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arxiv: 2605.00021 · v2 · submitted 2026-04-19 · ⚛️ physics.med-ph · quant-ph

Recognition: unknown

Quantum Entanglement Degree, Mean Positronium Lifetime, and the 3γ/2γ Annihilation-Rate Ratio as Novel PET Biomarkers for Hypoxia -- Concept, Challenges, and Predictions

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Pith reviewed 2026-05-10 04:41 UTC · model grok-4.3

classification ⚛️ physics.med-ph quant-ph
keywords quantum entanglementpositronium lifetimePET biomarkershypoxiaoxygen concentrationannihilation rate ratio3 gamma decaypositron emission tomography
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The pith

The quantum entanglement degree of photons from positronium can indicate oxygen concentration in tissues for PET hypoxia detection.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper proposes two methods to assess tissue oxygen levels using positronium produced in positron emission tomography. The first combines measurements of the mean ortho-positronium lifetime and the three-gamma to two-gamma annihilation rate ratio. The second uses the degree of quantum entanglement of the emitted photons, which is hypothesized to depend on oxygen concentration through different annihilation processes. Formulas are derived relating these quantities to partial pressure of oxygen, with numerical estimates provided for various materials at different oxygen levels. If accurate, these could enable new ways to detect hypoxic regions in the body during standard PET scans.

Core claim

The authors introduce quantum sensing approaches for hypoxia assessment in PET by linking oxygen concentration to ortho-positronium decay rates and to the degree of quantum entanglement of annihilation photons. They derive a formula for pO2 in terms of the 3γ/2γ ratio and mean lifetime, and under the hypothesis that pick-off annihilation photons are unentangled, they calculate specific entanglement degrees at zero oxygen for adipose tissue (0.890), isopropanol (0.886), water (0.867), cyclohexane (0.818), and isooctane (0.784). Theoretical models are given for how these parameters vary with oxygen pressure in different tissues.

What carries the argument

The degree of quantum entanglement C_QE of photons from ortho-positronium annihilation, which varies with the relative contributions of pick-off and conversion processes depending on oxygen concentration.

If this is right

  • A formula is provided for calculating pO2 from measured R_oPs-3γ/2γ and τ_oPs.
  • Measurement accuracies needed are estimated to distinguish hypoxic from physoxic conditions.
  • Quantitative predictions for C_QE, lifetime, and rate ratio as functions of pO2 are made for five specific materials.
  • At zero oxygen, C_QE values range from 0.784 to 0.890 depending on the material.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Validating these predictions experimentally could lead to integration of entanglement measurements into clinical PET systems.
  • This approach might complement existing hypoxia imaging methods by providing additional quantum information from the same scan.
  • The method could be tested first in vitro with controlled oxygen environments before in vivo applications.

Load-bearing premise

The working hypothesis that photons produced in the pick-off annihilation process are not quantum entangled.

What would settle it

Direct measurement of the quantum entanglement degree C_QE in controlled samples of water or adipose tissue at known zero oxygen concentration, to check if it matches the predicted values around 0.86-0.89.

Figures

Figures reproduced from arXiv: 2605.00021 by Pawel Moskal.

Figure 12
Figure 12. Figure 12: Entanglement witnesses CQE (left) and RQE (right) as a function of oxygen pressure pO2 estimated for water, isopropanol, cyclohexane, isooctane, and adipose. Right figure presents result of RQE obtained for θ= θ1 = θ2 = 81.7◦. Calculations were performed using earlier results for RQE and CQE as a function of α ( [PITH_FULL_IMAGE:figures/full_fig_p022_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: Pictorial illustration of the measure of quantum entanglement C(θS) in Compton scattering in the body, and the degree of quantum entanglement CQE depending on the annihilation mechanism. (Left) Photo of the modular J-PET scanner, the first Quantum Entanglement PET, with a superimposed patient and events illustrating annihilation photons (red￾yellow dashed arrows) and photons following scattering within th… view at source ↗
read the original abstract

This manuscript introduces a novel method to assess tissue oxygen concentration via the quantum entanglement (QE) of photons originating from positronium which is produced within the patient's body during positron emission tomography. We also investigate the possibility of assessing hypoxia by simultaneously detecting positronium lifetime and the positronium decay rate ratio. We introduce two distinct quantum sensing approaches. Method 1 utilizes the correlation between oxygen concentration and ortho-positronium (o-Ps) decay rates, relying on the simultaneous measurement of the mean o-Ps lifetime ($\tau_{\mathrm{oPs}}$) and the $3\gamma$-to-$2\gamma$ annihilation rate ratio of o-Ps ($R_{\mathrm{oPs-3\gamma/2\gamma}}$). Method 2 introduces a novel hypothesis: that the degree of QE is sensitive to the relative contribution of annihilation mechanisms (pick-off vs. conversion), which in turn depends on oxygen concentration. We derive a formula for partial pressure of oxygen ($p\mathrm{O}_2$) as a function of $R_{\mathrm{oPs-3\gamma/2\gamma}}$ and $\tau_{\mathrm{oPs}}$ and estimate the measurement accuracy required for these parameters - and for the degree of QE - to sense in-vivo oxygen pressure in the range between hypoxic and physoxic conditions. Theoretical models and quantitative estimates for $R_{\mathrm{oPs-3\gamma/2\gamma}}$, $\tau_{\mathrm{oPs}}$ and for the degree of QE ($C_{\mathrm{QE}}$ ) as a function of $p\mathrm{O}_2$ are provided for water, isopropanol, cyclohexane, isooctane, and adipose tissue. In particular, applying the formulas derived under the working hypothesis that in pick-off process the photons are not entangled, we estimated that for $p\mathrm{O}_2 = 0$, the degree of quantum entanglement $C_{\mathrm{QE}}$ is equal to 0.890 for adipose, 0.886 for isopropanol, 0.867 for water, 0.818 for cyclohexane, and 0.784 for isooctane.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 1 minor

