In order containment the signal-noise ratio of desire manner and the system null imaging system which it materializes converts

摘要

PROBLEM TO BE SOLVED: To reduce a radiation dose that a patient receives and to heighten dose efficiency while keeping noise at an allowable level and a good CNR (count noise level) level in an X-ray CT system.;SOLUTION: An imaging system (1) is equipped with a process to obtain projection data, a process to correct the projection data corresponding to beam hardening errors so as to generate projection data after correction, a process to process the projection data after the correction so as to generate a plurality of emitter current values corresponding to an imaging method, and a process to apply the emitter current values corresponding to an imaging object upon modulating X-ray power of the imaging system so as to retain desired imaging noise. Upon determining an optimum emitter tube voltage, characteristics of the imaging system are described so as to determine a system water equivalent path length corresponding to increase in relative noise and an object water equivalent path length is determined and compared with the system water equivalent path length so as to generate a comparison result. The optimum emitter tube voltage is recommended correspondingly to the comparison result.;COPYRIGHT: (C)2004,JPO