Fast field-cycling magnetic resonance detection of intracellular ultra-small iron oxide particles in vitro: Proof-of-concept

Hassan Abbas* (Corresponding Author), Lionel Broche, Aiarpi Ezdoglian, Dmitriy Li, Raif Yuecel, P James Ross, Lesley Cheyne, Heather M Wilson, David J Lurie, Dana K Dawson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)
15 Downloads (Pure)


Inflammation is central in disease pathophysiology and accurate methods for its detection and quantification are increasingly required to guide diagnosis and therapy. Here we explored the ability of Fast Field-Cycling Magnetic Resonance (FFC-MR) in quantifying the signal of ultra-small superparamagnetic iron oxide particles (USPIO) phagocytosed by J774 macrophage-like cells as a proof-of-principle.
Relaxation rates were measured in suspensions of J774 macrophage-like cells loaded with USPIO (0-200μg/ml Fe as ferumoxytol), using a 0.25 T FFC benchtop relaxometer and a human whole-body, in-house built 0.2 T FFC-MR prototype system with a custom test tube coil. Identical non-imaging, saturation recovery pulse sequence with 90o flip angle and 20 different evolution fields selected logarithmically between 80 μT and 0.2T (3.4kHz and 8.51 MHz proton Larmor frequency [PLF] respectively). Results were compared with imaging flow cytometry quantification of side scatter intensity and USPIO-occupied cell area. A reference colorimetric iron assay was used.
The T1 dispersion curves derived from FFC-MR were excellent in detecting USPIO at all concentrations examined (0-200μg/ml Fe as ferumoxytol) vs. control cells, p ≤ 0.001. FFC-NMR was capable of reliably detecting cellular iron content as low as 1.12ng/µg cell protein, validated using a colorimetric assay. FFC-MR was comparable to imaging flow cytometry quantification of side scatter intensity but superior to USPIO-occupied cell area, the latter being only sensitive at exposures ≥ 10µg/ml USPIO.
We demonstrated for the first time that FFC-MR is capable of quantitative assessment of intra-cellular iron which will have important implications for the use of USPIO in a variety of biological applications, including the study of inflammation.
Original languageEnglish
Article number106722
Number of pages10
JournalJournal of Magnetic Resonance
Early online date26 Mar 2020
Publication statusPublished - Apr 2020

Bibliographical note

DKD would like to declare funding from British Heart Foundation Project Grant PG/15/108/31928 with no financial conflict of interest. DJL would like to declare funding from the European Commission – ‘Improving Diagnosis by Fast Field-Cycling MRI’ grant number 668119 with no financial conflict of interest, and GE Healthcare in the form of funding for PhD studentship in radiofrequency coils for FFC-MRI, with potential financial conflict of interest. The authors have no additional financial interests.


  • fast field-cycling magnetic resonance
  • inflammation
  • ultrasmall superparamagnetic iron oxide particles (USPIO)
  • Fast field-cycling magnetic resonance
  • Ultrasmall superparamagnetic iron oxide particles (USPIO)
  • Inflammation


Dive into the research topics of 'Fast field-cycling magnetic resonance detection of intracellular ultra-small iron oxide particles in vitro: Proof-of-concept'. Together they form a unique fingerprint.

Cite this