Method For The Reduction Of Image Artifacts, In Particular Of Metal Artifacts, In CT Image Data

• US 20110280458A1
• Filed: 05/13/2011
• Published: 11/17/2011
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Schmidt, Bernhard, Raupach, Rainer, Flohr, Thomas, Krauss, Bernhard
• Granted Patent: US 8,634,625 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 6/5258 involving detection or reduction of artifacts or noise
• CPC Class Codes: G06T 11/008 Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/10144 Varying exposure
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2211/408 Dual energy
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing

Abstract

A method is disclosed for the reduction of image artifacts, in particular metal artifacts, during the generation of computed tomography image data of an object. In at least one embodiment of the method, two CT image data sets are generated with different medium x-ray energies. By way of a weighted combination of the two CT image data sets, a new image data set is calculated. The weighting factor employed in the weighted combination is here selected in such a way that the image artifacts in the new CT image data set are significantly reduced compared with the image artifacts in the two original CT image data sets. In this way it is possible in a simple manner significantly to reduce in particular metal artifacts in CT images.

Claims

1. A method, comprising:

generating at least two CT image data sets of the object volume with different medium x-ray energies; and

calculating a new CT image data set using a weighted combination of the at least two CT image data sets, wherein a weighting factor, used in the weighted combination, is selected such that image artifacts in the new CT image data set are relatively reduced compared with image artifacts in the at least two CT image data sets.

2. The method as claimed in claim 1, wherein the new CT image data set is obtained by way of a weighted subtraction of the two CT image data sets.

3. The method as claimed in claim 1, wherein the new CT image data set is obtained through calculation of a monoenergetic CT image data set with an x-ray energy, wherein the x-ray energy of the monoenergetic CT image data set is selected such that the image artifacts in the new CT image data set are relatively reduced compared with the image artifacts in the at least two CT image data sets.

4. The method as claimed in claim 3, wherein basis material decomposition of the at least two CT image data sets is performed for the calculation of the monoenergetic CT image data set.

5. The method as claimed in claim 1, wherein a user is enabled to bring about an interactive change of the weighting factor when examining one or more images of the new CT image data set, wherein the interactive change has an effect on the images of the new CT image data set represented in real time.

6. The method as claimed in claim 3, wherein a user is enabled to bring about an interactive change in the x-ray energy of the monoenergetic CT image data set when examining one or more images of the new CT image data set, wherein the interactive change has an effect on the images of the new CT image data set represented in real time.

7. The method as claimed in claim 1, wherein the image artifacts are metal artifacts.

8. The method as claimed in claim 2, wherein a user is enabled to bring about an interactive change of the weighting factor when examining one or more images of the new CT image data set, wherein the interactive change has an effect on the images of the new CT image data set represented in real time.

9. The method as claimed in claim 4, wherein a user is enabled to bring about an interactive change in the x-ray energy of the monoenergetic CT image data set when examining one or more images of the new CT image data set, wherein the interactive change has an effect on the images of the new CT image data set represented in real time.

10. A tangible computer readable medium including program segments for, when executed on a computer device, causing the computer device to implement the method of claim 1.

11. The method as claimed in claim 1, wherein the at least two CT image data sets are generated with different medium x-ray energies.

12. The method as claimed in claim 2, wherein the at least two CT image data sets are generated with different medium x-ray energies.

13. The method as claimed in claim 3, wherein the at least two CT image data sets are generated with different medium x-ray energies.