Patent ID: 9408579
Filing Date: 2016-08-09
CPC Classification: A61B,G06T

Claim Text:
1. A radiation imaging apparatus comprising: a radiation source that radiates X-rays; a detector that is arranged to be opposed to the radiation source and that outputs, frame by frame, a frame of digital electric two-dimensional data corresponding to the X-rays entering the detector; rotating means for relatively rotating the radiation source and the detector to the object, such that an object being imaged is located between the radiation source and the detector and a predetermined fixed point on a virtual line connecting the radiation source and the detector at each rotation angle is positionally changed to the object during the rotation in an imaging space provided between the radiation source and the detector; data acquiring means for acquiring, frame by frame, the data outputted from the detector while the radiation source and the detector, the detector, or the object is moved by the rotating means, the data acquired being produced into a three-dimensional image of an imaging portion of the object; a phantom arranged in the imaging space to be located at predetermined tomographic planes in the imaging space and configured to have markers with which known positional information in the imaging space is imaged with the X-rays; image producing means for producing, based on a tomosynthesis technique, an image from the data acquired by the data acquiring means in response to the X-rays emitted from the radiation source in a state where the phantom is arranged in the imaging space; first calculating means for calculating, based on the known positional information of the markers and information indicative of positions of the markers obtained from the image, information indicative of a distance between the radiation source and the detector and information indicative of a height of the radiation source relative to the detector; and second calculating means for calculating, based on results calculated by the first calculation means and the data, a parameter defining a positional relationship among the radiation source, the detector, and the tomographic planes in the imaging space by taking into account positional changes of the fixed point on the virtual line to the object when the radiation source and the detector are relatively rotated around the object.