A compact SQUID-detected magnetic resonance imaging system under microtesla field in a magnetically unshielded environment

Hsin Hsien Chen, Hong Chang Yang, Herng Er Horng, Shu Hsien Liao, Shieh Yueh, Li Min Wang

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In this study, we present a compact and sensitive SQUID-detected nuclear magnetic resonance spectrometer and imager (NMR/MRI) using flux coupling in microtesla fields. The pre-polarization coil, measuring coil, pulsed coil, and gradient coils were set up inside a three-layer aluminum box while the SQUID-detector was shielded with a high-Tc superconducting vessel. A compensation field was applied to improve the field homogeneity in magnetically unshielded environments. The spin precession of protons was inductively coupled to the SQUID magnetometer via a resonant flux transformer. We obtained a signal-to-noise ratio of 120 in one measurement, a spectral resolution better than 1 Hz, and a spatial resolution of 1.3 mm in the images.

Original languageEnglish
Article number093903
JournalJournal of Applied Physics
Issue number9
Publication statusPublished - 2011 Nov 1


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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