X-RAY CT DEVICE

摘要

Provided is an X-ray CT device for controlling the dose of X-rays to be applied depending on the variation of the position of an organ caused by breathing of the subject while improving the quality of image and lessening the dose. In the preparation process before scanning starts, the X-ray CT device (1) creates a three-dimensional cross section model from scanogram projection data about the subject.  The operator inputs the position of a region of interest, an expected variation of the position of the region, and a desired image quality index.  A scan planning section (405d) calculates an X-ray attenuation index from the three-dimensional cross section model and corrects the calculated X-ray attenuation index according to the inputted region of interest, expected variation, and image quality index.  The scan planning section (405d) determines a tube current modulation pattern (X-ray dose modulation pattern) according to the corrected X-ray attenuation index.  During scanning, the X-ray CT device controls the X-ray tube according to the determined X-ray dose modulation pattern so as to obtain an optimum X-ray emission.