Photon counting Toolkit (PcTK)

Photon counting Toolkit (PcTK)

Welcome to the home of Photon Counting Toolkit (PcTK), a software tool to help your research on photon counting x-ray computed tomography (PCD-CT).

The PcTK is a Matlab program for a PCD model which takes into account spatio-energetic cross-talk and correlation between PCD pixels. We have developed PcTK in collaboration with Siemens Healthineers (Forchheim, Germany) and wish to help the community by making PcTK  available to academic researchers.

One can use PcTK to generate spectral response functions, with or without correlation between PCD pixels, and to synthesize noisy PCD projections using the spectral response functions. Click here for more information on PcTK.

About us

  • We are “KU Lab,” a CT research group at Radiological Physics Division, Department of Radiology and Radiological Science, Johns Hopkins University. We believe that PCD-CT (or spectral CT) has a tremendous potential and is the future of CT. So we wish to promote research activities on PCD-CT in the community and that is the reason why we decided to release PcTK software.
  • Ken Taguchi, Ph.D. (The PI of KU lab) is the co-director of newly developed Medical Physics Ph.D. Program at JHU. The first class of students are being recruited as of fall/winter 2024 for matriculation in August, 2025.

Latest News

  • 2024-09-23. Ken Taguchi’s paper on scintillator-based photon counting detector has been published in Medical Physics. It shows a surprising result—in some way, scintillator is better than CdTe or CZT. Ha! 😁 Please read this paper. [Link]
  • 2024-09-20. Ken Taguchi’s paper on the number of energy windows (bins) for photon counting detector has been published in Journal of Medical Imaging. It finally answers a question that has been popping up at conferences and private conversations many, many times—What is the optimal number of energy windows? Two bins are not enough, but more bins increases noise, right? What would be your answer? 😜 [Link]
  • 2024-03-01. Donghyeon Lee’s Medical Physics paper on a photon counting detector model was highlighted as one of seven featured papers in the journal email. Congratulations Donghyeon!! [Link]
  • 2024-02-14. Ken’s (Scott S. Hsieh of Mayo Clinic is the first author) Medical Physics paper on silicon detector’s potential has been published. [Link]
  • 2024-01-11. Donghyeon Lee’s paper on improved photon counting detector model with pixel-to-pixel variation has been published in Medical Physics. [Link]
  • 2024-01-11. Ken Taguchi’s paper on direct energy binning has been published in Medical Physics. [Link]
  • 2023-12-13. Reaching 100 licenses!! Thank you for your support. [Post]
  • 2023-11-08. Ken Taguchi, PhD, presented strategies to combat charge sharing and pulse pileup problems at IEEE Medical Imaging Conference 2023.
  • 2023-11-08. Donghyeon Lee, PhD, presented a new photon counting simulator at IEEE Medical Imaging Conference 2023.
  • 2023-02-20. Donghyeon Lee, PhD, presented at SPIE Medical Imaging 2023 photon counting detector model which can model a global, count-rate-dependent deviation from the analytical model and local, pixel- and energy bin-specific deviations from the averaged (good) pixels.
  • 2023-02-20. Ken presented a charge sharing correction method using coincidence counters at SPIE Medical Imaging 2023.
  • 2022-07-15. The first paper on model-based (simultaneous) compensation for both pulse pileup and charge sharing has been published in Medical Physics. [Post]
  • 2022-05-27. Reaching world-wide 75 licenses. We appreciate your support.
  • 2022-01-18. “This is revolution, not evolution.” Our editorial on photon counting CT has been published in January 2022 issue of IEEE TRPMS. [Post]
  • 2021-09-27. The third paper on MEICC published in Medical Physics. It is on the performances with pulse pileups and charge sharing. [Post]
  • 2021-02-18. Presented MEICC performances with pulse pileups and charge sharing at SPIE Medical Imaging 2021.
  • 2021-01-27. Reaching 60 licenses in 3 years! Thank you everyone for your support and feedback.
  • 2020-08-14. Workflow ver 1.03a released with a bug fixed. We thank Shengzi Zhao of Tsinghua University for his help. [Post]
  • 2020-07-14. Our book on photon counting CT released, with Chapter 18 on PcTK. A copy is available at Amazon or CRC Press. [Post]
  • 2020-06-17. The second paper on MEICC published in IEEE TRPMS online, in which the stochastic version of PcTK has been upgraded to include both flat-field signals for low spatial resolution tasks and boxcar signals for high spatial resolution tasks. [Post]
  • 2020-05-01. PcTK ver 3.24 released, which fixed the bug in sup_offdiag.p. [Post]
  • 2020-04-03. The first paper on MEICC published in Medical Physics online, which used a stochastic version of PcTK.  [Post]
  • 2020-02-16. Presented MEICC and a use of spatially contained signals in simulations at SPIE Medical Imaging 2020. [Post][SPIE Digital Library].
  • 2019-02-25. Workflow ver 1.03 released, which is 17–40% more efficient than ver 1.02, thanks to Scott Hsieh of UCLA [Post].
  • 2019-02-25. Presented our view on PCD-CT and PcTK at SPIE Medical Imaging 2019 workshop [Post][SPIE MI website].
  • 2018-10-17. Presented PcTK at Advanced Development for Security Applications (ADSA) Workshop [ADSA Website].
  • 2018-09-07. Reaching 30 licenses and a world map of visitors. [Post]
  • 2018-08-23. The first paper that uses PcTK (on pixel-binning and -masking) published in Medical Physics online. [Post]
  • 2018-08-01. A talk presented as one of 4 panelists at a symposium on multi-energy multi-contrast CT during AAPM 2018 (Nashville, TN) [Post]
  • 2018-05-23. PcTK advertised during CT meeting (Salt Lake City, UT)
  • 2018-04-03. Correction: normrnd in the script with no correlation. [Post]
  • 2018-03-19. FAQ page created. [Post]
  • 2018-03-15. Minor version up (3.21a) for notes. [Post]
  • 2018-03-14. PcTK paper published in Medical Physics online. [Post]
  • 2018-02-07. PcTK presented at SPIE MI 2018. [Post]
  • 2018-02-03. PcTK ver 3.20 released (First public release) [Post]

