Image reconstruction method and X-ray CT apparatus
First Claim
1. An image reconstruction method for reconstructing an image of a specified image reconstruction plane based on data collected at different view angles while rotating at least one of an X-ray tube and a multi-row detector having first—
- J-th (J≧
2) detector rows around a center of rotation, comprising the steps of;
selecting a detector row which an X-ray passing through a pixel point g(x, y) enters based on a distance Δ
z from a scan center plane to an image reconstruction plane in a z-axis direction and a position (x, y) of the pixel point g in the image reconstruction plane; and
using data of said detector row to determine a pixel value of said pixel point g, where the scan center plane at a certain view angle is defined as an x-y plane, and a direction normal to said x-y plane, i.e., a detector row direction, is defined as the z-axis direction.
2 Assignments
0 Petitions
Accused Products
Abstract
For the purpose of reducing artifacts caused by a scan plane tilted with respect to a rotation plane when a multi-row detector is employed, a j-th detector row which an X-ray passing through a pixel point g(x, y) enters is selected based on the distance Δz from a scan center plane to an image reconstruction plane in a z-axis direction and the position (x, y) of the pixel point g in the image reconstruction plane, and data of the j-th detector row is used to determine the pixel value of the pixel point g, where the scan center plane at a certain view angle is defined as an x-y plane, and a direction normal to the x-y plane, i.e., a detector row direction, is defined as the z-axis direction.
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Citations
16 Claims
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1. An image reconstruction method for reconstructing an image of a specified image reconstruction plane based on data collected at different view angles while rotating at least one of an X-ray tube and a multi-row detector having first—
- J-th (J≧
2) detector rows around a center of rotation, comprising the steps of;selecting a detector row which an X-ray passing through a pixel point g(x, y) enters based on a distance Δ
z from a scan center plane to an image reconstruction plane in a z-axis direction and a position (x, y) of the pixel point g in the image reconstruction plane; andusing data of said detector row to determine a pixel value of said pixel point g, where the scan center plane at a certain view angle is defined as an x-y plane, and a direction normal to said x-y plane, i.e., a detector row direction, is defined as the z-axis direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- J-th (J≧
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9. An X-ray CT apparatus comprising:
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an X-ray tube; a multi-row detector having first—
J-th (J≧
2) detector rows;a data collecting device for collecting data at different view angles while rotating at least one of said X-ray tube and said multi-row detector around a center of rotation; a detector row selecting device for selecting a detector row which an X-ray passing through a pixel point g(x, y) enters based on a distance Δ
z from a scan center plane to a specified image reconstruction plane in a z-axis direction and a position (x, y) of the pixel point g in the image reconstruction plane, where the scan center plane at a certain view angle is defined as an x-y plane, and a direction normal to said x-y plane, i.e., a detector row direction, is defined as the z-axis direction; andan image producing device for reconstructing an image of the image reconstruction plane by adding data of the selected detector row for each view angle to determine a pixel value of said pixel point g. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification