X-ray CT method and X-ray CT apparatus
First Claim
1. An X-ray CT method comprising the steps of:
- rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
reconstructing an image by treating the acquired X-ray projection data;
displaying the reconstructed tomographic image; and
designating radiographic conditions for data acquisition, wherein;
a plurality of sets of radiographic conditions is designated for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is held unchanged in a depth direction substantially orthogonal to a rotation plane on which the rotation is made; and
an image is reconstructed under the plurality of sets of radiographic conditions during the conventional scan or cine scan.
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Accused Products
Abstract
In an X-ray CT apparatus, radiographic conditions (protocols) for imaging of each position represented by a z-coordinate are optimized in relation to an X-ray cone beam that spreads in a z direction. A slice thickness of a tomographic image is freely controlled in the z direction using a z filter during a conventional scan or a cine scan. For each tomographic image, a reconstruction function, an image filter, a scan field, a tomographic-image tilt angle, and a position of a tomographic image are freely adjusted or independently designated for scanning of each position in the z direction. Thus, a tomographic image is reconstructed. Moreover, the position of a beam formation X-ray filter in the z direction is shifted in order to optimize a patient dose that depends on the size of the scan field, and X-ray quality.
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Citations
16 Claims
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1. An X-ray CT method comprising the steps of:
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rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
reconstructing an image by treating the acquired X-ray projection data;
displaying the reconstructed tomographic image; and
designating radiographic conditions for data acquisition, wherein;
a plurality of sets of radiographic conditions is designated for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is held unchanged in a depth direction substantially orthogonal to a rotation plane on which the rotation is made; and
an image is reconstructed under the plurality of sets of radiographic conditions during the conventional scan or cine scan. - View Dependent Claims (6, 7, 8)
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2. An X-ray CT method comprising the steps of:
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rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
reconstructing an image by treating the acquired X-ray projection data;
displaying the reconstructed tomographic image; and
designating radiographic conditions for data acquisition, wherein;
for data acquisition, an X-ray beam that is asymmetric to a direction orthogonal to a rotation plane on which the rotation is made is irradiated to the rotation plane;
a plurality of sets of radiographic conditions is designated for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to the rotation plane on which the rotation is made; and
an image is reconstructed under the plurality of sets of radiographic conditions during the conventional scan or cine scan. - View Dependent Claims (3)
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4. An X-ray CT method comprising the steps of:
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rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
reconstructing an image by treating the acquired X-ray projection data;
displaying the reconstructed tomographic image; and
designating radiographic conditions for data acquisition, wherein;
prior to data acquisition, a rotation plane on which the rotation is made is tilted;
a plurality of sets of radiographic conditions is designated for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to the rotation plane on which the rotation is made; and
an image is reconstructed under the plurality of sets of radiographic conditions during the conventional scan or cine scan.
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5. An X-ray CT method comprising the steps of:
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rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
reconstructing an image by treating the acquired X-ray projection data;
displaying the reconstructed tomographic image;
designating radiographic conditions for data acquisition; and
storing radiographic conditions recommended for each radiographic region of the subject, wherein;
for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to a rotation plane on which the rotation is made, a radiographic region is delineated in a scout image of the subject, radiographic conditions recommended for the delineated radiographic region are retrieved, and a plurality of sets of radiographic conditions is designated based on the recommended radiographic conditions; and
an image is reconstructed under the plurality of sets of radiographic conditions during the conventional scan or cine scan.
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9. An X-ray CT apparatus comprising:
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an X-ray data acquisition device for rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
an image reconstruction device for reconstructing an image by treating the X-ray projection data acquired by the X-ray data acquisition device;
an image display device for displaying the reconstructed tomographic image; and
a radiographic condition designation device for use in designating radiographic conditions for data acquisition, wherein;
the radiographic condition designation device is used to designate a plurality of sets of radiographic conditions for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is held unchanged in a z direction substantially orthogonal to a rotation plane on which the rotation is made; and
the image reconstruction device reconstructs an image under the plurality of sets of radiographic conditions during the conventional scan or cine scan. - View Dependent Claims (14, 15, 16)
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10. An X-ray CT apparatus comprising:
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an X-ray data acquisition device for rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
an image reconstruction device for reconstructing an image by treating the X-ray projection data acquired by the X-ray data acquisition device;
an image display device for displaying the reconstructed tomographic image; and
a radiographic condition designation device for use in designating radiographic conditions for data acquisition, wherein;
the X-ray data acquisition device irradiates an X-ray beam, which is asymmetric to a direction orthogonal to a rotation plane on which the rotation is made, to the rotation plane so as to acquire X-ray data;
the radiographic condition designation device is used to designate a plurality of sets of radiographic conditions for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to the rotation plane on which the rotation is made; and
the image reconstruction device reconstructs an image under the plurality of sets of radiographic conditions during the conventional scan or cine scan. - View Dependent Claims (11)
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12. An X-ray CT apparatus comprising:
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an X-ray data acquisition device for rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
an image reconstruction device for reconstructing an image by treating the X-ray projection data acquired by the X-ray data acquisition device;
an image display device for displaying the reconstructed tomographic image; and
a radiographic condition designation device for use in designating radiographic conditions for data acquisition, wherein;
the X-ray data acquisition device acquires data with a rotation plane, in which the rotation is made, tilted;
the radiographic condition designation device is used to designate a plurality of sets of radiographic conditions for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to the rotation plane on which the rotation is made; and
the image reconstruction device reconstructs an image under the plurality of sets of radiographic conditions during the conventional scan or cine scan.
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13. An X-ray CT apparatus comprising:
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an X-ray data acquisition device for rotating an X-ray generator and an X-ray area detector, which has a matrix structure and is opposed to the X-ray generator, about a center of rotation located between the X-ray generator and X-ray area detector so as to acquire X-ray projection data of a subject lying down near the center of rotation;
an image reconstruction device for reconstructing an image by treating the X-ray projection data acquired by the X-ray data acquisition device;
an image display device for displaying the reconstructed tomographic image;
a radiographic condition designation device for use in designating radiographic conditions for data acquisition; and
a radiographic condition storage device in which radiographic conditions recommended for each radiographic region of the subject are stored, wherein;
for a conventional scan for which the X-ray generator and X-ray area detector make one rotation or a cine scan for which the position of the subject is fixed in a depth direction substantially orthogonal to a rotation plane on which the rotation is made, the radiographic condition designation device is used to delineate a radiographic region in a scout image of the subject, retrieve radiographic conditions recommended for the delineated radiographic region, and designate a plurality of sets of radiographic conditions according to the recommended radiographic conditions; and
the image reconstruction device reconstructs an image under the plurality of sets of radiographic conditions during the conventional scan or cine scan.
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Specification