Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jun 2.
doi: 10.1007/s10334-025-01261-3. Online ahead of print.

A dedicated phantom for exploring the interplay of fat and paramagnetic substances in quantitative susceptibility mapping

Simon Graf  1   2 , Josefine Trapp  3 , Maik Rothe  3   4 , Alexander Gussew  3   4 , Walter A Wohlgemuth  3   4 , Andreas Deistung  3   4
Affiliations

A dedicated phantom for exploring the interplay of fat and paramagnetic substances in quantitative susceptibility mapping

Simon Graf et al. MAGMA. .

Abstract

Objective: Accurate quantitative tissue characterization in organs with considerable fat content, like the liver, requires thorough understanding of fat's influence on the MR signal. To continue the investigations into the use of quantitative susceptibility mapping (QSM) in abdominal regions, we present a dedicated phantom that replicates liver-like conditions in terms of effective transverse relaxation rates (R2*) and proton density fat fractions.

Materials and methods: The spherical agar phantom consists of nine smaller spheres (diameter: 3 cm) doped with a paramagnetic substance (iron nanoparticles or manganese chloride) and fat (peanut oil), embedded in a large agar sphere (diameter: 14 cm), ensuring no barriers exist between the enclosed spheres and their surrounding medium. Concentrations were selected to represent both healthy and pathologic conditions. 3T MRI measurements for relaxometry, fat-water imaging, and QSM were conducted with the head coil and for 1H-spectroscopy with the knee coil at three time points, including a scan-rescan assessment and a follow-up measurement 14 months later.

Results: The phantoms' relaxation and magnetic properties are in similar range as reported for liver tissue. Substantial alterations in local field and susceptilibty maps were observed in regions with elevated fat and iron content, where fat correction of the local field via chemical shift-encoded reconstruction effectively reduced streaking artifacts in susceptibility maps and substantially increased susceptibility values. Linear regression analysis revealed a consistent linear relationship between R2* and magnetic susceptibility, as well as iron concentration and magnetic susceptibility. The relaxation, fat, and susceptibility measurements remained stable across scan-rescan assessment and long-term follow-up.

Discussion: We developed a versatile phantom to study fat-iron interactions in abdominal imaging, facilitating the optimization and comparison of susceptibility processing methods in future research.

Keywords: Iron; Phantom; Quantitative susceptibility mapping; Relaxometry; Water–fat separation.

PubMed Disclaimer

Conflict of interest statement

Declarations. Conflict of interest: The authors declare that they no conflict of interest. Ethical standards: This article does not contain any studies with human participants or animals performed by any ofthe authors.

Similar articles

See all similar articles

References

    1. Lieu PT, Heiskala M, Peterson PA et al (2001) The roles of iron in health and disease. Mol Aspects Med 22:1–87. https://doi.org/10.1016/S0098-2997(00)00006-6 - DOI - PubMed
    1. Hsu CC, Senussi NH, Fertrin KY et al (2022) Iron overload disorders Hepatol Commun 6:1842–1854. https://doi.org/10.1002/hep4.2012 - DOI - PubMed
    1. Hadzhieva M, Kirches E, Mawrin C (2014) Review: iron metabolism and the role of iron in neurodegenerative disorders. Neuropathol Appl Neurobiol 40:240–257. https://doi.org/10.1111/nan.12096 - DOI - PubMed
    1. Ward RJ, Zucca FA, Duyn JH et al (2014) The role of iron in brain ageing and neurodegenerative disorders. Lancet Neurol 13:1045–1060. https://doi.org/10.1016/S1474-4422(14)70117-6 - DOI - PubMed - PMC
    1. Brittenham GM, Cohen AR, McLaren CE et al (1993) Hepatic iron stores and plasma ferritin concentration in patients with sickle cell anemia and thalassemia major. Am J Hematol 42:81–85. https://doi.org/10.1002/ajh.2830420116 - DOI - PubMed

LinkOut - more resources