This study evaluates the robustness of a magnetic resonance (MR) fat quantification method to changes in R2* caused by an intravenous infusion of superparamagnetic iron oxide (SPIO) contrast agent. The R2* and proton density fat fraction (PDFF) were measured in liver and spine in 14 subjects using an investigational sequence (IDEAL IQ) provided by the MR scanner vendor. Measurements were made before and after SPIO infusion. Results showed SPIO significantly increased R2* in both liver (p=8.8×10(-8)) and spine (p=1.3×10(-2)) but PDFFs were not significantly different in either the liver (p=5.5×10(-1)) or the spine (p=5.6×10(-1)). These results confirm that the IDEAL IQ method of fat quantification is robust to changes in R2*.