How to obtain PcTK? Cost?

  • Please fill out the software license agreement and send to ken.pctk_AT_gmail.com (replace “_AT_” by an at mark).
  • Each user should submit the software license agreement. This is helpful for getting an accurate head count.
  • We are offering PcTK free of charge. Please consider making a donation to an animal rescue organization such as this or this, or adopting a dog.

Eligibility and restrictions

  • The licensees are limited to those in academic institutions.
  • The software may be used for research purposes only. No commercial use, either directly or indirectly, is permitted.
  • The software may not be modified, reverse-engineered, or de-compiled.
  • PcTK has been tested with Matlab 2016b.
  • We would appreciate it if you could cite the following references on PcTK when you publish papers.

References (PcTK)

  • Taguchi K. Photon Counting Detector Simulator: Photon Counting Toolkit (PcTK). (In) Spectral, Photon Counting Computed Tomography: Technology and Applications (Devices, Circuits, and Systems). Edited by Taguchi K, Blevis I, Iniewski K. (CRC Press, Taylor & Francis Books, Inc.). July 14, 2020 (ISBN-13: 978-1138598126, ISBN-10: 1138598127).
  • Taguchi K, Stierstorfer K, Polster C, Lee O, and Kappler S. Spatio-energetic cross-talk in photon counting detectors: N×N binning and sub-pixel masking. Medical Physics. 2018;45(10):4822–4843. DOI:10.1002/mp.13146. This is the first paper that uses PcTK and discusses the merit of anti-scatter grids on decreasing charge sharing between PCD pixels.
  • Taguchi K, Stierstorfer K, Polster C, Lee O, and Kappler S. Spatio-energetic cross-talk in photon counting detectors: Numerical detector model (PcTK) and workflow for CT image quality assessment. Medical Physics. 2018;45(5):1985–1998. DOI:10.1002/mp.12863 (PMID 29537627). This paper outlines PcTK version 3.2.
  • Taguchi K, Polster C, Lee O, Stierstorfer K, and Kappler S. Spatio-energetic cross-talk in photon counting detectors: Detector model and correlated Poisson data generator. Medical Physics. 2016;43(12):6386–6404. DOI:10.1118/1.4966699 (PMID 27908175) This paper outlines PcTK version 2.1.

References (Review articles and book on PCD and PCD-CT)

  • Taguchi K, Ballabriga R, Campbell M, Darambara DG. Photon counting detector computed tomography. IEEE T Radiation and Plasma Medical Sciences 2022;6(1):1–4. DOI:10.1109/TRPMS.2021.3133808.
  • Taguchi K, Blevis I, Iniewski K. Spectral, Photon Counting Computed Tomography: Technology and Applications (Devices, Circuits, and Systems). (CRC Press, Taylor & Francis Books, Inc.). July 14, 2020 (ISBN-13: 978-1138598126, ISBN-10: 1138598127). (link, link)
  • Taguchi K. Energy-sensitive photon counting detector-based x-ray computed tomography. Radiological Physics and Technology. 2017;10:8–22. DOI 10.1007/s12194-017-0390-9. (PMID 28138947).
  • Taguchi K and Iwanczyk JS. Vision 20/20: Single photon counting x-ray detectors in medical imaging. Medical Physics. 2013;40(10):100901. (PMC3786515).
  • McCollough CH, Chen GH, Kalender W, Leng S, Samei E, Taguchi K, Wang G, Yu L, and Pettigrew R. Achieving routine sub-millisievert CT scanning: Report from the summit on management of radiation dose in CT. Radiology. 2012;264(2):567–580. (PMC22692035).

