Radiation tomography apparatus

摘要

One object of this invention is to provide a radiation tomography apparatus for acquiring a tomographic image from a plurality of fluoroscopic images. The radiation tomography apparatus can acquire the tomographic image having superior visibility without being influenced by a shadow of a collimator appearing in the fluoroscopic image when radiation is applied only to a portion of an FPD through control of the collimator. In this invention, a boundary between a shadow area where the shadow of the collimator appears in the fluoroscopic image and a non-shadow area is identified, and the shadow area in the fluoroscopic image is complemented by the non-shadow area, etc., whereby a complement image is generated. Then the complement image is used for generating the tomographic image. According to this invention, an extremely dark area where the shadow of the collimator appears is removed and thereafter the tomographic image is generated. As a result, the tomographic image has superior visibility with no blurring due to the shadow of the collimator.

主权项

1. A radiation tomography apparatus comprising:
a radiation source for irradiating a subject with radiation; a collimator for collimating radiation from the radiation source; a radiation detecting device for detecting radiation applied to the subject; a top board between the radiation source and the radiation detecting device for supporting the subject placed thereon; a moving device for moving the radiation source and the radiation detecting device synchronously in opposite directions to each other along the top board; a movement controlling device for controlling the moving device; an image generating device for generating a fluoroscopic image in accordance with detection signals outputted from the radiation detecting device; a boundary identifying device for identifying from the fluoroscopic image a boundary between a shadow area in the fluoroscopic image and a non-shadow area, in the shadow area a shadow of the collimator appearing and in the non-shadow a shadow of the collimator not appearing; an image complement device for generating a complement image through complementing the shadow area in the fluoroscopic image with a complement value with reference to the boundary, the complement value indicating a pixel value of the non-shadow area or indicating a pixel value nearer to that of the non-shadow area than that of the shadow area; and a superimposing device for superimposing a series of the complement images generated from a series of the fluoroscopic images that are continuously taken while the radiation source and the radiation detecting device move to generate a tomographic image.