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Magnetocaloric materials as switchable high contrast ratio MRI labels
Author(s) -
Barbic Mladen,
Dodd Stephen J.,
Morris H. Douglas,
Dilley Neil,
Marcheschi Barbara,
Huston Alan,
Harris Tim D.,
Koretsky Alan P.
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27615
Subject(s) - magnetic refrigeration , materials science , magnetic field , magnetometer , nuclear magnetic resonance , magnetization , contrast (vision) , magnetic resonance imaging , magnet , annealing (glass) , condensed matter physics , optics , radiology , composite material , medicine , physics , quantum mechanics
Purpose To develop switchable and tunable labels with high contrast ratio for MRI using magnetocaloric materials that have sharp first‐order magnetic phase transitions at physiological temperatures and typical MRI magnetic field strengths. Methods A prototypical magnetocaloric material iron‐rhodium (FeRh) was prepared by melt mixing, high‐temperature annealing, and ice‐water quenching. Temperature‐ and magnetic field‐dependent magnetization measurements of wire‐cut FeRh samples were performed on a vibrating sample magnetometer. Temperature‐dependent MRI of FeRh samples was performed on a 4.7T MRI. Results Temperature‐dependent MRI clearly demonstrated image contrast changes due to the sharp magnetic state transition of the FeRh samples in the MRI magnetic field (4.7T) and at a physiologically relevant temperature (~37°C). Conclusion A magnetocaloric material, FeRh, was demonstrated to act as a high contrast ratio switchable MRI contrast agent due to its sharp first‐order magnetic phase transition in the DC magnetic field of MRI and at physiologically relevant temperatures. A wide range of magnetocaloric materials are available that can be tuned by materials science techniques to optimize their response under MRI‐appropriate conditions and be controllably switched in situ with temperature, magnetic field, or a combination of both.