Method for generating X-ray image data of an examination object with suppressed calcium signal
A method is for generating X-ray image data of an examination object with reduced calcium blooming. The X-ray image data is based on X-ray projection data acquired with an energy-selective X-ray detector and in respect of at least two energy windows. An embodiment of the method includes determining a calcium content in the X-ray projection data by way of a base material analysis, the calcium content describing the calcium-determined part of the X-ray attenuation caused by the examination object; generating a mixed X-ray projection data record with calcium content suppressed by way of a weighting factor of less than one; and reconstructing the X-ray image data from the mixed projection data record by applying a reconstruction algorithm.
1. A method for generating X-ray image data of an examination object, the X-ray image data being calculated from X-ray projection data including one first and at least one second X-ray projection data record acquired with an energy-selective X-ray detector and each acquired in respect of a respective specific energy window, comprising:
determining a calcium content in the X-ray projection data by way of a base material analysis, the calcium content describing a calcium-determined part of the X-ray attenuation caused by the examination object;
generating a mixed X-ray projection data record with calcium content suppressed by way of a weighting factor to less than one; and
reconstructing the X-ray image data from the mixed projection data record by applying a reconstruction algorithm.
2. The method of claim 1 , wherein the weighting factor for the calcium content is between 0.25 and 0.75.
3. The method of claim 1 , wherein the weighting factor for the calcium content is at least one of specifiable and adjustable by a user.
4. The method of claim 1 , wherein the weighting factor for the calcium content is determined in accordance with a desired visual impression of the reconstructed X-ray image data.
5. The method of claim 1 , wherein base material analysis and generation of the mixed X-ray projection data record is carried out before filter kernel convolution of the reconstruction algorithm.
6. The method of claim 1 , wherein, in addition to calcium, the base material analysis is carried out in respect of at least one of the following materials: iodine and human soft tissue.
7. An X-ray image data processing device for generating X-ray image data of an examination object, the X-ray image data being calculated from X-ray projection data including one first and at least one second X-ray projection data record acquired with an energy-selective X-ray detector and each acquired in respect of a respective specific energy window, the X-ray image data processing device comprising:
a memory storing computer-readable instructions; and
one or more processors configured to execute the computer-readable instructions such that the one or more processors are configured to
determine a calcium content in the X-ray projection data by way of a base material analysis, the calcium content describing a calcium-determined part of the X-ray attenuation caused by the examination object;
generate a mixed X-ray projection data record with calcium content suppressed by way of a weighting factor to less than one; and
reconstruct the X-ray image data from the mixed projection data record by applying a reconstruction algorithm.
8. An X-ray image data processing device for generating X-ray image data of an examination object, the X-ray image data being calculated from X-ray projection data including one first and at least one second projection data record acquired with an energy-selective X-ray detector and each acquired in respect of a respective specific energy window, comprising
a determining unit to determine a calcium content in the X-ray projection data by way of a base material analysis, the calcium content describing the calcium-determined part of the X-ray attenuation caused by the examination object;
a generating unit to generate a mixed X-ray projection data record with calcium content suppressed by way of a weighting factor to less than one; and
a reconstruction unit set up to generate X-ray image data from the mixed projection data record by applying a reconstruction algorithm.
9. An X-ray system, comprising:
an energy-selective X-ray detector to acquire one first and at least one second projection data record in respect of specific respective energy windows; and
the X-ray image data processing device of claim 7 .
10. A non-transitory computer readable medium directly loadable into a memory of an image data record processing device, including program code fragments to carry out the method of claim 1 when executed in the image data processing device.
11. The method of claim 2 , wherein the weighting factor for the calcium content is at least one of specifyable and adjustable by a user.
12. The method of claim 2 , wherein the weighting factor for the calcium content is determined in accordance with a desired visual impression of the reconstructed X-ray image data.
13. The method of claim 2 , wherein base material analysis and generation of the mixed X-ray projection data record is carried out before filter kernel convolution of the reconstruction algorithm.
14. The method of claim 2 , wherein, in addition to calcium, the base material analysis is carried out in respect of at least one of the following materials: iodine and human soft tissue.
15. An X-ray system, comprising:
an energy-selective X-ray detector to acquire one first and at least one second projection data record in respect of specific respective energy windows; and
the X-ray image data processing device of claim 8 .