Photon-counting x-ray detector, method for operation of a photon-counting x-ray detector and x-ray device

Patent metadata

Field	Value
Publication number	US-2025291069-A1
Application number	US-202519077242-A
Country	US
Kind code	A1
Filing date	Mar 12, 2025
Priority date	Mar 14, 2024
Publication date	Sep 18, 2025
Grant date	—

Abstract

In a first signal processing stage of a photon-counting x-ray detector, each pixel element has a comparator and a monoflop unit with a delay unit. The comparator is configured to compare an electrical signal with a signal threshold value and provide a digital pixel signal to the monoflop unit. The monoflop unit is configured to provide a pulse signal with a defined pulse length based on the digital pixel signal. In a second signal processing stage, an output of the first signal processing stage is coupled, for signaling purposes, to a delay unit, which is configured to delay the pulse signal to obtain an adjusted pulse signal. A counting element is configured to count a counting signal based on the adjusted pulse signal.

First claim

What is claimed is:

1 . A photon-counting x-ray detector, comprising:
a number of pixel elements; a converter element for conversion of x-ray radiation into electrical signals; a first signal processing stage for each respective pixel element of the number of pixel elements, the first signal processing stage including at least one comparator and at least one monoflop unit, wherein
the at least one comparator is configured to compare an electrical signal from a pixel element with a signal threshold value, and provide a digital pixel signal to the at least one monoflop unit based on the comparison,
the at least one monoflop unit is configured to, based on the digital pixel signal, provide a pulse signal with a defined pulse length to an output of the first signal processing stage;
a second signal processing stage for each respective pixel element of the number of pixel elements, the second signal processing stage including at least one delay unit and at least one counting element, wherein
each respective output of the first signal processing stage is coupled to a respective delay unit for signaling purposes,
each delay unit is configured to provide a pulse signal with a respective adjusted delay, as a respective adjusted pulse signal, to a respective counting element,
wherein the respective adjusted delay is based on a circuit-related delay of a respective pixel element of the number of pixel elements, and
each counting element is configured to count a counting signal based on the respective adjusted pulse signal.

2 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the first signal processing stage further includes a signal amplifier, and wherein the signal amplifier is configured to amplify the electrical signal and provide the amplified electrical signal to the at least one comparator.

3 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the at least one monoflop unit is configured to provide the pulse signal upon identifying a rising edge of the digital pixel signal.

4 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the first signal processing stage includes a number of comparators and a number of corresponding monoflop units, wherein each comparator is configured to compare the electrical signal with a respective signal threshold value, and provide a respective digital pixel signal to a corresponding monoflop unit based on the comparison, and wherein the corresponding monoflop unit is configured to, based on the respective digital pixel signal, provide a pulse signal with a defined pulse length to a respective output of the first signal processing stage.

5 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the second signal processing stage includes a number of delay units for at least one group of pixel elements of the number of pixel elements, each delay unit being coupled, for signaling purposes, to a coincidence logic and to a respective counting element, wherein adjusted pulse signals for the at least one group of pixel elements are configured to be provided to the coincidence logic, wherein the coincidence logic is configured to identify a coinciding occurrence of adjusted pulse signals of pixel elements, wherein respective counting elements of the at least one group of pixel elements are configured to
count a pixel-counting signal, which is based on a signal arriving directly in pixel elements of the at least one group of pixel elements, or
based on identification of a coincidence by the coincidence logic, count a coincidence-counting signal, which is based on the pixel-counting signal arriving directly in the respective pixel element and is based on a coinciding occurring signal of at least one further pixel element of the number of pixel elements.

6 . The photon-counting x-ray detector as claimed in claim 5 ,
wherein the second signal processing stage includes at least one first switching element configured to activate or deactivate the coincidence logic, and wherein the respective counting elements, of the at least one group of pixel elements, are configured to count the pixel-counting signal when the coincidence logic is deactivated.

7 . The photon-counting x-ray detector as claimed in claim 5 ,
wherein the at least one group of pixel elements comprises at least one pixel element and at least one further pixel element directly adjoining the at least one pixel element in a row or column.

8 . The photon-counting x-ray detector as claimed in claim 1 , further comprising:
a clock signal generation unit configured to provide a timing signal to at least one of the first signal processing stage or the second signal processing stage, and wherein the at least one of the first signal processing stage or the second signal processing stage is configured to adjust respective components included therein, the respective components configured for at least one of time-based processing or time-based provision with the aid of the timing signal.

9 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the first signal processing stage includes at least one second switching element configured to activate or to deactivate the at least one monoflop unit, and wherein the at least one comparator provides the digital pixel signal to the respective output of the first signal processing stage when the at least one monoflop unit is deactivated.

10 . The photon-counting x-ray detector as claimed in claim 1 ,
wherein the second signal processing stage includes at least one third switching element, which is configured to activate or to deactivate the at least one delay unit, and wherein, on deactivation of the at least one delay unit, the pulse signal is provided to the respective counting element without any delay.

11 . The photon-counting x-ray detector as claimed in claim 1 , wherein at least one of
the defined pulse length is between 1 ns and 20 ns, or the respective adjusted delay of is adjustable.

12 . A method for operation of the photon-counting x-ray detector of claim 1 , the method comprising:
receiving x-ray radiation at the photon-counting x-ray detector; converting the x-ray radiation into the electrical signals by the converter element; processing the electrical signals by the first signal processing stage and the second signal processing stage, wherein pulse signals are provided to outputs of the first signal processing stage, and the pulse signals are further processed by the second signal processing stage; and provisioning counting signals to the counting elements of the second signal processing stage.

13 . The method as claimed in claim 12 ,
wherein an x-ray image dataset is generated based on the counting signals.

14 . The method as claimed in claim 12 , wherein the provisioning comprises:
checking whether a counting signal has a coincidence-counting signal; increasing the defined pulse length and repeating the receiving, converting, processing and provisioning, in response to the counting signal not having a coincidence counting signal; and reducing the defined pulse length and repeating the receiving, converting, processing and provisioning in response to the counting signal having a coincidence counting signal and there having been no previous increase in the defined pulse length.

15 . An x-ray device, comprising:
an x-ray source; and the photon-counting x-ray detector as claimed in claim 1 , wherein
the x-ray source is configured to emit x-ray radiation for illumination of the photon-counting x-ray detector.

Assignees

• Siemens Healthineers Ag

Inventors

• Goederer Edgar
• Reitz Bodo
• Hosemann Michael
• Hupfer Martin
• Kreisler Bjoern

Classifications

• A61B6/03

  Computed tomography [CT] · CPC title

• G01N23/046

  using tomography, e.g. computed tomography [CT] · CPC title

• G01T1/242

  Stacked detectors, e.g. for depth information (constructional or manufacturing details H10W90/00) · CPC title

• G01T1/24 Primary

  with semiconductor detectors · CPC title

• G01T1/247 Primary

  Detector read-out circuitry (for processing gain or off-set correction H04N) · CPC title