Patent ID: 7248726
Filing Date: 2007-07-24
Classification: G06T

Abstract:
1. An energy subtraction processing method, comprising the steps of: i) obtaining a plurality of radiation image signals, each of which represents one of a plurality of radiation images of a single object and is made up of a series of image signal components, the plurality of the radiation images of the single object having been formed respectively with a plurality of kinds of radiation having different energy distributions, and ii) performing energy subtraction processing in accordance with predetermined parameters and on image signal components of the radiation image signals, which image signal components represent corresponding pixels in the radiation images, a desired tissue pattern embedded in the radiation images being thereby extracted or enhanced, wherein a parameter, which is among the predetermined parameters and concerns an image density shift quantity over an entire area of an energy subtraction image obtained from the energy subtraction processing, is calculated in accordance with the other parameters, which are among the predetermined parameters and are other than the parameter concerning the image density shift quantity, wherein the other parameters are calculated in accordance with a smoothed image signal, which is obtained by smoothing either one of two image signals to be subjected to the energy subtraction processing or by smoothing an addition image signal obtained from an addition of the two image signals to be subjected to the energy subtraction processing to each other, and wherein the energy subtraction processing is defined with Formula (1) shown below, and the parameter, which concerns the image density shift quantity, is calculated with Formula (2) shown below: wherein Sproc represents the energy subtraction image signal representing the energy subtraction image, H represents the high energy image signal, which is one of the two image signals to be subjected to the energy subtraction processing, L represents the low energy image signal, which is the other image signal to be subjected to the energy subtraction processing, Lu represents the smoothed low energy image signal, which is obtained from smoothing processing performed on the low energy image signal, Ka(Lu) and Kb(Lu) represent the other parameters, and Kc represents the parameter concerning the image density shift quantity.