Summary. The manuscript proposes two quantum-sensing methods for assessing tissue hypoxia via positronium in PET: Method 1 correlates pO2 with o-Ps lifetime τ_oPs and the 3γ/2γ rate ratio R_oPs-3γ/2γ; Method 2 introduces C_QE (degree of quantum entanglement of annihilation photons) as a biomarker, deriving pO2 formulas under the explicit working hypothesis that pick-off annihilation produces unentangled photons. It supplies theoretical models and numerical estimates for R_oPs-3γ/2γ, τ_oPs, and C_QE(pO2) in water, isopropanol, cyclohexane, isooctane, and adipose tissue, including specific C_QE values at pO2=0 (0.890 adipose, 0.886 isopropanol, 0.867 water, 0.818 cyclohexane, 0.784 isooctane) and required measurement accuracies.

Significance. If the non-entanglement hypothesis for pick-off can be independently validated, the work would introduce a genuinely new quantum observable (C_QE) into hypoxia imaging, with the provided multi-medium predictions and accuracy estimates enabling direct experimental tests. The explicit framing of the hypothesis and the derivation of pO2 expressions from measurable quantities are constructive features that support falsifiability.

major comments (3)
  1. [Abstract] Abstract (Method 2 paragraph): The quoted C_QE values at pO2=0 are obtained by direct substitution of the assumption that pick-off photons carry zero entanglement into the branching-ratio formula; this renders the numerical outputs equivalent to the input hypothesis by construction rather than an independent prediction.
  2. [Abstract] Abstract and theoretical models: No QED derivation or cited experimental bound is supplied to justify why pick-off events are separable while conversion events remain entangled; without such support the claimed sensitivity of C_QE to the hypoxic-to-physoxic range rests on an untested axiom whose violation would collapse the entire C_QE(pO2) mapping.
  3. [Method 2] pO2 formula derivation (Method 2): The mapping from measured R_oPs-3γ/2γ and τ_oPs to C_QE should include an explicit propagation of uncertainty under alternative entanglement assumptions for pick-off; the current estimates do not quantify how robust the reported C_QE differences remain if the hypothesis is relaxed.
minor comments (1)
  1. [Abstract] Notation for R_oPs-3γ/2γ and τ_oPs should be standardized in all equations and figure captions to avoid ambiguity between o-Ps-specific and total annihilation quantities.

Simulated Author's Rebuttal

3 responses · 1 unresolved

We are grateful to the referee for the detailed and constructive report. The comments accurately highlight the central role of our working hypothesis in Method 2 and the need for greater clarity on its implications. We respond to each major comment below and have revised the manuscript to improve transparency and robustness where possible.

read point-by-point responses
  1. Referee: [Abstract] Abstract (Method 2 paragraph): The quoted C_QE values at pO2=0 are obtained by direct substitution of the assumption that pick-off photons carry zero entanglement into the branching-ratio formula; this renders the numerical outputs equivalent to the input hypothesis by construction rather than an independent prediction.

    Authors: We agree that the reported C_QE values at pO2=0 follow directly from substituting the zero-entanglement assumption for pick-off into the branching-ratio expression. These are therefore conditional predictions under the stated hypothesis rather than independent results. We have revised the abstract to state explicitly that the values are obtained by applying the formulas derived under the working hypothesis of unentangled pick-off photons. revision: yes

  2. Referee: [Abstract] Abstract and theoretical models: No QED derivation or cited experimental bound is supplied to justify why pick-off events are separable while conversion events remain entangled; without such support the claimed sensitivity of C_QE to the hypoxic-to-physoxic range rests on an untested axiom whose violation would collapse the entire C_QE(pO2) mapping.

    Authors: The manuscript introduces the separability of pick-off photons as a novel working hypothesis motivated by the involvement of an uncorrelated medium electron, in contrast to the correlated pair in conversion annihilation. We acknowledge that no QED derivation or experimental bound is supplied to justify this distinction. The C_QE(pO2) sensitivity therefore depends on the validity of the hypothesis. We have added a dedicated paragraph in the discussion section that states the hypothesis explicitly, outlines its physical motivation, and calls for independent experimental tests to validate or refute it. revision: partial

  3. Referee: [Method 2] pO2 formula derivation (Method 2): The mapping from measured R_oPs-3γ/2γ and τ_oPs to C_QE should include an explicit propagation of uncertainty under alternative entanglement assumptions for pick-off; the current estimates do not quantify how robust the reported C_QE differences remain if the hypothesis is relaxed.

