Zinc doped copper ferrite particles as temperature sensors for magnetic resonance imaging

Abstract

We investigate the use of Cu0.35Zn0.65Fe2O4 particles as temperature-dependent sensors in magnetic resonance imaging (MRI). This material has a Curie temperature near 290 K, but in the large magnetic fields found in MRI scanners, there is a significant temperature-dependent magnetic moment near body temperature; 310 K. When the ferrite particles are doped into an agar gel, the temperature-dependent magnetic moment leads to a temperature-dependent broadening of the NMR linewidth for water protons and to a temperature-dependent image intensity for MRI, allowing one to make temperature maps within objects. The temperature resolution is about 1.3 K.