Frequency dependent combination of X-ray images of different modalities

Patent metadata

Field	Value
Publication number	US-9472007-B2
Application number	US-201214236668-A
Country	US
Kind code	B2
Filing date	Jul 27, 2012
Priority date	Aug 19, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

In phase-contrast imaging, different types of image information, such as absorption image information and differential phase-contrast image information, may be obtained by a single image acquisition process and have different image properties. A frequency dependent combination of different types of image information is obtained, the combined image having improved properties over the image information and respective image information types. Accordingly, an apparatus and a method for image processing in X-ray imaging of an object is provided, including receiving first and second image information of the object of first and second image information types, respectively, where the second image information type is different from the first image information type. The first and second image information is combined to obtain combined image information of the object, where the combined image information is frequency-dependent, depending on spatial frequencies of the first and second image information, respectively.

First claim

The invention claimed is:

1. A method for processing images obtained by X-ray imaging of an object, comprising receiving first image information of the object of a first image information type;
receiving second image information of the object of a second image information type, wherein the first image information type is attenuation image information and the second image information type is one of differential phase contrast image information, scatter image information, and de-coherence image information;
filtering the first image information with a first frequency-filter element;
filtering the second image information with a second frequency-filter element;
wherein the first filter element and the second filter element are configured as complementary filter elements; and
combining the filtered first image information and the filtered second image information to obtain combined image information of the object;
wherein the combined image information is frequency dependent according to spatial frequencies of the first image information and the second image information.

2. The method according to claim 1 ,
wherein the first filter element and the second filter element comprise a filter shape in accordance with

F
1

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(
k
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(
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wherein F 1 (k) and F 2 (k)) are filter shapes, and S 1 (k) and S 2 (k)) and noise power spectra of the first image information and the second image information, respectively.

3. The method according to claim 1 ; further comprising:
generating a plurality of first image sub-band information by splitting the first image information into sub-bands in the spatial frequency domain;
generating a plurality of second image sub-band information by splitting the second image information into sub-bands in the spatial frequency domain;
wherein the sub-bands of the first image sub-band information correspond to the sub-bands of the second image sub-band information; and
combining the plurality of first image sub-band information and the plurality of second image sub-band information to obtain combined image information of the object;
wherein each sub-band is weighed with a weight factor prior to combining; and
wherein the weight factors of a corresponding sub-band of the first image information and the second image information are dependent on the signal-to-noise ratio (SNR) of the respective first image sub-band information and the second image sub-band information.

4. The method according to claim 1 , wherein the combined image information is determined in accordance with equation

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Assignees

• Maack Hanns-Ingo
• Roessl Ewald
• Koehler Thomas
• Proska Roland
• Koninklijke Philips Nv

Inventors

• Maack Hanns-Ingo
• Roessl Ewald
• Koehler Thomas
• Proska Roland

Classifications

• A61B6/484

  involving phase contrast X-ray imaging · CPC title

• G06T2207/10116

  X-ray image · CPC title

• G06T11/60 Primary

  Creating or editing images; Combining images with text · CPC title

• G06T5/50 Primary

  using two or more images, e.g. averaging or subtraction · CPC title

• G06T2207/20056

  Discrete and fast Fourier transform, [DFT, FFT] · CPC title