    Authors: We agree that quantifying robustness under relaxed assumptions would strengthen the analysis. The present derivation is performed under the zero-entanglement hypothesis for pick-off. We have revised the Method 2 section to include a qualitative assessment of how C_QE values would shift if pick-off photons carry a non-zero entanglement degree, parameterized by an additional factor. Full quantitative uncertainty propagation would require an a priori value for that factor, which is not currently available; we therefore note that experimental determination of pick-off entanglement is required for precise error estimates, while showing that moderate deviations from zero still preserve detectable C_QE differences within the stated accuracy targets. revision: partial

standing simulated objections not resolved
  • No QED derivation or cited experimental bound is supplied to justify why pick-off events are separable while conversion events remain entangled.

Circularity Check

1 steps flagged

C_QE estimates at pO2=0 reduce directly to the non-entanglement hypothesis for pick-off by construction

specific steps
  1. self definitional [Abstract]
    "applying the formulas derived under the working hypothesis that in pick-off process the photons are not entangled, we estimated that for pO2 = 0, the degree of quantum entanglement C_QE is equal to 0.890 for adipose, 0.886 for isopropanol, 0.867 for water, 0.818 for cyclohexane, and 0.784 for isooctane."

    The C_QE numbers are produced by inserting the zero-entanglement assumption for pick-off directly into the derived C_QE formula. The output values are therefore equivalent to the hypothesis by algebraic construction rather than an independent prediction or measurement.

full rationale

The paper's Method 2 derives formulas for C_QE under an explicit working hypothesis that pick-off annihilation photons carry zero entanglement (while conversion photons are entangled). The reported numerical C_QE values at pO2=0 for multiple tissues are obtained by direct substitution of this hypothesis into those formulas, with no independent derivation, external data, or QED justification supplied. This renders the central quantitative biomarker claims tautological with the input assumption. The separate Method 1 relating pO2 to measured R_oPs-3γ/2γ and τ_oPs retains independent modeling content from rate equations and is not circular on the evidence given.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 1 invented entities

The proposal rests on one central ad-hoc assumption about photon entanglement in pick-off and on theoretical decay models for specific media without external benchmarks or experimental anchors.

free parameters (1)
  • C_QE for pO2=0 in each medium
    Numerical values computed directly from the non-entanglement assumption for adipose, isopropanol, water, cyclohexane, and isooctane
axioms (1)
  • ad hoc to paper Photons from pick-off annihilation are not quantum entangled
    Explicitly invoked as working hypothesis to derive C_QE values and oxygen sensitivity
invented entities (1)
  • C_QE as hypoxia biomarker no independent evidence
    purpose: To sense oxygen concentration through changes in annihilation mechanism
    New postulated observable with no independent experimental evidence or falsifiable handle outside the model

pith-pipeline@v0.9.0 · 5715 in / 1376 out tokens · 57016 ms · 2026-05-10T04:41:29.277329+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

130 extracted references · 119 canonical work pages

  1. [1]

    Defining normoxia, physoxia and hypoxia in tumours-implications for treatment response

    McKeown SR. Defining normoxia, physoxia and hypoxia in tumours-implications for treatment response. Br J Radiol. 2014 Mar;87(1035):20130676. doi: https://doi.org/10.1259/bjr.20130676

  2. [2]

    How best to interpret measures of levels of oxygen in tissues to make them effective clinical tools for care of patients with cancer and other oxygen-dependent pathologies

    Swartz HM, Flood AB, Schaner PE, Halpern H, Williams BB, Pogue BW, et al. How best to interpret measures of levels of oxygen in tissues to make them effective clinical tools for care of patients with cancer and other oxygen-dependent pathologies. Physiol Rep. 2020 Aug;8(15):e14541. doi: https://doi.org/10.14814/phy2.14541

  3. [3]

    Oxygenation status of malignant tumors vs

    Vaupel P , Flood AB, Swartz HM. Oxygenation status of malignant tumors vs. normal tissues: critical evaluation and updated data source based on direct measurements with pO2 microsensors. Appl Magn Reson. 2021 Jul;52(10):1451-79. doi: https://doi.org/10.1007/s00723-021-01383-6

  4. [4]

    Severe hypoxia is a typical characteristic of human hepatocellular carcinoma: scientific fact or fallacy? J Hepatol

    Cramer T, Vaupel P . Severe hypoxia is a typical characteristic of human hepatocellular carcinoma: scientific fact or fallacy? J Hepatol. 2022 Apr;76(4):975-80. doi: https://doi.org/10.1016/j.jhep.2021.12.028

  5. [5]

    Hypoxic microenvironment in cancer: molecular mechanisms and therapeutic interventions

    Chen Z, Han F , Du Y , Shi H, Zhou W. Hypoxic microenvironment in cancer: molecular mechanisms and therapeutic interventions. Signal Transduct Target Ther. 2023 Feb 17;8(1):70. doi: https://doi.org/10.1038/s41392-023-01332-8

  6. [6]

    Absolute oxygen- guided radiation therapy improves tumor control in three preclinical tumor models

    Gertsenshteyn I, Epel B, Giurcanu M, Barth E, Lukens J, Hall K, et al. Absolute oxygen- guided radiation therapy improves tumor control in three preclinical tumor models. Front Med (Lausanne). 2023 Oct;10:1269689. doi: https://doi.org/10.3389/fmed.2023.1269689. Erratum in: Front Med (Lausanne). 2023 Dec;10:1339872. doi: https://doi.org/10.3389/fmed.2023.1339872

  7. [7]

    Tumor hypoxia and radiotherapy: a major driver of resistance even for novel radiotherapy modalities

