Solutions of two paramagnetic ions for use in nuclear magnetic resonance phantoms

The introduction of paramagnetic ions to affect relaxation times has been used in a variety of nuclear magnetic resonance (NMR) applications. All such relaxants used in NMR phantoms to date have consisted of a single paramagnetic ion. The disadvantage of this is that only one relaxation time can be adjusted as desired, either T1 or T2. This study demonstrates that, by properly choosing two paramagnetic ions, it is possible to adjust both T1 and T2 independently over a wide range of values. Specifically, solutions of MnCl2 and NiCl2 were prepared that simultaneously matched target T1 and T2 values to within approximately 6%.