Patent ID: 6628983
Filing Date: 2003-09-30
Classification: A61B,G01T

Abstract:
A method of generating an image, comprising:providing a transmission radiation source emitting gamma rays at a plurality of energy levels and directing the emitted gamma rays through a subject to be imaged, the subject attenuating the transmission of the gamma rays; defining an energy range encompassing the emission energy levels; dividing the energy range into a plurality of energy subranges; detecting the gamma rays passing through the subject and falling within the defined energy range; determining positions and energies of the detected gamma rays; logging the determined position and energy information into a plurality of image data subsets based on the determined energy of the detected gamma rays, each image data subset corresponding to one of the energy subranges; repeating the steps of detecting, determining, and logging for a plurality of transmitted rays; comparing the image data subsets to determine one or both of: (1) variations in attenuation between different tissue types of the subject as a function of energy, and (2) variations in attenuation within each tissue type of the subject as a function of energy; based on the determined attenuation variations, assigning a weighting factor to each of the image data subsets and adding the image data subsets together in accordance with their assigned weighting factors to produce a weighted image data set, the weighting factors being assigned so as to enhance at least one structural feature in the weighted image data set; and generating an feature-enhanced transmission image representation representative of the weighted image data set.