    Beckers C, Pruschy M, Vetrugno I. Tumor hypoxia and radiotherapy: a major driver of resistance even for novel radiotherapy modalities. Semin Cancer Biol. 2023 Jan;98:19-30. doi: https://doi.org/10.1016/j.semcancer.2023.11.006

  8. [8]

    Partial pressure of oxygen in the human body: a general review

    Ortiz-Prado E, Dunn JF , Vasconez J, Castillo D, Viscor G. Partial pressure of oxygen in the human body: a general review. Am J Blood Res [Internet]. 2019 Feb 15 [cited 2026 Jan 5];9(1):1-14. Available from: https://hdl.handle.net/2445/152803

  9. [9]

    1–4.doi:10.1109/NSS/MIC42101.2019.9060020

    Moskal P . Positronium imaging. In: Proceedings of the 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC); 2019 Oct 26-Nov 2; Manchester, UK. IEEE; 2020. p. 1-3. doi: https://doi.org/10.1109/NSS/MIC42101.2019.9059856

  10. [10]

    Feasibility study of the positronium imaging with the J-PET tomograph

    Moskal P , Kisielewska D, Curceanu C, Czerwiński E, Dulski K, Gajos A, et al. Feasibility study of the positronium imaging with the J-PET tomograph. Phys Med Biol. 2019 Mar 7;64(5):055017. doi: https://doi.org/10.1088/1361-6560/aafe20

  11. [11]

    Positronium in medicine and biology

    Moskal P , Jasińska B, Stępień EŁ, Bass SD. Positronium in medicine and biology. Nat Rev Phys. 2019 Jun 21;1(9):527-9. doi: https://doi.org/10.1038/s42254-019-0078-7

  12. [12]

    Performance assessment of the 2γ positronium imaging with the total-body PET scanners

    Moskal P , Kisielewska D, Shopa RY , Bura Z, Chhokar J, Curceanu C, et al. Performance assessment of the 2γ positronium imaging with the total-body PET scanners. EJNMMI Phys. 2020 Jun 30;7(1):44. doi: https://doi.org/10.1186/s40658-020-00307-w

  13. [13]

    Science Advances7(42), 4394 (2021) https://doi.org/10.1126/sciadv.abh4394

    Moskal P, Dulski K, Chug N, Curceanu C, Czerwiński E, Dadgar M, et al. Positronium imaging with the novel multiphoton PET scanner. Sci Adv. 2021 Oct 13;7(42):eabh4394. doi: https://doi.org/10.1126/sciadv.abh4394

  14. [14]

    Science Advances10(37), 2840 (2024) https://doi.org/10.1126/sciadv.adp2840

    Moskal P , Baran J, Bass S, Choiński J, Chug N, Curceanu C, et al. Positronium image of the human brain in vivo. Sci Adv. 2024 Sep 13;10(37):eadp2840. doi: https://doi.org/10.1126/sciadv.adp2840

  15. [15]

    Journal of Nuclear Medicine66(9), 1464–1470 (2025) https://doi.org/ 10.2967/jnumed.125.270130

    Huang B, Dai B, Lapi SE, Liles G, Karp JS, Qi J. High-resolution positronium lifetime tomography at clinical activity levels on the PennPET Explorer. J Nucl Med. 2025 Sep;66(9):1464-70. doi: https://doi.org/10.2967/jnumed.125.270130

  16. [16]

    Likelihood-based inference for random networks with changepoints.IEEE Transactions on Network Science and Engineering, 13: 344–359, 2026

    Moskal P , Bilewicz A, Das M, Huang B, Khreptak A, Parzych S, et al. Positronium imaging: history, current status, and future perspectives. IEEE Trans Radiat Plasma Med Sci. 2025 Nov;9(8):981-1001. doi: https://doi.org/10.1109/TRPMS.2025.3583554

  17. [17]

    In vivo voxel- wise positronium lifetime imaging of thyroid cancer using clinically routine I-124 PET/CT

    Mercolli L, Steinberger WM, Läppchen T, Amon M, Bregenzer C, Conti M, et al. In vivo voxel- wise positronium lifetime imaging of thyroid cancer using clinically routine I-124 PET/CT. EANM Innov. 2026 Mar;2:100017. doi:https://doi.org/10.1016/j.eanmi.2025.100017

  18. [18]

    Towards total-body modular PET for positronium and quantum entanglement imaging

    Moskal P . Towards total-body modular PET for positronium and quantum entanglement imaging. In: Proceedings of the 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC); 2018 Nov 10-17; Sydney, NSW, Australia. IEEE; 2019. p. 1-

  19. [19]

    doi: https://doi.org/10.1109/NSSMIC.2018.8824622

  20. [20]

    Keliri, L

    Moskal P . Positronium and quantum entanglement imaging: a new trend in positron emission tomography. In: Proceedings of the 2021 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC); 2021 Oct 16-23; Piscataway, NJ, USA. IEEE; 2022. p. 1-3. doi: https://doi.org/10.1109/NSS/MIC44867.2021.9875524

  21. [21]

    Positronium as a biomarker of hypoxia

    Moskal P, Stępień EŁ. Positronium as a biomarker of hypoxia. Bio-Algorithms Med Syst. 2021 Dec 5;17(4):311-19. doi: https://doi.org/10.1515/bams-2021-0189

  22. [22]

    Nonmaximal entanglement of photons from positron-electron annihilation demonstrated using a plastic PET scanner

