Patent ID: 7460643
Filing Date: 2008-12-02
Classification: A61B,H04N

Abstract:
1. A radiographic apparatus for obtaining radiographic images based on radiation detection signals, comprising: radiation emitting means for emitting radiation toward an object under examination; radiation detecting means for detecting radiation transmitted through the object under examination; and signal sampling means for taking radiation detection signals from the radiation detecting means at predetermined sampling time intervals; said apparatus obtaining radiographic images based on the radiation detection signals outputted from the radiation detecting means at the predetermined sampling time intervals as radiation is emitted to the object under examination; said apparatus further comprising: time lag removing means for removing lag-behind parts from the radiation detection signals by a recursive computation, on an assumption that a lag-behind part included in each of said radiation detection signals taken at the predetermined sampling time intervals is due to an impulse response formed of a single exponential function or a plurality of exponential functions with different attenuation time constants; and initial value determining means for determining initial values for the recursive computation based on lag signal values remaining at a starting point of the recursive computation; wherein said time lag removing means is arranged to obtain corrected radiation detection signals by removing the lag-behind parts from the radiation detection signals through the recursive computation based on the initial values determined by the initial value determining means.