Method for operating an X-ray diagnostic device for the generation of high-resolution images

• US 20070196009A1
• Filed: 02/09/2007
• Published: 08/23/2007
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Deinzer, Frank
• Granted Patent: US 7,817,832 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 6/463 characterised by displaying multiple images or images and diagnostic data on one display
• CPC Class Codes: G06T 3/4069 by subpixel displacements

Abstract

The invention relates to a method for operating an X-ray diagnostic device with an X-ray source and an X-ray image detector with a sequence of images of low resolution single pictures with systems of coordinates that are different from each other being created, a harmonization of systems of coordinates of images being carried out, and finally a high resolution image being calculated from the images.

Claims

1-11. -11. (canceled)

12. A method for operating an x-ray diagnostic device comprising an x-ray source and an x-ray detector, comprising:

creating a sequence comprising a plurality of low resolution images, wherein the low resolution images comprises a plurality of coordinate systems that are different from each other;

performing a harmonization of the coordinate systems of the low resolution images; and

calculating a high resolution image from the low resolution images after harmonizing the coordinate systems.

13. The method as claimed in claim 12, wherein the harmonization of the coordinate systems is performed by an affine 2-D transformation.

14. The method as claimed in claim 13, wherein the sequence of the low resolution images are images of a stationery object under diagnosis and are offset or rotated relative to each other.

15. The method as claimed in claim 14, wherein the harmonization of the coordinate systems comprises steps of:

selecting an image from the low resolution images as a reference image g_R, calculating the affine transformation To for each image gi of the low resolution images as

$T_i=\left(\begin{array}{ccc}\cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& -\sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& x_i\\ \sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& \cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& y_i\\ 0& 0& 1\end{array}\right)$

in a homogenous coordinate system consisting of an angle of rotation α

_i and a translation (x_i, y_i) within an image plane,

determining a parameter that maps the image g_i onto the reference image g_R with a minimum error, and

transferring the low resolution images to the homogenous coordinate system by the affine transformation.

16. The method as claimed in claim 15, wherein the transferred low resolution images are superimposed by an image reconstruction and the high resolution image is calculated based on the superimposition.

17. The method as claimed in claim 15, wherein the angle of rotation and the translation are determined with sub-pixel accuracy.

18. The method as claimed in claim 15, wherein the transformation minimizes a dissimilarity for a suitable similarity between the images:

19. The method as claimed in claim 18, wherein a degree of similarity between the images is determined by surmming all pixel difference in the images.

20. The method as claimed in claim 19, wherein the x-ray detector comprises translational or rotational degrees of freedom.

21. The method as claimed in claim 12, wherein the sequence of the low resolution images are offset relative to each other.

22. The method as claimed in claim 12, wherein the sequence of the low resolution images are rotated relative to each other.

23. The method as claimed in claim 12, wherein the sequence of the low resolution images comprises some images that are offset relative to each other and the remaining images that are rotated to each other.

24. The method as claimed in claim 12, wherein the sequence of the low resolution images are offset and rotated relative to each other at the same time.

25. A method for operating an x-ray diagnostic device comprising an x-ray source and an x-ray detector, comprising:

creating a sequence comprising a plurality of low resolution images of an object under diagnosis, wherein the low resolution images comprises a plurality of coordinate systems that are different from each other;

selecting an image from the low resolution images as a reference image g_R;

calculating an affine transformation T_i for each image g_i of the low resolution images as

$T_i=\left(\begin{array}{ccc}\cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& -\sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& x_i\\ \sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& \cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& y_i\\ 0& 0& 1\end{array}\right)$

in a homogenous coordinate system consisting of an angle of rotation ai and a translation (x_i, y_i) within an image plane;

determining a parameter that maps the image g_i onto the reference image g_R with a minimum error;

transferring the low resolution images to the homogenous coordinate system by the affine transformation;

superimposing the transferred low resolution images; and

calculating a high resolution image based on the superimposition.

26. The method as claimed in claim 25, wherein the object is a stationery object.

27. The method as claimed in claim 25, wherein the angle of rotation and the translation are determined with sub-pixel accuracy.

28. The method as claimed in claim 25, wherein the transformation minimizes a dissimilarity for a suitable similarity between the images:

29. The method as claimed in claim 28, wherein a degree of similarity between the images is determined by summing all pixel difference in the images.

30. An x-ray device for diagnosing an object with a high resolution image, comprising:

an x-ray source that emits an x-ray radiation passing through the object;

an x-ray detector that detects a plurality of low resolution x-ray images of the object, wherein the low resolution images comprises a plurality of coordinate systems that are different from each other; and

an imaging processing unit that;

selects an image from the low resolution images as a reference image g_R,

calculates an affine transformation T_i for each image g_i of the low resolution images as

$T_i=\left(\begin{array}{ccc}\cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& -\sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& x_i\\ \sin <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& \cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\left({\mathrm{\alpha <br><br>}}_i\right)& y_i\\ 0& 0& 1\end{array}\right)$

in a homogenous coordinate system consisting of an angle of rotation α

_i and a translation (x_i, y_i) within an image plane,

determines a parameter that maps the image g_i onto the reference image g_R with a minimum error,

transfers the low resolution images to the homogenous coordinate system by the affine transformation,

superimposes the transferred low resolution images, and

calculates the high resolution image based on the superimposition.

31. The x-ray device as claimed in claim 30,

wherein the affine transformation minimizes a dissimilarity for a suitable similarity between the images:

T_i=arg min d(T{circle around (×

)}g_i, g_R)

and

wherein a degree of similarity between the images is determined by summing all pixel difference in the images.