Method and apparatus for determining an image from x-ray projections recorded when traversing a trajectory

US8213564B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Frank Dennerlein · Forchheim, DE
• Holger Scherl · Bad Hersfeld, DE

Key dates

• Filing date: Sep 22, 2010
• Grant date: Jul 3, 2012
• Expiry date: Jan 4, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G06T2211/421
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A method for determining attenuation coefficients for an object using a movable x-ray source and a detector for recording projections is provided. The method includes defining a trajectory for the movable x-ray source, defining filtering lines for the filtering of projection data, and defining positions on the filtering lines, at which the projection derivative is to be formed using a mathematical algorithm for a back-projection. The method also includes defining sampling positions on the trajectory, traversing, by the x-ray source, the trajectory and recording a projection for each sampling position. Projection derivatives with respect to the trajectory path are calculated numerically for each of the positions directly on the filtering lines, and using a mathematical algorithm, attenuation coefficients are determined for the object from the calculated projection derivatives, for the reconstruction.