Signal processing method and imaging system for scatter correction in computed tomography
A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.
1. A signal processing method, comprising:
detecting a total intensity of X-rays passing through an object comprising multiple materials via a detector of a computed tomography imaging system;
detecting an additional total intensity of X-rays passing through air;
obtaining, via a computer, at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object, wherein obtaining the basis material information of the multiple materials comprises obtaining projection data of the basis material information used to characterize the multiple materials along each projection beam of the X-rays;
estimating, via the computer, a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity;
obtaining, via the computer, an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component; and
reconstructing, via the computer, an X-ray image based on the intensity estimate;
wherein estimating the scatter intensity component comprises: using a scatter model according to the obtained at least one set of basis information and the detected total intensity to estimate the scatter intensity component, wherein the scatter model utilizes the detected additional total intensity in estimating the scatter intensity component, wherein the scatter model is in association with the at least one set of basis information, and wherein the scatter model is established based on the detected total intensity and the obtained projection data of the basis material information of each material along each projection beam.
2. A computed tomography imaging system, comprising:
a detector for detecting a total intensity of X-rays passing through an object comprising multiple materials and detecting an additional total intensity of X-rays passing through air; and
a computer configured to obtain at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object, estimate a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity, obtain an intensity estimate of primary X-rays incident on the detector based on the detected total intensity and the estimated scatter intensity component, and reconstruct an X-ray image based on the intensity estimate, wherein the computer is configured to obtain the basis material information of the multiple materials by obtaining projection data of the basis material information used to characterize the multiple materials along each projection beam of the X-rays;
wherein the computer is configured for using a scatter model according to the obtained at least one set of basis information and the detected total intensity to estimate the scatter intensity component, the scatter model being in association with the at least one set of basis information, wherein the scatter model utilizes the detected additional total intensity in estimating the scatter intensity component, and wherein the scatter model is established based on the detected total intensity and the obtained projection data of the basis material information of each material along each projection beam.