Method for the reconstruction of an image data set of computed tomography, computed tomography apparatus, computer program and electronically readable data carrier

A method for reconstructing an image data set from projection images of an examination object recorded at different projection directions with a computed tomography apparatus, the computed tomography apparatus including a nominal field of view acquired from all projection directions in respective projection images, at least one of the examination object and an additional object associated with the examination object extending partially out of the nominal field of view into an extended field of view, the method comprising:

• establishing an item of contour information describing a contour of at least one of the examination object and the additional object;
• enhancing projection data of the projection images, based upon the contour information established, by way of forward projection in regions in which at least one of the examination object and the additional object was not acquired in the projection data of a projection image;
• and
• reconstructing the image data set based upon the projection data enhanced,
• wherein, from sensor data of at least one camera, the examination object positioned for recording at least one of the projection images and the additional object is acquired, an item of sensor information at least partially describing at least one of the contour of the examination object and of the additional object being established and used for the establishing of the item of contour information, and
• wherein from the sensor data, at least one item of object information describing a type of the additional object used, and wherein a three-dimensional computer model is used in the establishing of the item of contour information describing the contour of the additional object.

A computed tomography apparatus, comprising:

• at least one camera;
• and
• a control device configured for reconstructing an image data set from projection images of an examination object recorded at different projection directions with a computed tomography apparatus, the computed tomography apparatus including a nominal field of view acquired from all projection directions in respective projection images, at least one of the examination object and an additional object associated with the examination object extending partially out of the nominal field of view into an extended field of view, the control device being configured to:
• establish an item of contour information describing a contour of at least one of the examination object and the additional object;
• enhance projection data of the projection images, based upon the contour information established, by way of forward projection in regions in which at least one of the examination object and the additional object was not acquired in the projection data of a projection image;
• and
• reconstruct the image data set based upon the projection data enhanced,
• wherein, from sensor data of at least one camera, the examination object positioned for recording at least one of the projection images and the additional object is acquired, an item of sensor information at least partially describing at least one of the contour of the examination object and of the additional object being established and used for establishing the item of contour information, and
• wherein, firstly through reconstruction of a provisional reconstruction data set from the original projection images for the extended field of view and threshold value formation, an item of preliminary information provisionally describing at least the contour of at least one of the examination object and of the additional object is established, the item of preliminary information being adapted based upon the item of sensor information.