Direct conversion radiation detector digital signal processing electronics
A system ( 100 ) includes a photon counting detector array ( 116 ) including a direct conversion material ( 118 ) and a plurality of detector pixels ( 120 ) affixed thereto, and a split signal corrector ( 126 ) that corrects the output of the plurality of detector pixels for split signals. A method includes receiving an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array, and correcting the output of the plurality of detector pixels for split signals. A computer readable storage medium encoded with computer readable instructions, which, when executed by a processer, cause the processor to: receive an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array, and correct the output of the plurality of detector pixels for split signals.
1. A system, comprising:
a photon counting detector array configured with a direct conversion material and a plurality of detector pixels affixed thereto; and
a split signal corrector configured to correct an output of the plurality of detector pixels for split signals, wherein the split signals comprise a first signal from one of the plurality of detector pixels indicative of a first sub-portion of a charge signal generated by direct conversion material in response to an incident photon and a second signal from at least another one of the plurality of detector pixels indicative of a second sub-portion of the same charge signal of the same incident photon, wherein a corrected first signal of the output comprises a sum of digital samples of the first signal and the second signal.
2. The system of claim 1 , the split signal corrector, comprising:
an analog-to-digital converter configured to convert the analog output signal of a pixel into a digital time series signal, wherein the split signal corrector corrects digital samples in the digital time series signal for split signals.
3. The system of claim 2 , the split signal corrector, further comprising:
a comparator configured to compare a value of each of the samples in each of the digital time series signals with a predetermined energy threshold and identifies samples as corresponding to detected photons in response to the value exceeding the energy threshold, wherein the split signal corrector corrects digital samples in the digital time series signal that correspond to detected photons.
4. The system of claim 3 , wherein an energy threshold for a pixel is determined based on a global and a local behavior of the analog output signal of the pixel.
5. The system of claim 4 , the split signal corrector, further comprising:
a smoothing filter configured to smooth the digital time series signal prior to further processing and increases the true signal to noise ratio.
6. The system of claim 5 , wherein the smoothing facilitates identifying samples to correspond to detector photons.
7. The system of claim 3 , the split signal corrector, further comprising:
a coincident photon detection identifier configured to identify samples corresponding to detected photons in neighboring pixels that occur in a same time range.
8. The system of claim 7 , the split signal corrector, further comprising:
a signal corrector configured to correct only the samples identified as samples corresponding to detected photons in the neighboring pixels that occur in the same time range.
9. The system of claim 1 , wherein the digital sample of the first signal is a larger magnitude than the digital sample of second signal.
10. The system of claim 1 , wherein the digital sample of the second signal is a lower magnitude than digital sample of the first signal, wherein the split signal corrector corrects the digital sample of the second signal by discarding the digital sample of the second signal.
11. A method, comprising:
receiving an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array; and
correcting the output signal of the plurality of detector pixels for split signals, wherein the split signals comprise a first signal from one of the plurality of detector pixels indicative of a first sub-portion of a charge signal generated by direct conversion material in response to an incident photon and a second signal from at least another one of the plurality of detector pixels indicative of a second sub-portion of the same charge signal of the same incident photon, wherein a corrected first signal of the output signal of the plurality of detect pixels comprises a sum of digital samples of the first signal and the second signal.
12. The method of claim 11 , further comprising:
converting an analog output signal of a pixel into a digital time series signal, wherein the split signal corrector corrects digital samples in the digital time series signal for split signals.
13. The method of claim 12 , further comprising:
smoothing the digital time series signal to increase the true signal to noise ratio prior to further processing.
14. The method of claim 13 , wherein the smoothing facilitates identifying samples to correspond to detector photons.
15. The method of claim 12 , further comprising:
comparing a value of each of the samples in each of the digital time series signals with a predetermined energy threshold; and
identifying samples as corresponding to detected photons in response to the value exceeding the energy threshold.
16. The method of claim 15 , further comprising:
determining an energy threshold for a pixel based on a global and a local behavior of the analog output signal of the pixel.
17. The method of claim 15 , further comprising:
identifying samples corresponding to detected photons in neighboring pixels that occur in a same time range.
18. The method of claim 17 , further comprising:
correcting only the samples identified as samples corresponding to detected photons in the neighboring pixels that occur in the same time range.
19. The method of claim 18 , further comprising:
determining a first magnitude of one of the samples of the neighboring pixels;
determining a second magnitude of the other of the samples of the neighboring pixels;
determining which of the first or second magnitude is larger; and
wherein the digital sample of the first signal is the larger magnitude.
20. The method of claim 11 , wherein a corrected second signal of the output comprises discarding the digital sample of the second signal, wherein a magnitude of the digital sample of the second signal is lower than a magnitude of the digital sample of the first signal.
21. A non-transitory computer readable storage medium encoded with computer readable instructions, which, when executed by a processor, cause the processor to:
receive an output signal of each of a plurality of detector pixels affixed to a direction conversion material of photon counting detector array; and
correct the output of the plurality of detector pixels for split signals, wherein the split signals comprise a first signal from one of the plurality of detector pixels indicative of a first sub-portion of a charge signal generated by the direct conversion material in response to an incident photon and a second signal from at least another one of the plurality of detector pixels indicative of a second sub-portion of the same charge signal of the same incident photon, wherein a corrected first signal of the output comprises a sum of digital samples of the first signal and the second signal.