Affiliations: National Key Laboratory for Electronic Measurement
Technology, North University of China, Taiyuan, Shanxi, China | Key Laboratory of Instrumentation Science and Dynamic
Measurement, North University of China, Taiyuan, Shanxi, China | State Key Laboratory of Management and Control for
Complex Systems, Institute of Automation, Chinese Academy of Sciences, Beijing,
China
Note: [] Corresponding author: Ping Chen, National Key Laboratory for
Electronic Measurement Technology, North University of China, Taiyuan 030051,
Shanxi, China. Tel.: +86 351 3557413; Fax: +86 351 3557413; E-mail:
[email protected]
Abstract: Energy auto-modulation is an important tool in X-ray imaging, as it
can improve the quality and longevity of an x-ray imaging system. Because of
the complex nature of imaged objects, X-ray energy auto-modulation may be
difficult. If there is a physical model about imaging mechanism, one can
forecast the best imaging parameters using a pre-scan that can be fed into this
model. This paper offers a physical model, which is called the
Voltage-Thickness-Gray (VTG) model. Based on equivalent single-energy, this
paper uses the empirical formula of X-ray attenuation and X-ray photon
intensity to build this VTG model. Then use linear regression to estimate the
model's parameters, by multi-voltage imaging about the steel wedge block. At
last, by the experiment of the steel step block, verify this model and forecast
the imaging tube voltage. The result shows this model can better reflect X-ray
attenuation imaging properties, and can be used to forecast the imaging
voltage. Also the forecast precision can achieve 90% or so.
Keywords: X-ray imaging, energy auto-modulation, VTG (Voltage-Thickness-Gray) model, parameter estimation
