MR images for T1 (a) and T2 (b) measurements, respectively. The circular images in the picture are MR images of aqueous samples of varying concentrations with the units of mM. While a dose-dependent increase in signal intensity is seen in the T1 measurements, a dose-dependent decrease in signal intensity is observed in the T2 measurements.
Bae et al. Nanoscale Research Letters 2012 7:44 doi:10.1186/1556-276X-7-44