| 摘要 |
PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus capable of photographing with increased continuity of modulation of an X-ray irradiation amount in helical scan.SOLUTION: On the basis of a tube current value that changes according to the rotation number of an X-ray tube ball 13 and a tube current value that changes according to the angle of the X-ray tube ball 13, an exposure control part 11 obtains a tube current value (tube current value in three-dimensional modulation) to be supplied to the X-ray tube ball 13 in helical scan. A data collecting part 15 collects X-rays detected by an X-ray detector 14 as projection data according to data collection control signals (VT signals) output from a control part 10. The exposure control part 11 makes a high voltage generation part 12 supply, to the X-ray tube ball 13, a tube current changing the tube current value according to the three-dimensional modulation smoothed according to T signals. |