    Moskal P , Kumar D, Sharma S, Beyene EY , Chug N, Coussat A, et al. Nonmaximal entanglement of photons from positron-electron annihilation demonstrated using a plastic PET scanner. Sci Adv. 2025 Apr 30;11(18):eads3046. doi: https://doi.org/10.1126/sciadv.ads3046

  23. [23]

    Perspectives on translation of positronium imaging into clinics

    Moskal P , Stępień EŁ. Perspectives on translation of positronium imaging into clinics. Front Phys. 2022 Sep 16;10:969806. doi: https://doi.org/10.3389/fphy.2022.969806

  24. [24]

    Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography

    Moskal P , Gajos A, Mohammed M, Chhokar J, Chug N, Curceanu C, et al. Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography. Nat Commun. 2021 Sep 27;12:5658. doi: https://doi.org/10.1038/s41467-021-25905-9

  25. [25]

    IEEE Transactions on Radiation and Plasma Medical Sciences, 1–1 (2025) https://doi.org/10.1109/TRPMS.2025.3621554

    Das M, Sharma S, Beyene EY , Bilewicz A, Choinski J, Chug N, et al. First positronium imaging using 44Sc with the J-PET scanner: a case study on the NEMA-image quality phantom. IEEE Transactions on Radiation and Plasma Medical Sciences. 2026;10(4):593. doi: https://doi.org/10.1109/TRPMS.2025.3621554

  26. [26]

    First positronium lifetime imaging using 52Mn and 55Co with a plastic-based PET scanner

    Das M, Sharma S, Beyene EY , Bilewicz A, Choiński J, Chug N, et al. First positronium lifetime imaging using 52Mn and 55Co with a plastic-based PET scanner. Sci Rep. Forthcoming 2026

  27. [27]

    Zeitschrift für Medizinische Physik, 0939388926000176 (2026) https://doi.org/10.1016/j.zemedi.2026.03.004

    Kubat K, Das M, Sharma S, Beyene EY , Bilewicz A, Choiński J, et al. First ex-vivo positronium imaging of tissues with modular J-PET scanner using 44Sc radionuclide. Zeitschrift für Medizinische Physik. 2026; In press. doi: https://doi.org/10.1016/j.zemedi.2026.03.004

  28. [28]

    EJNMMI Physics11(1), 76 (2024) https: //doi.org/10.1186/s40658-024-00678-4

    Steinberger WM, Mercolli L, Breuer J, Sari H, Parzych S, Niedzwiecki S, et al. Positronium lifetime validation measurements using a long-axial field-of-view positron emission tomography scanner. EJNMMI Phys. 2024 Aug 30;11(1):76. doi: https://doi.org/10.1186/s40658-024-00678-4

  29. [29]

    Phantom imaging demonstration of positronium lifetime with a long axial field-of-view PET/CT and 124I

    Mercolli L, Steinberger WM, Rathod N, Conti M, Moskal P , Rominger A, et al. Phantom imaging demonstration of positronium lifetime with a long axial field-of-view PET/CT and 124I. EJNMMI Phys. 2025 Aug 26;12(1):80. doi: https://doi.org/10.1186/s40658-025-00790- z

  30. [30]

    Frontiers in Nuclear Medicine5(2025) 20 https://doi.org/10.3389/fnume.2025.1648621

    Mercolli L, Steinberger WM, Grundler PV , Moiseeva A, Braccini S, Conti M, et al. First positronium lifetime imaging with scandium-44 on a long axial field-of-view PET/CT. Front Nucl Med. 2025 Nov 20;5:1648621. doi: https://doi.org/10.3389/fnume.2025.1648621

  31. [31]

    In vivo positronium lifetime measurements with a long axial field-of-view PET/CT

    Mercolli L, Steinberger WM, Sari H, Afshar-Oromieh A, Caobelli F , Conti M, et al. In vivo positronium lifetime measurements with a long axial field-of-view PET/CT. medRxiv:2024.10.19.24315509 [Preprint]. 2024 Oct 22 [cited 2026 Jan 5]. doi: https://doi.org/10.1101/2024.10.19.24315509

  32. [32]

    Quantification of radicals in aqueous solution by positronium lifetime: an experiment using a clinical PET scanner

    Takyu S, Matsumoto K-i, Hirade T, Nishikido F , Akamatsu G, Tashima H, et al. Quantification of radicals in aqueous solution by positronium lifetime: an experiment using a clinical PET scanner. Jpn J Appl Phys. 2024 Aug 12;63(8):086003. doi: https://doi.org/10.35848/1347-4065/ad679a

  33. [33]

    Positronium lifetime measurement using a clinical PET system for tumor hypoxia identification

    Takyu S, Nishikido F , Tashima H, Akamatsu G, Matsumoto K-i, Takahashi M, et al. Positronium lifetime measurement using a clinical PET system for tumor hypoxia identification. Nucl Instrum Methods Phys Res A. 2024 Aug;1065:169514. doi: https://doi.org/10.1016/j.nima.2024.169514

  34. [34]

    Communications Physics 8(1), 181 (2025) https://doi.org/10.1038/s42005-025-02100-6

    Huang B, Wang Z, Zeng X, Goldan AH, Qi J. Fast high-resolution lifetime image reconstruction for positron lifetime tomography. Commun Phys. 2025 Apr 26;8:181. doi: https://doi.org/10.1038/s42005-025-02100-6

  35. [35]

    Papanicolas, A

    Samanta S, Sun X, Li H, Li Y . Feasibility study of positronium imaging using the NeuroEXPLORER (NX) brain PET scanner. In: Proceedings of the 2023 IEEE Nuclear Science Symposium, Medical Imaging Conference and International Symposium on Room-Temperature Semiconductor Detectors (NSS MIC RTSD); 2023 Nov 4-11; Vancouver, BC, Canada. IEEE; 2023. p. 1-1. doi:...

