Title :
A post-processing method for improving contrast and reducing cupping artifacts in low-energy CBCT images
Author :
Thanasupsombat, Chalinee ; Pengvanich, Phongphaeth ; Aootaphao, Sorapong ; Thongvigitmanee, Saowapak S.
Author_Institution :
Dept. of Nucl. Eng., Chulalongkorn Univ., Bangkok, Thailand
fDate :
Oct. 27 2013-Nov. 2 2013
Abstract :
X-ray scattering in the cone beam computed tomography system can lead to undesirable reduction in contrast and overall image quality of reconstructed images. The scatters inside the object cause a serious problem, especially when the object is large and contains a lot of materials, such as bones and soft tissues. In this paper, the amount of X-ray scattering is numerically estimated using the Monte Carlo method based on the GEANT4 software. A new procedure that employs the numerical result to improve the contrast and the overall quality of the actual reconstructed images produced by a prototype dental CBCT system is introduced. The procedure has been primarily tested on various simple geometry CT objects, and found to be able to improve the contrast and the cupping artifacts of the reconstructed images. Further analysis also shows that the calculated CT numbers of the materials derived from the corrected image are more in line with the documented values than those from the uncorrected one.
Keywords :
Monte Carlo methods; X-ray scattering; computerised tomography; image reconstruction; medical image processing; prototypes; GEANT4 software; Monte Carlo method; X-ray scattering; cone beam computed tomography; contrast improvement; cupping artifact reduction; image quality z; low energy CBCT images; post processing method; prototype; reconstructed images; Computed tomography; Detectors; Image reconstruction; Materials; Phantoms; X-ray imaging; X-ray scattering;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2013 IEEE
Conference_Location :
Seoul
Print_ISBN :
978-1-4799-0533-1
DOI :
10.1109/NSSMIC.2013.6829267