TY - GEN
T1 - CT number variations in micro CT imaging systems
AU - Tu, Shu Ju
AU - Hsieh, Hui Ling
AU - Chao, Tsi Chian
PY - 2008
Y1 - 2008
N2 - CT numbers can be directly computed from the linear attenuation coefficients in the reconstructed CT images and are correlated to the electron densities of the chemical elements with specific atomic numbers. However, the computed CT numbers can be varied when different imaging parameters are used. Phantoms composed of clinically relevant and tissue-equivalent materials (lung, bone, muscle, and adipose) were scanned with a commercial circular-scanning micro CT imager. This imaging system is composed with a micro-focused x-ray tube and charged-coupled device (CCD) camera as the detector. The mean CT numbers and the corresponding standard deviations in terms of Hounsfield units were then computed from a pre-defined region of interest located within the reconstructed volumetric images. The variations of CT number were then identified from a series of imaging parameters. Those parameters include imaging acquisition modes (e.g., the metal filter used in the x-ray tube), reconstruction methods (e.g., Feldkamp and iterative algorithm), and post-image processing techniques (e.g., ring artifact, beam-hardening artifact, and smoothing processing). These variations of CT numbers are useful and important in tissue characterization, quantitative bone structure analysis, bone marrow density evaluation, and Monte Carlo dose calculations for the pilot small animal study when micro CT imaging systems are employed. Also these variations can be used as the quantification for the performance of the micro CT imaging systems.
AB - CT numbers can be directly computed from the linear attenuation coefficients in the reconstructed CT images and are correlated to the electron densities of the chemical elements with specific atomic numbers. However, the computed CT numbers can be varied when different imaging parameters are used. Phantoms composed of clinically relevant and tissue-equivalent materials (lung, bone, muscle, and adipose) were scanned with a commercial circular-scanning micro CT imager. This imaging system is composed with a micro-focused x-ray tube and charged-coupled device (CCD) camera as the detector. The mean CT numbers and the corresponding standard deviations in terms of Hounsfield units were then computed from a pre-defined region of interest located within the reconstructed volumetric images. The variations of CT number were then identified from a series of imaging parameters. Those parameters include imaging acquisition modes (e.g., the metal filter used in the x-ray tube), reconstruction methods (e.g., Feldkamp and iterative algorithm), and post-image processing techniques (e.g., ring artifact, beam-hardening artifact, and smoothing processing). These variations of CT numbers are useful and important in tissue characterization, quantitative bone structure analysis, bone marrow density evaluation, and Monte Carlo dose calculations for the pilot small animal study when micro CT imaging systems are employed. Also these variations can be used as the quantification for the performance of the micro CT imaging systems.
KW - Beam hardening artifact
KW - CT numbers
KW - Feldkamp reconstruction
KW - Micro CT
KW - Quantification
KW - Ring artifacts
UR - http://www.scopus.com/inward/record.url?scp=43149094712&partnerID=8YFLogxK
U2 - 10.1117/12.772160
DO - 10.1117/12.772160
M3 - 会议稿件
AN - SCOPUS:43149094712
SN - 9780819470973
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Medical Imaging 2008 - Physics of Medical Imaging
T2 - Medical Imaging 2008 - Physics of Medical Imaging
Y2 - 18 February 2008 through 21 February 2008
ER -