Method for determining a relative position of an object in relation to an x-ray imaging apparatus

Patent metadata

Field	Value
Publication number	US-11116469-B2
Application number	US-202016782244-A
Country	US
Kind code	B2
Filing date	Feb 5, 2020
Priority date	Feb 21, 2019
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

A method is provided for determining a relative position of an object in relation to an x-ray imaging apparatus for creating an x-ray and a recorded image. The method includes bringing an object in a ray path of an x-ray into a first position. In a first recorded image, at least one defined geometry in and/or on the object is imaged. A measure for a change in the first focus point towards a second focus point is undertaken at the x-ray source. In the second recorded image, the at least one defined geometry is imaged. A distance from the object to the x-ray source and/or to the x-ray detector is determined based on the change in the focus point, as well as on the basis of the images of the at least one defined geometry in the first and the second recorded image.

First claim

The invention claimed is:

1. A method for determining a relative position of an object in relation to an x-ray imaging apparatus having an x-ray source with a variable focus point for creating x-rays and an x-ray detector for creating recorded images, the method comprising:
positioning the object in a ray path of a first x-ray in a first position of the object in relation to the x-ray source and the x-ray detector of the x-ray imaging apparatus, wherein the object is positioned between the x-ray source and the x-ray detector in the first position, and wherein the first x-ray is created with a first focus point by the x-ray source and by the first x-ray focused on the first focus point;
creating a first recorded image of the object in the first position with the first focus point, wherein at least one defined geometry in the object and/or on the object is imaged in the first recorded image;
undertaking a measure for a change in focus point towards a second focus point at the x-ray source with the x-ray source, the x-ray detector, and the object remaining in the first position, wherein a second x-ray with the second focus point is created by the x-ray source and by the second x-ray focused on the second focus point;
creating a second recorded image of the object in the first position with the second focus point, wherein the at least one defined geometry is imaged in the second recorded image, and wherein a same part of a collimator of the x-ray source is imaged in both the first recorded image and the second recorded image; and
determining a distance from the object to the x-ray source and/or to the x-ray detector based on the change in the focus point between the first focus point and the second focus point and the recorded images of the at least one defined geometry in the first recorded image and the second recorded image,
wherein a value of the change in the focus point is established based on the respective imaging of the same part of the collimator in the first recorded image and the second recorded image, and
wherein the value of the change in the focus point is included for the determination of the distance of the object to the x-ray source and/or to the x-ray detector.

2. The method of claim 1 , wherein a plurality of defined geometries each at a different distance from the x-ray source and/or from the x-ray detector is imaged in the first recorded image and the second recorded image,
wherein the respective distance to the x-ray source or to the x-ray detector is established for each defined geometry of the plurality of defined geometries, and
wherein the distance of the object to the x-ray source or to the x-ray detector is established based on the established distances of the plurality of defined geometries.

3. The method of claim 1 , wherein structures imaged in the first recorded image are related to a reference point,
wherein, in the second recorded image, a change in the corresponding imaged structures in relation to the reference point occurring through the change in the focus point is corrected such that the structures imaged in the second recorded image each have a same relationship to the reference point as the respective structures imaged in the first recorded image, and
wherein a corrected second recorded image is created based on this same relationship to the reference point.

4. The method of claim 3 , wherein a video sequence is created based on the first recorded image and the corrected second recorded image.

5. The method of claim 1 , wherein the at least one defined geometry in the object comprises a tissue structure of a patient, a structure implanted into the patient, or a combination thereof.

6. The method of claim 1 , wherein a marker is attached to a part of a body of a patient, and wherein the marker is imaged as the at least one defined geometry on the object.

7. The method of claim 1 , wherein the object is a part of a body of a patient.

8. The method of claim 7 , wherein the part of the body of the patient is a bone structure of the body of the patient.

9. A method for determining a relative position of an object in relation to an x-ray imaging apparatus having an x-ray source with a variable focus point for creating x-rays and an x-ray detector for creating recorded images, the method comprising:
positioning the object in a ray path of a first x-ray in a first position of the object in relation to the x-ray source and the x-ray detector of the x-ray imaging apparatus, wherein the object is positioned between the x-ray source and the x-ray detector in the first position, and wherein the first x-ray is created with a first focus point by the x-ray source and by the first x-ray focused on the first focus point;
creating a first recorded image of the object in the first position with the first focus point;
undertaking a measure for a change in focus point towards a second focus point at the x-ray source with the x-ray source, the x-ray detector, and the object remaining in the first position, wherein a second x-ray with the second focus point is created by the x-ray source and by the second x-ray focused on the second focus point;
creating a second recorded image of the object in the first position with the second focus point, wherein a plurality of defined geometries each at a different distance from the x-ray source and/or from the x-ray detector is imaged in the first recorded image and the second recorded image; and
determining a distance from the object to the x-ray source and/or to the x-ray detector based on the change in the focus point between the first focus point and the second focus point and the first and second recorded images,
wherein a respective distance to the x-ray source or to the x-ray detector is established for each defined geometry of the plurality of defined geometries in the first recorded image and the second recorded image, and
wherein the distance of the object to the x-ray source or to the x-ray detector is established based on the established distances of the plurality of defined geometries.

10. The method of claim 9 , wherein structures imaged in the first recorded image are related to a reference point,
wherein, in the second recorded image, a change in the corresponding imaged structures in relation to the reference point occurring through the change in the focus point is corrected such that the structures imaged in the second recorded image each have a same relationship to the reference point as the respective structures imaged in the first recorded image, and
wherein a corrected second recorded image is created based on this same relationship to the reference point.

11. The method of claim 10 , wherein a video sequence is created based on the first recorded image and the corrected second recorded image.

12. The method of claim 9 , wherein the object is a part of a body of a patient.

13. The method of claim 9 , wherein at least one defined geometry of the plurality of defined geometries in the object comprises a tissue structure of a patient, a structure implanted into the patient, or a combination thereof.

14. The method of claim 9 , wherein a marker is attached to a part of a body of a patient, and
wherein the marker is imaged as at least one defined geometry of the plurality of defined geometries.

15. A method for automatic positioning of an object in relation to an x-ray imaging apparatus having an x-ray source with a variable focus point to create x-rays and an x-ray detector to create recorded images, the method comprising:
predetermining a required distance of the object to the x-ray source and/or to the x-ray detector;
positio

Assignees

• Siemens Healthcare Gmbh

Inventors

• Bartl Peter
• Brauweiler Robert

Classifications

• A61B6/5235

  combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT · CPC title

• A61B6/4441 Primary

  the rigid structure being a C-arm or U-arm · CPC title

• A61B6/589

  Setting distance between source unit and patient · CPC title

• A61B6/06

  Diaphragms · CPC title

• A61B6/0492

  using markers or indicia for aiding patient positioning · CPC title