Image reconstruction method and X-ray CT apparatus
AssigneeGE Medical Systems Global Technology Company, LLC
InventorAkira Hagiwara
Life of this patent
Estimating the term…
Abstract
An image reconstruction method includes a reconstruction algorithm of pixel data, weighting coefficients by which first projection data and second projection data at which a corresponding X-ray beam passes through a pixel lying on a reconstruction plane and which are opposite in view angle direction to each other, are to be multiplied, are calculated by equations each using a term of a distance between an X-ray generator and detector system and the reconstruction plane plus an offset distance at the acquisition of the projection data.
Claims22
An image reconstruction method for reconstructing a Computer Tomography (CT) image, said method comprising:
- acquiring projection data by a helical scan for performing each scan while relatively linearly moving an X-ray generator and detector system in a direction of a body axis of a subject, wherein the X-ray generator and detector system includes an X-ray tube for radiating X-rays and an X-ray detector having at least one detector row for detecting an X-ray transmitted through the subject;
- and
- obtaining image data of the CT image, using projection data lying in a view range including views each corresponding to a time at which a reconstruction plane of the CT image and a reference position of the X-ray generator and detector system coincide with each other in a body-axis direction, by performing a backprojection arithmetic operation including weighting based on a distance in the body-axis direction between the reconstruction plane and the reference position of the X-ray generator and detector system corresponding to the view for the projection data, wherein the weighting is performed based on a distance obtained by adding a predetermined value greater than zero to the distance, in place of the distance.
An X-ray Computed Tomography (CT) apparatus comprising:
- an X-ray generator;
- a detector system;
- a data acquiring device configured to acquire projection data by a helical scan for performing each scan while relatively linearly moving the X-ray generator and the detector system in a direction of a body axis of a subject, wherein said X-ray generator and detector system comprises an X-ray tube configured to radiate X-rays and an X-ray detector comprising at least one detector row configured to detect X-rays transmitted through the subject;
- and
- an image reconstructing device configured to reconstruct a CT image using the acquired projection data,
- wherein said image reconstructing device is configured to obtain image data of the CT image, using projection data lying in a view range including views each corresponding to a time at which a reconstruction plane of the CT image and a reference position of said X-ray generator and detector system coincide with each other in the body-axis direction, by performing a backprojection arithmetic operation including weighting based on a distance in the body-axis direction between the reconstruction plane and the reference position of said X-ray generator and detector system, corresponding to the view for the projection data, and
- wherein the weighting is performed based on a distance obtained by adding a predetermined value greater than zero to the distance, in place of the distance.
Dependencies are inferred from the claim text.