  36. [36]

    Pickoff and spin conversion of orthopositronium in oxygen

    Shinohara N, Suzuki N, Chang T, Hyodo T. Pickoff and spin conversion of orthopositronium in oxygen. Phys Rev A. 2001 Sep;64(4):042702. doi: https://doi.org/10.1103/PhysRevA.64.042702

  37. [37]

    Oxygen sensing ability of positronium atom for tumor hypoxia imaging

    Shibuya K, Saito H, Nishikido F , Takahashi M, Yamaya T. Oxygen sensing ability of positronium atom for tumor hypoxia imaging. Commun Phys. 2020 Oct 1;3:173. doi: https://doi.org/10.1038/s42005-020-00440-z

  38. [38]

    Interaction of positronium with dissolved oxygen in liquids

    Stepanov PS, Selim FA, Stepanov SV , Bokov AV , Ilyukhina OV , Duplâtre G, et al. Interaction of positronium with dissolved oxygen in liquids. Phys Chem Chem Phys. 2020 Jan 29;22:5123-31. doi: https://doi.org/10.1039/C9CP06105C

  39. [39]

    Colloquium: positronium physics and biomedical applications

    Bass SD, Mariazzi S, Moskal P , Stępień EŁ. Colloquium: positronium physics and biomedical applications. Rev Mod Phys. 2023 May;95(2):021002. doi: https://doi.org/10.1103/RevModPhys.95.021002

  40. [40]

    J-PET: A New Technology for the Whole-body PET Imaging

    Niedźwiecki S, Białas P , Curceanu C, Czerwiński E, Dulski K, Gajos A et al. J-PET: A New Technology for the Whole-body PET Imaging. Acta Phys. Polon. B 2017;48:1567

  41. [41]

    Test of a single module of the J-PET scanner based on plastic scintillators

    Moskal P , Niedźwiecki S, Bednarski T, Czerwiński E, Kapłon Ł, Kubicz E, et al. Test of a single module of the J-PET scanner based on plastic scintillators. Nucl Instrum Methods Phys Res A. 2014 Nov 11;764:317-21. doi: https://doi.org/10.1016/j.nima.2014.07.052

  42. [42]

    Determination of the 3γ fraction from positron annihilation in mesoporous materials for symmetry violation experiment with J-PET scanner

    Jasińska B, Gorgol M, Wiertel M, Zaleski R, Alfs D, Bednarski T, et al. Determination of the 3γ fraction from positron annihilation in mesoporous materials for symmetry violation experiment with J-PET scanner. Acta Phys Pol B. 2016;47(2):453-60. doi: https://doi.org/10.5506/APhysPolB.47.453

  43. [43]

    Three-gamma annihilations as a new modality in PET

    Kacperski K, Spyrou NM. Three-gamma annihilations as a new modality in PET. In: Proceedings of the 2004 IEEE Symposium Conference Record, Nuclear Science; 2004 Oct 16-22; Rome, Italy. IEEE; 2005. p. 3752-6. doi: https://doi.org/10.1109/NSSMIC.2004.1466696

  44. [44]

    TOF-PET tomograph and a method of imaging using a TOF- PET tomograph, based on a probability of production and lifetime of a positronium

    Moskal P , Moskal I, Moskal G. TOF-PET tomograph and a method of imaging using a TOF- PET tomograph, based on a probability of production and lifetime of a positronium. Polish patent PL 227658, 2018 Jan 31; European patent EP 3039453, 2020 Apr 29; United States patent US 9851456, 2017 Dec 26

  45. [45]

    A new PET diagnostic indicator based on the ratio of positron annihilation

    Jasińska B, Moskal P . A new PET diagnostic indicator based on the ratio of positron annihilation. Acta Phys Pol B. 2017;48(10):1577-82. doi: https://doi.org/10.5506/APhysPolB.48.1577

  46. [46]

    The three-photon yield from e+ annihilation in various fluids

    Mercurio K, Zerkel P , Laforest R, Sobotka LG, Charity RJ. The three-photon yield from e+ annihilation in various fluids. Phys Med Biol. 2006 Aug 15;51(17):N323-9. doi: https://doi.org/10.1088/0031-9155/51/17/N05

  47. [47]

    Developing a novel positronium biomarker for cardiac myxoma imaging

    Moskal P , Kubicz E, Grudzień G, Czerwiński E, Dulski K, Leszczyński B, et al. Developing a novel positronium biomarker for cardiac myxoma imaging. EJNMMI Phys. 2023 Mar 24;10(1):22. doi: https://doi.org/10.1186/s40658-023-00543-w

  48. [48]

    Unparalleled and revolutionary impact of PET imaging on research and day to day practice of medicine

