Methods of image reconstruction to reduce artifacts in rapid cbct scans

A computer-implemented method for correcting artifacts within CT images of a subject, the method comprising:

• a. providing a CT volumetric image set obtained from the subject;
• b. providing a high-contrast mask comprising voxels from high-attenuation regions within the CT volumetric image set;
• c. combining, using a computing device, the high-contrast mask with the CT volumetric image to produce a masked CT volumetric image set;
• and
• d. iteratively correcting, using the computing device, the masked CT volumetric image set by:
• i. overpainting the high-contrast mask within the masked CT volumetric image set by evaluating a model function to produce an overpainted CT volumetric image set;
• ii. forward-projecting the overpainted CT volumetric data into a projection space to produce overpainted CT projections;
• iii. updating the overpainted CT projections using a gradient descent based on previous overpainted CT projections to produce corrected CT projections;
• iv. back-projecting the corrected CT projections to produce a corrected volumetric image set;
• v. comparing the corrected CT volumetric image set against a previous corrected CT volumetric image set to determine if the corrected CT volumetric image set is converged;
• and
• vi. repeating steps i.-v. if the corrected CT volumetric image set is converged, or overpainting the high contrast mask in the corrected CT volumetric image to produce the final CT volumetric image set.