X-ray phase contrast detector

1. A phase-contrast imaging detector, comprising:

a plurality of pixel elements, each pixel element comprising:

a detection material that generates a measurable parameter in response to X-ray photons;

a plurality of electrodes coupled to and interacting with the detection material, wherein the plurality of electrodes are in an alternating pattern of interleaved comb members with a spacing therebetween corresponding to a frequency of a phase-contrast interference pattern; and

readout circuitry coupled to the plurality of electrodes and configured to read out signals from the plurality of electrodes;

wherein the alternating pattern of interleaved comb members of the plurality of electrodes are aligned in the same direction as an X-ray radiation beam emitted from an X-ray source;

wherein a path of the X-ray radiation beam is incident on multiple pixel elements aligned in the direction of the X-ray radiation beam; and

wherein the pixel elements change in length in the direction of the path of X-ray radiation beam.

2. The phase-contrast imaging detector of claim 1 , wherein the detection material comprises a direct-conversion material capable of generating a charge cloud in response to each X-ray photon, wherein the charge cloud is measured by the plurality of electrodes.

3. The phase-contrast imaging detector of claim 1 , wherein the plurality of electrodes function as a detector-side analyzer grating in a phase-contrast imaging system.

4. The phase-contrast imaging detector of claim 1 , wherein signals acquired from the plurality of electrodes are usable to simultaneously determine an amplitude, an offset, and a phase of the phase-contrast interference pattern without multiple acquisitions at different phase steps of an analyzer grating.

5. The phase-contrast imaging detector of claim 1 , wherein the readout circuitry is configured to localize a center of a charge cloud to a respective electrode using coincidence logic, wherein the charge cloud is generated in response to an incident X-ray photon.

6. The phase-contrast imaging detector of claim 1 , wherein the read out signals from the plurality of electrodes are used to simultaneously determine an offset, amplitude, and a phase of the phase-contrast interference pattern.

7. The phase-contrast imaging detector of claim 6 , wherein an intensity distribution I(x) of the phase-contrast interference pattern is given as:

I

⁡

(

x

)

=

A

DC

+

A

2

⁢

sin

(

2

⁢

π

⁢

⁢

x

p

-

φ

)

with period p, offset A DC , amplitude A, and phase φ.

8. A phase-contrast imaging system, comprising:

an X-ray source configured to emit X-rays through an imaging volume during operation;

at least one grating structure in a path of X-rays through the imaging volume, wherein the X-rays, upon passing though the at least one grating structure have a phase-contrast interference pattern;

a phase-sensitive detector configured to generate signals in response to X-rays emitted by the X-ray source and passing through the at least one grating structure, wherein the phase-sensitive detector comprises:

a plurality of pixel elements, wherein some or all of the pixel elements each comprise a plurality of electrodes, wherein the plurality of electrodes are in an alternating pattern of interleaved comb members with a spacing therebetween corresponding to a frequency of the phase-contrast interference pattern; and

one or more processing components configured to process the signals generated by the plurality of electrodes to generate images;

wherein the alternating pattern of interleaved comb members of the plurality of electrodes are aligned in the same direction as the X-rays emitted from the X-ray source;

wherein a path of the X-ray radiation beam is incident on multiple pixel elements aligned in the direction of the X-ray radiation beam; and

wherein the pixel elements change in length in the direction of the path of X-ray radiation beam.

9. The phase-contrast imaging system of claim 8 , wherein the pixel elements further comprise a direct-conversion material capable of generating a charge cloud in response to each X-ray photon, wherein the charge cloud is measured by the plurality of electrodes.

10. The phase-contrast imaging system of claim 8 , wherein the images comprise one or more of a phase image, an absorption image, or a darkfield image.

11. A phase-contrast imaging method comprising:

operating an X-ray source of an imaging system to emit X-rays through an imaging volume;

receiving the X-rays at a phase-sensitive detector after the X-rays pass through at least one grating structure that imparts a phase-contrast interference pattern to the X-rays, wherein the phase-sensitive detector comprises a plurality of pixel elements, wherein some or all of the pixel elements each comprise a plurality electrodes, wherein the plurality of electrodes are in an alternating pattern of interleaved comb members with a spacing therebetween corresponding to a frequency of the phase-contrast interference pattern;

processing signals generated by the plurality of electrodes to simultaneously determine an amplitude, an offset, and a phase of the phase-contrast interference pattern; and

generating a phase image, an absorption image, or a darkfield image using at least one of the phase, the amplitude, and the offset;

wherein the alternating pattern of interleaved comb members of the plurality of electrodes are aligned in the same direction as the X-rays emitted from the X-ray source;

wherein a path of the X-ray radiation beam is incident on multiple pixel elements aligned in the direction of the X-ray radiation beam; and

wherein the pixel elements change in length in the direction of the path of X-ray radiation beam.

12. The phase-contrast imaging method of claim 11 , wherein the phase, the amplitude, and the offset are determined without multiple acquisitions at different phase steps of an analyzer grating.

13. The phase-contrast imaging method of claim 11 , further comprising processing the signals generated by the plurality of electrodes to localize an incident X-ray photon.

14. The phase-contrast imaging method of claim 11 , wherein the signals comprise measured voltages, and processing the signals comprises:

comparing each signal to a threshold voltage;

generating a time stamp and digital output for those signals exceeding the threshold voltage;

using the time stamps, identifying occurrences where signals generated in response to a respective X-ray photon were measured at more than one of the electrodes;

for occurrences where signals generated in response to the respective X-ray photon were measured at more than one of the electrodes, determining a location of the respective X-ray photon from respective signals from the more than one electrodes; and

incrementing a counter associated with the respective electrode.

15. The phase-contrast imaging method of claim 14 , wherein processing the signals further comprises:

shaping and amplifying a signal generated from at least one of a generated charge cloud and one or more lower-energy photons in response to each incident X-ray photon prior to comparing each signal to the threshold voltage.