title: Metal artifact reduction through MVCBCT and kVCT in radiotherapy.
abstract: This study proposes a new method for removal of metal artifacts from megavoltage cone beam computed tomography (MVCBCT) and kilovoltage CT (kVCT) images. Both images were combined to obtain prior image, which was forward projected to obtain surrogate data and replace metal trace in the uncorrected kVCT image. The corrected image was then reconstructed through filtered back projection. A similar radiotherapy plan was designed using the theoretical CT image, the uncorrected kVCT image, and the corrected image. The corrected images removed most metal artifacts, and the CT values were accurate. The corrected image also distinguished the hollow circular hole at the center of the metal. The uncorrected kVCT image did not display the internal structure of the metal, and the hole was misclassified as metal portion. Dose distribution calculated based on the corrected image was similar to that based on the theoretical CT image. The calculated dose distribution also evidently differed between the uncorrected kVCT image and the theoretical CT image. The use of the combined kVCT and MVCBCT to obtain the prior image can distinctly improve the quality of CT images containing large metal implants.
authors.affiliation: Second People's Hospital of Changzhou, Nanjing Medical University, Changzhou 213003, China.
authors.forename: Gao
authors.initials: G
authors.lastname: Liugang
authors.affiliation: Second People's Hospital of Changzhou, Nanjing Medical University, Changzhou 213003, China.
authors.forename: Sun
authors.initials: S
authors.lastname: Hongfei
authors.affiliation: Second People's Hospital of Changzhou, Nanjing Medical University, Changzhou 213003, China.
authors.forename: Ni
authors.initials: N
authors.lastname: Xinye
authors.affiliation: Changzhou Cancer Hospital of Soochow University, Changzhou 213001, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Mingming
authors.affiliation: The Third Affiliated Hospital of Anhui Medical University, Anhui 230000, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Second People's Hospital of Changzhou, Nanjing Medical University, Changzhou 213003, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Tao
mesh_terms: D016477:Artifacts; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008670:Metals / Q000737:chemistry*; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D008670:Metals