Patent ID: 6115487
Filing Date: 2000-09-05
Classification: A61B,G01N,Y10S

Abstract:
A method for correcting an image having dense object-induced spectral artifacts generated using data collected in a computed tomography system, said method comprising the steps of:(a) reconstructing an image BWEQ of a calibration object;(b) reconstructing an image WEQ of a water equivalent cylinder having about a same diameter as the calibration object;(c) generating a ratio of images BWEQ and W(d) extracting a region of interest by multiplying the generated ratio by a function II(r) to obtain a calibration pattern CP;(e) averaging the calibration pattern in azimuth to obtain a calibration vector;(f) removing low frequency components from the vector;(g) multiplying the result of step (f) by a CT number scale factor (ctscale) and an apodizing window Aw(r) to generate a calibration error vector CEV representative of an image error introduced by the non-corrected dense object-induced artifact.