Phantom device, dark field imaging system and method for acquiring a dark field image

Patent metadata

Field	Value
Publication number	US-10507004-B2
Application number	US-201716321504-A
Country	US
Kind code	B2
Filing date	Dec 18, 2017
Priority date	Dec 22, 2016
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

The present invention relates to phantom device for a dark field imaging system. Although dark field imaging is known to be sensitive to changes in the micro-structure of the tissue of a human subject that may be caused during a disease progression, there may be a need to quantify information provided by an image of the human subject. A detector signal component representing the dark image may be altered by changes of the X-ray spectrum which passes tissue of the human subject comprising micro-structures. This may be caused due to an attenuation of the X-ray radiation previously provided by an X-ray source, wherein the attenuation may be caused by tissue of the human subject, which covers said micro-structure comprising tissue. In order to provide information in clinical practice regarding the influence of attenuation to the X-ray radiation before it passes the micro-structure issue of the human subject, the phantom device for dark field imaging is proposed. The phantom device comprises a main body, wherein the main body comprises a plurality of reference parts. Each of the reference parts comprises an attenuation part and a de-coherence part. The attenuation part and the de-coherence part of the same reference part are stacked on top of each other. As a result, the different reference parts may imitate different portions of the human subject extending along a propagation direction of an X-ray radiation, which is propagated from an X-ray source of the dark field imaging system towards the corresponding X-ray detector. Thus, if the phantom device is scanned simultaneously or subsequently with the human subject, a dark field image may be acquired, which represents the human subject as well as the phantom device. From the image parts of the dark field image caused by the phantom device, a clinician may assess and classify the corresponding parts of the image, which relates to the human subject, for instance to the portions of the lung. The present invention further relates to an imaging system configured to scan a human subject together with the phantom device as well as a corresponding method.

First claim

The invention claimed is:

1. A phantom device for a dark field imaging system, the phantom device comprising:
a main body,
reference parts formed of an attenuation part and a de-coherence part being stacked on the attenuation part, such that the attenuation part and the de-coherence part of the respective reference part are arranged consecutively along a predefined direction of the main body;
wherein each de-coherence part is configured to cause de-coherence disturbance to an X-ray beam, if said X-ray beam passes the respective de-coherence part along the predefined direction;
wherein each attenuation part is configured to cause attenuation disturbance to an X-ray beam, if said X-ray beam passes the respective attenuation part along the predefined direction;
wherein the main body comprises a first group of at least two reference parts;
wherein each of the de-coherence parts of the first group are configured to cause the same first degree of de-coherence disturbance; and
wherein the attenuation parts of the first group are configured to cause mutually different degrees of attenuation disturbance.

2. Phantom device according to claim 1 ,
wherein the main body comprises a second group of at least two reference parts;
wherein each of the de-coherence parts of the second group are configured to cause the same second degree of de-coherence disturbance;
wherein the attenuation parts of the second group are configured to cause mutually different degrees of attenuation disturbance; and
wherein the de-coherence parts of the first and second group are configured, such that the first degree of de-coherence disturbance is different from the second degree of de-coherence disturbance.

3. Phantom device according to claim 1 , wherein each group comprises at least three reference parts.

4. Phantom device according to claim 1 , wherein each reference part comprises a constant cross-section in a plane perpendicular to the predefined direction.

5. Phantom device according to claim 1 , wherein each de-coherence part comprises a micro-structure configured to cause small-angle X-ray scattering to an X-ray beam, if it passes the respective de-coherence part in the predefined direction.

6. Phantom device according to claim 1 , wherein the micro-structure of each de-coherence part is formed by a plurality of micro-spheres integrated in a resin of the respective de-coherence part.

7. Phantom device according to claim 1 , wherein the micro-spheres of the first group are each formed by and/or filled with a first material, wherein the micro-spheres of the second group are each formed by and/or filled with a second material, and wherein the first material is different from the second material.

8. Phantom device according to claim 6 , wherein a size of each of the micro-spheres is between 10 μm and 300 μm.

9. Phantom device according to claim 6 , wherein the micro-spheres of the same group are each of the same size.

10. Phantom device according to claim 6 , wherein the micro-spheres of the first group and the micro-spheres of the second group are of a different size.

11. Phantom device according to claim 1 , wherein the reference parts are integrated into and surrounded by a casting compound of the main body.

12. A dark field imaging system, comprising:
a source for generating X-ray radiation;
a detector for detecting X-ray radiation;
a phantom device according to claim 1 ;
a receiving space arranged between the source and the detector;
a support device for supporting a human subject and/or the phantom device;
an interferometer for creating interference pattern;
a control unit for controlling the source and the interferometer; and
a processing unit coupled to the detector for receiving a detector signal from the detector representing detected X-ray radiation;
wherein the support device is arrangeable at the receiving space, such that X-ray radiation generated by the source and transmitted through the human subject and the phantom device is detectable by the detector;
wherein the interferometer is arranged between the source and the detector;
wherein the control unit is configured to cause a scan of a region of interest of the human subject and the phantom device, such that X-ray radiation generated by the source is projected towards the region of interest of the human subject and the phantom device;
wherein the control unit is configured to control the interferometer, such that the interferometer influences X-ray radiation transmitted through the region of interest of the human subject and/or the phantom device; and
wherein the processing unit is configured to determine an image, representing the region of interest of the human subject and the phantom, based on a de-coherence component of the detector signal of the detector caused by the scan.

13. A method for acquiring an image, comprising:
performing a scan of a region of interest of a human subject and a phantom device according to claim 1 , wherein the performing comprises:
generating X-ray radiation by a source, such that the X-ray radiation is transmitted towards the region of interest of a human subject and the phantom device resulting in transmitted X-ray radiation,
influencing the transmitted X-ray radiation by an interferometer resulting in influenced X-ray radiation, and
detecting the influenced X-ray radiation by a detector resulting in a detector signal; and

determining an image, representing the region of interest of the human subject and the phantom device, based on a de-coherence component of the detector signal.

14. A non-transitory computer readable medium having stored one or more executable instructions, which when executed by a processor, cause the processor to perform a method claim 13 .

Assignees

• Koninklijke Philips Nv

Inventors

• Daerr Heiner
• Koehler Thomas
• Maack Hanns-Ingo

Classifications

• G21K2207/005

  Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast · CPC title

• G01N23/041

  Phase-contrast imaging, e.g. using grating interferometers · CPC title

• A61B6/484

  involving phase contrast X-ray imaging · CPC title

• G01N2223/3035

  phantom · CPC title

• A61B6/48 Primary

  Diagnostic techniques (A61B6/022, A61B6/025 A61B6/032, A61B6/037 take precedence) · CPC title