Method and apparatus for reduction of artifacts in computed tomography images

A method for reducing artifacts in image data generated by a computed tomography system, the artifacts being due to the presence of a high density object in a subject of interest, the method comprising:

• receiving measured sinogram data from the computed tomography system, the sinogram data representative of a plurality of sinogram elements;
• reconstructing the measured sinogram data to generate initial reconstructed image data;
• generating corrected sinogram data using the measured sinogram data;
• assigning a weight measure to each sinogram element in the corrected sinogram data, wherein the weight measure corresponds to a function that is inversely proportional to a variance or to a standard deviation of a signal associated with each sinogram element in the measured sinogram data;
• and
• iteratively reconstructing the corrected sinogram data to generate improved reconstructed image data based on the weight measure, throughout the iterative reconstruction.

A computed tomography system for reducing artifacts in image data, the artifacts being due to the presence of a high density object in a subject of interest, the system comprising:

• an X-ray source configured to project an X-ray beam from a plurality of positions through the subject of interest;
• a detector configured to produce a plurality of electrical signals corresponding to the X-ray beam;
• and
• a processor configured to process the electrical signals to generate measured sinogram data, the sinogram data representative of a plurality of sinogram elements, wherein the processor is further configured to reconstruct the measured sinogram data to generate initial reconstructed image data;
• generate corrected sinogram data using the measured sinogram data and iteratively reconstruct the corrected sinogram data to generate an improved reconstructed image data based on a weight measure associated with each sinogram element, wherein the weight measure corresponds to a function that is inversely proportional to a variance or to a standard deviation of a signal associated with each sinogram element in the measured sinogram data, throughout the iterative reconstruction.

At least one computer-readable medium storing computer instructions for instructing a computer system to reduce artifacts in image data generated by a computed tomography system, the artifacts being due to the presence of a high density object in a subject of interest, the computer instructions comprising:

• receiving measured sinogram data from the computed tomography system, the sinogram data representative of a plurality of sinogram elements;
• reconstructing the measured sinogram data to generate initial reconstructed image data;
• generating corrected sinogram data using the measured sinogram data;
• and
• iteratively reconstructing the corrected sinogram data to generate an improved reconstructed image data based on a weight measure associated with each sinogram element, wherein the weight measure corresponds to a function that is inversely proportional to a variance or to a standard deviation of a signal associated with each sinogram element in the measured sinogram data, throughout the iterative reconstruction.

At least one computer-readable medium storing computer instructions for instructing a computer system to reduce artifacts in image data generated by a computed tomography system, the artifacts being due to the presence of a high density object in a subject of interest, the computer instructions comprising:

• receiving measured sinogram data from the computed tomography system, the sinogram data representative of a plurality of sinogram elements;
• reconstructing the measured sinogram data to generate initial reconstructed image data;
• generating corrected sinogram data using the measured sinogram data;
• assigning a weight measure to each sinogram element in the corrected sinogram data, wherein the weight measure corresponds to a function that is inversely proportional to a variance or to a standard deviation of a signal associated with each sinogram element in the measured sinogram data;
• and
• iteratively reconstructing the corrected sinogram data to generate improved reconstructed image data based on the weight measure, throughout the iterative reconstruction.