COMPUTED TOMOGRAPHY METHOD, COMPUTER SOFTWARE, COMPUTING DEVICE AND COMPUTED TOMOGRAPHY SYSTEM FOR DETERMINING A VOLUMETRIC REPRESENTATION OF A SAMPLE

• US 20110129055A1
• Filed: 11/24/2010
• Published: 06/02/2011
• Est. Priority Date: 11/27/2009
• Status: Active Grant

• Current Assignee: GE Sensing & Inspection Technologies GmbH (General Electric Company)
• Original Assignee: GE Sensing & Inspection Technologies GmbH (General Electric Company)
• Inventors: Neuser, Eberhard, Hoetter, Michael, Frost, Anja, Rothe, Nils, Suppes, Alexander
• Granted Patent: US 8,526,570 B2
• Time in Patent Office: Days
• US Class Current: 378/4
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 2211/424 Iterative

Abstract

A computed tomography method for determining a volumetric representation of a sample comprises using reconstructed volume data of the sample from x-ray projections of the sample taken by an x-ray system, computing a set of artificial projections of said sample by a forward projection from said reconstructed volume data , and determining, essentially from process data of said reconstruction including said reconstructed volume data and/or said x-ray projections, individual confidence measures for single voxels of said volume data based on calculating, for each of said measured x-ray projections, the difference between the contribution of this measured x-ray projection to the voxel under inspection and the contribution from a corresponding artificial projection to the voxel under inspection.

Claims

1. A method of using computed tomography for determining a volumetric representation of a sample, comprising:

receiving reconstructed volume data of the sample from measured x-ray projections of the sample taken by an x-ray system;

computing a set of artificial projections of the sample by a forward projection from said reconstructed volume data;

and determining individual confidence measures for single voxels of the reconstructed volume data, wherein determining individual confidence measures for single voxels of the reconstructed volume data comprises calculating, for each of the measured x-ray projections, a difference between a contribution of the measured x-ray projection to the voxel under inspection and a contribution from a corresponding artificial projection to the voxel under inspection.

2. The method according to claim 1, wherein the individual confidence measure of a voxel under inspection is calculated from a sum over squares, or a sum over absolute values, of the differences between the contributions of the measured x-ray projections to the voxel under inspection and the contributions from the corresponding artificial projections to the voxel under inspection.

3. The method according to claim 1, further comprising changing a value of voxels of the reconstructed volume data.

4. The method according to claim 3, comprising iteratively repeating the step of changing the value of voxels of the reconstructed volume data.

5. The method according to claim 1, further comprising using the confidence measures in an automated defect recognition procedure applied to the reconstructed volume data.

6. The method according to claim 1, further comprising displaying voxels with different confidence measures by different optical codings.

7. The method according to claim 1, further comprising iteratively repeating the volume data reconstruction based on the determined confidence measures.

8. The method according to claim 1, further comprising performing volume compression based on the determined confidence measures.

9. Computer program which, when implemented on a computer, causes the computer to execute the computed tomography method according to claim 1.

10. Computing device, programmed to run a software for executing the computed tomography method according to claim 1.

11. Computed tomography system, comprising an x-ray system adapted to take a set of x-ray projections of a sample, and a computing device according to claim 10.