References (PCD algorithms, PCD modeling, and PCD-CT)

  • Taguchi K, Polster C, Segars WP, Aygun N, Stierstorfer K. Model-based pulse pileup and charge sharing compensation for photon counting detectors: a simulation study. Med Phys 2022 (online). DOI:10.1002/mp15779.
  • Taguchi K and Iwanczyk JS. Assessment of multi-energy inter-pixel coincidence counters for photon-counting detectors at the presence of charge sharing and pulse pileup: A simulation study. Med Phys 2021;48(9):4909–4925. DOI:10.1002/mp.15112.
  • Lee O, Rajendran K, Polster C, Stierstorfer K, Kappler S, Leng S, McCollough CH, Taguchi K. X-ray transmittance model-based material decomposition using photon-counting detector CT system. IEEE T Radiation and Plasma Medical Sciences 2021;5(4):508–516. DOI:10.1109/TRPMS.2020.3028363.
  • Taguchi K. Assessment of multi-energy inter-pixel coincidence counters (MEICC) for charge sharing correction or compensation for photon counting detectors with boxcar signals. IEEE T Radiation and Plasma Medical Sciences 2021;5(4):465–475. DOI:10.1109/TRPMS.2020.3003251. PMID 34250325.
  • Taguchi K. Multi-energy inter-pixel coincidence counters for charge sharing correction and compensation in photon counting detectors. Med Phys 2020;47(5):2085–2098. DOI:10.1002/mp.14047.
  • Lee O, Kappler S, Polster C, and Taguchi K. Estimation of basis line-integrals in a spectral distortion-modeled photon counting detector using low-rank approximation-based x-ray transmittance modeling: K-edge imaging application. IEEE Trans. Medical Imaging. 2017;36(11):2389–2403. DOI:10.1109/TMI.2017.2746269
  • Lee O, Kappler S, Polster C, and Taguchi K. Estimation of basis line-integrals for spectral distortion compensation in photon counting detector using low-order Gram polynomials. IEEE Trans. Medical Imaging. 2017;36(2):560–573. (PMID 27810801).
  • Cammin J, Kappler S, Weidinger T, and Taguchi K. Evaluation of models of spectral distortions in photon-counting detectors for CT. Journal of Medical Imaging. 2016;3(2):023503 (12 pages). PMID 27213165; PMCID: PMC4859407).
  • Sisniega A, Zbijewski W, Stayman JW, Xu J, Taguchi K, Fredenberg E, Lundqvist M, and Siewerdsen JH. Volumetric Cone Beam CT image with sparse detectors: application to Si-strip photon counting CT. Physics in Medicine and Biology. 2016;61(1):90–113. (PMID 26611740; PMC5070652; NIHMS820155).
  • Nakada K, Taguchi K*, Fung GSK, and Amaya K. Joint estimation of tissue types and linear attenuation coefficients for photon counting CT. Medical Physics. 2015;41:5329–5341. *Corresponding author. This paper was selected to be highlighted under the Editor’s Pick column as one of four highest quality papers in September issue. (PMID 26328982).
  • Xu J, Zbijewski W, Gang G, Stayman JW, Taguchi K, Lundqvist M, Fredenberg E, Carrino JA, Siewerdsen JH. Cascaded systems modeling of signal, noise, and DQE for x-ray photon counting detectors. Medical Physics. 2014;41(10):101907. (PMC4281040). This paper was selected to be highlighted under the Editor’s Pick column as one of four highest quality papers in October issue. This paper also received Moses and Sylvia Greenfield Award selected by AAPM for the best paper published in Medical Physics in 2014.
  • Cammin J, Xu J, Barber WC, Iwanczyk JS, Nygard E, Hartsough NE, and Taguchi K. A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT. Medical Physics. 2014;41(4):041905.(PMC3979165).
  • Wang X, Meier D, Taguchi K, Wagenaar D, Patt BE, and Frey EC. Material separation in x-ray CT with energy resolved photon-counting detectors. Medical Physics. 2011;37(3):1534–1546. (PMC3060934).
  • Taguchi K, Zhang M, Frey EC, Wang X, Iwanczyk JS, Nygard E, Hartsough NE, Tsui MWT, and Barber WC. Modeling the performance of a photon counting x-ray detector for CT: energy response and pulse pileup effects. Medical Physics. 2011;37(2):1089–1102. (PMC3045417).
  • Taguchi K, Frey EC, Wang X, Iwanczyk JS, Barber WC. An analytical model of the effects of pulse pileup on the energy spectrum recorded by energy resolved photon counting x-ray detectors. Medical Physics. 2010;36(8):3957–3969. (PMC20879558).

Acknowledgement

  • The development of PcTK was supported by Siemens Healthineers and Siemens Medical Solutions through JHU-2015-CT-1xx-01-Taguchi-C00219287 and JHU-2016-CT-1-01-Taguchi_C0022. We are grateful for their expertise and generosity, and our friendly and supportive relationship.

Contact

  • ken.pctk_AT_gmail.com (replace “_AT_” by an at mark).
  • Katsuyuki (Ken) Taguchi, Ph.D.
    • Professor
    • Department of Radiology and Radiological Science, Johns Hopkins University