US 12,229,927 B2
Metal artifact reduction in computed tomography
Adam Michal Strzelecki, Daettwil (CH); Igor Peterlik, Kuenten (CH); Dieter Marc Seghers, Zürich (CH); Mathieu Plamondon, Glattburg (CH); Mathias Lehmann, Zürich (CH); Pascal Paysan, Basel (CH); and Alexander Heinz, Lörrach (DE)
Assigned to SIEMENS HEALTHINEERS INTERNATIONAL AG, (CH)
Filed by SIEMENS HEALTHINEERS INTERNATIONAL AG, Palo Alto, CA (US)
Filed on Dec. 9, 2021, as Appl. No. 17/546,081.
Claims priority of provisional application 63/250,050, filed on Sep. 29, 2021.
Prior Publication US 2023/0095240 A1, Mar. 30, 2023
Int. Cl. G06T 5/77 (2024.01); A61B 6/00 (2006.01); A61N 5/10 (2006.01); G06T 5/50 (2006.01); G06T 11/00 (2006.01)
CPC G06T 5/77 (2024.01) [A61B 6/5258 (2013.01); G06T 5/50 (2013.01); G06T 11/008 (2013.01); A61N 5/10 (2013.01); G06T 2207/10081 (2013.01); G06T 2207/20212 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method for modifying X-ray projection images of a subject region, the method comprising:
generating a set of combined two-dimensional (2D) projections of a subject region, based on a set of initial 2D projections of the subject region and a set of 2D projection metal masks for the subject region, wherein each combined 2D projection includes one or more mask-bordering pixels and one or more mask-edge pixels;
arranging the set of combined 2D projections sequentially to form a three-dimensional (3D) matrix;
based on the 3D matrix, generating a linear algebraic system for determining pixel values for pixels indicated in the set of 2D projection metal masks, wherein a first change in slope of pixel value associated with a mask-edge pixel of a combined 2D projection is constrained to equal a second change in slope of pixel value associated with a mask-bordering pixel of a combined 2D projection, and wherein the mask-bordering pixel is adjacent to the mask-edge pixel;
determining values for a variable vector of the linear algebraic system, wherein each element of the variable vector represents an inpainted pixel value; and
generating a set of inpainted 2D projections by modifying the initial 2D projections with values for the variable vector.