METHOD AND SYSTEM FOR THE CALIBRATION OF AN X-RAY SCANNER USING AN OFF-CENTERED CIRCULAR PHANTOM

摘要

A method and system to calibrate an X-ray scanner uses a single circular phantom. The circular phantom is off-centered with respect to the axis of rotation of the scanner so as to introduce different paths in the phantom for each channel, depending on the angular positions of the scanner. This results in different attenuation measurements which are compared with values obtained by the computation of the path lengths which depend on the off-centered coordinates r and PHI and on the position of the scanner, thus enabling computation of the polynomial approximation coefficients to be applied to the measurements.