    Alavi A, Werner TJ, Stępień EŁ, Moskal P . Unparalleled and revolutionary impact of PET imaging on research and day to day practice of medicine. Bio-Algorithms Med Syst. 2021 Nov 16;17(4):203-12. doi: https://doi.org/10.1515/bams-2021-0186

  49. [49]

    Prospects and clinical perspectives of total-body PET imaging using plastic scintillators

    Moskal P , Stępień EŁ. Prospects and clinical perspectives of total-body PET imaging using plastic scintillators. PET Clin. 2020 Oct;15(4):439-52. doi: https://doi.org/10.1016/j.cpet.2020.06.009

  50. [50]

    Electric field effect on positronium formation in liquids

    Stepanov SV , Byakov VM. Electric field effect on positronium formation in liquids. J Chem Phys. 2002 Apr;116(14):6178-95. doi: https://doi.org/10.1063/1.1451244

  51. [51]

    Measurement of positron lifetime to probe the mixed molecular states of liquid water

    Kotera K, Saito T, Yamanaka T. Measurement of positron lifetime to probe the mixed molecular states of liquid water. Phys Lett A. 2005 Sep 26;345(1-3):184-90. doi: https://doi.org/10.1016/j.physleta.2005.07.018

  52. [52]

    Hierarchical nature of nanoscale porosity in bone revealed by positron annihilation lifetime spectroscopy

    Ahn T, Gidley DW, Thornton AW, Wong-Foy AG, Orr BG, Kozloff KM, et al. Hierarchical nature of nanoscale porosity in bone revealed by positron annihilation lifetime spectroscopy. ACS Nano. 2021 Mar 23;15(3):4321-34. doi:https://doi.org/10.1021/acsnano.0c07478

  53. [53]

    Applications of slow positrons to cancer research: search for selectivity of positron annihilation to skin cancer

    Jean YC, Li Y , Liu G, Chen H, Zhang J, Gadzia JE. Applications of slow positrons to cancer research: search for selectivity of positron annihilation to skin cancer. Appl Surf Sci. 2006 Feb 28;252(9):3166-71. doi: https://doi.org/10.1016/j.apsusc.2005.08.101

  54. [54]

    Applications of positron annihilation spectroscopy to life science

    Chen HM, van Horn JD, Jean YC. Applications of positron annihilation spectroscopy to life science. Defect Diffus Forum. 2012 Sep;331:275-93. doi: https://doi.org/10.4028/www.scientific.net/DDF .331.275

  55. [55]

    Ortho- positronium lifetime for soft-tissue classification

    Avachat AV , Mahmoud KH, Leja AG, Xu JJ, Anastasio MA, Sivaguru M, et al. Ortho- positronium lifetime for soft-tissue classification. Sci Rep. 2024 Sep 10;14(1):21155. doi:https://doi.org/10.1038/s41598-024-71695-7

  56. [56]

    Probing biomembranes with positrons

    Sane P , Salonen E, Falck E, Repakova J, Tuomisto F , Holopainen JM, et al. Probing biomembranes with positrons. J Phys Chem B. 2009 Feb 19;113(7):1810-2. doi: https://doi.org/10.1021/jp809308j

  57. [57]

    Ceramide increases free volume voids in DPPC membranes

    Axpe E, García-Arribas AB, Mujika JI, Mérida D, Alonso A, Lopez X, et al. Ceramide increases free volume voids in DPPC membranes. RSC Adv. 2015 May;5(55):44282-90. doi: https://doi.org/10.1039/C5RA05142H

  58. [58]

    Positronium: review of symmetry, conserved quantities and decay for the radiological physicist

    Harpen MD. Positronium: review of symmetry, conserved quantities and decay for the radiological physicist. Med Phys. 2004 Jan;31(1):57-61. doi: https://doi.org/10.1118/1.1630494

  59. [59]

    Human tissues investigation using PALS technique

    Jasińska B, Zgardzińska B, Chołubek G, Gorgol M, Wiktor K, Wysogląd K, et al. Human tissues investigation using PALS technique. Acta Phys Pol B. 2017;48(10):1737-1747. doi: https://doi.org/10.5506/APhysPolB.48.1737

  60. [60]

    Three-photon annihilation of an electron–positron pair

    Ore A, Powell JL. Three-photon annihilation of an electron–positron pair. Phys Rev. 1949 Jun;75(11):1696-9. doi: https://doi.org/10.1103/PhysRev.75.1696

  61. [61]

    QED and fundamental symmetries in positronium decays

    Bass SD. QED and fundamental symmetries in positronium decays. Acta Phys Pol B. 2019;50(7):1319-33. doi: https://doi.org/10.5506/APhysPolB.50.1319

  62. [62]

    Positron annihilation in insulators

    Bisi A, Fasana A, Gatti E, Zappa L. Positron annihilation in insulators. Nuovo Cimento. 1961 Oct;22(2):266-74. doi: https://doi.org/10.1007/BF02783017

  63. [63]

    Anomalous three-quantum decay of positrons in alkaline earth oxides

    Bussolati C, Zappa L. Anomalous three-quantum decay of positrons in alkaline earth oxides. Phys Rev. 1964 Nov;136(3A):A657-9. doi: https://doi.org/10.1103/PhysRev.136.A657

  64. [64]

    New precision measurement of the decay rate of singlet positronium

    Al-Ramadhan AH, Gidley DW. New precision measurement of the decay rate of singlet positronium. Phys Rev Lett. 1994 Mar 14;72(11):1632-5. doi: https://doi.org/10.1103/PhysRevLett.72.1632

