Impact of Iron Particle Sizes on R2* Estimation in Phantoms Mimicking Hepatic Iron Overload and Steatosis Using MRI

Size and concentration of iron will affect the dephasing of an MRI signal. However, iron particle size is often unaccounted for in phantom studies investigating iron overload. In this study, phantoms utilizing iron nanoparticles of different diameters were used to mimic in vivo iron deposits, and R2* quantification was analyzed using different signal models. Our results show that R2* was higher and more unstable in phantoms with iron particles of 500nm diameter in comparison to those with 250nm and 130nm particles potentially due to clustering. High iron concentrations and large iron particle sizes were also shown to confound fat quantification.