Patent ID: 9119560
Filing Date: 2015-09-01
Classification: A61B,G06T

Abstract:
1. An X-ray CT apparatus comprising: an X-ray irradiation unit that irradiates X-rays from periphery of an object; an X-ray detection unit that detects X-rays transmitted through the object as X-ray information; an image reconstruction unit that generates a reconstructed image of the object from the X-ray information and that, according to scanning conditions, acquires an irradiated X-ray image which is a distribution of an irradiation intensity of X-rays irradiated to the object by the X-ray irradiation unit, performs projection conversion of the irradiated X-ray image and the reconstructed image, and generates an exposure dose image, which is an image showing a distribution of an exposure dose of the object, and also calculates the exposure dose using the projection-converted reconstructed image and an irradiated X-ray image corresponding to a generation region of the reconstructed image; and a display unit that displays the exposure dose image and the exposure dose, wherein the image reconstruction unit generates irradiation dose data by performing time integration of the irradiated X-ray image at each time at predetermined intervals from start of irradiation to end of irradiation, and generates an image, which shows a distribution of a dose of X-rays irradiated to the object, on the basis of the irradiation dose data, wherein the image reconstruction unit generates an attenuation coefficient image, which is an image showing a distribution of an attenuation coefficient, by converting a CT value of the reconstructed image into an attenuation coefficient on the basis of information indicating a relationship between the CT value and the attenuation coefficient, and wherein the image reconstruction unit generates projection data of the attenuation coefficient image and projection data of the irradiation dose image by performing forward projection processing, which is a transformation from a Cartesian coordinate system to a projection coordinate system, on the attenuation coefficient image and the irradiation dose image, and generates an irradiation dose correction image, which is an image showing a reduction result of the amount of attenuation with respect to the irradiation dose image, by performing reverse attenuation correction processing on the projection data of the irradiation dose image using the projection data of the attenuation coefficient image and performing reverse projection processing, which is a transformation from the projection coordinate system to the Cartesian coordinate system, on projection data of the irradiation dose image after the reverse attenuation correction processing.