Reconstruction of image data by means of contour data

Patent metadata

Field	Value
Publication number	US-9589336-B2
Application number	US-201414510425-A
Country	US
Kind code	B2
Filing date	Oct 9, 2014
Priority date	Oct 14, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A method is based on first projection data, recorded during a relative rotational movement between an x-ray source of a CT device and at least one examination object lying partly outside the field of view of the CT device. Contour data of the surface of the examination object is useable to enhance the reconstruction of the incomplete first projection data. The spatial correlation between the first projection data and the contour data is known. The first projection data is expanded by way of the contour data to modified projection data, so that the modified projection data includes information about the contour of the examination object lying outside the field of view of the CT device. In an embodiment of the inventive reconstruction of image data by way of the modified projection data, fewer or no artifacts occur by comparison with reconstruction of image data from just the first image data.

First claim

What is claimed is:

1. A method for reconstruction of image data, wherein first projection data has been recorded during relative rotational movement between an x-ray source of a computed tomography (CT) device and at least one examination object, wherein contour data of a surface of the at least one examination object has been recorded via a camera, wherein at least a portion of the at least one examination object is outside the field of view of the CT device, and wherein a spatial correlation between the first projection data and the contour data is known, the method comprising:
expanding the first projection data by way of the contour data to generate modified projection data; and
reconstructing the image data using the modified projection data.

2. The method of claim 1 , wherein
the expanding the first projection data includes
reconstructing first image data from the first projection data,
modifying the first image data by way of the contour data, and
creating the modified projection data from the modified first image data; and

the reconstructing reconstructs the image data from the first projection data and the modified projection data.

3. The method of claim 2 , wherein the modifying the first image data comprises:
modifying the first image data based on a correlation between the first image data and the contour data, to define a boundary surface of the at least one examination object in the first image data.

4. The method of claim 3 , wherein
the boundary surface includes the surface of the at least one examination object; and
the modifying the first image data further includes modifying pixel values in an area outside the field of view and within an area delimited by the surface.

5. The method of claim 4 , wherein
the at least one examination object includes a patient;
at least one anatomical landmark is identified in the contour data; and
the pixel values in an area of the anatomical landmark are modified as a function of x-ray absorption of the anatomical landmark.

6. The method of claim 1 , wherein the expanding the first projection data comprises:
determining a sinogram from the first projection data; and
extrapolating the sinogram to generate the modified projection data.

7. The method of claim 1 , wherein the expanding the first projection data comprises:
expanding the first projection data by weighting in accordance with the contour data.

8. The method of claim 1 , wherein
the at least one examination object includes a first examination and a second examination object;
the first examination object includes a patient; and
the method further includes
identifying the second examination object by way of the contour data, and
generating an output as a function of the identity and position of the second examination object.

9. The method of claim 8 , wherein
the second examination object includes a medical device for intervention; and
the output includes a graphical representation of at least one part of the first and second examination objects and a specification of the position of the first and second examination objects relative to one another.

10. The method of claim 8 , wherein the output includes a warning message.

11. The method of claim 1 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

12. The method of claim 2 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

13. The method of claim 8 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

14. The method of claim 9 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

15. An imaging system, comprising:
a computed tomography (CT), device, including a rotatable x-ray source and an x-ray detector, the CT device configured to record first projection data of at least one examination object, at least a portion of the at least one examination object being outside the field of view of the CT device;
a camera configured to record contour data of a surface of the at least one examination object, wherein a spatial correlation between the first projection data and the contour data is known; and
at least one processor configured to execute computer readable instructions to
expand the first projection data by use of the contour data to generate modified projection data, and
reconstruct image data using the modified projection data.

16. The imaging system of claim 15 , wherein
the at least one examination object includes a first examination object and a second examination object;
the first examination object includes a patient;
the second examination object is identified by way of the contour data; and
the imaging system further includes an output unit connected to the CT device, the output unit configured to provide an output as a function of the identity and position of the second examination object.

17. The imaging system of claim 15 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

18. The imaging system of claim 16 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

19. The method of claim 9 , wherein the output includes a warning message.

20. The method of claim 19 , wherein the camera is a 3D camera and the contour data includes 3D contour data.

Assignees

• Siemens Ag

Inventors

• Flohr Thomas
• Schmidt Bernhard
• Sedlmair Martin

Classifications

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• G06T12/20

  Inverse problem, i.e. transformations from projection space into object space · CPC title

• A61B6/5211

  involving processing of medical diagnostic data · CPC title

• G06T2211/436

  Limited angle · CPC title

• A61B6/5205

  involving processing of raw data to produce diagnostic data · CPC title