Affiliations: School of Mechanical Engineering and Automation,
Beijing University of Aeronautics and Astronautics, Beijing, China | China Information Security Certification Center,
Beijing, China | National Institute of Metrology, Beijing, China | State Key Laboratory of Multiphase Complex Systems,
Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China | School of Mechanical Engineering, Sungkyunkwan
University, Seoul, Korea
Note: [] Corresponding authors: Min Yang, School of Mechanical
Engineering and Automation, Beijing University of Aeronautics and Astronautics,
Beijing 100191, China. E-mail: [email protected]; Fanyong Meng, State Key
Laboratory of Multiphase Complex Systems, Institute of Process Engineering,
Chinese Academy of Sciences, Beijing 100190, China. E-mail: [email protected]
Abstract: Fast-continuous-rotation is an effective measure to improve the
scanning speed and decrease the radiation dose for cone-beam CT. However,
because of acceleration and deceleration of the motor, as well as the response
lag of the scanning control terminals to the host PC, uneven-distributed and
redundant projections are inevitably created, which seriously decrease the
quality of the reconstruction images. In this paper, we first analyzed the
aspects of the theoretical sequence chart of the fast-continuous-rotation mode.
Then, an optimized sequence chart was proposed by extending the rotation angle
span to ensure the effective 2π-span projections were
situated in the stable rotation stage. In order to match the rotation angle
with the projection image accurately, structure similarity (SSIM) index was
used as a control parameter for extraction of the effective projection sequence
which was exactly the complete projection data for image reconstruction. The
experimental results showed that SSIM based method had a high accuracy of
projection view locating and was easy to realize.
Keywords: Cone-beam CT, fast-continuous-rotation scanning, data redundancy, structural similarity
