DocumentCode :
686928
Title :
Improving image quality of a mobile Cone-Beam CT by use of scatter and beam-hardening corrections
Author :
Miran Park ; Hee-Sin Lee ; Kyong-Woo Kim ; Seungryong Cho
Author_Institution :
Dept. of Nucl. & Quantum Eng., KAIST, Daejeon, South Korea
fYear :
2013
fDate :
Oct. 27 2013-Nov. 2 2013
Firstpage :
1
Lastpage :
3
Abstract :
Cone-beam computed tomography (CBCT) imaging system has been widely used in various applications, and takes an important role for diagnosis of emergency patient. However large size of detector causes high scatter-to-primary ratios on CBCT projection data. Also, beam hardening artifacts in reconstructed CT images is resulted by the polychromatic spectrum of X-ray beam. These two phenomena lead to unwanted results of reconstructed image such as cupping artifact, worsen soft tissue contrast, and lower CT grey value. This paper studies the result of investigation into the effect of the scatter kernel superposition (SKS) method and polynomial beam hardening correction on the measurement soft tissue contrast of head phantom for reconstructed data from half-fan CBCT system. The measurement imaging system was PHION, which is mobile CT system of NanoFocusRay Co., Ltd, and PH-3 angiographic CT head phantom ACS was used for experiments at 120 kVp and 15 mAs. The data was processed by scatter correction and beam hardening correction which is a linearization method based on polynomial curves of second order. The image was reconstructed using a filtered back projection algorithm. After scatter and beam hardening correction, contrast to noise ratio of reconstructed images is increased and soft tissues are seen more clearly. Image with scatter correction and beam hardening correction has clear boundary between skull and soft tissues, but only scatter corrected image has unclear boundary.
Keywords :
bone; computerised tomography; diagnostic radiography; image reconstruction; medical image processing; noise; CBCT projection data; CT grey value; CT image reconstruction; PH-3 angiographic CT head phantom ACS; X-ray beam; contrast-to-noise ratio; cupping artifact; current 15 mA; filtered back projection algorithm; image quality; linearization method; mobile cone-beam computed tomography imaging system; patient diagnosis; polychromatic spectrum; polynomial beam hardening correction; polynomial curves; scatter kernel superposition method; skull; soft tissue contrast measurement; voltage 120 kV; Biological tissues; Biomedical imaging; Computed tomography; Detectors; Image reconstruction; Mobile communication; X-ray imaging;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2013 IEEE
Conference_Location :
Seoul
Print_ISBN :
978-1-4799-0533-1
Type :
conf
DOI :
10.1109/NSSMIC.2013.6829362
Filename :
6829362
Link To Document :
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