  65. [65]

    First test of O(α2) correction of the orthopositronium decay rate

    Kataoka Y , Asai S, Kobayashi T. First test of O(α2) correction of the orthopositronium decay rate. Phys Lett B. 2009 Jan 19;671(2):219-23. doi: https://doi.org/10.1016/j.physletb.2008.12.008

  66. [66]

    Witnessing entanglement in Compton scattering processes via mutually unbiased bases

    Hiesmayr BC, Moskal P . Witnessing entanglement in Compton scattering processes via mutually unbiased bases. Sci Rep. 2019 Jun 3;9:8166. doi: https://doi.org/10.1038/s41598-019-44570-z

  67. [67]

    Three-party entanglement from positronium

    Acín A, Latorre JI, Pascual P . Three-party entanglement from positronium. Phys Rev A. 2001 Mar 19;63(4):042107. doi: https://doi.org/10.1103/PhysRevA.63.042107

  68. [68]

    Delgado-Bonal, Entropy of radiation: the unseen side of light, Sci

    Hiesmayr BC, Moskal P . Genuine multipartite entanglement in the 3-photon decay of positronium. Sci Rep. 2017 Nov 10;7(1):15349. doi: https://doi.org/10.1038/s41598-017- 15356-y

  69. [69]

    Three-photon entanglement from ortho-positronium revisited

    Nowakowski M, Bedoya Fierro D. Three-photon entanglement from ortho-positronium revisited. Acta Phys Pol B. 2017;48(10):1955-60. doi: https://doi.org/10.5506/APhysPolB.48.1955

  70. [70]

    Testing entanglement of annihilation photons

    Ivashkin A, Abdurashitov D, Baranov A, Guber F , Morozov S, Musin S, et al. Testing entanglement of annihilation photons. Sci Rep. 2023 May 9;13(1):7559. doi: https://doi.org/10.1038/s41598-023-34767-8

  71. [71]

    Kinematic analysis of multiple Compton scattering in quantum-entangled two-photon systems

    Caradonna P . Kinematic analysis of multiple Compton scattering in quantum-entangled two-photon systems. Ann Phys. 2024 Nov;470:169779. doi: https://doi.org/10.1016/j.aop.2024.169779

  72. [72]

    Stokes-parameter representation for Compton scattering of entangled and classically correlated two-photon systems

    Caradonna P , D’Amico I, Jenkins DG, Watts DP . Stokes-parameter representation for Compton scattering of entangled and classically correlated two-photon systems. Phys Rev A. 2024 Mar 20;109(3):033719. doi: https://doi.org/10.1103/PhysRevA.109.033719

  73. [73]

    Compton scattering mediated by quantum entanglement

    Caradonna P . Compton scattering mediated by quantum entanglement. Phys Rev A. 2025 May 8;111(5):053708. doi: https://doi.org/10.1103/PhysRevA.111.053708

  74. [74]

    Measuring the evolution of entanglement in Compton scattering

    Tkachev I, Musin S, Abdurashitov D, Baranov A, Guber F , Ivashkin A, et al. Measuring the evolution of entanglement in Compton scattering. Sci Rep. 2025 Feb 19;15(1):6064. doi: https://doi.org/10.1038/s41598-025-87095-4

  75. [75]

    A reconciliation of the Pryce-Ward and Klein- Nishina statistics for semi-classical simulations of annihilation photon correlations

    Žugec P , Vivoda EA, Makek M, Friščić I. A reconciliation of the Pryce-Ward and Klein- Nishina statistics for semi-classical simulations of annihilation photon correlations. Phys. Lett. B. 2026; 875:140346

  76. [76]

    Towards optimal imaging with PET: an in silico feasibility study

    McNamara AL, Toghyani M, Gillam JE, Wu K, Kuncic Z. Towards optimal imaging with PET: an in silico feasibility study. Phys Med Biol. 2014 Nov 21;59(24):7587. doi: https://doi.org/10.1088/0031-9155/59/24/7587

  77. [77]

    Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Toghyani M, Gillam JE, McNamara AL, Kuncic Z. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET. Phys Med Biol. 2016 Jul 13;61(15):5803. doi: https://doi.org/10.1088/0031-9155/61/15/5803

  78. [78]

    Study of multi-pixel scintillator detector configurations for measuring polarized gamma radiation

    Kožuljević AM, Bosnar D, Kuncic Z, Makek M, Parashari S, Žugec P . Study of multi-pixel scintillator detector configurations for measuring polarized gamma radiation. Condens Matter. 2021 Nov 16;6(4):43. doi: https://doi.org/10.3390/condmat6040043

  79. [79]

    Probing entanglement in Compton interactions

    Caradonna P , Reutens D, Takahashi T, Takeda S, Vegh V . Probing entanglement in Compton interactions. J Phys Commun. 2019 Oct 11;3(10):105005. doi: https://doi.org/10.1088/2399-6528/ab45db

  80. [80]

    Photon quantum entanglement in the MeV regime and its application in PET imaging

    Watts DP , Bordes J, Brown JR, Cherlin A, Newton R, Allison J, et al. Photon quantum entanglement in the MeV regime and its application in PET imaging. Nat Commun. 2021 May 11;12(1):2646. doi: https://doi.org/10.1038/s41467-021-22907-5

Showing first 80 references.