Method for producing a computed tomography display of tissue structures by applying a contrast medium

• US 20060134000A1
• Filed: 12/15/2005
• Published: 06/22/2006
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Siemens Healthcare GMBH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Heismann, Bjoern
• Granted Patent: US 7,643,866 B2
• Time in Patent Office: Days
• US Class Current: 424/9.400
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4021 involving movement of the focal spot
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/405 Source units specially adapted to modify characteristics of the beam during the data acquisition process A61B6/4021, A61B6/4035 take precedence
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography

Abstract

A method is disclosed for producing a computed tomography display of tissue structures by applying a contrast medium. A contrast medium is applied to a patient for better visualization of the tissue structure to be examined. An X-ray scan is performed during the presence of the one contrast medium, and computed tomography 2- or 3-dimensional pictures are subsequently reconstructed from the X-ray scan data obtained. In the method, absorption data are measured for at least two different energy spectra, a computed tomography intermediate image is reconstructed per energy spectrum, and the distribution of the one contrast medium in the tissue is determined from the different energy-specific absorption behavior between tissue and contrast medium.

Claims

1. A method of determining the distribution of a contrast medium in a tissue structure, an X-ray scan being performed during the presence of the one contrast medium, comprising:

measuring absorption data for at least two different energy spectra;

reconstructing a computed tomography intermediate image per energy spectrum; and

determining the distribution of the one contrast medium in the tissue structure from the different energy-specific absorption behavior between tissue structure and contrast medium.

2. The method as claimed in claim 1, wherein the atomic number distribution is ascertained in order to determine the contrast medium distribution.

3. The method as claimed in claim 1, wherein a significant statement referring to the distribution of the contrast medium is calculated from the at least two intermediate images.

4. The method as claimed in claim 3, wherein the significant statement is calculated by forming the quotient of the intermediate images.

5. The method as claimed in claim 3, wherein the significant statement is calculated by a linear combination of the intermediate images.

6. The method as claimed in claim 3, wherein, in a CT image, display image values with a positive significant statement referring to the presence of contrast medium at this point obtain a predetermined image value.

7. The method as claimed in claim 6, wherein the image value is a at least one of a maximum and minimum gray scale value.

8. The method as claimed in claim 6, wherein the image value is a color value that is not present in the remaining image display.

9. The method as claimed in claim 1, wherein a dedicated radiation source is used per spectrum to determine the absorption data for the at least two different energy spectra.

10. The method as claimed in claim 1, wherein a dedicated anode material per spectrum is used in the radiation source to determine the absorption data for the at least two different energy spectra.

11. The method as claimed in claim 1, wherein a combination of anode material and contrast medium is used, the anode material having an intensity maximum in the bremsstrahlung spectrum, and the contrast medium having an absorption maximum in the energy range of the intensity maximum of the bremsstrahlung generated by the anode material.

12. The method as claimed in claim 1, wherein a spring focus is used.

13. The method as claimed in claim 1, wherein a dedicated detector is used per spectrum to determine the absorption data for the at least two different energy spectra.

14. The method as claimed in claim 1, wherein to determine the absorption data for the at least two different spectral energies, use is made of at least one detector that can resolve the energy spectrum of the detected radiation for at least two different energies.

15. The method as claimed in claim 4, wherein, in a CT image, display image values with a positive significant statement referring to the presence of contrast medium at this point obtain a predetermined image value.

16. The method as claimed in claim 5, wherein, in a CT image, display image values with a positive significant statement referring to the presence of contrast medium at this point obtain a predetermined image value.

17. A method for producing a computer tomography display of tissue structure by applying a contrast medium, the method comprising:

applying a contrast medium to a patient for better visualization of the tissue structure to be examined;

performing an X-ray scan during the presence of the a contrast medium;

measuring absorption data for at least two different energy spectra;

reconstructing a computed tomography intermediate image per energy spectrum;

determining the distribution of the one contrast medium in the tissue structure from the different energy-specific absorption behavior between tissue structure and contrast medium; and

reconstructing computed tomography 2- or 3-dimensional pictures.

18. The method as claimed in claim 17, wherein the atomic number distribution is ascertained in order to determine the contrast medium distribution.

19. The method as claimed in claim 18, wherein a significant statement referring to the distribution of the contrast medium is calculated from the at least two intermediate images.

20. The method as claimed in claim 19, wherein the significant statement is calculated by forming the quotient of the intermediate images.