CT scanner with scatter radiation correction and method of using same
AssigneeArineta Ltd.
InventorsDavid Ruimi, Olga Shapiro, Ehud Dafni
Life of this patent
Estimating the term…
Abstract
A CT scanner with scatter correction device and a method for scatter correction are provided. The method of correcting CT images from artifacts caused by scattered radiation comprises affixing to the non-rotating frame of the CT gantry a plurality of shields for shielding some of the CT detector elements from direct X ray radiation, while allowing scattered radiation to arrive at said shielded elements; measuring scatter signals from said shielded elements, indicative of scattered radiation intensity; and correcting for scatter by subtracting scatter intensity values estimated from said measured scatter signals from signals measured by unshielded detector elements.
Claims29
A method for CT imaging of a subject while correcting for scattered radiation, the method comprising:
- a. providing a CT scanner comprising at least a first source of X ray radiation capable of rotating about the subject and a detector capable of receiving radiation that has been attenuated by the subject;
- b. providing an array of radiation shields, said shields being operative to shield parts of an area of the detector from the X ray source at some source rotation angles and not to shield same parts of the detector area at other source rotation angles of said X ray source;
- c. irradiating said subject by said first X ray source while the source is rotating about said subject and acquiring X ray data from said detector, wherein X rays received by said detector comprise direct radiation from the source that was attenuated by said subject and scattered radiation that was scattered by said subject, and wherein parts of the detector area are substantially irresponsive to direct radiation and responsive to scattered radiation while they are shielded from said first X ray source by said shields;
- d. computing scattered radiation data indicative of the part of the X-ray data due to scattered radiation for all parts of the detector area at all rotation angles, said computation being based on data received by parts of the detector area while shaded by said shields;
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- e. correcting the data acquired by parts of the detector area not shielded by said shields by substantially subtracting said computed scattered radiation data from the total measured data.
A system for CT imaging of a subject while correcting for scattered radiation, the system comprising:
- a. at least a first source of X ray radiation capable of rotating about the subject;
- b. a detector capable of receiving radiation that has been attenuated by said subject;
- c. an array of radiation shields, said shields being operative to shield parts of an area of said detector from said first X ray source at some source rotation angles and not to shield same parts of an area of the detector at other source rotation angles;
- d. a controller capable of irradiating said subject by the X ray source while the source is rotating about the subject and acquiring X ray data from said detector, wherein X rays received by said detector comprise direct radiation from the source that was attenuated by the subject and scattered radiation that was scattered by the subject, and wherein parts of the detector area are substantially irresponsive to direct radiation and responsive to scattered radiation while they are shielded from the X ray source by said shields;
- e. a first image processor capable of computing the part of the X-ray data due to scattered radiation for all parts of the detector area at all rotation angles, said computation being based on data received by parts of said detector area while shielded by said shields;
- and
- f. a second image processor capable of correcting the data received by parts of the detector area not shielded by the shields by subtraction of the computed scattered radiation data from the total measured data.
Dependencies are inferred from the claim text.