title: A level set method for cupping artifact correction in cone-beam CT.
abstract: OBJECTIVE
  To reduce cupping artifacts and improve the contrast-to-noise ratio in cone-beam computed tomography (CBCT).
  
  
  METHODS
  A level set method is proposed to reduce cupping artifacts in the reconstructed image of CBCT. The authors derive a local intensity clustering property of the CBCT image and define a local clustering criterion function of the image intensities in a neighborhood of each point. This criterion function defines an energy in terms of the level set functions, which represent a segmentation result and the cupping artifacts. The cupping artifacts are estimated as a result of minimizing this energy.
  
  
  RESULTS
  The cupping artifacts in CBCT are reduced by an average of 90%. The results indicate that the level set-based algorithm is practical and effective for reducing the cupping artifacts and preserving the quality of the reconstructed image.
  
  
  CONCLUSIONS
  The proposed method focuses on the reconstructed image without requiring any additional physical equipment, is easily implemented, and provides cupping correction through a single-scan acquisition. The experimental results demonstrate that the proposed method successfully reduces the cupping artifacts.
authors.affiliation: College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210003, China.
authors.forename: Shipeng
authors.initials: S
authors.lastname: Xie
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 611731, China.
authors.forename: Chunming
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210003, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Li
authors.affiliation: College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210003, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ge
mesh_terms: D000465:Algorithms; D016477:Artifacts; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008327:Mammography / Q000379:methods; D008670:Metals; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D012886:Skull / Q000000981:diagnostic imaging
chemical_list: D008670:Metals