X-RAY CT APPARATUS, A METHOD FOR CHANGING THE HELICAL PITCH, AN IMAGE RECONSTRUCTION PROCESSING APPARATUS, AN IMAGE RECONSTRUCTION PROCESSING METHOD, AND AN IMAGE RECONSTRUCTION PROCESSING PROGRAM
First Claim
1. An X-ray CT apparatus having an X-ray tube emitting an X-ray, a detector detecting X-rays transmitted through a subject to be examined, and a bed on which said subject to be examined is placed, wherein, after a pre-scan causing said X-ray tube to emit X-rays with said X-ray tube, said detector and said bed at stopped positions, said X-ray tube and said detector are moved relative to said bed to perform a scan over an reconstruction area of an image, comprising:
- a reconstruction part configured to reconstruct the pre-scan image of said subject to be examined from transmission data detected by said detector during said pre-scan, and also to reconstruct the scan image of said subject to be examined from the transmission data detected by said detector during said scan;
a switching control part configured to switch from said pre-scan to said scan; and
a scan controlling part, when it is switched to said scan by said switching control part, configured to scan by changing the helical pitch from the stopped position for said pre-scan directly to the position toward an ending edge of the reconstruction area of the image, wherein;
said scan controlling part scans at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and then, after X-rays for the predetermined number of views is emitted, the scan at a predetermined second helical pitch is controlled to continue.
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Accused Products
Abstract
The X-ray CT apparatus that performs a scan after a pre-scan, comprising a reconstruction part reconstructing the pre-scan image of said subject to be examined from transmission data detected by said detector during said pre-scan, and also reconstructing the scan image of said subject to be examined from the transmission data detected by said detector during said scan; and a scan controlling part initiating a scan by directly changing the helical pitch of said bed from the stopped position for said pre-scan to the position toward an ending edge of the reconstruction area of the image. The scan controlling part initiates the scan at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and, after X-rays for the predetermined number of views is emitted, the scan at a second helical pitch continues.
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Citations
31 Claims
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1. An X-ray CT apparatus having an X-ray tube emitting an X-ray, a detector detecting X-rays transmitted through a subject to be examined, and a bed on which said subject to be examined is placed, wherein, after a pre-scan causing said X-ray tube to emit X-rays with said X-ray tube, said detector and said bed at stopped positions, said X-ray tube and said detector are moved relative to said bed to perform a scan over an reconstruction area of an image, comprising:
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a reconstruction part configured to reconstruct the pre-scan image of said subject to be examined from transmission data detected by said detector during said pre-scan, and also to reconstruct the scan image of said subject to be examined from the transmission data detected by said detector during said scan; a switching control part configured to switch from said pre-scan to said scan; and a scan controlling part, when it is switched to said scan by said switching control part, configured to scan by changing the helical pitch from the stopped position for said pre-scan directly to the position toward an ending edge of the reconstruction area of the image, wherein; said scan controlling part scans at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and then, after X-rays for the predetermined number of views is emitted, the scan at a predetermined second helical pitch is controlled to continue. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for changing the helical pitch of an X-ray CT apparatus having an X-ray tube emitting an X-ray, a detector detecting X-rays transmitted through a subject to be examined, and a bed on which said subject to be examined is placed, wherein, after a pre-scan causing said X-ray tube to emit X-rays with said X-ray tube, said detector and said bed at stopped positions, said X-ray tube and said detector are moved relative to said bed to perform a scan over an reconstruction area of the image, comprising:
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reconstructing the pre-scan image of said subject to be examined from transmission data based on X-rays detected by said detector during said pre-scan; switching between said pre-scan and said scan; and initiating the scan, in response to the switching, by changing the helical pitch from a stopped position for said pre-scan directly to the position toward an ending edge of the reconstruction area of the image; and reconstructing the scan image of said subject to be examined from the transmission data based on X-rays detected by said detector during said scan, wherein; for initiating the scan, the scan is initiated at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and wherein, after X-rays for said predetermined number of views is emitted, the scan at a predetermined second helical pitch is controlled to continue. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. An X-ray CT apparatus having an X-ray tube emitting an X-ray, a detector detecting X-rays transmitted through a subject to be examined, and a bed on which said subject to be examined is placed, said X-ray CT apparatus reconstructing the image of the subject to be examined from a transmission data obtained by emitting X-rays to the subject to be examined, comprising:
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an input part configured to specify the area which is reconstructed in synchronization with a biological signal and the area which is reconstructed in asynchronization with the biological signal; a scan controlling part configured to perform a helical scan by moving said X-ray tube and said detector relative to said bed, and also to change the moving speed of said bed during a continuous single helical scan; a detecting part configured to detect the biological signal of the subject to be examined; a memory part configured to store the transmission data obtained during said helical scan and the said biological signal data in a correlated way; a segmentation part configured to segment said transmission data into a first transmission data that corresponds to the area reconstructed in synchronization with said biological signal and a second transmission data that corresponds to the area reconstructed in asynchronization with said biological signal, while partly overlapping in the vicinity of both boundaries; a biological-signal synchronization reconstructing part configured to reconstruct a synchronized image of said subject to be examined based on said biological signal data and said first transmission data; a biological-signal asynchronization reconstructing part configured to reconstruct an asynchronized image of said subject to be examined from said second transmission data without using said biological signal data; and a combining part configured to create a combined image that the synchronized image reconstructed by said biological-signal synchronization reconstructing part and the asynchronized image reconstructed by said biological-signal asynchronization reconstructing part are combined with weighting addition at said partly overlapped area. - View Dependent Claims (16, 17, 18, 19)
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20. An image reconstruction processing apparatus, comprising:
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an input part configured to specify the area which is reconstructed in synchronization with a biological signal and the area which is reconstructed in asynchronization with the biological signal; a memory part configured to store the transmission data obtained by a continuous single helical scan and a biological signal data of the subject to be examined obtained during said helical scan in a correlated way; a segmentation part configured to segment said transmission data into a first transmission data that corresponds to the area reconstructed in synchronization with said biological signal and a second transmission data that corresponds to the area reconstructed in asynchronization with said biological signal, while partly overlapping in the vicinity of both boundaries; a biological-signal synchronization reconstructing part configured to reconstruct a synchronized image of said subject to be examined based on said biological signal data and said first transmission data; a biological-signal asynchronization reconstructing part configured to reconstruct an asynchronized image of said subject to be examined from said second transmission data without using said biological signal data; and a combining part configured to create a combined image that the synchronized image reconstructed by said biological-signal synchronization reconstructing part and the asynchronized image reconstructed by said biological-signal asynchronization reconstructing part are combined with weighting addition at said partly overlapped area. - View Dependent Claims (21, 22, 23)
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24. An image reconstruction processing method comprising:
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storing a transmission data of a subject to be examined obtained by a continuous single helical scan and a biological signal data of the subject to be examined obtained during said helical scan; segmenting said transmission data into a first transmission data that corresponds to the area reconstructed in synchronization with said biological signal and a second transmission data that corresponds to the area reconstructed in asynchronization with said biological signal, while partly overlapping in the vicinity of both boundaries; reconstructing a synchronized image of said subject to be examined based on said biological signal data and said first transmission data; reconstructing an asynchronized image of said subject to be examined from said second transmission data without using said biological signal data; and creating a combined image that the synchronized image reconstructed in said reconstruction with synchronization and the asynchronized image reconstructed in said reconstruction with asynchronization are combined with weighting addition at said partly overlapped area. - View Dependent Claims (25, 26, 27)
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28. A program product including programming code for image reconstruction processing, the program product being stored on a computer readable medium, the programming code comprising:
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specifying the area which is reconstructed in synchronization with a biological signal and the area which is reconstructed in asynchronization with the biological signal on a computer; storing the transmission data obtained during a continuous single helical scan and the said biological signal data of the subject to be examined obtained during said helical scan in a correlated way; segmenting said transmission data into a first transmission data that corresponds to the area reconstructed in synchronization with said biological signal and a second transmission data that corresponds to the area reconstructed in asynchronization with said biological signal, while partly overlapping in the vicinity of both boundaries; reconstructing a synchronized image of said subject to be examined based on said biological signal data and said first transmission data; reconstructing an asynchronized image of said subject to be examined from said second transmission data without using said biological signal data; and creating a combined image that the synchronized image reconstructed in said reconstruction with synchronization and the asynchronized image reconstructed in said reconstruction with asynchronization are combined with weighting addition at said partly overlapped area. - View Dependent Claims (29, 30, 31)
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Specification