Characterizing longitudinal and transverse relaxation rates of ferrofluids in microtesla magnetic fields

Ming Jye Chen, Shu Hsien Liao, Hong Chang Yang, Hsin Yi Lee, Yi Jia Liu, Hsin Hsien Chen, Herng Er Horng, Shieh Yueh Yang

Research output: Contribution to journalArticle

8 Citations (Scopus)


Shortening spin-lattice relaxation rates (1/T 1) or spin-spin relaxation rates (1/T 2) is the purpose of magnetic resonance imaging contrast agents. In this work, an ultralow field nuclear magnetic resonance spectrometer and imager are set up to characterize the spin relaxation rates of Fe 3O 4 superparamagnetic iron oxide (SPIO) for image contrast. It was found that both 1/T 1 and 1/T 2 increase linearly when the magnetic susceptibility of SPIO increases by increasing the concentration of SPIO dispersed in water. In an applied field, magnetic moments of SPIO generate microscopic field gradients that weaken the field homogeneity, in turn de-phasing the proton's nuclear spin and enhancing the relaxation rates. A T 1-contrast image is demonstrated, using SPIO as the contrast agent and high-T c superconducting quantum interference devices as the detector. T 1-contrast imaging in microtesla fields might provide a potential modality for discriminating cancer.

Original languageEnglish
Article number123911
JournalJournal of Applied Physics
Issue number12
Publication statusPublished - 2011 Dec 15


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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