Method for acquiring a series of x-ray images

Abstract

During tomosynthesis a plurality of x-ray images is acquired. The angular position of the x-ray tube is changed from x-ray image to x-ray image. Absorption in the imaged object (patient) and also in the patient table changes as a function of the angle. To compensate for this, backlight is applied while the x-ray images are being acquired. The intensity of the back light is selected as a function of the angle of the x-ray tube to the normal of the flat x-ray detector. Backlight can also be directed during reading, with only the areas already read in each instance being irradiated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention is described below with reference to the drawing, in which:

FIG. 1A shows a schematic diagram of the acquisition situation during tomosynthesis,

FIG. 1B shows the acquisition situation in a first angular position,

FIG. 1C shows the acquisition situation in a second angular position, with

FIG. 1D showing the different distances through the patient table in the two angular positions according to FIG. 1B and FIG. 1C,

FIG. 2 shows a schematic diagram of the temporal link between the application of backlight and the operation of the x-ray system, and

FIG. 3 shows the variables used to calculate an angle-dependent backlight application.

Claims

1.-4. (canceled)

5. A method for acquiring a series of x-ray images by an x-ray device comprising an x-ray tube and a flat x-ray detector in a medical procedure, comprising: successively moving the x-ray tube into a plurality of different angular positions;switching the flat x-ray detector to sensitive over a time window in each of the different angular positions;emitting an x-ray radiation to the flat x-ray detector by the x-ray tube within the time window;applying a backlight to the flat x-ray detector within the time window;acquiring an x-ray image in each of the different angular positions by the flat x-ray detector within the time window based on the x-ray radiation and the backlight; andsetting a backlight intensity differently in each of the different angular positions.

6. The method as claimed in claim 5, wherein the backlight is applied over the entire time window.

7. The method as claimed in claim 5, wherein the backlight intensity is a function of a dose of the x-ray radiation.

8. The method as claimed in claim 5, wherein the flat x-ray detector is read area by area after the time window.

9. The method as claimed in claim 8, wherein a further backlight is applied to an area that is already read while reading the flat x-ray detector after the time window to eliminate a residual image structure.

10. The method as claimed in claim 5, wherein the backlight is generated by a plurality of light emitting electrodes.

11. The method as claimed in claim 10, wherein the light emitting electrodes are attached to an opposite side of the flat x-ray detector from a side that receives the x-ray radiation.

12. The method as claimed in claim 5, wherein an angle between a connecting line from the x-ray tube to a point on the flat x-ray detector and a surface normal of the flat x-ray detector is different in each of the different angular positions.

13. The method as claimed in claim 5, wherein the method is used in tomosynthesis.

14. An x-ray device for acquiring a series of x-ray images of an object in a medical procedure, comprising: an x-ray tube that is successively moved into a plurality of different angular positions and emits an x-ray radiation to the object within a time window in each of the different angular positions;a flat x-ray detector arranged under the object that is switched into sensitive within the time window and acquires an x-ray image of the object;a light emitting electrode that applies a backlight to the flat x-ray detector within the time window; anda control device that sets a backlight intensity differently in each of the different angular positions.

15. The x-ray device as claimed in claim 14, wherein the flat x-ray detector acquires the x-ray image of the object by detecting the x-ray radiation and the backlight.

16. The x-ray device as claimed in claim 14, wherein the light emitting electrode is attached to an opposite side of the flat x-ray detector from a side that receives the x-ray radiation.

17. The x-ray device as claimed in claim 14, wherein the backlight is applied over the entire time window.

18. The x-ray device as claimed in claim 14, wherein the backlight intensity is a function of a dose of the x-ray radiation.

19. The x-ray device as claimed in claim 14, wherein the flat x-ray detector is read area by area after the time window.

20. The x-ray device as claimed in claim 19, wherein a further backlight is applied to an area that is already read while reading the flat x-ray detector after the time window to eliminate a residual image structure.

21. The x-ray device as claimed in claim 14, wherein the object is a patient.