发明名称 |
Correction of off-focal radiation |
摘要 |
An x-ray tube of CT or other radiographic scanner has a focal spot (30) from which x-rays with an energy distribution (32) are generated. As the x-ray source rotates a peak (34), the radiation energy distribution seen by each detector (24) through a physical collimator shifts. Each line of data generated by the detectors has a shifting energy distribution across its data values which creates artifacts in reconstructed images. A filter (50) includes a convolver (52) which convolves the lines of data with deconvolution functions from a memory (54) in a recursive loop (56) in accordance with a relative angular position of the x-ray tube and the corresponding detector. Filtered data lines are subtracted (56) from unconvolved data values to generate values with reduced off-focal radiation components. Filtered data is conveyed to a convolver (82) and a backprojector (84) which backprojects the data across an image memory (86)./!
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申请公布号 |
US5757951(A) |
申请公布日期 |
1998.05.26 |
申请号 |
US19940359608 |
申请日期 |
1994.12.20 |
申请人 |
PICKER INTERNATIONAL, INC. |
发明人 |
TUY, HEANG K. |
分类号 |
A61B6/03;G06T11/00;(IPC1-7):G06K9/00;G01N23/083 |
主分类号 |
A61B6/03 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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