Automatic estimating and reducing scattering in computed tomography scans

A method to determine scattered radiation contained in x-ray projections for computed tomography (CT) reconstruction, comprising:

• reconstructing a first CT volume based on a plurality of projection images generated by CT scanning of an object using an x-ray radiation source and a detector panel;
• constructing an object model based on the CT volume, wherein the object model contains a plurality of voxels, and the constructing of the object model comprises assigning each of the plurality of voxels to at least one material type with density based on each of the plurality of voxels' Hounsfield Units (HU) value;
• constructing a virtual CT scanning environment having a virtual radiation source based on the x-ray radiation source and having a virtual detector panel based on the detector panel, wherein the virtual detector panel contains a plurality of virtual pixels;
• performing a simulated CT scanning of the object model by simulating macroscopic behavior of particles being emitted from the virtual radiation source, passing through the object model, and being detected by the virtual detector panel;
• generating a plurality of simulated scatter images corresponding to the plurality of projection images by estimating a first subset of particles scattered during the simulated CT scanning of the object model, wherein each simulated scatter image in the plurality of simulated scatter images is generated by
• constructing a Boltzmann Transport Equation (BTE) for the first subset of particles scattered during the simulated CT scanning of the object model,
• using a deterministic method to solve the BTE and calculate corresponding particle fluence distribution values in the plurality of voxels, and
• generating the simulated scatter image based on the corresponding particle fluence distribution values in the plurality of voxels;
• and
• reconstructing a second CT volume with reduced scatter artifacts based on the plurality of projection images and the plurality of simulated scatter images.

A scatter-estimation system configured to estimate scattered radiation contained in x-ray projections for computed tomography (CT) reconstruction, comprising:

• a scan-simulation module configured to
• construct an object model based on a plurality of projection images generated by CT scanning of an object using an x-ray radiation source and a detector panel, wherein the object model contains a plurality of voxels, and the construction of the object model comprises assigning each of the plurality of voxels to at least one material type with density based on each of the plurality of voxels' Hounsfield Units (HU) value,
• construct a virtual radiation source based on the x-ray radiation source,
• construct a virtual detector panel based on the detector panel, and
• perform a simulated CT scanning of the object model by simulating macroscopic behavior of particles being emitted from the virtual radiation source, passing through the object model, and being detected by the virtual detector panel;
• and
• an image-correction module coupled with the scan-simulation module, wherein the image-correction module is configured to
• generate a simulated scatter image by
• constructing a Boltzmann Transport Equation (BTE) for a first subset of particles scattered during the simulated CT scanning of the object model,
• using a deterministic method to solve the BTE and calculate corresponding particle fluence distribution values in the plurality of voxels, and
• generating the simulated scatter image based on the corresponding particle fluence distribution values in the plurality of voxels, and
• estimate a scatter-reduced image corresponding to one of the plurality of projection images based on the simulated scatter image.