Tomographic imaging apparatus, method of controlling the same, and computer program product

Patent metadata

Field	Value
Publication number	US-10713822-B2
Application number	US-201816147378-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Jan 11, 2018
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

A tomographic imaging apparatus includes an X-ray detector comprising a plurality of dual mode pixels and configured to detect radiation that has passed through an object, and at least one processor configured to obtain scan data from the X-ray detector, and control each pixel of the plurality of dual mode pixels to operate in one of a first mode and a second mode, wherein each pixel of the plurality of dual mode pixels includes a sensor configured to generate a scan signal by converting incident radiation into an electric signal, a first signal path circuit configured to transmit the scan signal in the first mode, a second signal path circuit configured to transmit the scan signal in the second mode, and a photon counter configured to count photons from the scan signal transmitted through one of the first and second signal path circuits.

First claim

What is claimed is:

1. A tomographic imaging apparatus comprising:
an X-ray detector comprising a plurality of dual mode pixels and configured to detect radiation that has passed through an object; and
at least one processor configured to obtain scan data from the X-ray detector, and control each pixel of the plurality of dual mode pixels to operate in one of a first mode and a second mode,
wherein each pixel of the plurality of dual mode pixels comprises:
a sensor configured to generate a scan signal by converting incident radiation into an electric signal;
a first signal path circuit configured to transmit the scan signal in the first mode;
a second signal path circuit configured to transmit the scan signal in the second mode; and
a photon counter configured to count photons from the scan signal transmitted through one of the first and second signal path circuits,

wherein a minimum time interval of transmitting the scan signal of the second signal path circuit is smaller than that of the first signal path circuit.

2. The tomographic imaging apparatus of claim 1 , wherein the first signal path circuit comprises:
a first preamplifier configured to amplify the scan signal; and
a pulse shaper configured to shape a waveform of the scan signal.

3. The tomographic imaging apparatus of claim 1 , wherein the second signal path circuit comprises:
a second preamplifier configured to amplify the scan signal; and
a reset circuit configured to reset input and output levels of the second preamplifier when the output level of the second preamplifier exceeds a first level.

4. The tomographic imaging apparatus of claim 1 , wherein the at least one processor is further configured to generate a model selection signal for selecting one of the first mode and the second mode and output the mode selection signal to the X-ray detector, wherein each of the plurality of dual mode pixels further comprises:
a first switch configured to transmit, to one of the first signal path circuit and the second signal path circuit, the scan signal output from the sensor, according to the mode selection signal; and
a second switch configured to connect, to one of the first signal path circuit and the second signal path circuit, an input terminal of the photon counter, according to the mode selection signal.

5. The tomographic imaging apparatus of claim 1 , wherein the X-ray detector comprises a plurality of binning pixels comprising a plurality of sub-pixels, wherein the plurality of dual mode pixels are grouped as sub-pixels to be included in the plurality of binning pixels, and
the at least one processor is further configured to control at least one first dual mode pixel in each of the plurality of binning pixels to operate in the first mode and control remaining at least one second dual mode pixel excluding the at least one first dual mode pixel to operate in the second mode.

6. The tomographic imaging apparatus of claim 1 , wherein the X-ray detector further comprises an anti-scatter grid provided on the plurality of dual mode pixels, and
the at least one processor is further configured to control, from among the plurality of dual mode pixels, dual mode pixels provided around a frame of the anti-scatter grid to operate in the first mode and control remaining dual mode pixels excluding the dual mode pixels provided around the frame to operate in the second mode.

7. The tomographic imaging apparatus of claim 1 , wherein the at least one processor is further configured to control, from among the plurality of dual mode pixels, dual mode pixels provided at an outer region to operate in the first mode and control remaining dual mode pixels excluding the dual mode pixels provided at the outer region to operate in the second mode.

8. The tomographic imaging apparatus of claim 1 , further comprising an input device configured to receive a first control signal, wherein the at least one processor is further configured to control a mode of each of the plurality of dual mode pixels of the X-ray detector based on the first control signal.

9. The tomographic imaging apparatus of claim 1 , further comprising an X-ray generator configured to generate and output X-rays,
wherein the at least one processor is further configured to control a mode of each of the plurality of dual mode pixels based on at least one of a tube voltage and a tube current of the X-ray generator.

10. The tomographic imaging apparatus of claim 1 , wherein the at least one processor controls a mode of each of the plurality of dual mode pixels based on an imaging protocol.

11. The tomographic imaging apparatus of claim 1 , wherein the photon counter comprises:
a plurality of comparators configured to compare the scan signal transmitted via one of the first signal path circuit and the second signal path circuit with a threshold voltage; and
a plurality of counters respectively configured to count output signals of the plurality of comparators.

12. A method of controlling a tomographic imaging apparatus, wherein an X-ray detector of the tomographic imaging apparatus comprises a plurality of dual mode pixels operating in a first mode or a second mode, wherein each pixel of the plurality of dual mode pixels comprises a first signal path circuit configured to transmit a scan signal output from a sensor in the first mode, a second signal path circuit configured to transmit the scan signal in the second mode, and a photon counter configured to count photons from the scan signal, the method comprising:
controlling each pixel of the plurality of dual mode pixels to operate in one of the first mode and the second mode; and
obtaining scan data output from the X-ray detector, wherein a minimum time interval of transmitting the scan signal of the second signal path circuit is smaller than that of the first signal path circuit.

13. The method of claim 12 , further comprising:
shaping, by a pulse shaper included in the first signal path circuit, a waveform of the scan signal, in the first mode; and
resetting, by a reset circuit included in the second signal path circuit, input and output levels of a second preamplifier of the second signal path circuit when the output level of the second preamplifier exceeds a first level, in the second mode.

14. The method of claim 12 , wherein the plurality of dual mode pixels are grouped as sub-pixels and included in a plurality of binning pixels, and
the method further comprises:
controlling at least one first dual mode pixel in each of the plurality of binning pixels to operate in the first mode; and
controlling remaining at least one second dual mode pixel excluding the at least one first dual mode pixel to operate in the second mode.

15. The method of claim 12 , wherein the X-ray detector further comprises an anti-scatter grid provided on the plurality of dual mode pixels, and
the method further comprises:
controlling, from among the plurality of dual mode pixels, dual mode pixels provided around a frame of the anti-scatter grid to operate in the first mode; and
controlling remaining dual mode pixels excluding the dual mode pixels provided around the frame to operate in the second mode.

16. The method of claim 12 , further comprising:
controlling, from among the plurality of dual mode pixels, dual mode pixels provided at an outer region to operate in the first mode; and
controlling remaining dual mode pixels excluding the dual mode pixels provided at the outer region to operate in the second mode.

17. The method of claim 12 , further comprising:
receiving a first control signal; and
c

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Sang-Min
• Kang Dong-Uk
• Kim Do-Il

Classifications

• G06T12/00

  Tomographic reconstruction from projections · CPC title

• H04N25/77

  Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components · CPC title

• H04N25/773

  comprising photon counting circuits, e.g. single photon detection [SPD] or single photon avalanche diodes [SPAD] · CPC title

• H04N25/30

  for transforming X-rays into image signals · CPC title

• H04N25/57

  Control of the dynamic range · CPC title