Scientific Reports (Sep 2024)

Ortho-positronium lifetime for soft-tissue classification

  • Ashish V. Avachat,
  • Kholod H. Mahmoud,
  • Anthony G. Leja,
  • Jiajie J. Xu,
  • Mark A. Anastasio,
  • Mayandi Sivaguru,
  • Angela Di Fulvio

DOI
https://doi.org/10.1038/s41598-024-71695-7
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 9

Abstract

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Abstract The objective of this work is to showcase the ortho-positronium lifetime as a probe for soft-tissue characterization. We employed positron annihilation lifetime spectroscopy to experimentally measure the three components of the positron annihilation lifetime—para-positronium (p-Ps), positron, and ortho-positronium (o-Ps)—for three types of porcine, non-fixated soft tissues ex vivo: adipose, hepatic, and muscle. Then, we benchmarked our measurements with X-ray phase-contrast imaging, which is the current state-of-the-art for soft-tissue analysis. We found that the o-Ps lifetime in adipose tissues (2.54 ± 0.12 ns) was approximately 20% longer than in hepatic (2.04 ± 0.09 ns) and muscle (2.03 ± 0.12 ns) tissues. In addition, the separation between the measurements for adipose tissue and the other tissues was better from o-Ps lifetime measurement than from X-ray phase-contrast imaging. This experimental study proved that the o-Ps lifetime is a viable non-invasive probe for characterizing and classifying the different soft tissues. Specifically, o-Ps lifetime as a soft-tissue characterization probe had a strong sensitivity to the lipid content that can be potentially implemented in commercial positron emission tomography scanners that feature list-mode data acquisition.

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