The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 2002
Filed:
Dec. 07, 1998
Siemens Aktiengesellschaft, Munich, DE;
Abstract
In a method for reconstruction of a three-dimensional image of an object scanned in linear or circular fashion in the context of a tomosynthesis. The object is transirradiated with X-rays from various projection angles &phgr; for the recording of the projection images, and the radiation exiting from the object is recorded by a detector that supplies digital output image signals. The output image signals representing the projection image data are supplied to a computer for image reconstruction. In the context of the reconstruction a filter is first produced, on the basis of the following steps: A 3D transmission function H (&ohgr; ,&ohgr; ,&ohgr; ) is calculated from the recording geometry for the individual projection image recording and the back-projection of the individual projection images into the 3D reconstruction image volume. By approximation, the 3D transmission function H (&ohgr; ,&ohgr; ,&ohgr; ) is inverted for the determination of an inversion function H (&ohgr; ,&ohgr; ,&ohgr; ). A 3D filtering function H (&ohgr; ,&ohgr; ,&ohgr; ) is produced dependent on one or more desired image characteristics of the reconstruction image. A resulting 3D filtering function H (&ohgr; ,&ohgr; ,&ohgr; ) is determined by multiplication of the 3D filtering function H (&ohgr; ,&ohgr; ,&ohgr; ) and the inversion function H (&ohgr; ,&ohgr; ,&ohgr; ). A 2D filtering function H (&ohgr; ,&ohgr; ) is determined from the resulting 3D filtering function H (&ohgr; ,&ohgr; &ohgr; ) by coordinate transformation of the 3D object space into the 2D projection image space of the respective individual projection images at the projection angle &phgr;. After calculating the filter, the reconstruction of the image takes place in the computer by application of the 2D filtering function H (&ohgr; ,&ohgr; ) to the associated individual projection image data, and production of the reconstruction image by back-projection of the filtered individual projection image data, into the 3D reconstruction image volume.