| 摘要 |
PROBLEM TO BE SOLVED: To make the effective energy of X-rays invariable and to improve the separation performance of elements when executing modulation by dual energy scan, in an X-ray CT apparatus.SOLUTION: An X-ray CT apparatus 1 includes: an X-ray tube for generating X-rays; an X-ray detector for detecting the X-rays; a high voltage power source for alternately applying a high tube voltage and a low tube voltage to the X-ray tube and making dual energy scan be executed; a modulation tube current value computing part 53 for calculating a time-sequentially varying modulation tube current value to be supplied to the X-ray tube on the basis of the tube current condition of the X-ray tube and a modulation condition; an actual control tube current value computing part 54 for calculating falling time from the high tube voltage to the low tube voltage on the basis of the modulation tube current value, and calculating an actual control tube current value on the basis of the falling time; and a filament current value computing part 55 for calculating the filament current value of the X-ray tube so that the tube current value of the X-ray tube may become the actual control tube current value, and supplying the filament current value to the filament of the X-ray tube. |
