CT IMAGING SYSTEM AND METHOD FOR DETERMINING CT COLLIMATOR SLIT PROFILE

摘要

The present invention relates to a CT imaging system and a method for determining a CT collimator slit profile. The method comprises: determining a profile of two opposite edges of the collimator slit in a longitudinal direction thereof based on the following: a vertical distance between a focus of a radiation source to the collimator slit, a vertical distance between the focus and the radiation detector, an inclination angle between adjacent detector elements, a length of each detector element, a desired width of projection on the radiation detector by the radiation rays passing through the slit whose longitudinal edge profile is to be determined, and an offset angle of a connecting line from a point on a longitudinal center line of the slit to the focus relative to a plane passing said focus and perpendicular to the slit. The CT collimator slit determined according to such a method can enable the actual projection distribution of the radiation beam projected on the radiation detector to be completely equal or very close to the ideal projection distribution, thereby reducing the additional radiation dose while maintaining detection accuracy. In addition, the method of the present invention can also be used to determine one or more slits to meet the different detection requirements. FIG.1