A New Instrument Designed to Measure the Magnetic Susceptibility of Human Liver Tissue In Vivo

All existing superconducting instrumentation for measuring the concentration of iron stored in the human liver requires liquid helium for its operation. We report the mathematical modeling, optimization, and instrumental performance of an instrument that uses high-transition-temperature (high-T
_c
) superconductors. Requiring only liquid nitrogen to operate, the susceptometer represents the first medical application of the phenomenon of high-temperature superconductivity with the potential for widespread clinical utility.