Characterizing The Field-Dependent T-1-Relaxation And Imaging Of Ferrofluids Using High-T-C Superconducting Quantum Interference Device Magnetometer In Low Magnetic Fields

In this paper, we investigate the field-dependent T-1-relaxation and T-1-contrast imaging of ferrofluids using high-T-c superconducting quantum interference device (SQUID)-detected nuclear magnetic resonance and imaging in low magnetic fields, where T-1 is the spin-lattice relaxation time. It was found that the 1/T-1 of ferrofluids increases when the prepolarization field increases. We attribute this to the enhanced magnetic-field gradients generated from the induced magnetization that accelerates the T-1-relaxation more in a high strength of fields in comparison to a low strength of fields. Using phantoms with different relaxation times, the T-1-contrast images are demonstrated in low magnetic fields, which can be promising for discriminating tumors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770304]