Multi-spectral CT imaging

Patent metadata

Field	Value
Publication number	US-10290122-B2
Application number	US-201615092784-A
Country	US
Kind code	B2
Filing date	Apr 7, 2016
Priority date	Apr 14, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A multi-spectral CT imaging method, preferably a CT imaging method, is described. Spectrally resolved projection scan data is acquired from a region to be imaged of an examination object. The data is assigned to a plurality of pre-determined different partial spectra. Spectrally resolved image data is reconstructed with a plurality of attenuation values for each image point of the region to be imaged. The attenuation values are each assigned to one of the pre-determined different partial spectra. Furthermore, an extremal attenuation value is determined for each image point on the basis of the plurality of attenuation values. A representative image data set is determined such that the determined extremal attenuation value is assigned to each image point.

First claim

The invention claimed is:

1. A multi-spectral imaging method, the method comprising:
acquiring spectrally resolved projection scan data from a region to be imaged of an examination object, the scan data being assigned to a plurality of pre-determined different partial spectra, the pre-determined different partial spectra based on energy thresholds of an x-ray detector;
reconstructing spectrally resolved image data, the image data comprising a plurality of attenuation values for each image point of the region to be imaged, the attenuation values each being from respective ones of the pre-determined different partial spectra;
determining an extremal attenuation value for each image point, the extremal attenuation value of each of the image points being an extremal one of the plurality of attenuation values for the respective image point;
generating a representative image data set, wherein the determined extremal attenuation value of each image point is assigned to each respective image point of the representative image data set; and
displaying an image from the determined extremal attenuation values of the representative image data set.

2. The method as claimed in claim 1 , wherein reconstructing comprises assigning the partial spectra to the different frequency intervals or different base materials.

3. The method as claimed in claim 1 , wherein determining comprises determine the extremal attenuation value as a maximum value or a minimum value.

4. The method as claimed in claim 1 , wherein on generation of the representative image data set, in addition, an item of information relating to the partial spectrum assigned to the determined extremal attenuation value is assigned to each of the image points.

5. The method as claimed in claim 1 , wherein a spectral value is assigned to each of the partial spectra.

6. The method as claimed in claim 1 , wherein the representative image data set is divided into a plurality of slices that are represented as two-dimensional image data, wherein a two-dimensional representation is carried out as a spatial maximum intensity projection, minimum intensity projection, or multi-planar reconstruction representation.

7. The method as claimed in claim 3 , wherein on generation of the representative image data set, in addition, an item of information relating to the partial spectrum assigned to the determined extremal attenuation value is assigned to each of the image points.

8. The method as claimed in claim 4 , wherein a spectral value is assigned to each of the partial spectra.

9. The method as claimed in claim 7 , wherein the item of information relating to the partial spectrum assigned to the determined extremal attenuation value comprises an extremal spectral value assigned to the respectively assigned extremal partial spectrum.

10. An image data determining device for multi-spectral CT imaging, the image data determining device comprising:
an input interface configured to acquire spectrally resolved projection scan data from a region to be imaged of an examination object, the scan data assigned to a plurality of pre-determined different partial spectra; and
a controller configured to reconstruct spectrally resolved image data comprising a plurality of attenuation values assigned to the pre-determined partial spectra for each image point of the region to be imaged, determine an extremal attenuation value for each image point from the plurality of attenuation values for the respective image point, the extremal attenuation value being a maximum for each image point, and generate a representative image data set, wherein the determined extremal attenuation value for each image point is assigned to each respective image point for the representative image data set.

11. The image data determining device of claim 10 wherein the controller is part of a computed tomography system.

12. A non-transitory computer-readable medium on which program portions which are readable and executable by a computer unit are stored, the program portions comprising instructions for:
acquiring spectrally resolved projection scan data from a region to be imaged of an examination object, the scan data being assigned to a plurality of pre-determined different partial spectra;
reconstructing spectrally resolved image data, the image data comprising a plurality of attenuation values for each image point of the region to be imaged, the attenuation values each being assigned to one of the pre-determined different partial spectra;
determining an extremal attenuation value for each image point (x i ) on the basis of the plurality of attenuation values for each of the respective image points;
generating a representative image data set, wherein the determined extremal attenuation value for each image point is assigned to each respective image point of the representative image data set; and
displaying an image from the determined extremal attenuation values of the representative image data set.

13. The method as claimed in claim 4 , wherein the item of information relating to the partial spectrum assigned to the determined extremal attenuation value comprises an extremal spectral value assigned to the respectively assigned extremal partial spectrum.

14. The method as claimed in claim 1 , wherein the representative image data set is represented such that the extremal attenuation values assigned to each image point are represented as gray-scale values.

15. The method as claimed in claim 4 , wherein the representative image data set is represented such that the extremal attenuation values assigned to each image point are represented depending on the assigned extremal spectral value with different colors, an intensity of the colors depending on a size of the respective extremal attenuation value.

16. The method as claimed in claim 4 , wherein for each image point, an additional second-largest or second-smallest spectral attenuation value or further additional spectral attenuation values are determined and in the act of generating a representative image data set, in addition, the determined additional spectral attenuation values and the partial spectra assigned to the additional spectral attenuation values and/or the spectral values corresponding to the partial spectra are assigned to each image point.

17. The method as claimed in claim 4 , wherein the representative image data set is represented such that the extremal and additional spectral attenuation values assigned to a common image point are represented depending on the respectively assigned spectral value with different colors, an intensity of the different colors being dependent on the size of the respective spectral attenuation value, and the extremal and additional spectral attenuation values assigned to the common image point are represented together as color mixtures of the colors assigned to the extremal and additional spectral attenuation values assigned to the common image point.

18. The method as claimed in claim 4 , wherein the representative image data set is represented such that the extremal attenuation values assigned to each image point are represented as gray-scale values.

19. The method as claimed in claim 7 , wherein the representative image data set is represented such that the extremal attenuation values assigned to each image point are represented depending on the assigned extremal spectral value with different colors, an intensity of the colors depending on a size of the respective extremal attenuation value.

20. The method as claimed in claim 7 , wherei

Assignees

• Allmendinger Thomas
• Raupach Rainer
• Schmidt Bernhard
• Schoendube Harald
• Siemens Ag

Inventors

• Allmendinger Thomas
• Raupach Rainer
• Schmidt Bernhard
• Schöndube Harald

Classifications

• G06T12/30 Primary

  Image post-processing, e.g. metal artefact correction · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• A61B6/52

  Devices using data or image processing specially adapted for radiation diagnosis · CPC title

• G06T2207/10081

  Computed x-ray tomography [CT] · CPC title

• G06T2211/408

  Dual energy · CPC title