from the radiation source and having a screen (12) opposing the object (6), the image converter (14) receiving a first radiation image on the screen (12) and converting the first radiation image into a converted image when the radiation shielding means (54, 56, 70, 72) is in the first state, and the image converter receiving a second radiation image on the screen (12) and converting the second radiation image into a converted image when the radiation shielding means (54, 56, 70, 72) is in the second state; an imaging device, arranged to oppose the converted images of the image converter (14), for converting the respective converted images of the first and second radiation images into electrical signals, thereby obtaining image data; and reproduction/display means, electrically connected to the imaging device, for storing the image data of the first and second radiation images and electrically processing the image data of the first radiation image based on the image data of the second radiation image, thereby reproducing and displaying a two-dimensional transmitted image of the object (6) which is free from the influence of the scattered radiation beams (8).

Claim 26

An apparatus according to claim 21, characterized in that the radiation shielding means includes first and second radiation shielding elements (54, 56) arranged between the object (6) and the screen (12) of the image converter (14), and a driver for switching the first and second radiation shielding elements (54, 56) in one of the first and second states, the first radiation shielding element (54) passing some of the transmitted primary radiation beams and some of scattered radiation beams (8) when the radiation beams (4) are irradiated from the first and second positions, the second radiation shielding element (56) passing the transmitted primary radiation beams and some of the scattered radiation beams (8) transmitted through the first radiation shielding element (54) when the radiation beams (4) are irradiated from the first position (50), and the second radiation shielding element (56) shielding the transmitted primary radiation beams transmitted through the first radiation shielding element (54) and passing some of the scattered radiation beams (8) transmitted through the first radiation shielding element (54) when the radiation beams (4) are irradiated from the second position (52).

Claim 27

An apparatus according to claim 21, characterized in that the radiation shielding means includes a first radiation shielding element (70) which is interposed between the radiation source and the object (6), a second radiation shielding element (72) which is interposed between the object (6) and the screen (12) of the image converter (14), and a driver for switching the first and second radiation shielding elements (70, 72) in one of the first and second states, the first radiation shielding element (70) passing some incident radiation beams when the radiation beams (4) are irradiated from the first and second positions (68, 66), the second radiation shielding element (72) passing some of the transmitted primary radiation beams and some of the scattered radiation beams (8) transmitted through the first radiation shielding element (70) and the object (6) when the radiation beams (4) are irradiated from the first position (68), and the second radiation shielding element (72) shielding the transmitted primary radiation beams transmitted through said first radiation shielding element (70) and the object (6) and passing some of the scattered radiation beams (8) transmitted through the first radiation shielding element (70) when the radiation beams (4) are irradiated from the second position (66).

Claim 29

An apparatus according to claim 21, characterized in that said radiation irradiating means (50, 52, 66, 68) comprises a bifocul radiation tube having two focul points within a single vaccume tube.