International Journal on Magnetic Particle Imaging
Vol 8 No 1 (2022): Int J Mag Part Imag

Research Articles

MPI region of interest (ROI) analysis and quantification of iron in different volumes

Main Article Content

Olivia C. Sehl  (Robarts Research Institute, Western University, London, Canada), Brice Tiret  (Magnetic Insight Inc., Alameda, USA), Maryam A. Berih  (Robarts Research Institute, Western University, London, Canada), Ashley V. Makela  (The Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, USA), Patrick W. Goodwill  (Magnetic Insight Inc., Alameda, USA), Paula J. Foster (Robarts Research Institute, Western University, London, Canada)


MPI directly detects superparamagnetic iron oxides (SPIONs), which should enable precise, accurate, and linear quantification. However, selecting a region of interest (ROI) has strong effects on MPI quantification results. Ideally, ROI selection should be simple, user-independent, and widely applicable. In this work, we describe and compare four MPI ROI selection methods and assess their performance in vitro and in vivo. To explore the effect of ROI selection, ten ferucarbotran phantoms were imaged, each contained the same amount of iron but varied in volume. Three users tested the accuracy of the ROI methods for quantification of these samples. Lastly, the four ROI methods were applied to quantify ferucarbotran in vivo after intravenous, intramuscular, and subcutaneous injections in mice. We discuss the strengths and limitations of each ROI method, such as the ability to capture MPI signals of custom shapes (i.e. size of the ROI), degree of user variability, speed of analysis, and quantification accuracy of SPIONs in different volumes.
Int. J. Mag. Part. Imag. 8(1), 2022, Article ID: 2208002, DOI: 10.18416/IJMPI.2022.2208002

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